Abstract：
OBJECTIVE: It is well established that, together with a multitude of other adverse effects on health, severe obstructive sleep apnoea causes reduced cerebral perfusion and, in turn, reduced cerebral function. Less clear is the impact of moderate obstructive sleep apnoea (OSA). Our aim was to determine if cerebral blood flow is impaired in people diagnosed with moderate OSA.
METHODS: Twenty-four patients diagnosed with moderate OSA (15 ≤ apnoea-hypopnea index (AHI) < 30) were recruited (aged 32-72, median 59 years, 10 female). Seven controls (aged 42-73 years, median 62 years, 4 female) with an AHI < 5 were also recruited. The OSA status of all participants was confirmed at baseline by unattended polysomnography and they had an MRI arterial-spin-labelling scan of cerebral perfusion.
RESULTS: Neither global perfusion nor voxel-wise perfusion differed significantly between the moderate-OSA and control groups. We also compared the average perfusion across three regional clusters, which had been found in a previous study to have significant perfusion differences with moderate-severe OSA versus control, and found no significant difference in perfusion between the two groups. The perfusions were also very close, with means of 50.2 and 51.8 mL/100 g/min for the moderate-OSAs and controls, respectively, with a negligible effect size (Cohen\'s d = 0.10).
CONCLUSIONS: We conclude that cerebral perfusion is not impaired in people with moderate OSA and that cerebral flow regulatory mechanisms can cope with the adverse effects which occur in moderate OSA. This is an important factor in clinical decisions for prescription of continuous positive airway pressure therapy (CPAP).
METHODS: Twenty-four patients diagnosed with moderate OSA (15 ≤ apnoea-hypopnea index (AHI) < 30) were recruited (aged 32-72, median 59 years, 10 female). Seven controls (aged 42-73 years, median 62 years, 4 female) with an AHI < 5 were also recruited. The OSA status of all participants was confirmed at baseline by unattended polysomnography and they had an MRI arterial-spin-labelling scan of cerebral perfusion.
RESULTS: Neither global perfusion nor voxel-wise perfusion differed significantly between the moderate-OSA and control groups. We also compared the average perfusion across three regional clusters, which had been found in a previous study to have significant perfusion differences with moderate-severe OSA versus control, and found no significant difference in perfusion between the two groups. The perfusions were also very close, with means of 50.2 and 51.8 mL/100 g/min for the moderate-OSAs and controls, respectively, with a negligible effect size (Cohen\'s d = 0.10).
CONCLUSIONS: We conclude that cerebral perfusion is not impaired in people with moderate OSA and that cerebral flow regulatory mechanisms can cope with the adverse effects which occur in moderate OSA. This is an important factor in clinical decisions for prescription of continuous positive airway pressure therapy (CPAP).
摘要：
目标：众所周知，以及对健康的许多其他不利影响，严重的阻塞性睡眠呼吸暂停导致脑灌注减少，反过来,大脑功能下降.尚不清楚中度阻塞性睡眠呼吸暂停（OSA）的影响。我们的目的是确定诊断为中度OSA的患者的脑血流是否受损。
方法：招募24例诊断为中度OSA（15≤呼吸暂停低通气指数（AHI）<30）的患者（年龄32-72岁，中位数59岁，10女）。七个对照组（年龄42-73岁，中位数62岁，还招募了AHI<5的4名女性）。所有参与者的OSA状态在基线时通过无人值守的多导睡眠图得到确认，他们进行了脑灌注的MRI动脉自旋标记扫描。
结果：中度OSA组和对照组的整体灌注和体素灌注均无显著差异。我们还比较了三个区域集群的平均灌注，在先前的研究中发现，与对照组相比，中重度OSA的灌注存在显着差异，两组之间的灌注没有显着差异。灌注也非常接近，中度OSAs和对照组的平均值为50.2和51.8mL/100g/min，分别,效果大小可忽略不计(科恩的d=0.10)。
结论：我们得出结论，中度OSA患者的脑灌注没有受损，脑流量调节机制可以应对中度OSA的不良反应。这是临床决定连续气道正压通气治疗（CPAP）的重要因素。
方法：招募24例诊断为中度OSA（15≤呼吸暂停低通气指数（AHI）<30）的患者（年龄32-72岁，中位数59岁，10女）。七个对照组（年龄42-73岁，中位数62岁，还招募了AHI<5的4名女性）。所有参与者的OSA状态在基线时通过无人值守的多导睡眠图得到确认，他们进行了脑灌注的MRI动脉自旋标记扫描。
结果：中度OSA组和对照组的整体灌注和体素灌注均无显著差异。我们还比较了三个区域集群的平均灌注，在先前的研究中发现，与对照组相比，中重度OSA的灌注存在显着差异，两组之间的灌注没有显着差异。灌注也非常接近，中度OSAs和对照组的平均值为50.2和51.8mL/100g/min，分别,效果大小可忽略不计(科恩的d=0.10)。
结论：我们得出结论，中度OSA患者的脑灌注没有受损，脑流量调节机制可以应对中度OSA的不良反应。这是临床决定连续气道正压通气治疗（CPAP）的重要因素。
