Association of circadian syndrome with the risks of incident multiple chronic diseases and multimorbidity in middle-aged and older adults

Objective To investigate the association of circadian syndrome (CircS) with the risks of 10 incident chronic diseases and multimorbidity (≥2 diseases).

Methods Based on the baseline data from the 2011 China Health and Retirement Longitudinal Study (CHARLS), 8, 093 participants were enrolled (CircS group: n=3, 091; non-CircS group: n=5, 002). Cox proportional hazards models were used to assess the association of CircS with the risks of incident chronic diseases and multimorbidity. Additionally, dose-response analyses, stratified analyses by follow-up duration (≤4 years vs > 4 years), and analyses of dynamic changes in CircS status were performed.

Results CircS was significantly associated with the increased risks of incident stroke (HR=2.07), memory-related diseases (HR=1.62), liver diseases (HR=1.38), heart diseases (HR=1.27), kidney diseases (HR=1.28) and digestive system diseases (HR=1.23). Dose-response analyses revealed that the participants with CircS scores ≥6 points had a 170% increase in the risk of incident stroke (HR=2.70, 95% CI: 2.12–3.44), and a 66% increase in the risk of incident heart diseases (HR=1.66, 95% CI: 1.35–2.04). The risk of incident stroke was significantly increased during the short-term follow-up (≤4 years), whereas the risks of incident kidney diseases, digestive system diseases, and liver diseases emerged predominantly after the long-term follow-up (> 4 years). Regarding multimorbidity, CircS was significantly associated with higher risks of developing ≥2 (HR=1.30), ≥3 (HR=1.42), ≥4 (HR=1.53) and ≥5 (HR=1.49) diseases in the participants, and the risks of incident multimorbidity (≥5 diseases) were most pronounced in those with CircS scores ≥6 points (HR=2.74). The analyses of dynamic changes in CircS status revealed that persistent CircS conferred the highest risk of incident diseases (stroke: HR=3.04). Notably, residual risks of incident stroke, heart diseases and liver diseases remained even after CircS remission.

Conclusion CircS is significantly associated with the risks of incident multiple chronic diseases and multimorbidity. This association exhibits dose-response gradients and time-varying patterns. The risks of incident diseases remain even after CircS remission, suggesting that CircS may serve as a potential indicator for the risk assessment of chronic diseases.