Multimorbidity patterns and 15-year trajectories of physical performance: a population-based study

Background: Chronic diseases can impact physical function, yet little is known about how specific disease combinations relate to long-term physical performance trajectories and whether these associations vary across different performance measures. This population-based study explored the association between multimorbidity patterns and 15-year changes in physical performance among older adults. Methods: We analyzed 15-year longitudinal data on 3112 dementia-free individuals aged 60 and older participating in the Swedish National study on Aging and Care in Kungsholmen. Physical performance was assessed through walking speed and chair-stand tests, further combined into a z-standardized overall measure. Latent class analysis was used to identify groups of individuals with similar patterns of diseases. Linear mixed models were used to evaluate the association between multimorbidity patterns and changes in physical performance scores over time. Inverse probability weighting was used to account for attrition over the follow-up. Results: Four multimorbidity patterns were identified: 1) psychiatric, respiratory, & musculoskeletal, 2) anemia & sensory impairment, 3) cardiometabolic & inflammatory, and 4) unspecific. Compared to individuals without multimorbidity (≤ 1 disease), all patterns were associated with faster annual declines in physical performance, with the steepest decline observed for the cardiometabolic & inflammatory pattern (β*time = -0.066, 95%CI: -0.111, -0.021), followed by the anemia & sensory impairment pattern (β*time = -0.043, 95%CI: -0.063, -0.023). Results remained consistent after adjustment for the number of chronic diseases. Conclusions: Multimorbidity patterns are differentially associated with the rate of decline in physical performance, with the cardiometabolic & inflammatory pattern being associated with the fastest decrease. Classifying individuals according to multimorbidity patterns may help guide targeted strategies to preserve physical function in later life.