The association of nighttime sleep duration and daytime napping duration with hypertension in Chinese rural areas: a population-based study

We aimed to investigate the association of self-reported nighttime sleep duration and daytime napping duration with hypertension in rural areas of China. The participants, who were from rural areas of Hunan Province in China, were enrolled during 2016-2017. Nighttime sleep duration (<7 h, 7-8 h, and >= 9 h) and daytime napping duration(no nap, 0-1 h, and >1 h) were determined by a self-reported questionnaire. Hypertension was defined as a mean systolic blood pressure >= 140 mmHg and/or a mean diastolic blood pressure >= 90 mmHg or a self-reported physician diagnosis of hypertension and current use of antihypertensive medication. Of 1763 enrolled participants, 52% had hypertension. A total of 640 (36%) were male and 1123 (64%) were female; the mean age was 56 years. After adjusting for potential confounders, participants who slept for >= 9 h per night had a 1.29-fold (95% CI: 1.03, 1.60) increased odds of hypertension compared to the reference group (7-8 h per night). Daytime napping >1 h was negatively associated with hypertension, with an adjusted OR (95% CI) of 0.70 (0.51, 0.97), and the protective effect of longer daytime napping was still found in the subgroup sleeping 7-8 h per night. Among the rural population in China, long nighttime sleep duration is associated with a higher prevalence of hypertension, and longer daytime napping is related to a decreased prevalence of hypertension.