Dose-response associations of clinical markers of obesity and duration of exposure to excess weight with chronic musculoskeletal pain: cross-sectional analysis at baseline of ELSA-Brasil Musculoskeletal cohort.

The objective of this study is to investigate the association of clinical markers of obesity and weight trajectories with chronic musculoskeletal pain (CMP). This is a cross-sectional study using baseline data from ELSA-Brasil MSK cohort. CMP was evaluated at nine body sites (neck, shoulders, upper back, elbows, lower back, wrists/hands, hips/thighs, knees, ankles/feet), and defined as pain lasting > 6 months in the past year. General and abdominal obesity levels were classified according to accepted cut-offs for body mass index (BMI), waist circumference (WC) and waist-height ratio (WHtR). Binomial and multinomial logistic regressions tested for associations with CMP at any site, at ≥ 3 sites (multisite) and in upper + lower limbs + axial skeleton (generalized). A total of 2899 participants (mean age 56.0 ± 8.93) were included, 55.0% reported CMP, 19.1% had multisite, and 10.3% had generalized CMP. After adjustments for sex, age, education, physical activity and depressive symptoms, nearly all the investigated markers of obesity were associated with any CMP, multisite and generalized CMP, with strongest associations being observed for general obesity level II/III: OR 2.08 (95% CI 1.45-2.99), OR 3.19 (95% CI 2.06-4.94) and OR 3.65 (2.18-6.11), respectively. Having excess weight currently or both at age 20 and currently was also associated with all CMP presentations. Associations of greater magnitude were consistently observed at higher obesity levels and longer exposures to excess weight (dose-response). These results may support the contribution of obesity-derived mechanical and inflammatory mechanisms of CMP, and indicate a role for the accumulation of exposure to excess weight across the adult life course.