Sleep apnea and hypertension: pathophysiologic mechanisms

Abstract

This article reviews the pathophysiology of hypertension (HTN) in obstructive sleep apnea (OSA). The article is divided into 3 sections. The first section describes epidemiologic studies of the relationship of sleep-related breathing disorders, including OSA, to HTN and argues that OSA contributes to the genesis of HTN. The second section describes the known immediate physiologic consequences of 3 components of OSA that may contribute to the genesis of persistent systemic HTN. The 3 components are (1) the large negative intrathoracic pressure changes associated with OSA, (2) intermittent hypoxemia, and (3) arousal from sleep. The last section reviews current physiologic models of essential HTN genesis and attempts to integrate them with the suspected HTN-generating aspects of OSA. In its summary, the authors conclude that OSA contributes to the genesis of HTN and advise physicians not to ignore the contribution of frequently comorbid non-OSA factors, such as obesity, to the genesis of OSA-related HTN.