Associations of sedentary time, sleep duration and physical exercise with multimorbidity among older adults in Shanghai, China: a cross-sectional study based on national physical fitness surveillance data.

Background: Multimorbidity has emerged as a significant challenge for healthcare systems globally. This study aims to examine the associations between key determinants of lifestyle behavior and various multimorbidity patterns.

Methods: In a cross-sectional sample of older adults (aged 60-79) from the Fifth National Physical Fitness Surveillance in Shanghai, latent class analysis (LCA) was used to identify multimorbidity patterns among 9 chronic diseases. Multinomial logistic regression was performed to analyze the associations between sedentary time, sleep duration, physical exercise, and the different multimorbidity patterns. Weighted analysis was performed to appropriately account for complex sampling designs and provide more robust results.

Results: Among 13,465 study participants (unweighted mean age 69.3 years; weighted mean age 67.4 years, 50.7% female), the overall prevalence of multimorbidity was 40.9%-42.3%. Four latent classes among the older adults were identified, with the relatively healthy class (63.6%-64.6%) had an average of less than 1 chronic disease. The other 3 classes, namely the metabolic-cardiovascular-joint-digestive-respiratory disease class (2.9%-3.0%), the metabolic-cardiovascular disease class (14.5%-15.5%), and the joint-digestive-respiratory disease class (17.9%-18.0%), each had an average of more than 2 chronic diseases, representing different multimorbidity patterns. Prolonged sedentary time (> 3 h/day) increased the odds of belonging to the metabolic-cardiovascular-joint-digestive-respiratory disease class by 56%-57% (unweighted odds ratio [OR] 1.57, 95% confidence interval [CI] 1.27-1.94; weighted OR 1.56, 95% CI 1.36-1.80), the metabolic-cardiovascular disease class by 38% (unweighted OR 1.38, 95% CI 1.25-1.53; weighted OR 1.38, 95% CI 1.29-1.48), and the joint-digestive-respiratory disease class by 30%-32% (unweighted OR 1.32, 95% CI 1.19-1.45; weighted OR 1.30, 95% CI 1.22-1.38). Shorter sleep duration (< 7 h/day) also increased the odds of membership in the metabolic-cardiovascular disease class by 48%-49% (unweighted OR 1.49, 95% CI 1.35-1.65; weighted OR 1.48, 95% CI 1.38-1.58), the metabolic-cardiovascular-joint-digestive-respiratory disease class by 37%-47% (unweighted OR 1.47, 95% CI 1.19-1.80; weighted OR 1.37, 95% CI 1.19-1.58), and the joint-digestive-respiratory disease class by 41%-42% (unweighted OR 1.42, 95% CI 1.29-1.56; weighted OR 1.41, 95% CI 1.32-1.50). Each additional daily hour of low-intensity physical exercise (LIPE) reduced the odds of membership in the metabolic-cardiovascular-joint-digestive-respiratory disease class by 24%-25% (unweighted OR 0.76, 95% CI 0.64-0.90; weighted OR 0.75, 95% CI 0.66-0.84), the joint-digestive-respiratory disease class by 20%-21% (unweighted OR 0.79, 95% CI 0.73-0.86; weighted OR 0.80, 95% CI 0.76-0.85), and the metabolic-cardiovascular disease class by 11%-12% (unweighted OR 0.88, 95% CI 0.81-0.95; weighted OR 0.89, 95% CI 0.85-0.94). Compared to LIPE, high-intensity physical exercise (HIPE) showed a significant advantage only in reducing the odds of the metabolic-cardiovascular disease class by 18%-23% (unweighted OR 0.77, 95% CI 0.62-0.97; weighted OR 0.82, 95% CI 0.71-0.95).

Conclusions: Over 40% of older adults in Shanghai, China, suffer from multimorbidity. Prolonged sedentary behavior and shorter sleep duration were associated with membership in the metabolic-cardiovascular-joint-digestive-respiratory disease class, the metabolic-cardiovascular disease class, and the joint-digestive-respiratory disease class. Physical exercise showed varying degrees of protection against these 3 multimorbidity patterns, with special attention warranted for LIPE. Identifying the relationship between determinants of lifestyle behavior and patterns of multimorbidity can help develop more targeted prevention and management strategies.