Obstructive sleep apnea and hypertension: epidemiology, mechanisms and treatment effects.

Obstructive sleep apnea (OSA) is a highly prevalent disorder of breathing during sleep. A growing body of cvidence suggests that OSA is independently associated with an increased risk of cardiovascular disease, although the extent of this risk and underlying mechanisms remain to be elucidated. However, there is clearer evidence from epidemiological and pathophysiological research of a causal link between OSA and hypertension. The acute hemodynamic and autonomic per turbations that accompany obstructive apneas during sleep, with associated repeated arousals and intermittent hypoxemia, appear to result in sustained hypertension. In addition to the etabolic and humoral effects from obesity, OSA appears to predispose individuals to autonomic imbalance characterized by sympathetic overactivity and altered baroreflex mechanisms as well as alterations to vascular function. Treatment of OSA restores normal sleep architecture and generally mitigates the acute hemodynamic effects of OSA. Treatment of symptomatic OSA, particular at the severe end of the spectrum, appears to be associated with improvements in blood pressure. both during sleep and wakefulness, and there may also be additional gains in subjects who are hypertensive and/or resistant to anti-hypertensive medications. The severe group appears to be particularly at risk for developing fatal and non-fatal cardiovascular events and treatment with continuous positive airway pressure appears to markedly reduce that risk. Future treatment studies will need to be extended for greater than the current average of 1~2 months in order to more fully evaluate any time dependent improvements in blood pressure, and consequent cardiovascular risk.

參考譯文

阻塞性陲眠呼吸障礙與高血壓

——流行病學(xué)、機制及療效

阻塞性睡眠呼吸暫停是一種高發(fā)的睡眠呼吸紊亂。盡管阻塞性睡眠呼吸暫停作為一個獨立的危險因素的危險程度和發(fā)病機制還有待進一步明確，但是越來越多的證據(jù)顯示阻塞性睡眠呼吸暫停的確是心血管疾病發(fā)病的一個獨立危險因素。不管怎樣，現(xiàn)在已經(jīng)有了更確實的流行病學(xué)和病理生理學(xué)方面的證據(jù)證明兩者之間的相關(guān)性。伴隨著阻塞性睡眠呼吸暫停出現(xiàn)的急性的血流動力學(xué)和自律性的紊亂，以及與此相關(guān)的反復(fù)出現(xiàn)的周期性低氧血癥都會導(dǎo)致持續(xù)性的高血壓。除了肥胖引起的代謝和體液作用以外，對于以交感活動過度和壓力反射改變引起的自主神經(jīng)紊亂和血管功能改變，阻塞性睡眠呼吸暫停的個體也表現(xiàn)出易感性。阻塞性睡眠呼吸暫停除了能重建正常的睡眠結(jié)構(gòu)之外通常還能緩解由此引起的急性血流動力學(xué)效應(yīng)。對有癥狀阻塞性睡眠呼吸暫?；颊哂绕涫侵匕Y患者的治療顯示，治療后，患者睡眠和清醒狀態(tài)下的血壓都有很大的改善。這樣的結(jié)果對高血壓及對高血壓藥物抵抗的高血壓患者來說也是一個意外的收獲。阻塞性睡眠呼吸暫停嚴重組的患者，對于致命或非致命的心血管疾病都顯示出顯著的危險性，而持續(xù)正壓通氣的治療則能明顯地降低這種危險。相比目前平均1~2個月的治療時間，未來的治療研究應(yīng)該嘗試更長期的治療，以期更全面地評估治療對于血壓改善情況和隨之引起的心血管疾病風(fēng)險改變的情況。

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