Associations of objectively measured sleep characteristics and incident hypertension among police officers: The role of obesity

This study investigated the associations of baseline sleep onset latency, wake after sleep onset, longest wake episode, number of awakenings, sleep efficiency and sleep duration with incident hypertension during a 7-year follow-up (n = 161, 68% men) and the joint effect of insufficient sleep and obesity on incident hypertension. Sleep parameters were derived from 15-day actigraphy data. Relative risks and 95% confidence intervals were estimated using a robust Poisson regression model. Each 10-min increase in sleep onset latency was associated with an 89% higher risk of hypertension (95% confidence interval [CI] = 1.12-3.20). Each 10-min increase in longest wake episode was associated with a 23% higher risk of hypertension (95% CI = 1.01-1.50) and each 10% decrease in sleep efficiency was associated with a 50% higher risk of hypertension (95% CI = 1.02-2.22). These associations were independent of demographic and lifestyle characteristics, depressive symptoms, shift work, sleep duration and body mass index. Having <6 hr of sleep and a body mass index >= 30 kg/m(2) increased the risk of hypertension (relative risk = 2.81; 95% CI = 1.26-6.25) compared with having >= 6 hr of sleep and a body mass index <30 after controlling for confounders. Relative excess risk due to interaction was 3.49 (95% CI = -1.69-8.68) and ratio of relative risk was 3.21 (95% CI = 0.72-14.26). These results suggest that poor sleep quality is a risk factor for hypertension. Longitudinal studies with larger sample sizes are warranted to examine the joint effect of insufficient sleep and obesity on development of hypertension.