Disputation: Siri Bjorland – Genetics and persistent pain

Cand.med. Siri Bjorland at Institute of Clinical Medicine will be defending the thesis “Genetic variability and persistent low back and lumbar radicular pain” for the degree of Philosophiae doctor (PhD).

Trial lecture – time and place

See trial lecture.

Adjudication committee

  • First opponent: Professor Charlotte Leboeuf-Yde, University of Southern Denmark
  • Second opponent: Professor Pål Klepstad, Norwegian University of Science and Technology

  • Committee chair: Professor Anne Marit Mengshoel, University of Oslo

Chair of defence

Professor Bård Natvig, University of Oslo

Principal supervisor

Professor Cecilie Røe, University of Oslo


Back pain is a common and major source of disability. Although the majority of patients recover, 10–20% develops persistent pain. Twin studies estimate the heritability regarding back pain to 30-40%. Such studies measure the total heredity, but do not explore single genes which might play a role in development of persistent pain.

In this thesis, genetic variants regarding persistence of back pain and disc degeneration was addressed. In patients with low back pain and lumbar radicular pain (sciatica) the correlation between 8 genetic polymorphisms (VDR, COL11, MMP1, MMP9, IL-1α, IL-1RN, OPRM1, COMT) and pain recovery as well as the association between genetic variability and DD were assessed.

The data demonstrated that the rare allele of matrixim metalloproteinase 9 (MMP9 rs17576 A>G) was associated with poor recovery and that the rare allele of opoid receptor 1 (OPRM1 rs1799971 A>G) was associated with better pain recovery at 5-year follow-up. The association between MMP9 rs17576 A>G and pain recovery did not change substantially after adjusting for the level of emotional distress. No association between the genetic factors and change in disc degeneration was observed, and no association between disc degeneration and persistent pain was revealed. Age and disc degeneration at baseline were associated with development of disc degeneration over a 5-year period.  The negative finding regarding genetic factors and MRI changes might suggest that MMP9 rs 17576 A>G affect pain recovery but not disc degeneration. Findings from analyses of relationship between genetics, MRI changes and pain can point to mechanisms, but also help to identify new targets for future clinical trials.

Additional information

Contact the Research support staff.

Published Jan. 10, 2019 3:24 PM - Last modified Jan. 10, 2019 3:25 PM