Age- and gender-specific associations between sleep duration and incident hypertension in a Chinese population: the Kailuan study.

The objective of this study was to explore the age- and sex-dependent association between sleep duration and incident hypertension in a Chinese population. The Kailuan prospective cohort study recruited 101 510 participants. Those participants were followed for an average of 3.98 years and the data obtained from 32 137 participants out of 101 510 were analyzed in this study. Sleep duration was categorized as five groups of⩽5, 6, 7, 8 and ⩾9 h. Cox proportional-hazards models were used to analyze the association of sleep duration with incident hypertension. The 3.98 years' follow-up data showed that 12 732 out of 32 137 participants developed hypertension. Short duration of sleep (⩽5 h per night) was associated with an increased risk of hypertension in woman (hazard ratio (HR) 1.27; 95% confidence interval (CI) 1.02 to 1.58) and participants aged <60 years (HR 1.11; 95% CI 1.02-1.21), when compared with the group reported with 7 h of sleep per day. This study suggested that short sleep duration could cause an increased risk of hypertension in Chinese females and population aged <60 years.