The Institute of Pulmonary Medicine, Assaf Harofeh Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Zerifin, Israel.
Sleep Breath. 2012 Sep;16(3):821-7. doi: 10.1007/s11325-011-0582-1. Epub 2011 Sep 4.
Obstructive sleep apnea is associated with cognitive impairment, but whether hypoxemia or repeated arousals and sleepiness are the underlying mechanism is controversial. Studies using a wide range of attention and executive functions tests in patients with severe sleep apnea are lacking.
In a prospective cohort study, 40 patients aged 30-70 years, diagnosed with obstructive sleep apnea (apnea-hypopnea index ≥5) were recruited. Patients with known cardiovascular, pulmonary, psychiatric, or neurological disease, and or patients receiving anti-psychotic, sedatives, or stimulant medications were excluded. Patients underwent full overnight polysomnography including continuous oxygen saturation measurements followed by extensive neuropsychological testings in attention and executive function domains. The correlation between sleep apnea severity and patients' performance on the neuropsychological tests was examined.
The patients' performance on measures of attention and executive function was significantly worse compared to the average in a normal population. Attention, as reflected by the number of omissions and by the reaction time on the Conners' Continuous Performance Test correlated significantly with the apnea-hypopnea index (r = 0.6, p < 0.001 and r = 0.48, p = 0.003, respectively) and with parameters of hypoxemia, namely the average SpO(2) (r = -0.51, p = 0.002 and r = -0.39, p = 0.02, respectively) and the percent time spent with SpO(2) < 90% (r = 0.57, p < 0.001 and r = 0.39, p = 0.02, respectively), but not with the degree of sleepiness. Executive dysfunction did not correlate with sleep parameters.
Attention is the predominant cognitive function affected in patients with obstructive sleep apnea and correlates primarily with nocturnal hypoxemia rather than daytime sleepiness or sleep fragmentation. Executive functions, while below average in some patients, do not correlate with polysomnographic parameters.
阻塞性睡眠呼吸暂停与认知障碍有关，但低氧血症或反复觉醒和嗜睡是否是其潜在机制仍存在争议。目前缺乏针对严重睡眠呼吸暂停患者使用广泛注意力和执行功能测试的研究。
在一项前瞻性队列研究中，共招募了 40 名年龄在 30-70 岁之间、被诊断为阻塞性睡眠呼吸暂停（呼吸暂停低通气指数≥5）的患者。排除已知患有心血管、肺部、精神或神经疾病的患者，或正在服用抗精神病药、镇静剂或兴奋剂的患者。所有患者均进行了整夜多导睡眠图检查，包括连续血氧饱和度测量，随后进行广泛的注意力和执行功能领域的神经心理学测试。研究检查了睡眠呼吸暂停严重程度与患者神经心理学测试表现之间的相关性。
与正常人群的平均水平相比，患者的注意力和执行功能测试表现明显更差。注意力的反映指标，包括 Conners 连续操作测试中的遗漏次数和反应时间，与呼吸暂停低通气指数显著相关（r=0.6，p<0.001 和 r=0.48，p=0.003），与低氧血症参数显著相关，即平均 SpO2（r=-0.51，p=0.002 和 r=-0.39，p=0.02）和 SpO2<90%的时间百分比（r=0.57，p<0.001 和 r=0.39，p=0.02），但与嗜睡程度无关。执行功能障碍与睡眠参数无关。
注意力是阻塞性睡眠呼吸暂停患者受影响最明显的认知功能，主要与夜间低氧血症相关，而不是白天嗜睡或睡眠片段化。在某些患者中，执行功能虽然低于平均水平，但与多导睡眠图参数无关。
