Jonny Hisdal

• Nordén, Kristine Røren; semb, anne grete; Dagfinrud, Hanne; Hisdal, Jonny; Sexton, Joseph & Fongen, Camilla [Vis alle 12 forfattere av denne artikkelen] (2024). Effect of high-intensity interval training in physiotherapy primary care for patients with inflammatory arthritis: The ExeHeart randomised controlled trial. RMD Open. ISSN 2056-5933. 10(1). doi: 10.1136/rmdopen-2023-003440.
• Sletten, Ole Jakob; Aalen, John; Smiseth, Otto Armin; Khan, Faraz Hameed; Fosså, Alexander & Kiserud, Cecilie E. [Vis alle 10 forfattere av denne artikkelen] (2023). Mental Stress Reduces Left Ventricular Strain: Can It Lead to Misinterpretation of Cancer Therapy–Related Cardiac Dysfunction? Journal of the American Society of Echocardiography. ISSN 0894-7317. doi: 10.1016/j.echo.2023.11.010.
• Lie, Sole Lindvåg; Hisdal, Jonny; Rehn, Marius & Høiseth, Lars Øivind (2023). Hemodynamic effects of supplemental oxygen versus air in simulated blood loss in healthy volunteers: a randomized, controlled, double-blind, crossover trial. Intensive Care Medicine Experimental. ISSN 2197-425X. 11(1). doi: 10.1186/s40635-023-00561-z. Fulltekst i vitenarkiv
• Nordén, Kristine Røren; Dagfinrud, Hanne; Semb, Anne Grete; Hisdal, Jonny; Metsios, George S. & Sexton, Joseph [Vis alle 9 forfattere av denne artikkelen] (2023). Criterion Validity and Responsiveness of Estimated Cardiorespiratory Fitness Models in Patients with Inflammatory Joint Disease. Journal of Clinical Medicine. ISSN 2077-0383. 12(21). doi: 10.3390/jcm12216753. Fulltekst i vitenarkiv
• Mansoor, Saira Mauland; Rabben, Toril; Hisdal, Jonny & Jørgensen, Jørgen Joakim (2023). Eleven-Year Outcomes of a Screening Project for Abdominal Aortic Aneurysm (AAA) in 65-Year-Old Men. Vascular Health and Risk Management. ISSN 1176-6344. 19, s. 459–467. doi: 10.2147/VHRM.S412954. Fulltekst i vitenarkiv
• Høiseth, Lars Øivind; Fjose, Lars Olav; Hisdal, Jonny; Comelon, Marlin; Rosseland, Leiv Arne & Lenz, Harald (2023). Haemodynamic effects of methoxyflurane versus fentanyl and placebo in hypovolaemia: a randomised, double-blind crossover study in healthy volunteers. BJA Open. ISSN 2772-6096. 7. doi: 10.1016/j.bjao.2023.100204. Fulltekst i vitenarkiv
• Kyte, Karoline Holsen; Lunde, Cecilie & Hisdal, Jonny (2023). Post-Exercise Ankle–Brachial Index Is Reduced in Healthy, Young Individuals at a Level Indicating Peripheral Artery Disease. Clinics and Practice. ISSN 2039-7283. 13(2), s. 529–536. doi: 10.3390/clinpract13020049. Fulltekst i vitenarkiv
• Nordén, Kristine Røren; Semb, Anne Grete; Dagfinrud, Hanne; Hisdal, Jonny; Ødegård, Sigrid & Sexton, Joseph [Vis alle 11 forfattere av denne artikkelen] (2023). Associations between cardiovascular risk factors, disease activity and cardiorespiratory fitness in patients with inflammatory joint disease: a cross-sectional analysis. BMC sports science, medicine and rehabilitation. ISSN 2052-1847. 15, s. 1–11. doi: 10.1186/s13102-023-00678-4. Fulltekst i vitenarkiv
• Nyhus Hagum, Cathrine ; Tønnessen, Espen; Hisdal, Jonny & Shalfawi, Shaher A. I. (2023). The effect of progressive and individualised sport-specific training on the prevalence of injury in football and handball student athletes: a randomised controlled trial. Frontiers in Sports and Active Living. ISSN 2624-9367. 5, s. 1–11. doi: 10.3389/fspor.2023.1106404. Fulltekst i vitenarkiv
• Kyte, Karoline Holsen; Haakstad, Lene Annette Hagen; Hisdal, Jonny; Sunde, Andrine & Stensrud, Trine (2023). Bone health in Norwegian female elite runners: A cross-sectional, controlled study. BMJ Open sport & exercise medicine. ISSN 2055-7647. 9. doi: 10.1136/bmjsem-2022-001472. Fulltekst i vitenarkiv Vis sammendrag

  Objective: The primary objective was to compare bone mineral density (BMD) in Norwegian female elite long-distance runners with a control group of inactive females. Secondary objectives were to identify cases of low BMD, to compare the concentration of bone turnover markers, vitamin D and symptoms of low energy availability (LEA) between the groups, and to identify possible associations between BMD and selected variables. Methods: Fifteen runners and fifteen controls were included. Assessments included dual-energy X-ray absorptiometry measurement of BMD in the total body, lumbar spine and dual proximal femur. Blood samples included endocrine analyses and circulating bone turnover markers. The risk of LEA was assessed through a questionnaire. Results: Runners had higher Z-scores in the dual proximal femur (1.30 (0.20 to 1.80) vs 0.20 (−0.20 to 0.80), p<0.021) and total body (1.70 (1.20 to 2.30) vs 0.90 (0.80 to 1.00), p<0.001). The lumbar spine Z-score was similar between groups (0.10 (−0.70 to 0.60) vs −0.10(−0.50 to 0.50), p=0.983). Three runners had low BMD (Z-score <−1) in the lumbar spine. Vitamin D and bone turnover markers showed no differences between the groups. Forty-seven per cent of the runners were at risk of LEA. Dual proximal femur BMD showed a positive correlation to estradiol and a negative correlation to LEA symptoms in runners. Conclusion: Norwegian female elite runners had higher BMD Z-score in the dual proximal femur and total body compared with controls, while no difference was observed in the lumbar spine. The advantages of long-distance running on bone health seem to be site specific, and there is still a need for the prevention of LEA and menstrual disorders in this group.

• Tronstad, Christian; Amini, Maryam; Olesen, Eline; Qvigstad, Elisabeth; Pabst, Oliver & Martinsen, Tormod [Vis alle 11 forfattere av denne artikkelen] (2022). Diabetic foot assessment using skin impedance in a custom made sensor-sock. Journal of Electrical Bioimpedance. ISSN 1891-5469. 13(1), s. 136–142. doi: 10.2478/joeb-2022-0019. Fulltekst i vitenarkiv
• Tronstad, Christian; Pabst, Oliver; Amini, Maryam; Kleggetveit, Inge Petter; Elvebakk, Ole & Martinsen, Ørjan Grøttem [Vis alle 10 forfattere av denne artikkelen] (2022). Development of a prototype toe sensor for detection of diabetic peripheral small fiber neuropathy. Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). ISSN 2694-0604. doi: 10.1109/EMBC48229.2022.9871101.
• Aune, Susanne Kristine; Bonnevie-Svendsen, Martin; Nyborg, Christoffer; Trøseid, Marius; Seljeflot, Ingebjørg & Hisdal, Jonny [Vis alle 7 forfattere av denne artikkelen] (2022). Gut Leakage and Cardiac Biomarkers after Prolonged Strenuous Exercise. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 54(9), s. 1476–1482. doi: 10.1249/MSS.0000000000002948.
• Melsom, Helene Støle; Randa, Anders; Hisdal, Jonny; Stang, Julie & Stensrud, Trine (2022). Prevalence of asthma among Norwegian elite athletes. Translational Sports Medicine (TSM). ISSN 2573-8488. 2022, s. 1–10. doi: 10.1155/2022/3887471. Fulltekst i vitenarkiv Vis sammendrag

  Objective. Asthma is a common problem among elite athletes and represents a health risk interfering with the athlete’s performance status. This study aimed to evaluate the asthma prevalence among Norwegian summer and winter elite athletes and asthma prevalence across sport categories. We also aimed to examine whether bronchial hyperresponsiveness (BHR), lung function, fraction of exhaled nitric oxide (FENO), and allergy status differed between asthmatic and non-asthmatic elite athletes. Methods. Norwegian athletes qualifying for the Beijing Olympic Summer Games 2008 (n = 80) and the Vancouver Olympic Winter Games 2010 (n = 55) were included. The athletes underwent clinical respiratory examination including lung function measurement, methacholine bronchial challenge for assessment of BHR, FENO, and skin prick testing. Asthma was diagnosed based on respiratory symptoms and clinical examination including objective measurements. Results. Asthma was more prevalent among winter athletes (50%) than summer athletes (20%). Thirty-three (52%) endurance athletes, 3 (6%) team sport athletes, and 7 (33%) technical sport athletes had medically diagnosed asthma. Significantly lower lung function (p<0.001) and higher prevalence of severe BHR (p<0.001) were found in asthmatic athletes compared with non-asthmatic athletes. Conclusion. Asthma is common among Norwegian elite athletes, with winter and endurance athletes showing the highest prevalence. Asthmatic athletes were characterized by lower lung function and more severe BHR compared with non-asthmatic counterparts. The high prevalence among winter and endurance athletes demonstrates a need for increased attention to prevent and reduce the prevalence of asthma among those athletes.

• Melsom, Helene Støle; Heiestad, Christina Mathisen; Eftestøl, Einar; Torp, May-Kristin; Gundersen, Kristian & Bjørnebekk, Astrid [Vis alle 9 forfattere av denne artikkelen] (2022). Reduced arterial elasticity after anabolic–androgenic steroid use in young adult males and mice. Scientific Reports. ISSN 2045-2322. 12(1). doi: 10.1038/s41598-022-14065-5. Fulltekst i vitenarkiv
• Pettersen, Erik Mulder; Hoel, Henrik; Torp, Hans; Hisdal, Jonny & Seternes, Arne (2022). The Effect of 12-Week Treatment with Intermittent Negative Pressure on Blood Flow Velocity and Flowmotion, Measured with a Novel Doppler Device (Earlybird). Secondary Outcomes from a Randomized Sham-Controlled Trial in Patients with Peripheral Arterial Disease. Annals of Vascular Surgery. ISSN 0890-5096. 86, s. 144–157. doi: 10.1016/j.avsg.2022.04.025. Fulltekst i vitenarkiv
• Kazmi, Syed Sajid Hussain; Safi, Natkai; Berge, Simen Tveten; Kazmi, Marryam; Sundhagen, Jon Otto & Julien, Kari [Vis alle 10 forfattere av denne artikkelen] (2022). Plasma α-Glutathione S-Transferase in Patients with Chronic Mesenteric Ischemia and Median Arcuate Ligament Syndrome. Vascular Health and Risk Management. ISSN 1176-6344. 18, s. 567–574. doi: 10.2147/VHRM.S365625. Fulltekst i vitenarkiv Vis sammendrag

  Background: Chronic mesenteric ischemia (CMI) due to either atherosclerosis of the mesenteric arteries or median arcuate ligament syndrome (MALS) is an underdiagnosed entity. The etiology of MALS and its existence have been debated and questioned. We aimed to identify plasma biomarkers indicating mesenteric ischemia in patients with CMI and MALS. Methods: Plasma α-glutathione S-transferase (α-GST), intestinal fatty acid-binding protein (I-FABP), citrulline, and ischemia modified albumin (IMA) were analyzed in fifty-eight patients with CMI (Group A, n=44) and MALS (Group B, n=14) before and after revascularization. The plasma levels of these potential biomarkers were compared with those of healthy individuals (Group C, n=16). Group comparison was performed with the Mann–Whitney U-test. Cross-tabulation and its derivatives were obtained. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were calculated. Results: Plasma levels of α-GST were significantly raised in the patients with CMI (7.8 ng/mL, p< 0.001) and MALS (8.4 ng/mL, p< 0.001), as compared with the control Group C (3.3 ng/mL). The threshold for normal median plasma α-GST levels of 4 ng/mL yielded a sensitivity of 93% and 86%, specificity of 86% and 88%, respectively, for the diagnosis of CMI due to atherosclerosis and MALS. AUC of ROC curves was 0.96 (p< 0.0001) for CMI and 0.85 (p< 0.002) for MALS. The patient groups did not differ from the healthy controls in any other biomarkers. Conclusion: Plasma α-GST levels are elevated in CMI and MALS patients. Elevated plasma levels of α-GST suggest ischemia as the etiology of MALS.

• Djupedal, Håvard; Nøstdal, Torkjell; Hisdal, Jonny; Landsverk, Svein A. & Høiseth, Lars Øivind (2022). Effects of experimental hypovolemia and pain on pre-ejection period and pulse transit time in healthy volunteers. Physiological Reports. ISSN 2051-817X. 10(12), s. 1–10. doi: 10.14814/phy2.15355. Fulltekst i vitenarkiv Vis sammendrag

  Trauma patients may suffer significant blood loss, and noninvasive methods to diagnose hypovolemia in these patients are needed. Physiologic effects of hypovolemia, aiming to maintain blood pressure, are largely mediated by increased sympathetic nervous activity. Trauma patients may however experience pain, which also increases sympathetic nervous activity, potentially confounding measures of hypovolemia. Elucidating the common and separate effects of the two stimuli on diagnostic methods is therefore important. Lower body negative pressure (LBNP) and cold pressor test (CPT) are experimental models of central hypovolemia and pain, respectively. In the present analysis, we explored the effects of LBNP and CPT on pre-ejection period and pulse transit time, aiming to further elucidate the potential use of these variables in diagnosing hypovolemia in trauma patients. We exposed healthy volunteers to four experimental sequences with hypovolemia (LBNP 60 mmHg) or normovolemia (LBNP 0 mmHg) and pain (CPT) or no pain (sham) in a 2 × 2 fashion. We calculated pre-ejection period and pulse transit time from ECG and ascending aortic blood velocity (suprasternal Doppler) and continuous noninvasive arterial pressure waveform (volume-clamp method). Fourteen subjects were available for the current analyses. This experimental study found that pre-ejection period increased with hypovolemia and remained unaltered with pain. Pulse transit time was reduced by pain and increased with hypovolemia. Thus, the direction of change in pulse transit time has the potential to distinguish hypovolemia and pain.

• Safi, Natkai; Ånonsen, Kim Vidar; Berge, Simen Tveten; Medhus, Asle Wilhelm; Sundhagen, Jon Otto & Hisdal, Jonny [Vis alle 7 forfattere av denne artikkelen] (2022). Early Identification of Chronic Mesenteric Ischemia with Endoscopic Duplex Ultrasound. Vascular Health and Risk Management. ISSN 1176-6344. s. 233–243. doi: 10.2147/VHRM.S358570. Fulltekst i vitenarkiv
• Kyte, Karoline Holsen; Stensrud, Trine; Berg, Tore Julsrud; Seljeflot, Ingebjørg & Hisdal, Jonny (2022). Vascular Function in Norwegian Female Elite Runners: A Cross-Sectional, Controlled Study. Sports. ISSN 2075-4663. 10(3). doi: 10.3390/sports10030037. Fulltekst i vitenarkiv Vis sammendrag

  In general, aerobic exercise has a positive impact on the vascular system, but the syndrome of relative energy-deficiency in sports (RED-S) makes this impact less clear for the athlete. The present cross-sectional controlled study aimed to investigate the vascular function in female elite long-distance runners, compared to inactive women. Sixteen female elite long-distance runners and seventeen healthy controls were recruited. Assessments of vascular function and morphology included endothelial function, evaluated by flow-mediated dilatation (FMD), vascular stiffness, evaluated with pulse wave velocity (PWV), carotid artery reactivity (CAR %), and carotid intima-media thickness (cIMT). Blood samples included hormone analyses, metabolic parameters, lipids, and biomarkers reflecting endothelial activation. RED-S risk was assessed through the low energy availability in female questionnaire (LEAF-Q), and body composition was measured by dual-energy X-ray absorptiometry (DXA). We found no significant differences in brachial FMD, PWV, CAR %, cIMT, or biomarkers reflecting endothelial activation between the two groups. Forty-four percent of the runners had a LEAF-Q score consistent with being at risk of RED-S. Runners showed significantly higher HDL-cholesterol and insulin sensitivity compared to controls. In conclusion, Norwegian female elite runners had an as good vascular function and morphology as inactive women of the same age.

• Nordén, Kristine Røren; Dagfinrud, Hanne; Semb, Anne Grete; Hisdal, Jonny; Viktil, Kirsten Kilvik & Sexton, Joseph [Vis alle 11 forfattere av denne artikkelen] (2022). Effect of high-intensity exercise on cardiorespiratory fitness, cardiovascular disease risk and disease activity in patients with inflammatory joint disease: Protocol for the ExeHeart randomised controlled trial. BMJ Open. ISSN 2044-6055. 12(2). doi: 10.1136/bmjopen-2021-058634. Fulltekst i vitenarkiv Vis sammendrag

  Introduction Inflammatory joint disease (IJD) is associated with increased risk of cardiovascular disease (CVD) fostered by systemic inflammation and a high prevalence of CVD risk factors. Cardiorespiratory fitness (CRF) is an important health parameter and CRF-measures are advocated in routine health evaluations. CRF associates with CVD risk, and exercise modalities such as high intensity interval training (HIIT) can increase CRF and mitigate CVD risk factors. In IJD, exercise is rarely used in CVD risk management and the cardioprotective effect of HIIT is unclear. Furthermore, the clinical applicability of HIIT to primary care settings is largely unknown and warrants investigation. The primary aim is to assess the effect of a HIIT programme on CRF in patients with IJD. Second, we will evaluate the effect of HIIT on CVD risk and disease activity in patients with IJD, feasibility of HIIT in primary care and validity of non-exercise algorithms to detect change in CRF. Methods and analysis ExeHeart is a single-blinded, randomised controlled trial. Sixty patients with IJD will be recruited from the Preventive Cardio-Rheuma clinic at Diakonhjemmet Hospital, Norway. Patients will be assigned to receive standard care (relevant lifestyle advice and cardio-preventive medication) or standard care plus a 12-week HIIT intervention by physiotherapists in primary care. HIIT sessions will be prescribed at 90%–95% of peak heart rate. Outcomes include CRF (primary outcome), CVD risk factors, anthropometric measures, disease activity and patient-reported outcomes related to pain, fatigue, disease, physical activity and exercise and will be assessed at baseline, 3 months (primary endpoint) and 6 months postbaseline. Ethics and dissemination Ethical approval has been obtained from the Regional Committee for Medical and Health Research Ethics (201227). Participants are required to sign a written informed consent form. Results will be discussed with patient representatives, submitted to peer-reviewed journals and presented at relevant platforms. Trial registration number NCT04922840.

• Kazmi, Syed Sajid Hussain; Safi, Natkai; Berge, Simen Tveten; Kazmi, Marryam; Sundhagen, Jon Otto & Hisdal, Jonny (2022). Laparoscopic Surgery for Median Arcuate Ligament Syndrome (MALS): A Prospective Cohort of 52 Patients. Vascular Health and Risk Management. ISSN 1176-6344. 18, s. 139–151. doi: 10.2147/VHRM.S350841. Fulltekst i vitenarkiv Vis sammendrag

  Background: The selection of patients with MALS for surgical treatment depends upon the reliability of the symptom interpretation and the diagnostic work-up. We aimed to follow up the results of the laparoscopic decompression of the patients with MALS. Patients and Methods: In a single-center, 52 consecutive MALS patients were followed-up, prospectively, after transperitoneal laparoscopic decompression. MALS was diagnosed with a computed tomography angiography (CTA) verified stenosis, ≥ 50% of the celiac artery (CA), and with duplex ultrasound, a peak systolic velocity (PSV) ≥ 2.0 m/s. Postoperative, CTA, and duplex ultrasound were performed, and the patients were followed-up at 3, 6, 12 months, and yearly after that. Results: Mean age of the patients was 47 ± 21 years, and 65% were females. The patients had a mean weight loss of 8.4 ± 7.2 kg. Fifty-one patients had the laparoscopic operation with a mean operation time of 102 ± 28 minutes. Forty-seven patients (90%) achieved relief from the symptoms either completely (67%) or partially (23%) at 3– 6 months of follow-up. Significant improvement in postoperative PSV was found compared to the preoperative values, p< 0.001. Five patients (10%) with no immediate effect of the operation, but two of them became free from symptoms during the mean study follow-up of 2.4 ± 2 years. Five patients (10%) had operative complications, including one trocar injury to the liver, one pneumothorax, and three cases of bleeding from the branches of CA. Two patients died of cancer disease during the study period. Only two patients (4%) had symptoms relapse, both later treated successfully. Conclusion: Laparoscopic transperitoneal decompression provides most of the patients a persistent relief from MALS symptoms. Keywords: median arcuate ligament syndrome, postprandial pain, laparoscopy, mesenteric ischemia

• Wiegerinck, Anouk; Thomsen, Andreas; Hisdal, Jonny; Kalvøy, Håvard & Tronstad, Christian (2021). Electrical impedance plethysmography versus tonometry to measure the pulse wave velocity in peripheral arteries in young healthy volunteers: a pilot study. Journal of Electrical Bioimpedance. ISSN 1891-5469. 12(1), s. 169–177. doi: 10.2478/joeb-2021-0020. Fulltekst i vitenarkiv
• Johnsen, Lydia; Hisdal, Jonny; Jonung, Torbjörn; Braaten, Audun Ole & Pedersen, Gustav (2021). Three-dimensional ultrasound volume and conventional ultrasound diameter changes are equally good markers of endoleak in follow-up after endovascular aneurysm repair. Journal of Vascular Surgery. ISSN 0741-5214. doi: 10.1016/j.jvs.2021.08.103.
• Hoel, Henrik; Pettersen, Erik Mulder; Høiseth, Lars Øivind; Mathiesen, Iacob; Seternes, Arne & Hisdal, Jonny (2021). Lower Extremity Intermittent Negative Pressure for Intermittent Claudication. Follow-Up after 24 Weeks of Treatment. Annals of Vascular Surgery. ISSN 0890-5096. 75, s. 253–258. doi: 10.1016/j.avsg.2021.03.016. Fulltekst i vitenarkiv Vis sammendrag

  Background Treatment with lower extremity intermittent negative pressure (INP) of -40 mm Hg for one hour twice daily for 12 weeks, increases walking capacity in patients with intermittent claudication (IC). However, the effects of INP treatment beyond 12 weeks have not been elucidated. The aim of the present study was to investigate the clinical effects of INP treatment after 24 weeks in patients with IC. Methods This was a follow-up study after a randomized sham-controlled trial, where patients randomized to the active treatment group were offered to continue treatment for 12 additional weeks (24 weeks in total). Treatment with -40 mm Hg INP was applied in a pressure chamber sealed around the lower leg, and the patients were instructed to treat themselves at home one hour in the morning and one hour in the evening. Pain free walking distance (PWD), maximal walking distance (MWD), resting ankle-brachial index (ABI) and post exercise ABI were measured at baseline, after 12 and 24 weeks. Results Ten out of 32 patients (31%) from the active treatment group in the initial trial were included in this follow-up study. At baseline, PWD was (mean ±SD) 151 ± 91 m and MWD was 362 ±159 m. There was a significant increase in both PWD and MWD after 24 weeks of treatment, compared to baseline (ANOVA; P= 0.006 and P= 0.012, respectively). Post hoc tests revealed that PWD increased significantly from baseline to 12 weeks (mean 81 m; 95% CI [6, 156]; P = 0.032), and that MWD increased significantly from 12 to 24 weeks (mean 145 m; 95% CI [22, 268]; P = 0.018). There were no significant changes in resting ABI or post exercise ABI during the 24-week treatment period (ANOVA; P= 0.157 and P= 0.450, respectively). Conclusion Both PWD and MWD improved after treatment with – 40 mm Hg INP for one hour twice daily for 24 weeks, compared to baseline. The main improvement in PWD occurred during the first 12 weeks of treatment, whereas the main improvement in MWD occurred between 12 and 24 weeks of treatment.

• Pettersen, Erik Mulder; Avdal, Jørgen; Fiorentini, Stefano; Salvesen, Øyvind; Hisdal, Jonny & Torp, Hans [Vis alle 7 forfattere av denne artikkelen] (2021). Validation of a novel ultrasound Doppler monitoring device (earlybird) for measurements of volume flow rate in arteriovenous fistulas for hemodialysis. Journal of Vascular Access. ISSN 1129-7298. s. 1–9. doi: 10.1177/11297298211060960. Vis sammendrag

  Background: Controversy exists regarding surveillance of arteriovenous fistulas for hemodialysis to increase patency. A significant reduction in volume flow rate (VFR) should lead to diagnostic evaluation and eventually intervention. Several methods are available for VFR measurements, but all of them are associated with low reproducibility. VFR trend analysis is suggested as an improved solution. It is therefore a need to find user-friendly, cost and time-effective modalities. We present a novel Doppler ultrasound device (earlybird) which could bridge this gap. It includes an easy-to-use and light-weight single element transducer. Methods: In an experimental and clinical setting, we compared earlybird to duplex ultrasound to assess VFR. In a closed circuit of blood-mimicking fluid, 36 paired calculations of calibrated, duplex ultrasound and earlybird VFR was measured. In addition, 23 paired recordings of duplex ultrasound and earlybird VFR was measured in 16 patients with underarm arteriovenous fistulas. Pearson correlation, intraclass correlation coefficient, root-mean-square and Bland-Altman plots were analyzed. Results: Strong correlation (r = 0.991, p < 0.001), and excellent level of agreement (ICC = 0.970 (95% CI 0.932 - 0.985), p < 0.001) between earlybird and the calibrated VFR was found in the experimental setup. This was confirmed in the clinical setting, with a strong correlation (r = 0.781, p < 0.001) and moderate to good level of agreement (ICC = 0.750 (95% CI 0.502–0.885), p < 0.001) between earlybird and duplex ultrasound VFR measured at the arteriovenous fistulas outflow veins. In the Bland-Altman plot-analysis for the experimental setup, we found smaller limits of agreement, a smaller consistent and proportional bias, as well as greater accuracy of earlybird than DUS when compared to the calibrated VFR. Conclusion: Earlybird is a feasible tool for VFR measurements and could be a future promising device for easy assessment and surveillance of AVF for hemodialysis.

• Melau, Jørgen; Hisdal, Jonny & Solberg, Paul Andre (2021). Impact of a 10,000-m Cold-Water Swim on Norwegian Naval Special Forces Recruits. Journal of Special Operations Medicine. ISSN 1553-9768. 21(3), s. 55–59. doi: 10.55460/QE23-511P.
• Nyborg, Christoffer; Bonnevie-Svendsen, Martin; Melsom, Helene Støle; Melau, Jørgen; Seljeflot, Ingebjørg & Hisdal, Jonny (2021). Reduced L-Arginine and L-Arginine-ADMA-Ratio, and Increased SDMA after Norseman Xtreme Triathlon. Sports. ISSN 2075-4663. 9(9). doi: 10.3390/sports9090120. Fulltekst i vitenarkiv Vis sammendrag

  Endothelial vasodilatory function is dependent on the NO synthesis from L-arginine by endothelial NO-synthetase (eNOS). eNOS can be inhibited by asymmetric dimethylarginine (ADMA) by competitive inhibition on the binding site, and symmetric dimethylarginine (SDMA) can reduce the L-arginine availability intracellularly through competing for transport over the cellular membrane. To study the NO synthesis after prolonged exercise, we assessed circulatory L-arginine, the L-arginine/ADMA ratio, and SDMA before, after, and on the day after the Norseman Xtreme triathlon, an Ironman distance triathlon. We found significantly reduced levels of L-arginine and the L-arginine/ADMA ratio and increased levels of SDMA after the race (all p < 0.05). L-arginine rose toward baseline levels the day after the race, but ADMA increased beyond baseline levels, and SDMA remained above baseline the day after the race. The reduced levels of L-arginine and the L-arginine/ADMA ratio, and increased SDMA, after the race indicate a state of reduced capability of NO production. Increased levels of ADMA and SDMA, and reduced L-arginine/ADMA ratio, as seen the day after the race, are known risk markers of atherosclerosis and warrant further studies.

• Konstantin, Friedrich; Rollefstad, Silvia Christin Hellerud; Ikdahl, Eirik; Wibetoe, Grunde; Sexton, Joseph & Hisdal, Jonny [Vis alle 7 forfattere av denne artikkelen] (2021). Degree of arterial stiffness is comparable across inflammatory joint disease entities. Scandinavian Journal of Rheumatology. ISSN 0300-9742. doi: 10.1080/03009742.2021.1920169. Fulltekst i vitenarkiv
• Lie, Sole Lindvåg; Hisdal, Jonny & Høiseth, Lars Øivind (2021). Cerebral blood flow velocity during simultaneous changes in mean arterial pressure and cardiac output in healthy volunteers. European Journal of Applied Physiology. ISSN 1439-6319. s. 1–11. doi: 10.1007/s00421-021-04693-6. Fulltekst i vitenarkiv
• Nyborg, Christoffer; Melsom, Helene Støle; Bonnevie-Svendsen, Martin; Melau, Jørgen; Seljeflot, Ingebjørg & Hisdal, Jonny (2021). Transient reduction of fmd-response and l-arginine accompanied by increased levels of e-selectin, vcam, and icam after prolonged strenuous exercise. Sports. ISSN 2075-4663. 9(6), s. 1–10. doi: 10.3390/sports9060086. Fulltekst i vitenarkiv Vis sammendrag

  We assessed endothelial function by flow-mediated dilatation (FMD), levels of the NO-precursor L-arginine, and markers of endothelial inflammation before, at the finish line, and one week after the Norseman Xtreme triathlon. The race is an Ironman distance triathlon with a total elevation of 5200 m. Nine male participants were included. They completed the race in 14.5 (13.4–15.3) h. FMD was significantly reduced to 3.1 (2.1–5.0)% dilatation compared to 8.7 (8.2–9.3)% dilatation before the race (p < 0.05) and was normalized one week after the race. L-arginine showed significantly reduced levels at the finish line (p < 0.05) but was normalized one week after the race. Markers of endothelial inflammation E-Selectin, VCAM-1, and ICAM-1 all showed a pattern with increased values at the finish line compared to before the race (all p < 0.05), with normalization one week after the race. In conclusion, we found acutely reduced FMD with reduced L-arginine levels and increased E-Selectin, VCAM-1, and ICAM-1 immediately after the Norseman Xtreme triathlon. Our findings indicate a transient reduced endothelial function, measured by the FMD-response, after prolonged strenuous exercise that could be explained by reduced NO-precursor L-arginine levels and increased endothelial inflammation.

• Høiseth, Lars Øivind; Melau, Jørgen; Bonnevie-Svendsen, Martin; Nyborg, Christoffer; Eijsvogels, Thijs M. H. & Hisdal, Jonny (2021). Core temperature during cold-water triathlon swimming. Sports. ISSN 2075-4663. 9(6), s. 1–7. doi: 10.3390/sports9060087. Fulltekst i vitenarkiv Vis sammendrag

  Triathlon and other endurance races have grown in popularity. Although participants are generally fit and presumably healthy, there is measurable morbidity and mortality associated with participation. In triathlon, most deaths occur during the swim leg, and more insight into risk factors, such as hypothermia, is warranted. In this study, we measured the core temperature of 51 participants who ingested temperature sensor capsules before the swim leg of a full-distance triathlon. The water temperature was 14.4–16.4 °C, and the subjects wore wetsuits. One subject with a low body mass index and a long swim time experienced hypothermia (<35 °C). Among the remaining subjects, we found no association between core temperature and swim time, body mass index, or sex. To conclude, the present study indicates that during the swim leg of a full-distance triathlon in water temperatures ≈ 15–16 °C, subjects with a low body mass index and long swim times may be at risk of hypothermia even when wearing wetsuits.

• Hoel, Henrik; Pettersen, Erik Mulder; Høiseth, Lars Øivind; Mathiesen, Iacob; Seternes, Arne & Seljeflot, Ingebjørg [Vis alle 7 forfattere av denne artikkelen] (2021). Effects of intermittent negative pressure treatment on circulating vascular biomarkers in patients with intermittent claudication. Vascular Medicine. ISSN 1358-863X. 26(5), s. 489–496. doi: 10.1177/1358863X211007933. Fulltekst i vitenarkiv Vis sammendrag

  The aim of this study was to investigate the effects of lower extremity intermittent negative pressure (INP) treatment for 1 hour twice daily for 12 weeks, on circulating vascular biomarkers in patients with intermittent claudication. Patients were randomized to treatment with –40 mmHg INP (treatment group), or –10 mmHg INP (sham control group). Venous blood samples were collected at baseline and after 12 weeks, and concentrations of vascular adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1), E-selectin, P-selectin, von Willebrand factor (vWF), l-arginine, asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) were analyzed. A larger proportion of the patients in the treatment group (25/31) had a reduction in vWF levels after 12 weeks, compared to the sham control group (17/30) (p = 0.043). Within the treatment group there was a significant mean (SEM) reduction in the concentration of vWF of –11% (4) (p = 0.019), whereas there was no significant change in the levels of vWF in the sham control group (1% (6); p = 0.85). There were no significant differences in the change of any of the biomarker levels between the groups after 12 weeks of treatment. In conclusion, there were no differences in the change of the circulating levels of the measured biomarkers between the treatment group and the sham control group after 12 weeks of INP treatment. However, the observed changes in vWF might indicate a beneficial effect of INP treatment on endothelial activation and endothelial injury. Clinicaltrials.gov Identifier: NCT03640676

• Hoel, Henrik; Pettersen, Erik Mulder; Høiseth, Lars Øivind; Mathiesen, Iacob; Seternes, Arne & Hisdal, Jonny (2021). A randomized controlled trial of treatment with intermittent negative pressure for intermittent claudication. Journal of Vascular Surgery. ISSN 0741-5214. 73(5), s. 1750–1758.e1. doi: 10.1016/j.jvs.2020.10.024. Vis sammendrag

  Objective: We investigated the effects of lower extremity intermittent negative pressure (INP) treatment for 1 hour two times daily for 12 weeks on the walking distance of patients with intermittent claudication (IC). Methods: Patients with IC were randomized to treatment with 40 mm Hg INP (treatment group) or 10 mm Hg INP (sham control group). Pain-free walking distance (PWD) and maximal walking distance (MWD) on a treadmill, resting and postexercise ankle-brachial index, resting and postischemic blood flow (plethysmography), and quality of life (EQ-5D-5L and Vascuqol-6) were measured at baseline and after 12 weeks of treatment. Results: A total of 72 patients were randomized, and 63 had data available for the intention-to-treat analyses. The between-group comparisons showed a significant change in the PWD, favoring the treatment group over the sham control group (estimated treatment effect, 50 m; 95% confidence interval [CI], 11-89; P ¼ .014). The PWD had increased by 68 m (P < .001) in the treatment group and 18 m (P ¼ .064) in the sham control group. No significant difference was found in the change in the MWD between the two groups (estimated treatment effect, 42 m; 95% CI, 14 to 97; P ¼ .139). The MWD had increased by 62 m (P ¼ .006) in the treatment group and 20 m (P ¼ .265) in the sham control group. For patients with a baseline PWD of <200 m (n ¼ 56), significant changes had occurred in both PWD and MWD between the two groups, favoring the treatment group (estimated treatment effect, 42 m; 95% CI, 2-83; P ¼ .042; and estimated treatment effect, 62 m; 95% CI, 5-118; P ¼ .032; respectively). Both overall and for the group of patients with a PWD <200 m, no significant differences were found in the changes in the resting and postexercise ankle-brachial index, resting and postischemic blood flow, or quality of life parameters between the two groups. Conclusions: Treatment with 40 mm Hg INP increased the PWD compared with sham treatment in patients with IC. For the patients with a baseline PWD of <200 m, an increase was found in both PWD and MWD compared with sham treatment. (J Vasc Surg 2021;73:1750-8.)

• Illidi, Camilla Rønn; Stang, Julie; Melau, Jørgen; Hisdal, Jonny & Stensrud, Trine (2021). Does Cold-Water Endurance Swimming Affect Pulmonary Function in Healthy Adults? Sports. ISSN 2075-4663. 9(1), s. 1–12. doi: 10.3390/sports9010007. Fulltekst i vitenarkiv Vis sammendrag

  The acute effects of cold-water endurance swimming on the respiratory system have received little attention. We investigated pulmonary responses to cold-water endurance swimming in healthy recreational triathletes. Pulmonary function, alveolar diffusing capacity (DLCO), fractional exhaled nitric oxide (FENO) and arterial oxygen saturation by pulse oximetry (SpO2) were assessed in 19 healthy adults one hour before and 2.5 h after a cold-water (mean ± SD, 10 ± 0.9 °C) swim trial (62 ± 27 min). In addition, 12 out of the 19 participants measured pulmonary function, forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) 3, 10, 20 and 45 min post-swim by maximal expiratory flow volume loops and DLCO by the single breath technique. FVC and FEV1 were significantly reduced 3 min post-swim (p = 0.02) (p = 0.04), respectively, and five of 12 participants (42%) experienced exercise-induced bronchoconstriction (EIB), defined as a ≥ 10% drop in FEV1. No significant changes were observed in pulmonary function 2.5 h post-swim. However, mean FENO and DLCO were significantly reduced by 7.1% and 8.1% (p = 0.01) and (p < 0.001), respectively, 2.5 h post-swim, accompanied by a 2.5% drop (p < 0.001) in SpO2. The absolute change in DLCO correlated significantly with the absolute decline in core temperature (r = 0.52; p = 0.02). Conclusion: Cold-water endurance swimming may affect the lungs in healthy recreational triathletes lasting up to 2.5 h post-swim. Some individuals appear to be more susceptible to pulmonary impairments than others, although these mechanisms need to be studied further.

• Johnsen, Lydia; Hisdal, Jonny; Jonung, Torbjörn; Braaten, Audun Ole & Pedersen, Gustav (2020). Contrast-enhanced ultrasound detects type II endoleaks during follow-up for endovascular aneurysm repair. Journal of Vascular Surgery. ISSN 0741-5214. 72(6), s. 1952–1959. doi: 10.1016/j.jvs.2020.02.020.
• Stens, Niels Anton; Hisdal, Jonny; Bakke, Espen; Kaur, Narinder; Sharma, Archana & Stranden, Einar [Vis alle 8 forfattere av denne artikkelen] (2020). Factors mediating the pressor response to isometric muscle contraction: An experimental study in healthy volunteers during lower body negative pressureFactors mediating the pressor response to isometric muscle contraction: An experimental study in healthy volunteers during lower body negative pressure. PLOS ONE. ISSN 1932-6203. 15:e0243627(12), s. 1–15. doi: 10.1371/journal.pone.0243627. Fulltekst i vitenarkiv
• Tønnessen, Espen; Hisdal, Jonny & Rønnestad, Bent (2020). Influence of interval training frequency on time-trial performance in elite endurance athletes. International Journal of Environmental Research and Public Health (IJERPH). ISSN 1661-7827. 17(9). doi: 10.3390/ijerph17093190.
• Elstad, Tiril; Ulleberg, Pål; Klonteig, Sandra; Hisdal, Jonny; Dyrdal, Gunvor Marie & Bjørndal, Arild (2020). The effects of yoga on student mental health: a randomised controlled trial. Health Psychology and Behavioral Medicine. ISSN 2164-2850. 8(1), s. 573–586. doi: 10.1080/21642850.2020.1843466. Fulltekst i vitenarkiv
• Berge, Simen Tveten; Safi, Nathkai; Medhus, Asle Wilhelm; Sundhagen, Jon Otto; Hisdal, Jonny & Kazmi, Syed Sajid Hussain (2020). Perioperative microcirculatory changes detected with gastroscopy assisted laser doppler flowmetry and visible light spectroscopy in patients with median arcuate ligament syndrome. Vascular Health and Risk Management. ISSN 1176-6344. 16, s. 331–341. doi: 10.2147/VHRM.S252192. Fulltekst i vitenarkiv
• Storsve, Andreas B.; Johnsen, Line; Nyborg, Christoffer; Melau, Jørgen; Hisdal, Jonny & Burri, Lena (2020). Effects of Krill Oil and Race Distance on Serum Choline and Choline Metabolites in Triathletes: A Field Study. Frontiers in Nutrition. ISSN 2296-861X. 7. doi: 10.3389/fnut.2020.00133. Fulltekst i vitenarkiv
• Nyborg, Christoffer; Melau, Jørgen; Bonnevie-Svendsen, Martin; Mathiassen, Maria; Melsom, Helene Støle & Storsve, Andreas Berg [Vis alle 7 forfattere av denne artikkelen] (2020). Biochemical markers after the Norseman Extreme Triathlon. PLOS ONE. ISSN 1932-6203. 15:e0239158(9), s. 1–15. doi: 10.1371/journal.pone.0239158. Fulltekst i vitenarkiv Vis sammendrag

  Prolonged exercise is known to cause changes in common biomarkers. Occasionally, competition athletes need medical assistance and hospitalisation during prolonged exercise events. To aid clinicians treating patients and medical teams in such events we have studied common biomarkers after at The Norseman Xtreme Triathlon (Norseman), an Ironman distance triathlon with an accumulated climb of 5200 m, and an Olympic triathlon for comparison. Blood samples were collected before, immediately after, and the day following the Norseman Xtreme Triatlon (n = 98) and Oslo Olympic Triathlon (n = 15). Increased levels of clinical significance were seen at the finish line of the Norseman in white blood cells count (WBC) (14.2 [13.5-14.9] 109/L, p

• Hilde, Janne Mykland; Hisdal, Jonny; Skjørten, Ingunn; Hansteen, Viggo; Melsom, Morten Nissen & Grøtta, Ole Jørgen [Vis alle 11 forfattere av denne artikkelen] (2020). Left ventricular dysfunction in COPD without pulmonary hypertension. PLOS ONE. ISSN 1932-6203. 15(7), s. 1–15. doi: 10.1371/journal.pone.0235075. Fulltekst i vitenarkiv
• Amini, Maryam; Niemi, Essi Maria; Hisdal, Jonny; Kalvøy, Håvard; Tronstad, Christian & Scholz, Hanne [Vis alle 8 forfattere av denne artikkelen] (2020). Monitoring the quality of frozen-thawed venous segments using bioimpedance spectroscopy . Physiological Measurement. ISSN 0967-3334. 41(4). doi: 10.1088/1361-6579/ab85b7. Fulltekst i vitenarkiv
• Amini, Maryam; Hisdal, Jonny; Rosales, Antonio; Kalvøy, Håvard & Martinsen, Ørjan Grøttem (2020). Evaluating the Effects of Cold Storage on Vascular Grafts Using Bioimpedance Measurement Techniques. International Federation for Medical and Biological Engineering Proceedings. ISSN 1680-0737. s. 127–132. doi: 10.1007/978-981-13-3498-6_19.
• Stensrud, Trine; Rossvoll, Øyvind; Mathiassen, Maria; Melau, Jørgen; Illidi, Camilla Rønn & Østgaard, Hege Nymo [Vis alle 8 forfattere av denne artikkelen] (2020). Lung function and oxygen saturation after participation in Norseman Xtreme Triathlon. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 30(6), s. 1008–1016. doi: 10.1111/sms.13651. Fulltekst i vitenarkiv Vis sammendrag

  Objectives: To examine evidence of exercise-induced bronchoconstriction (EIB) defined as ≥10% reduction in forced expiratory volume in one second (FEV1 ) and exercise-induced arterial hypoxemia (EIAH) defined as ≥4% reduction in oxygen saturation (SpO2 ) from before to after participation in the Norseman Xtreme Triathlon. Secondarily, to assess whether changes in FEV1 and SpO2 are related to respiratory symptoms, training volume, and race time. Methods: In this quasi-experimental non-controlled study, we included 63 triathletes (50♂/13♀) aged 40.3 (±9.0) years (mean ± SD). Fifty-seven (46♂/11♀) measured lung function and 54 (44♂/10♀) measured SpO2 before the race, 8-10 minutes after the race (post-test 1) and the day after the race (post-test 2). Respiratory symptoms and training volume were recorded with modified AQUA questionnaire. ANOVA for repeated measures was used to detect differences in lung function and SpO2 . Statistical significance was accepted at 0.05 level. Results: Twenty-six participants (46%) presented with EIB at post-test 1 and 16 (28%) at post-test 2. Lung function variables were significantly reduced from baseline to post-test 1 and 2. Thirty-five participants (65%) showed evidence of mild to moderate EIAH. No significant correlations were observed except a weak correlation between maximal reduction in FEV1 and respiratory symptoms (r = 0.35, P = .016). Conclusion: Our results demonstrated that 46% of the participants presented with EIB and 65% showed evidence of EIAH after the Norseman Xtreme Triathlon. Changes in FEV1 and SpO2 were not correlated to weekly training hours or race time. We observed a weak correlation between maximal reduction in FEV1 and respiratory symptoms.

• Valsdottir, Thorhildur; Henriksen, Christine; Odden, Nancy; Nellemann, Birgitte; Jeppesen, Per B & Hisdal, Jonny [Vis alle 8 forfattere av denne artikkelen] (2019). Effect of a Low-Carbohydrate High-Fat Diet and a Single Bout of Exercise on Glucose Tolerance, Lipid Profile and Endothelial Function in Normal Weight Young Healthy Females. Frontiers in Physiology. ISSN 1664-042X. 10, s. 1–15. doi: 10.3389/fphys.2019.01499. Fulltekst i vitenarkiv
• Berge, Simen Tveten; Safi, Nathkai; Medhus, Asle Wilhelm; Ånonsen, Kim Vidar; Sundhagen, Jon Otto & Hisdal, Jonny [Vis alle 7 forfattere av denne artikkelen] (2019). Gastroscopy assisted laser Doppler flowmetry and visible light spectroscopy in patients with chronic mesenteric ischemia. Scandinavian Journal of Clinical and Laboratory Investigation. ISSN 0036-5513. 79(7), s. 541–549. doi: 10.1080/00365513.2019.1672084. Fulltekst i vitenarkiv
• Svanteson, Mona; Rollefstad, Silvia Christin Hellerud; Kløw, Nils-Einar; Hisdal, Jonny; Ikdahl, Eirik & Sexton, Joseph [Vis alle 8 forfattere av denne artikkelen] (2019). Effects of long-term statin-treatment on coronary atherosclerosis in patients with inflammatory joint diseases. PLOS ONE. ISSN 1932-6203. 14(12), s. 1–15. doi: 10.1371/journal.pone.0226479. Fulltekst i vitenarkiv
• Pettersen, Erik Mulder; Avdal, Jørgen; Hisdal, Jonny; Torp, Hans & Seternes, Arne (2019). Validation of a novel ultrasound Doppler monitoring device (earlybird) for detection of microvascular circulatory changes. Clinical Hemorheology and Microcirculation. ISSN 1386-0291. doi: 10.3233/CH-190707.
• Hoff, Ingrid Elise Taraldsrud; Hisdal, Jonny; Landsverk, Svein A.; Røislien, Jo; Kirkebøen, Knut Arvid & Høiseth, Lars Øivind (2019). Respiratory variations in pulse pressure and photoplethysmographic waveform amplitude during positive expiratory pressure and continuous positive airway pressure in a model of progressive hypovolemia. PLOS ONE. ISSN 1932-6203. 14:e0223071(9), s. 1–15. doi: 10.1371/journal.pone.0223071. Fulltekst i vitenarkiv
• Hoel, Henrik; Høiseth, Lars Øivind; Sandbæk, Gunnar; Sundhagen, Jon Otto; Mathiesen, Iacob & Hisdal, Jonny (2019). The acute effects of different levels of intermittent negative pressure on peripheral circulation in patients with peripheral artery disease. Physiological Reports. ISSN 2051-817X. 7:e14241(20), s. 1–8. doi: 10.14814/phy2.14241. Fulltekst i vitenarkiv
• Gundersen, Kristian Magnus; Nyborg, Christoffer; Heiberg Sundby, Øivind & Hisdal, Jonny (2019). The effects of sympathetic activity induced by ice water on blood flow and brachial artery flow-mediated dilatation response in healthy volunteers. PLOS ONE. ISSN 1932-6203. 14(9). doi: 10.1371/journal.pone.0219814. Fulltekst i vitenarkiv Vis sammendrag

  Objective To investigate the association between sympathetic activity, reactive hyperemia and brachial artery flow-mediated dilation (FMD). Background It is claimed that major surgery has an impact on endothelial function, as observed by post-operative reduced brachial artery FMD response. However, another explanation for the observed reduced FMD response post-operatively may be sympathetic stress-induced reduction in blood flow. Methods Seventeen healthy volunteers with a median age (25th-75th percentiles) of 23.5 (23–24.8) years were recruited. Participants’ brachial blood flow and FMD response were measured (i) during normal non-stress conditions (Normal1); (ii) during exposure to ice water; and (iii) afterwards, under normal non-stress conditions (Normal2). We continuously measured arterial blood pressure (Finometer), heart rate (ECG), skin blood flow of the index finger (laser Doppler), and brachial artery blood flow and diameter (Ultrasound Doppler). Measurements were taken at baseline; before a 5-min suprasystolic forearm occlusion; and following a 3-min post-occlusion, to measure reactive hyperemia and FMD. Results Median (25th-75th percentiles) FMD response after exposure to ice water was reduced compared to non-stress conditions [4.9 (2.9–8.4) % during ice water vs. 9.7 (7.6–12.2) % Normal1 and 9.7 (6.4–10.3) % Normal2, P < 0.001]. Blood flow 60 s after cuff-deflation during ice water exposure was significantly reduced to 328 (289–421) mL compared to non-stress conditions (both P < 0.05). No differences were observed between Normal1 [446 (359–506) mL] and Normal2 [455 (365–515) mL] (both P > 0.05). Heart rate significantly increased during ice water exposure [67 (59–69) beats/min)] compared to 55 (49–60) beats/min during Normal1 and 54 (47–60) beats/min during Normal2 (both P < 0.05). MAP did not change during Normal1 [72 (64–84)] or during Normal2 [71 (65–81) mm Hg] (both P > 0.05), but increased to 86 (75–98) mm Hg during ice water exposure (P < 0.05). Conclusions Increased sympathetic activity resulted in decreased blood flow and brachial artery FMD response in healthy volunteers, independent of endothelial dysfunction. Future studies should adjust for blood flow when interpreting the FMD response.

• Holder, Sophie M; Dawson, Ellen A; Brislane, Aine; Hisdal, Jonny; Green, Daniel J. & Thijssen, Dick HJ (2019). Fluctuation in shear rate, with unaltered mean shear rate, improves brachial artery flow-mediated dilation in healthy, young men. Journal of applied physiology. ISSN 8750-7587. 126(6), s. 1687–1693. doi: 10.1152/japplphysiol.00009.2019.
• Hisdal, Jonny; Landsverk, Svein A.; Hoff, Ingrid Elise Taraldsrud; Hagen, Ove Andreas; Kirkebøen, Knut Arvid & Høiseth, Lars Øivind (2019). Associations between changes in precerebral blood flow and cerebral oximetry in the lower body negative pressure model of hypovolemia in healthy volunteers. PLOS ONE. ISSN 1932-6203. 14(6), s. 1–14. doi: 10.1371/journal.pone.0219154. Fulltekst i vitenarkiv
• Melau, Jørgen; Mathiassen, Maria; Stensrud, Trine; Tipton, Mike & Hisdal, Jonny (2019). Core temperature in triathletes during swimming with wetsuit in 10^◦c cold water. Sports. ISSN 2075-4663. 7(6). doi: 10.3390/sports7060130. Fulltekst i vitenarkiv
• Aalen, John; Storsten, Petter; Remme, Espen W.; Sirnes, Per A.; Gjesdal, Ola & Larsen, Camilla Kjellstad [Vis alle 11 forfattere av denne artikkelen] (2018). Afterload hypersensitivity in patients with left bundle branch block. JACC Cardiovascular Imaging. ISSN 1936-878X. s. 1–11. doi: 10.1016/j.jcmg.2017.11.025.
• Bjørnsen, Thomas; Wernbom, Mathias; Løvstad, Amund T.; Paulsen, Gøran; D'Souza, Randall F & Cameron-Smith, David [Vis alle 10 forfattere av denne artikkelen] (2018). Delayed myonuclear addition, myofiber hypertrophyand increases in strength with frequent low-load blood flow restricted training to volitional failure. Journal of applied physiology. ISSN 8750-7587. doi: 10.1152/japplphysiol.00397.2018. Vis sammendrag

  PURPOSE: To investigate muscle hypertrophy, strength, myonuclear and satellite cell (SC) responses to high-frequency blood flow restricted resistance exercise (BFRRE). METHODS: Thirteen individuals (24±2 years [mean ± SD], 9 males) completed two 5-day-blocks of 7 BFRRE sessions, separated by a 10-day rest period. Four sets of unilateral knee extensions to voluntary failure at 20% of 1RM were conducted with partial blood flow restriction (90-100 mmHg). Muscle samples obtained before-, during, 3- and 10 days after training were analyzed for muscle fiber area (MFA), myonuclei, SC, and mRNA and miRNA expression. Muscle size was measured by ultrasonography and magnetic resonance imaging, and strength with 1RM knee-extension. RESULTS: With the first block of BFRRE, SC number increased in both fiber types (70-80%, p<0.05), while type I and II MFA decreased by 6±7% and 15±11% (p<0.05), respectively. With the second block of training, muscle size increased by 6-8%, while the number of SC (type I: 80±63%, type II 147±95%), myonuclei (type I: 30±24%, type II: 31±28%) and MFA (type I: 19±19%, type II: 11±19%) peaked 10 days after the second block of BFRRE, whereas strength peaked after 20 days of detraining (6±6%, p<0.05). Pax7- and p21 mRNA expression were elevated during the intervention, while myostatin, IGF1R, MyoD, myogenin, cyclinD1 and -D2 mRNA did not change until 3-10 days post intervention. CONCLUSION: High frequency low-load BFRRE induced robust increases in SC, myonuclei and muscle size, but modest strength gains. Intriguingly, the responses were delayed and peaked 10-20 days after the training intervention, indicating overreaching.

• Amini, Maryam; Hisdal, Jonny & Kalvøy, Håvard (2018). Applications of bioimpedance measurement techniques in tissue engineering . Journal of Electrical Bioimpedance. ISSN 1891-5469. 9(1), s. 142–158. doi: 10.2478/joeb-2018-0019. Fulltekst i vitenarkiv
• Skjørten, Ingunn; Mykland Hilde, Janne; Melsom, Morten Nissen; Hisdal, Jonny; Hansteen, Viggo & Steine, Kjetil [Vis alle 7 forfattere av denne artikkelen] (2018). Exercise capacity in COPD patients with exercise-induced pulmonary hypertension. The International Journal of Chronic Obstructive Pulmonary Disease. ISSN 1176-9106. 13, s. 3599–3610. doi: 10.2147/COPD.S161175. Fulltekst i vitenarkiv
• Rambøl, Mia Marie-Elisabeth; Hisdal, Jonny; Sundhagen, Jon Otto; Brinchmann, Jan E. & Rosales, Antonio (2018). Recellularization of decellularized venous grafts using peripheral blood: a critical evaluation. EBioMedicine. ISSN 2352-3964. 32, s. 215–222. doi: 10.1016/j.ebiom.2018.05.012. Fulltekst i vitenarkiv
• Heiberg Sundby, Øivind; Irgens, Ingebjørg; Høiseth, Lars Øivind; Mathiesen, Iacob; Lundgaard, Eivind & Haugland, Hanne [Vis alle 10 forfattere av denne artikkelen] (2018). Intermittent mild negative pressure applied to the lower limb in patients with spinal cord injury and chronic lower limb ulcers: A crossover pilot study. Spinal Cord. ISSN 1362-4393. 56, s. 372–381. doi: 10.1038/s41393-018-0080-4.
• Skjørten, Ingunn; Mykland Hilde, Janne; Melsom, Morten Nissen; Hisdal, Jonny; Hansteen, Viggo & Steine, Kjetil [Vis alle 7 forfattere av denne artikkelen] (2018). Cardiopulmonary exercise test and PaO2 in evaluation of pulmonary hypertension in COPD. The International Journal of Chronic Obstructive Pulmonary Disease. ISSN 1176-9106. 2018:13, s. 91–100. doi: 10.2147/COPD.S150034.
• Heiberg Sundby, Øivind; Høiseth, Lars Øivind; Irgens, Ingebjørg; Mathiesen, Iacob; Lundgaard, Eivind & Haugland, Hanne [Vis alle 10 forfattere av denne artikkelen] (2017). Intermittent negative pressure applied to the lower limb increases foot macrocirculatory and microcirculatory blood flow pulsatility in people with spinal cord injury. Spinal Cord. ISSN 1362-4393. s. 1–10. doi: 10.1038/s41393-017-0049-8.
• Svanteson, Mona; Rollefstad, Silvia Christin Hellerud; Kløw, Nils-Einar; Hisdal, Jonny; Ikdahl, Eirik & Semb, Anne Grete [Vis alle 7 forfattere av denne artikkelen] (2017). Associations between coronary and carotid artery atherosclerosis in patients with inflammatory joint diseases. RMD Open. ISSN 2056-5933. 3(2). doi: 10.1136/rmdopen-2017-000544.
• Dedichen, Hans Henrik; Hisdal, Jonny; Skogvoll, Eirik; Aadahl, Petter & Kirkeby-Garstad, Idar (2017). Reduced reactive hyperemia may explain impaired flow-mediated dilation after on-pump cardiac surgery. Physiological Reports. ISSN 2051-817X. 5(10), s. 1–7. doi: 10.14814/phy2.13274. Fulltekst i vitenarkiv
• Broch, Kaspar; De Marchi, Stefano; Massey, Richard J; Hisdal, Jonny; Aakhus, Svend & Gullestad, Lars [Vis alle 7 forfattere av denne artikkelen] (2017). Left Ventricular Contraction Pattern in Chronic Aortic Regurgitation and Preserved Ejection Fraction: Simultaneous Stress-Strain Analysis by Three-Dimensional Echocardiography. Journal of the American Society of Echocardiography. ISSN 0894-7317. 30(4), s. 422–430.e2. doi: 10.1016/j.echo.2016.11.012.
• Sundby, Øyvind Heiberg; Høiseth, Lars Øivind; Mathiesen, Iacob; Weedon-Fekjær, Harald; Sundhagen, Jon Otto & Hisdal, Jonny (2017). The acute effects of lower limb intermittent negative pressure on foot macro-and microcirculation in patients with peripheral arterial disease. PLOS ONE. ISSN 1932-6203. 12:e0179001(6), s. 1–16. doi: 10.1371/journal.pone.0179001. Fulltekst i vitenarkiv
• Sundby, Øyvind Heiberg; Høiseth, Lars Øivind; Mathiesen, Iacob; Jørgensen, Jørgen J.; Sundhagen, Jon Otto & Hisdal, Jonny (2016). The effects of intermittent negative pressure on the lower extremities' peripheral circulation and wound healing in four patients with lower limb ischemia and hard‐to‐heal leg ulcers: a case report. Physiological Reports. ISSN 2051-817X. 4(20). doi: 10.14814/phy2.12998. Fulltekst i vitenarkiv Vis sammendrag

  Peripheral circulation is severely compromised in the advanced stages of peripheral arterial disease. Recently, it was shown that the application of −40 mmHg intermittent negative pressure (INP) to the lower leg and foot enhances macro‐ and microcirculation in healthy volunteers. In this case report, we describe the effects of INP treatment on four patients with lower limb ischemia and hard‐to‐heal leg and foot ulcers. We hypothesized that INP therapy may have beneficial hemodynamic and clinical effects in the patients. Four patients (age range: 61–79 years) with hard‐to‐heal leg and foot ulcers (6–24 months) and ankle‐brachial pressure indices of ≤0.60 on the affected side were included. They were treated with an 8‐week intervention period of −40 mmHg INP (10 sec negative pressure and 7 sec atmospheric pressure) on the lower limbs. A custom‐made vacuum chamber was used to apply INP to the affected lower leg and foot for 2 h per day. After 8 weeks of INP therapy, one ulcer healed completely, while the other three ulcers were almost completely healed. These cases suggest that INP may facilitate wound healing. The theoretical foundation is that INP assists wound healing by improving blood flow to the small blood vessels in the affected limb, increasing the flow of oxygen and nutrients to the cells.

• Ikdahl, Eirik; Rollefstad, Silvia Christin Hellerud; Wibetoe, Grunde; Olsen, Inge Christoffer; Berg, Inger Jorid & Hisdal, Jonny [Vis alle 11 forfattere av denne artikkelen] (2016). Predictive value of arterial stiffness and subclinical carotid atherosclerosis for cardiovascular disease in patients with rheumatoid arthritis. Journal of Rheumatology. ISSN 0315-162X. 43(9), s. 1622–1630. doi: 10.3899/jrheum.160053.
• Semb, Anne Grete; Ikdahl, Eirik; Hisdal, Jonny; Olsen, Inge Christoffer & Rollefstad, Silvia Christin Hellerud (2016). Exploring cardiovascular disease risk evaluation in patients with inflammatory joint diseases. International Journal of Cardiology. ISSN 0167-5273. 223, s. 331–336. doi: 10.1016/j.ijcard.2016.08.129.
• Sundby, Øyvind Heiberg; Høiseth, Lars Øivind; Mathiesen, Iacob; Jørgensen, Jørgen J.; Weedon-Fekjær, Harald & Hisdal, Jonny (2016). Application of intermittent negative pressure on the lower extremity and its effect on macro- and microcirculation in the foot of healthy volunteers. Physiological Reports. ISSN 2051-817X. 4(17). doi: 10.14814/phy2.12911. Fulltekst i vitenarkiv
• Rimehaug, Audun Eskeland; Hoff, Ingrid E Taraldsrud; Høiseth, Lars Øivind; Hisdal, Jonny; Aadahl, Petter & Kirkeby-Garstad, Idar (2016). Cardiac power parameters during hypovolemia, induced by the lower body negative pressure technique, in healthy volunteers. BMC Anesthesiology. ISSN 1471-2253. 16(31). doi: 10.1186/s12871-016-0195-0. Fulltekst i vitenarkiv Vis sammendrag

  Background Changes in cardiac power parameters incorporate changes in both aortic flow and blood pressure. We hypothesized that dynamic and non-dynamic cardiac power parameters would track hypovolemia better than equivalent flow- and pressure parameters, both during spontaneous breathing and non-invasive positive pressure ventilation (NPPV). Methods Fourteen healthy volunteers underwent lower body negative pressure (LBNP) of 0, −20, −40, −60 and −80 mmHg to simulate hypovolemia, both during spontaneous breathing and during NPPV. We recorded aortic flow using suprasternal ultrasound Doppler and blood pressure using Finometer, and calculated dynamic and non-dynamic parameters of cardiac power, flow and blood pressure. These were assessed on their association with LBNP-levels. Results Respiratory variation in peak aortic flow was the dynamic parameter most affected during spontaneous breathing increasing 103 % (p < 0.001) from baseline to LBNP −80 mmHg. Respiratory variation in pulse pressure was the most affected dynamic parameter during NPPV, increasing 119 % (p < 0.001) from baseline to LBNP −80 mmHg. The cardiac power integral was the most affected non-dynamic parameter falling 59 % (p < 0.001) from baseline to LBNP −80 mmHg during spontaneous breathing, and 68 % (p < 0.001) during NPPV. Conclusions Dynamic cardiac power parameters were not better than dynamic flow- and pressure parameters at tracking hypovolemia, seemingly due to previously unknown variation in peripheral vascular resistance matching respiratory changes in hemodynamics. Of non-dynamic parameters, the power parameters track hypovolemia slightly better than equivalent flow parameters, and far better than equivalent pressure parameters.

• Ikdahl, Eirik; Rollefstad, Silvia Christin Hellerud; Hisdal, Jonny; Olsen, Inge Christoffer; Pedersen, Terje Rolf & Kvien, Tore Kristian [Vis alle 7 forfattere av denne artikkelen] (2016). Sustained improvement of arterial stiffness and blood pressure after long-term rosuvastatin treatment in patients with inflammatory joint diseases: Results from the rora-as study. PLOS ONE. ISSN 1932-6203. 11(4). doi: 10.1371/journal.pone.0153440.
• Mykland Hilde, Janne; Skjørten, Ingunn; Hansteen, Viggo; Melsom, Morten Nissen; Atar, Dan & Hisdal, Jonny [Vis alle 8 forfattere av denne artikkelen] (2016). Assessment of right ventricular afterload in COPD. COPD: Journal of Chronic Obstructive Pulmonary Disease. ISSN 1541-2555. 13(2), s. 176–185. doi: 10.3109/15412555.2015.1057275.
• Amini, Maryam; Hisdal, Jonny; Gjøvaag, Terje; Kapetanovic, Nihad; Strand, Trond-Eirik & Owe, Jan Ove [Vis alle 8 forfattere av denne artikkelen] (2016). Near-Infrared Spectra in Buccal Tissue as a Marker for Detection of Hypoxia. Aerospace Medicine and Human Performance. ISSN 2375-6314. 87(5), s. 498–504. doi: 10.3357/AMHP.4510.2016. Vis sammendrag

  Abstract: INTRODUCTION: Hypoxia caused by high altitude exposure can impair cerebral and mental functions. Blood flow and oxygenation of the buccal tissue can be reliable markers to detect hypoxia. In this study, near infrared spectroscopy was used in combination with a novel optical probe to evaluate the applicability of the novel probe in measuring hypoxia markers in buccal tissue under a hypoxic condition. METHODS: Six healthy participants were tested at altitudes from 2000 to 16,000 ft inside a hypobaric chamber. The buccal reference measurements of blood flow and oxygen saturation were synchronized with the spectral measurements of the novel near infrared probe and the relationship between the reference measurements and spectral data were evaluated by multivariate partial least square method. In addition, finger oxygen saturation was measured during the experiment and the recordings were compared with buccal oxygen saturation. RESULTS: The spectral analysis illustrated that the spectral data from the near infrared probe correlated strongly with the absorption features of both buccal flow and oxygenation measured by the reflectance sensors (average R2 = 0.89). The results showed probably overestimated values for buccal oxygen saturation recorded by the reference pulse oximeter in comparison with finger oxygen saturation, with the mean difference increasing from 1.8% at 2000 ft to 11.4% at 16,000 ft. CONCLUSION: The novel near infrared probe showed promising results for simultaneous measurement of blood flow and oxygen saturation in the buccal tissue. The suggested method can be used as a new technique for early indication of hypoxia in future clinical applications.

• Gjøvaag, Terje; Mirtaheri, Peyman; Simon, Kristoffer; Berdal, Gøran; Tuchel, Irja & Westlie, Tonje [Vis alle 9 forfattere av denne artikkelen] (2016). Hemodynamic responses to resistance exercise in patients with coronary artery disease. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 48(4), s. 581–588. doi: 10.1249/MSS.0000000000000811.
• Dedichen, Hans Henrik; Kirkeby-Garstad, Idar; Aadahl, Petter; Hisdal, Jonny & Amundsen, Brage H. (2016). Cardiac function assessed by exercise echocardiography on the first morning after coronary artery bypass grafting. Clinical Physiology and Functional Imaging. ISSN 1475-0961. 36(4), s. 274–280. doi: 10.1111/cpf.12224.
• Ikdahl, Eirik; Hisdal, Jonny; Rollefstad, Silvia Christin Hellerud; Olsen, Inge Christoffer; Kvien, Tore Kristian & Pedersen, Terje Rolf [Vis alle 7 forfattere av denne artikkelen] (2015). Rosuvastatin improves endothelial function in patients with inflammatory joint diseases, longitudinal associations with atherosclerosis and arteriosclerosis: Results from the RORA-AS statin intervention study. Arthritis Research & Therapy. ISSN 1478-6354. 17. doi: 10.1186/s13075-015-0795-y.
• Gjerdalen, Gard Filip; Hisdal, Jonny; Solberg, Erik Ekker; Andersen, Thor Einar; Radunovic, Zoran & Steine, Kjetil (2015). Atrial size and function in athletes. International Journal of Sports Medicine (IJSM). ISSN 0172-4622. 36(14), s. 1170–1176. doi: 10.1055/s-0035-1555780. Vis sammendrag

  We wanted to explore whether change in LA (left atrium) size would influence LA function, or increase regurgitation in the atrioventricular valves. 595 male elite football players and 47 non-athletic controls were included. End-systolic LA volume and RA area and end-diastolic LV volume and RV area were measured by 2-dimensional (2D) echocardiography Pulsed and colour Doppler were used to estimate tricuspid and mitral regurgitations. 2D longitudinal strain of the 50 football players with the largest LA volumes were compared with the 50 players with the smallest LA volumes. The LA volumes in some athletes with large atria were more than tripled, compared to athletes with small atria. 2D strain however, could not reveal any impairment of LA function in the players with the largest atria, compared to those with the smallest LA. Tricuspid valve regurgitation was found in 343 (58%) of the athletes, compared to 17 (36%) of the controls (p<0.01), while mitral regurgitation was found in 116 (20%) football players and 7 (15%) controls (NS). Furthermore, the RA area was significantly larger in athletes with tricuspid regurgitation compared to athletes without. The present study demonstrated a huge variation in atrial size between the athletes. This variation, however, had no impact on LA function. Tricuspid regurgitation was significantly more prevalent among the athletes, than among the controls.

• Rollefstad, Silvia Christin Hellerud; Ikdahl, Eirik; Hisdal, Jonny; Kvien, Tore Kristian; Pedersen, Terje Rolf & Semb, Anne Grete (2015). Association of Chest Pain and Risk of Cardiovascular Disease with Coronary Atherosclerosis in Patients with Inflammatory Joint Diseases. Frontiers in medicine. ISSN 2296-858X. doi: 10.3389/fmed.2015.00080.
• Høiseth, Lars Øivind; Hisdal, Jonny; Hoff, Ingrid E Taraldsrud; Hagen, Ove Andreas; Landsverk, Svein A. & Kirkebøen, Knut Arvid (2015). Tissue Oxygen Saturation and Finger Perfusion Index in Central Hypovolemia: Influence of Pain. Critical Care Medicine. ISSN 0090-3493. 43(4). doi: 10.1097/CCM.0000000000000766. Vis sammendrag

  Objectives: Tissue oxygen saturation and peripheral perfusion index are proposed as early indirect markers of hypovolemia in trauma patients. Hypovolemia is associated with increased sympathetic nervous activity. However, many other stimuli, such as pain, also increase sympathetic activity. Since pain is often present in trauma patients, its effect on the indirect measures of hypovolemia needs to be clarified. The aim of this study was, therefore, to explore the effects of hypovolemia and pain on tissue oxygen saturation (measurement sites: cerebral, deltoid, forearm, and thenar) and finger photoplethysmographic perfusion index. Design: Experimental study. Setting: University hospital clinical circulation and research laboratory. Subjects: Twenty healthy volunteers. Interventions: Central hypovolemia was induced with lower body negative pressure (–60 mm Hg) and pain by the cold pressor test (ice water exposure). Interventions were performed in a 2 × 2 fashion with the combination of lower body negative pressure or not (normovolemia), and ice water or not (sham). Each subject was thus exposed to four experimental sequences, each lasting for 8 minutes. Measurements and Main Results: Measurements were averaged over 30 seconds. For each person and sequence, the minimal value was analyzed. Tissue oxygenation in all measurement sites and finger perfusion index were reduced during hypovolemia/sham compared with normovolemia/sham. Tissue oxygen saturation (except cerebral) and perfusion index were reduced by pain during normovolemia. There was a larger reduction in tissue oxygenation (all measurement sites) and perfusion index during hypovolemia and pain than during normovolemia and pain. Conclusions: Pain (cold pressor test) reduces tissue oxygen saturation in all measurement sites (except cerebral) and perfusion index. In the presence of pain, tissue oxygen saturation and perfusion index are further reduced by hypovolemia (lower body negative pressure, –60 mm Hg). Thus, pain must be considered when evaluating tissue oxygen saturation and perfusion index as markers of hypovolemia in trauma patients.

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• Hove, Christine; Sæter, Frode Wirum; Stepanov, Alexey; Bøtke-Rasmussen, Kasper Gade; Seeberg, Trine Margrethe & Westgaard, Espen [Vis alle 10 forfattere av denne artikkelen] (2024). EVALUATION OF A PROTOTYPE CUFFLESS MULTI-SENSOR DEVICE TO TRACK BLOOD PRESSURE CHANGES.
• Melsom, Helene Støle; Randa, Anders; Hisdal, Jonny; Stang, Julie & Stensrud, Trine (2022). Prevalence of asthma among Norwegian elite athletes.
• Lie, Sole Lindvåg; Hisdal, Jonny; Rehn, Marius & Høiseth, Lars Øivind (2022). Effects of supplemental oxygen on systemic and cerebral hemodynamics in experimental hypovolemia: Protocol for a randomized, double blinded crossover study. PLOS ONE. ISSN 1932-6203. 17(6). doi: 10.1371/journal.pone.0270598. Vis sammendrag

  Supplemental oxygen is widely administered in trauma patients, often leading to hyperoxia. However, the clinical evidence for providing supplemental oxygen in all trauma patients is scarce, and hyperoxia has been found to increase mortality in some patient populations. Hypovolemia is a common finding in trauma patients, which affects many hemodynamic parameters, but little is known about how supplemental oxygen affects systemic and cerebral hemodynamics during hypovolemia. We therefore plan to conduct an experimental, randomized, double blinded crossover study to investigate the effect of 100% oxygen compared to room air delivered by a face mask with reservoir on systemic and cerebral hemodynamics during simulated hypovolemia in the lower body negative pressure model in 15 healthy volunteers. We will measure cardiac output, stroke volume, blood pressure, middle cerebral artery velocity and tolerance to hypovolemia continuously in all subjects at two visits to investigate whether oxygen affects the cardiovascular response to simulated hypovolemia. The effect of oxygen on the outcome variables will be analyzed with mixed linear regression. Trial registration: The study is registered in the European Union Drug Regulating Authorities Clinical Trials Database (EudraCT, registration number 2021-003238-35).

• Hoel, Henrik & Hisdal, Jonny (2021). The FlowOx device for the treatment of peripheral artery disease: current status and future prospects. Expert Review of Medical Devices. ISSN 1743-4440. 18(3), s. 217–220. doi: 10.1080/17434440.2021.1895750.
• Wang, Eivind; Hisdal, Jonny & Solberg, Trine (2021). Ekspertens effektive råd: – Gjør dette to ganger i uka, så vil du se utrolig effekt på kort tid. [Avis]. iharstad.no.
• Wang, Eivind; Hisdal, Jonny & Solberg, Trine (2021). Ekspert mener mange lurer seg selv - slik går du deg sprek. [Avis]. Nettavisen Pluss.
• Lund, Tormod; Svindland, Aud; Bay, Dag; Sundhagen, Jon Otto; Hisdal, Jonny & Flørnes, Tor Leif (2020). Histological Analysis of a Long Term Patent Subintimal Canal in theSuperficial Femoral Artery. EJVES Short Reports. ISSN 2405-6553. 50, s. 19–23. doi: 10.1016/j.ejvsvf.2020.12.023. Fulltekst i vitenarkiv
• Johnsen, Lydia; Hisdal, Jonny; Jonung, Torbjörn; Braaten, Audun Ole & Pedersen, Gustav (2019). 3D Ultralyd volum og konvensjonell ultralyd dimeterendringer er likeverdige markører for endolekkasje i oppfølging etter EVAR.
• Melau, Jørgen; Bonnevie-Svendsen, Martin; Mathiassen, Maria; Mykland Hilde, Janne; Oma, Lars & Hisdal, Jonny (2019). Late-presenting swimming-induced pulmonary edema: A case report series from the norseman xtreme triathlon. Sports. ISSN 2075-4663. 7(6). doi: 10.3390/sports7060137. Fulltekst i vitenarkiv
• Bø, Elisabeth & Hisdal, Jonny (2018). Endovaskulær behandling etterfulgt av trening for perifer arteriell sirkulasjonssvikt - Langtidsoppfølging av en randomisert kontrollert studie.
• Johnsen, Lydia; Hisdal, Jonny; Jonung, Torbjörn; Braaten, Audun Ole; Laxdal, Elin Hanna & Kjøsnes, Thomas [Vis alle 7 forfattere av denne artikkelen] (2017). Kontrastforsterket ultralyd detekterer endolekkasje etter EVAR.
• Johnsen, Lydia; Hisdal, Jonny; Jonung, Torbjörn; Braaten, Audun Ole; Laxdal, Elin Hanna & Kjøsnes, Thomas [Vis alle 7 forfattere av denne artikkelen] (2017). Contrast Enhanced Ultrasound Detects Endoleak in follow-up after EVAR.
• Bø, Elisabeth; Slagsvold, Carl-Erik & Hisdal, Jonny (2017). PTA OG TRENING – LANGTIDSOPPFØLGING AV EN RANDOMISERT KONTROLLERT STUDIE.
• Jåbekk, Pål; Sandåker, Lars & Hisdal, Jonny (2017). Lars og Pål:Episode 30 Jonny Hisdal om fysiologi, trening og kroppens tåleevne (Mensen Ernst, Wim Hof). [Radio]. Podcast: Lars og Pål.
• Høiseth, Lars Øivind; Hisdal, Jonny; Landsverk, Svein A. & Kirkebøen, Knut Arvid (2015). The authors reply: Pain and tissue oxygenation. Critical Care Medicine. ISSN 0090-3493. 43(10), s. e463–e464. doi: 10.1097/CCM.0000000000001206.
• Bø, Elisabeth; Hisdal, Jonny; Cvancarova, Milada; Stranden, Einar; Jørgensen, Jørgen J. & Sandbæk, Gunnar [Vis alle 8 forfattere av denne artikkelen] (2015). PTA og trening hos pasienter med claudicatio intermittens - en randomisert kontrollert studie.
• Johnsen, Lydia; Hisdal, Jonny; Jonung, Torbjörn & Pedersen, Gustav (2021). Ultrasound in follow-up after endovascular aneurysm repair. Universitetet i Bergen. ISSN 9788230858776.
• Amini, Maryam; Mirtaheri, Peyman; Gjøvaag, Terje & Hisdal, Jonny (2017). A novel optical probe for detection of hypoxia in the deeper layers of human buccal tissue. Universitetet i Oslo.

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