Gender-specific association of sleep duration with blood pressure in rural Chinese adults

Background: There are limited data about the role of gender on the relationship between sleep duration and blood pressure (BP) from rural populations. Methods: We conducted a cross-sectional rural population-based study. This report includes 1033 men and 783 women aged 18-65 years from a cohort of twins enrolled in Anhui, China, between 2005 and 2008. Sleep duration was derived from typical bedtime, wake-up time, and sleep latency as reported on a standard sleep questionnaire. Primary outcomes included measured systolic blood pressure (SBP) and diastolic blood pressure (DBP). High blood pressure (HBP) was defined as SBP >= 130 mmHg, DBP >= 85mmHg, or physician diagnosed hypertension. Linear and logistic regression models were used to assess gender-specific associations between sleep duration and BP or HBP, respectively, with adjustment for known risk factors including adiposity and sleep-related disorder risk from the questionnaires. Generalized estimating equations were used to account for intra-twin pair correlations. Results: Compared with those sleeping 7 to <9 h, women sleeping <7 h had a higher risk of HBP (odds ratios [ORs] 3.0, 95% confidence interval [CI], 1.4-6.6); men sleeping >= 9 h had a higher risk of HBP (ORs = 1.5, 95%CI: 1.1-2.2). Conclusions: Among rural Chinese adults, a gender-specific association of sleep duration with BP exists such that HBP is associated with short sleep duration in women and long sleep duration in men. Longitudinal studies are needed to further examine the temporal relationship and biological mechanisms underlying sleep duration and BP in this population. Our findings underscore the potential importance of appropriate sleep duration for optimal blood pressure. (C) 2011 Elsevier B.V. All rights reserved.