Longitudinal associations between BMI changes and musculoskeletal pain in older European males and females

Abstract Background Musculoskeletal pain affects nearly 200 million European citizens and is a leading cause of disability. This study examines the associations between body mass index (BMI) trajectories over time and self-reported musculoskeletal pain, and explores how these associations differ by sex. Methods We conducted a longitudinal cohort study using data from waves 5–9 (2013–2022) of the Survey of Health, Ageing and Retirement in Europe. A total of 73,469 participants (mean age 70 years; 56% female) contributed at least two BMI measurements across study waves. Baseline and follow-up BMI values were categorized into sex-stratified quartiles, resulting in 16 distinct BMI trajectories. Associations between these trajectories and incident back, hip, knee, and other joint pain were examined using mixed-effects logistic regression models, adjusted for age, region, education, income, household partnership, comorbidities, and smoking. Stable low BMI served as the reference group. Results Compared with stable low BMI trajectory, both upward and downward BMI trajectories, as well as stable high BMI, were associated with increased odds of musculoskeletal pain, with the strongest associations observed for stable high BMI. Stable high or changing BMI showed consistent associations with incident back, hip, and knee pain, while associations with other joint pain were weaker and less consistent. Overall, the associations were stronger for females than for males, but sex differences were most pronounced for hip and knee pain. Notably, maintaining a stable high BMI was associated with one of the highest odds of incident knee pain in females (odds ratio = 4.17, CI = 3.33–5.23). Conclusions Elevated BMI at any time point was associated with increased odds of musculoskeletal pain, even among individuals who lost weight. The findings suggest that the cumulative duration of exposure to high BMI may be a critical factor in the development and prevention of musculoskeletal pain.