Population-based cross-sectional study of sex-specific dose-response associations between night sleep duration and hypertension in Islamic Republic of Iran

Abstract

Background: Several studies have suggested that sleep disorders have adverse effects on blood pressure. However, the findings remain controversial and only a few studies have investigated the association between sleep duration and hypertension among all age and sex subgroups. Aim: To evaluate the dose-response association between sleep duration and blood pressure in the Iranian population using the Ravansar non-communicable disease cohort study. Methods: This was a cross-sectional study of 9865 participants aged 35–65 years from the 2014–2017 Ravansar noncommunicable disease cohort study. Night sleep duration was classified as ≤5 hours, 6 hours, 7 hours, 8 hours, 9 hours, and ≥10 hours. The association between self-reported sleep duration and hypertension was examined using multivariable logistic regression in STATA version 14. Restricted cubic spline analysis showed the dose-response association between sleep duration and hypertension. Results: The age-adjusted prevalence of hypertension was 16.50% among men, 24.20% among women and 20.50% in the total population. Compared with reference sleep duration (7 hours) in the total population, the multivariable odds ratio [OR (95% CI)] for hypertension was 0.70 (0.55–0.88) for the group with 9 hours sleep duration and 0.90 (0.74–1.09) for the group with ≤5 hours sleep duration. Among pre-menopausal women, we observed an inverse association between 9 hours sleep duration and hypertension [0.62 (0.42–0.90)]. The age-adjusted cubic spline suggested a linear inverse association between sleep duration and prevalence of hypertension among men and the total population and a non-linear association among women. Conclusion: Longer sleep duration (from 9 hours) had a negative association with hypertension. Further studies are needed to identify the risk factors associated with sleep duration and hypertension among the general population in the Islamic Republic of Iran.