——该类病人甚至在白天不瞌睡的时候同样有心脏病患病的风险
研究显示那些即使白天没有睡意的轻度睡眠呼吸暂停的病人也可能增加心血管病患病的风险。该研究成果刊登在美国呼吸与急症医学杂志上，该研究是将64例轻度患病的人对比15例没有患病的参与者所得的结论。
为对比患心脏疾病的风险，研究者测试了内皮功能（即细胞在血管内的功能）和动脉僵硬度，它们在动脉粥样硬化或动脉硬化中起重要作用。中度到重度的睡眠呼吸暂停已经被证实与动脉僵硬、内皮功能障碍和高血压有关。英国牛津大学呼吸内科研究中心Malcolm Kohler硕士与其同事发现相对于没有患病的对照组，轻度睡眠呼吸暂停的病人有更严重的内皮功能障碍和动脉僵硬度。研究者同时测定了血压值，这是评价心血管疾病风险的另一个途径，发现该值大同小异。他们写道：“虽然这与血压升高关系不大，该研究结果还是说明了即使有最轻微的阻塞性睡眠呼吸暂停症状的病人其患心血管疾病的风险还是在增大，他们会得更加严重的疾病。
在新闻稿中，Kohler说道：”已知阻塞性睡眠呼吸暂停症状的病人可以严重到影响到白天的精神，并可能导致患心血管疾病增高，但是该研究成果提示更多的人有患此类疾病的风险，甚至他们中有些人可能完全没有意识到他们有睡眠呼吸暂停的症状。”同时在一篇社论中，Geraldo Lorenzi-Filho博士指出有五分之一的该类病人抱怨白天总是打瞌睡，“现在知道了这是阻塞性睡眠呼吸暂停症状引发的一系列生物反应，包括交感神经活性，系统性炎症，氧化应激和代谢紊乱，这都对心血管系统产生危害。”Kohler和同事们正在研究持续气道正压通气治疗对睡眠呼吸暂停的病人其动脉僵硬度和内皮功能紊乱的影响。
原文：
Mild Sleep Apnea May Raise Heart Risk
——Even Sleep Apnea Patients Who Don't Feel Drowsy in Daytime Are at Risk for Heart Disease
Oct. 24, 2008 -- Sleep apnea -- even if it is so mild that people have no daytime drowsiness -- may increase the risk of cardiovascular disease, a study shows.
The study, published in the American Journal of Respiratory and Critical Care Medicine, compared patients with mild sleep apnea to a comparison group that didn't have sleep apnea. There were 64 participants with mild sleep apnea and 15 participants without sleep apnea.
To compare the risk for heart disease, researchers tested endothelial function, which is how well the cells in the lining of the blood vessels work, and artery stiffness. Endothelial dysfunction and arterial stiffness are involved in developing atherosclerosis, or hardening of the arteries. Moderate to severe sleep apnea has already been linked to increased artery stiffness, endothelial dysfunction, and high blood pressure.
Malcolm Kohler, MD, from the Oxford Centre for Respiratory Medicine in England, and colleagues found that patients with mild sleep apnea had worse endothelial function and greater arterial stiffness than the comparison group without sleep apnea.
Researchers also tested blood pressure, another way to gauge cardiovascular disease risk. The groups tested similarly on blood pressure.
The researchers write that "although this was not associated with significantly increased blood pressure, the findings of this study suggest that patients with minimally symptomatic OSA [obstructive sleep apnea] are at increased cardiovascular risk, as has been demonstrated in more severe disease."
"It was previously known that people with OSA (obstructive sleep apnea) severe enough to affect their daytime alertness and manifest in other ways are at increased risk of cardiovascular disease, but this finding suggests that many more people -- some of whom may be completely unaware that they even have OSA -- are at risk than previously thought," Kohler says in a news release.
In an accompanying editorial, Geraldo Lorenzi-Filho MD, PhD, points out that just one in five patients with sleep apnea complains of drowsiness during the day. "It is now recognized that OSA triggers a cascade of biological reactions, including increased sympathetic activity, systemic inflammation, oxidative stress, and metabolic alterations that are potentially harmful to the cardiovascular system," he writes in the editorial.
Kohler and colleagues are now investigating the effects of continuous positive airway pressure (CPAP) therapy on arterial stiffness and endothelial function in patients with sleep apnea.
http://www.webmd.com/sleep-disorders/sleep-apnea/news/20081024/mild-sleep-apnea-may-up-heart-risk
