G-4132

Circadian Rest Period Irregularities and Heart Conditions Risk: Findings from a Cohort Study

 Alireza Dehghani ¹ ℗, Mozhgan Seif ² ©, Abbas Rezaianzadeh ³   

 
Abstract

Introduction: Circadian rest period plays a vital role in maintaining cardiovascular, metabolic, and hormonal health. As modern lifestyles disrupt circadian rest period patterns, extreme rest periods have become more common and may contribute to chronic diseases. While traditional risk factors for cardiovascular disease (CVD) are well known, the impact of circadian rest period as a modifiable behavior remains less clear. This study investigates the association between circadian rest period irregularities and heart conditions in a large adult population, highlighting potential risks of both short and long rest periods. Methods and Materials: This prospective cohort study analyzed data from 10,663 adults participating in the PERSIAN (Prospective Epidemiological Research Studies in Iran) cohort study, collected through a census approach. After obtaining informed consent, trained interviewers gathered data using standardized questionnaires, which were electronically recorded. heart conditions status was defined based on self-reported medical history. Circadian rest period was self-reported and categorized into five groups: 6 hours (short), 6–6.9 hours, 7–7.9 hours (standard), 8–8.9 hours, and ≥9 hours (long). Descriptive statistics compared baseline characteristics across rest period categories. Logistic regression models estimated crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for the association between circadian rest period and heart conditions, stratified by gender. Adjusted models controlled for age, BMI, blood pressure, cholesterol, diabetes, and smoking. A sensitivity analysis excluded participants with extreme circadian rest period to assess robustness. Results: Among participants, 19.5% slept 6 hours, 28.4% slept 7–7.9 hours, and 8.6% slept ≥9 hours, with remaining individuals distributed across other groups. Significant differences in gender, age, and heart conditions prevalence were observed across sleep categories (p-values 0.05). In crude analysis, males with 6 hours of sleep had an OR of 1.42 (95% CI: 1.01–2.02; p=0.046), while females in this category had an OR of 1.44 (95% CI: 1.22–1.70; p0.001). After adjusting for confounders, the association in males was no longer significant (OR=1.31; 95% CI: 0.90–1.92; p=0.153), but remained significant in females with 6 hours (OR=1.37; 95% CI: 1.13–1.67; p=0.001) and ≥9 hours (OR=1.25; 95% CI: 1.04–1.50; p=0.016). Sensitivity analysis modestly attenuated these associations in both genders. Conclusion and Discussion: Both short and long circadian rest periods were associated with increased heart conditions risk, particularly in females, with stronger associations at extreme circadian rest period. These findings suggest that maintaining optimal circadian rest period may be important for heart conditions risk management and highlight the need for gender-specific interventions and further research into the mechanisms linking rest period and heart health.

Keywords: Cardiovascular Diseases, Circadian Rest Periods, Sleep Disorders