Effects of sleep duration and body mass index on hypertension

Objective To explore the effect of sleep duration and body mass index (BMI) on hypertension. Methods The data was collected from the database of the China Health and Retirement Longitudinal Study (CHARLS), and the data of the 2015 National Longitudinal Study were selected. A total of 8, 889 subjects were included in this study. Questionnaires, health status, physical examination and laboratory information were collected. The interactive effect of sleep duration and BMI on hypertension was analyzed by multiplicative model and additive model. Results The prevalence rate of hypertension was 28.86%. Logistic regression results showed that night sleep duration ＜6 h (OR=1.138, 95% CI: 1.024-1.265) and ＞8 h (OR=1.136 5, 95% CI: 1.167-1.598); overweight (OR=1.736, 95% CI: 1.557-1.936) and obesity (OR=2.076, 95% CI: 1.973-2.710) were all risk factors for hypertension (P＜0.05). Stratified results showed that the risk of hypertension in the normal group was 1.193(95% CI: 1.023-1.393) times and 1.555(95% CI: 1.244-1.943) times of those with sleep duration 6-8 h, respectively. The risk of hypertension was 1.392(95% CI: 1.066-1.818) times higher than that of sleep duration 6-8 h. The interaction showed that night sleep duration and BMI had a multiplicative interaction (OR=2.120, 95% CI: 1.767-2.543) and a additive interaction on hypertension [RERI=1.242(95% CI: 0.326-2.157), SI=3.697 (95% CI: 2.658-5.143), AP=0.460 (95% CI: 0.324-0.595)]. Conclusions Insufficient and excessive sleep duration at night and BMI both increase the risk of hypertension, and have a multiplicative and additive interaction. Reasonable adjustment of nighttime sleep duration and BMI may prevent the occurrence of hypertension.