Association between Sleep Duration and Dyslipidemia: Insights from the Fasa Adults Cohort Study (FACS), 2014–2021

Background & Objectives: Sleep duration is increasingly recognized as a critical determinant of overall health, particularly in relation to cardiovascular risk. Dyslipidemia, a leading contributor to cardiovascular disease, has been linked inconsistently to sleep duration, especially among rural populations. Materials & Methods: This population-based cohort study utilized data from the Fasa Adults Cohort Study (2014–2021), comprising 10,118 adults aged 35 to 70 years from the rural districts of Sheshdeh and Qarabolagh, Fasa County, Iran. Participants were categorized based on self-reported sleep duration (<7 hours vs. ≥7 hours). Anthropometric measurements, blood pressure, and fasting lipid profiles were collected. Dyslipidemia was defined according to Adult Treatment Panel III (ATP III) criteria. Statistical analyses included chi-square tests, t-tests, and multivariable logistic regression. Results: Individuals with short sleep duration (<7 hours) exhibited significantly higher body mass index (BMI), waist circumference, and low-density lipoprotein cholesterol (LDL-C) levels, as well as lower high-density lipoprotein cholesterol (HDL-C) levels (all p-values < 0.001). Short sleep duration was significantly associated with increased odds of dyslipidemia (adjusted odds ratio [OR] = 1.119; 95% confidence interval [CI]: 1.024–1.223; p = 0.013) and low HDL-C (adjusted OR = 1.239; 95% CI: 1.140–1.347; p < 0.001). No significant associations were observed with total cholesterol, triglycerides, or LDL-C. Conclusion: Short sleep duration is significantly associated with dyslipidemia and adverse lipid profiles, particularly reduced HDL-C levels. These findings highlight the importance of sleep health in mitigating cardiovascular risk, especially in underserved rural populations. Promoting sufficient sleep may serve as a viable preventive strategy against metabolic disorders. Further longitudinal studies are warranted to clarify underlying causal mechanisms.