SAT0700 The relationship between musculoskeltal pain, inflammation and depression in men

Abstract

Background Up to 40% of persons with musculoskeletal (MSK) pain report depression. High sensitivity C-reactive protein (hsCRP), a sensitive marker of chronic low grade inflammation, is elevated in persons with MSK pain when compared to those who are pain free, and in those with MSK pain is positively associated with increasing pain severity. High levels of hsCRP are also associated with depression. Whether hsCRP is the mechanism linking MSK pain to depression has not been tested. Objectives To test the hypothesis that MSK pain predicts depression and the relationship would at least in part be explained by hsCRP. Methods 3309 men aged 40–79 in the multicentre European Male Ageing Study completed a postal questionnaire asking about MSK pain (classified as chronic widespread painAmerican College of Rheumatology 1990 criteria) (CWP), some pain that was not CWP (SP), or no pain (NP)) and depression (Beck Depression Inventory-II (BDI-II), score range 0–21). At a research clinic, fasting morning blood samples were shipped to one Centre where hsCRP was measured using a solid-phase, chemiluminescent immunometric assay with a sensitivity of 0.01 mg/dL. Covariates were date of birth, education level, body mass index (BMI), tobacco use, and frequency of alcohol consumption. Participants were followed up (mean 4.4 (SD 0.3) years) and completed the BDI-II. Linear regression tested the association between baseline pain and follow up BDI score (outcome), with adjustments for age, centre and baseline BDI. In a final model hsCRP and covariates were added and the impact on the relationship between pain and BDI-II examined. Results are expressed as β coefficients with 95% confidence intervals (CI). Results 2404 (72.7%) men had complete baseline and follow-up data. At baseline 1003 (41.7%) reported NP, 1205 (50.1%) SP, and 196 (8.2%) CWP. Mean (SD) age was 59.3 (10.6), CRP 0.41 (0.74) mg/l, and BDI 6.6 (6.2). Mean BMI was 27.8 (10.6), 30.1% were current smokers, 23.6% drank alcohol 5–7 days/week and 53.9% had gone on to further education. After adjusting for age, Centre and baseline BDI-II when compared to those with NP having SP (β=0.7, 95% CI (0.3, 1.1)) or CWP (1.3 (0.5, 2.0)) at baseline was associated with higher BDI-II scores at follow-up. Baseline hs-CRP did not predict follow up BDI-II (0.05 (-0.2, 0.3)). The relationship between SP (0.7 (0.2, 1.1)) or CWP (1.5 (0.7, 2.3)) and follow up BDI-II persisted after adjustment for hs-CRP and all covariates. Conclusions The excess rate of depression in men with MSK pain remains to be explained. A broader assessment of inflammatory markers (e.g. TNF-α, Interleukins, and IFN-γ1) may identify mechanisms linking MSK pain with subsequent depression. Acknowledgements The European Make Ageing Study was funded by the Commission of the European Communities Fifth Framework Programme, grant QLK6-CT-2001–00 258. Disclosure of Interest None declared