From the School of Medicine, Universidad Espíritu Santo-Ecuador, Samborondon (O.H.D.B., A.F.C.).
Department of Epidemiology, Gilead Sciences, Inc, Foster City, CA (R.M.M.).
Stroke. 2019 Sep;50(9):2486-2491. doi: 10.1161/STROKEAHA.119.026095. Epub 2019 Jul 26.
Background and Purpose- The apnea-hypopnea index (AHI) is associated with cerebral small vessel disease (cSVD), but pathogenesis of this association is elusive. We aimed to assess the effect of nighttime heart rate variability (HRV)-as a proxy of sympathetic upregulation-on the aforementioned association. Methods- Atahualpa residents aged ≥60 years undergoing brain magnetic resonance imaging, polysomnography, and 24-hour Holter monitoring (N=176) were included. The presence of moderate-to-severe white matter hyperintensities, deep cerebral microbleeds, lacunar infarcts, and >10 enlarged basal ganglia perivascular spaces were added for estimating the cSVD score. Interaction models were fitted to assess the effect modification of nighttime HRV in the association between the AHI and the cSVD score, and mediation analysis was utilized to assess the proportion of total effect by nighttime HRV on this association. Results- Generalized linear models showed a significant association between the AHI and the cSVD score (P=0.025), as well as a significant inverse association between nighttime HRV and the cSVD score (P=0.002), but no association between daytime HRV and the cSVD score (P=0.097). Interaction models showed a significant interaction of nighttime HRV on the association between AHI and the cSVD score (P=0.001), and mediation analysis found that the percent of total effect between AHI and cSVD score mediated by HRV was 30.8%. Predictive marginal means of the cSVD score were highly significant when the 10th percentile of nighttime HRV was compared across categories of 10th and 90th percentiles of the AHI (cSVD score margins, 0.61 [95% CI, 0.37-0.86] versus 1.67 [95% CI, 1.26-2.09]). Contour plots showed the effect of nighttime (but not daytime) HRV on the association between AHI and the cSVD score. Conclusions- This study shows an important effect of nighttime HRV on the association between the AHI and the cSVD score and provides further support for the role of sympathetic overactivity on this association.
背景与目的-呼吸暂停低通气指数（AHI）与脑小血管病（cSVD）相关，但该关联的发病机制尚不清楚。我们旨在评估夜间心率变异性（HRV）-作为交感神经上调的替代指标-对上述关联的影响。
方法-在接受脑部磁共振成像、多导睡眠图和 24 小时动态心电图监测的 Atahualpa 居民中，纳入年龄≥60 岁的患者（N=176）。为了评估 cSVD 评分，添加了中度至重度脑白质高信号、深部脑微出血、腔隙性梗死和>10 个扩大的基底节血管周围间隙。交互模型用于评估夜间 HRV 对 AHI 和 cSVD 评分之间关联的修饰作用，并且进行中介分析以评估夜间 HRV 对该关联的总效应的比例。
结果-广义线性模型显示，AHI 与 cSVD 评分之间存在显著关联（P=0.025），夜间 HRV 与 cSVD 评分之间存在显著负相关（P=0.002），但日间 HRV 与 cSVD 评分之间无关联（P=0.097）。交互模型显示，夜间 HRV 对 AHI 和 cSVD 评分之间关联的交互作用具有统计学意义（P=0.001），中介分析发现 HRV 介导的 AHI 和 cSVD 评分之间的总效应比例为 30.8%。当将夜间 HRV 的第 10 百分位数与 AHI 的第 10 百分位和第 90 百分位的类别进行比较时，cSVD 评分的预测边缘均值具有统计学意义（cSVD 评分边缘，0.61[95%置信区间，0.37-0.86]与 1.67[95%置信区间，1.26-2.09]）。轮廓图显示了夜间（而非日间）HRV 对 AHI 和 cSVD 评分之间关联的影响。
结论-本研究表明夜间 HRV 对 AHI 和 cSVD 评分之间的关联有重要影响，并进一步支持交感神经过度活跃在该关联中的作用。
