The relationship between sleep health characteristics and risk of multimorbidity: A cross-sectional study based on public health surveillance system in southern Tehran-Iran.

Objective: Sleep is essential for optimal health and is associated to development of chronic diseases. This study examines the association between sleep characteristics and multimorbidity among population in southern Tehran and its suburbs. Methods: This is a secondary cross-sectional study conducted in January 2025. We used data from 1311 participating adults in the Integrated Repeated Public Health Surveillance System (IRPHS) in Tehran (May-September 2023). Information on sleep duration, sleep satisfaction, and chronic disease (diabetes, hypertension, cardiovascular, dyslipidemia) was collected through telephone interviews. Multimorbidity was defined as having two or more chronic conditions. Associations between sleep and multimorbidity were examined using logistic regression model. Results: Multimorbidity was found in 78 participants (5.9 %) with more prevalence among older adults (≥65 years: 37.2 %, n = 29), females (7.6 %, n = 60), and those with high depressive mood (16.8 %, n = 19). Long sleep duration (≥9 h) was significantly associated with higher odds of multimorbidity (adjusted odds ratio (AOR): 1.94; 95 % CI: 1.04-3.65; p = 0.039). Short sleep (≤6 h) (AOR: 1.70; 95 % CI: 0.92-3.11) and poor sleep satisfaction (AOR: 1.48; 95 % CI: 0.85,2-56) showed nonsignificant associations. Conclusion: Long sleep duration may indicate higher odds of multimorbidity. Routine sleep assessment could help identify high risk individuals and support preventive interventions.