Abstract and Introduction
Abstract
Obstructive sleep apnea (OSA) has emerged as a new and important risk factor for cardiovascular disease (CVD). Over the last decade, epidemiologic and clinical research has consistently supported the association of OSA with increased cardiovascular (CV) morbidity and mortality. Such evidence prompted the American Heart Association to issue a scientific statement describing the need to recognize OSA as an important target for therapy in reducing CV risk. Emerging facts suggest that marked racial differences exist in the association of OSA with CVD. Although both conditions are more prevalent in blacks, almost all National Institutes of Health–funded research projects evaluating the relationship between OSA and CV risk have been conducted in predominantly white populations. There is an urgent need for research studies investigating the CV impact of OSA among high-risk minorities, especially blacks. This article first examines the evidence supporting the association between OSA and CVD and reviews the influence of ethnic/racial differences on this association. Public health implications of OSA and future directions, especially regarding minority populations, are discussed.
Introduction
Obstructive sleep apnea (OSA), the most common type of sleep-disordered breathing (SDB), is a major public health problem in the United States, particularly among blacks. It is often characterized by loud snoring, breathing interruptions, awakenings, gasping or choking, and daytime sleepiness as a result of upper airway collapse and intermittent impairment of ventilation during sleep. Although OSA was clinically recognized as a disease approximately 3 decades ago, awareness of the condition outside the specialized field of sleep medicine has been slow to develop, and most of those affected, particularly blacks, remain undiagnosed. In general, OSA is common in adults, with men, older individuals, and the obese being at higher risk.
Studies suggest that OSA is associated with hypertension, cardiac arrhythmia, coronary heart disease (CHD), heart failure (HF), pulmonary hypertension, stroke, traffic accidents, and increased mortality. Cardiovascular disease (CVD), despite recent decline, remains the leading cause of death in both blacks and whites in the United States. However, the decline is less steep for blacks who carry a substantially higher cardiac mortality burden with a higher sudden cardiac death rate and significantly lower life expectancy. Convincing evidence has unequivocally demonstrated disproportional burden of CVD in blacks with a marked racial disparities in care and outcome by race in the United States.
Despite these observations, large studies evaluating OSA and the CV connection have not focused on black participants. Moreover, inclusion of blacks in most longitudinal sleep studies is limited or nonexistent, with the exception of the Jackson Heart Study ( Table I ). In this article, we review findings supporting the associations between OSA and CVD, and we examine the influence of ethnic/racial differences on these associations. The public health implications of CV risk attributed to OSA, especially as it applies to minority populations, are also discussed. Finally, proposals for future directions are offered.