Considerable evidence is now available of an independent association between
obstructive sleep apnea syndrome (OSAS) and
cardiovascular disease. The association is particularly strong for systemic arterial
hypertension, but there is growing evidence of an association with
ischemic heart disease and
stroke. The mechanisms underlying
cardiovascular disease in patients with OSAS are still poorly understood. However, the pathogenesis is likely to be a multifactorial process involving a diverse range of mechanisms, including sympathetic overactivity, selective activation of inflammatory molecular pathways, endothelial dysfunction, abnormal coagulation, and metabolic dysregulation, the latter particularly involving
insulin resistance and disordered lipid metabolism.
Therapy with
continuous positive airway pressure (CPAP) has been associated with significant benefits to cardiovascular morbidity and mortality, both in short-term studies addressing specific aspects of morbidity, such as
hypertension, and more recently in long-term studies that have evaluated major outcomes of cardiovascular morbidity and mortality. However, there is a clear need for further studies evaluating the impact of CPAP
therapy on cardiovascular outcomes. Furthermore, studies on the impact of CPAP
therapy have provided useful information concerning the role of basic cell and molecular mechanisms in the pathophysiology of OSAS.