We examine whether cardiorespiratory fitness modifies the association of obstructive sleep apnea (OSA) severity with MRI-assessed measures of cerebral structure and perfusion.
Using data from a cross-sectional sample of participants (n = 129, 51% female, age range 49.6-85.3 years) in the Wisconsin Sleep Cohort study, we estimated linear models of MRI-assessed total and regional gray matter (GM) and white matter (WM) volumes, WM hyperintensity (WMH:ICV ratio), total lesion volume, and arterial spin labeling (ASL) cerebral blood flow (CBF), using an estimated measure of cardiorespiratory fitness (CRF) and OSA severity as predictors. Participants\' sleep was assessed using overnight in-laboratory polysomnography, and OSA severity was measured using the apnea-hypopnea index (AHI), or the mean number of recorded apnea and hypopnea events per hour of sleep. The mean±SD time difference between PSG data collection and MRI data collection was 1.7±1.5 years (range: [0, 4.9 years]).
OSA severity was associated with reduced total GM volume (β=-0.064; SE = 0.023; p = 0.007), greater total WM lesion volume (interaction p = 0.023), and greater WMHs (interaction p = 0.017) in less-fit subjects. Perfusion models revealed significant differences in the association of AHI and regional CBF between fitness groups (interaction ps < 0.05).
This work provides new evidence for the protective role of cardiorespiratory fitness against the deleterious effects of OSA on brain aging in late-middle age to older adults.
目的:我们研究心肺适应性是否改变了阻塞性睡眠呼吸暂停(OSA)严重程度与MRI评估的脑结构和灌注指标的相关性。
方法:使用来自参与者横断面样本的数据(n=129,51%为女性,年龄范围49.6-85.3岁)在威斯康星州睡眠队列研究中,我们估计了MRI评估的总和区域灰质(GM)和白质(WM)体积的线性模型,WM高强度(WMH:ICV比),总病变体积,和动脉自旋标记(ASL)脑血流量(CBF),使用心肺功能(CRF)和OSA严重程度的估计指标作为预测因子。参与者的睡眠使用过夜的实验室多导睡眠图进行评估,使用呼吸暂停低通气指数(AHI)测量OSA严重程度,或每小时睡眠记录的呼吸暂停和呼吸不足事件的平均数。PSG数据收集和MRI数据收集之间的平均±SD时间差为1.7±1.5年(范围:[0,4.9年])。
结果:OSA严重程度与总GM体积减少相关(β=-0.064;SE=0.023;p=0.007),总WM病变体积更大(相互作用p=0.023),在不太适合的受试者中,WMHs更大(相互作用p=0.017)。灌注模型显示,健身组之间AHI和区域CBF的关联存在显着差异(相互作用ps<0.05)。
结论:这项工作提供了新的证据,证明了心肺适应性对OSA对中年人脑老化的有害影响的保护作用。