Sleep disordered breathing and hypertension: does self-reported sleepiness modify the association?

STUDY

OBJECTIVES

Epidemiologic studies that demonstrate increased risk of hypertension in persons with sleep disordered breathing indicate that only a minority of these persons report significant subjective sleepiness. Studies also suggest that presence of self-reported sleepiness may identify a subset of persons with sleep disordered breathing who are at greatest risk of cardiovascular sequelae, including hypertension. We explore whether self-reported sleepiness modifies the relationship between sleep disordered breathing and prevalent hypertension.

DESIGN

Cross-sectional.

SETTING

Multicenter study.

PARTICIPANTS

6046 subjects from the Sleep Heart Health Study.

MEASUREMENTS: Polysomnography, systolic and diastolic blood pressure, antihypertensive medication use, questionnaire determined excessive sleepiness and Epworth Sleepiness Scale, and covariates.

RESULTS

The odds of hypertension at higher apnea hypopnea index categories were larger in participants identified as sleepy based on responses to a frequency of sleepiness question or the Epworth score. For example, for those with AHI > or =30 compared to AHI <1.5, the adjusted odds ratio for hypertension was 2.83 (1.33-6.04) among those reporting sleepiness > or =5 days per month, but only 1.22 (0.89-1.68) among those reporting less frequent daytime sleepiness. In adjusted logistic regression models, there was statistical evidence for effect modification by frequency of sleepiness (P = 0.033) of the association between apnea hypopnea index and hypertension. In adjusted models that included the Epworth score as a continuous variable, the interaction term fell slightly short of statistical significance (beta = 0.010, P = 0.07).

CONCLUSION

This study finds that the association of sleep disordered breathing with hypertension is stronger in individuals who report daytime sleepiness than in those who do not.