Association of long-term sleep habits and hypertension: a cross-sectional study in Chinese adults

Poor sleep has been associated with risk of hypertension, but previous studies were limited by treating one or two sleep factors as predictor. Our previous study has developed a sleep factor questionnaire (SFQ) to comprehensively assess wide range of sleep characteristics including sleep duration, sleep quality, light at night (LAN) exposure, night/shift work, daytime napping, and frequency of nighttime waking, insomnia, and snoring. In this cross-sectional study we used the SFQ to evaluated the associations between these sleep domains and hypertension. Comparing with the subjects who slept 7-8 h, subjects with sleep duration 6-7 h (OR = 1.42, 95% CI: 1.01, 2.00), 8-9 h (OR = 1.60, 95% CI: 1.07, 2.40), and over 9 h (OR = 2.39, 95% CI: 1.60, 3.58) had an increased prevalence of hypertension. The associations were significant among individuals under 45 years sleeping 6-7 h and those over 45 years sleeping over 8 h. The OR of prevalent hypertension was 0.80 (95% CI: 0.62, 0.97) for habitual daytime napping compared with never napping, and the association was also significant among individuals over 45 years old. Moreover, among subjects with sleep duration 7-8 h, habitual daytime napping may decrease prevalent hypertension (OR = 0.635, 95% CI: 0.437, 0.924). In conclusion, our data suggested a positive association between both short (6-7 h) and long sleep duration and hypertension, and a preventive pattern for habitual daytime napping among over 45 years old and hypertension. Moreover, interaction analysis indicated that habitual midday nap may decrease prevalent hypertension among subjects with sleep duration 7-8 h.