客観的な眠気が主観的な訴えなしに高血圧リスクを低下させる

Excessive daytime sleepiness (EDS) has been associated with significant cardiovascular morbidity. Objective sleepiness, as measured by short sleep onset latencies (SOL), has been associated with poor cognitive performance in otherwise healthy individuals who do not complain of EDS, but its association with cardiovascular morbidity has not been explored. Thus, we investigated the association of objective sleepiness without a complaint of EDS with hypertension risk in a large random general population sample.

From 1741 adults of the Penn State Cohort, 1590 individuals without a complaint of EDS were included in the cross-sectional analysis. From those, 659 subjects without hypertension were followed-up for an average of 7.5 years and were included in the longitudinal analysis. Objective sleepiness was defined as SOL≤7 minutes during overnight 8-hour polysomnography. Prevalent hypertension was defined as either high blood pressure (BP) or medication use, whereas incident hypertension was determined by self-report of receiving treatment for high BP. Binary logistic regression was performed while controlling for multiple potential covariates.

The prevalence and incidence of hypertension was significantly lower in individuals with objective sleepiness than control group (22.1% vs. 32.3% and 8.8% vs. 17.3%, respectively). Objective sleepiness was less likely to be associated with prevalent (OR=0.44; 95%CI=0.23-0.81; p=0.010) or incident (OR=0.31; 95%CI=0.10-0.96; p=0.043) hypertension respectively compared to control group. The combination of objective sleepiness with subjective EDS eliminated the protective effect on hypertension risk.

Our novel and unexpected findings suggest that objective sleepiness without EDS has a protected effect against hypertension risk, a useful finding for practicing clinicians in assessing hypertension risk in their patients.