Obstructive Sleep Apnoea: A Risk Factor for Hypertension

Abstract

Obstructive Sleep Apnoea (OSA) is the most prevalent condition among sleep disordered breathing that leads to increased risk of cardiovascular (CV) and cerebrovascular morbidity and mortality. The most common comorbidity associated with OSA is systemic hypertension (HTN). Various epidemiological studies suggest a link between OSA and hypertension that involves complex interactions between various pathophysiological mechanisms and metabolic risk factors. OSA causes changes in normal physiological functions during nocturnal apneic episodes which in-turn lead to daytime hypertension. The widely accepted mechanisms by which the OSA contributes to the development of hypertension include sympathetic activation, inflammation, oxidative stress, and endothelial dysfunction. OSA and hypertension coexist in millions of people and both have been associated with heart disease, stroke, and premature death. Worldwide the prevalence of hypertension in OSA is estimated between 30 and 70%, thus setting it off as a major public health problem. Furthermore, not only has OSA been implicated in causing new hypertension but also it is said to promote resistant hypertension in already existent hypertensive patients, which may further grim the clinical and therapeutic outcomes. It is necessary to recognize the underlying OSA in-order to decrease the overall healthcare burden in terms of rigorous antihypertensive therapy instituted to OSA subjects. The review summarizes an up-to-date scenario of obstructive sleep apnoea as a cause of systemic hypertension and the overall cardiovascular risks.