PURPOSE:Hypertension is a major public health concern and recent literature has supported that obstructive sleep apnea may be a risk factor for high blood pressure and contribute to cardiovascular morbidity and mortality. The prevalence of hypertension is disproportionately high among African Americans. Limited literature exists on race differences in sleep apnea.
METHODS:This is a cross-sectional study of 648 patients who underwent polysomnography at the VA Connecticut Health Care System. The diagnosis of obstructive sleep apnea was determined based on an apnea-hypopnea index of 5 or higher. Hypertension was determined based on physician diagnosis and/or medication use. Logistic regression models were constructed to determine the association of race and obstructive sleep apnea with hypertension.
RESULTS:Compared to Caucasians, African Americans had significantly higher rates of obesity (p=.05) and prevalent hypertension (p=.03). African Americans had more severe sleep apnea at presentation (p=.06), a significantly lower nadir oxygen saturation during sleep (p=.02), and yet reported significantly fewer symptoms based on the Epworth Sleepiness Scale (p=.05). Participants with severe obstructive sleep apnea had over double the risk of hypertension (p<.01). The logistic regression analysis indicated that there was a significant interaction between obstructive sleep apnea and race when predicting hypertension (p=.0675). Alternative measures of sleep severity, including measures of hypoxia and arousal, were also significant predictors of hypertension.
CONCLUSION:This study provides evidence that African Americans have more severe sleep apnea at presentation compared to Caucasians. An interaction between race and sleep apnea was found in our analysis indicating that sleep apnea contributes to the racial differences in prevalent hypertension. Additional prospective studies are needed to investigate these race differences and evaluate the temporal relationship between OSA and hypertension.
CLINICAL IMPLICATIONS:OSA may be one factor contributing to the racial differences in hypertension, however further investigation is needed to gain a better understanding of this relationship.
DISCLOSURE:Megan Sands, None.