COMT genotype and non-recovery after a whiplash injury in a Northern European population

The COMT ( Catechol-O-Methyl Transferase) gene may influence a person’s vulnerability to develop long-term pain and some COMT single nucleotide polymorphisms (SNPs) may associate with patterns of acute or chronic pain. Many patients with whiplash-associated disorders ( WADs) suffer from long-term pain and other related symptoms, but it is less known if genetic factors play a role in the recoveryprocess. The primary aim of this study was to evaluate whether self-reported non- recovery, including pain, was related to COMT genotype in patients with WAD. The secondary aim was to investigate whether or not background factors, including mental health, were related to genotype and non- recovery. A total of 133 patients with neck painafter a whiplashtrauma were included. Background factors were collected and blood samples were taken during the acute phase after the accident. DNA was isolated from blood and used to genotype the SNPs rs6269, rs4633, rs4818 and rs4680 in the COMT gene; additionally haplotypeswere estimated and haplogenotypes inferred. The patients were followed up after 12 months and asked to rate their recoveryincluding pain, mental health and quality of life. The overall reported non- recoveryrate at 12 months was 44% with no significant differences in distribution of the COMT haplotypes. High levels of self-reported pain (OR 7.2) and anxiety (OR 4.4) after the accident were associated with non- recovery, but not related to the haplotypes. None of the other background factors were related to the haplotypesor non- recovery. No association between self-reported non- recoveryor pain levels and COMT haplotypesin patients with acute whiplash injuriescould be detected. Independent replications are necessary to discard the hypothesis that COMT haplotypesdo not influence non- recoveryor pain levels in patients with acute whiplash injuries. High levels of initial pain and anxiety were associated with non- recovery, thereby confirming previously published reports.