C-Reactive Protein and Pain Sensitivity: Findings from Female Twins

Background Systemic inflammation and pain sensitivity may contribute to the development and maintenance of chronic pain conditions. Purpose We examined the relationship between systemic inflammation as measured by C-reactive protein (CRP) and cold pain sensitivity in 198 female twins from the University of Washington Twin Registry. We also explored the potential role of familial factors in this relationship. Methods Linear regression modeling with generalized estimating equations examined the overall and within-pair associations. Results Higher levels of CRP were associated with higher pain sensitivity ratings at pain threshold (p=0.02) and tolerance (p=0.03) after adjusting for age, body mass index, time to reach pain threshold or tolerance, and clinical pain status. The magnitude of the associations remained the same in within-pair analyses controlling for familial factors. Conclusions The link between CRP and pain sensitivity may be due to non-shared environmental factors. CRP and pain sensitivity can be examined as potential biomarkers for chronic pain and other inflammatory conditions.