The effect of sleep apnea severity on cardiac autonomic activity during night time in obstructive sleep apnea patients

ABSTRACT CONTEXT AND OBJECTIVE: Impaired autonomic cardiac function is an important consequence of obstructive sleep apnea (OSA). This impairment is mainly due to intermittent hypoxia episodes following apneas. However, the impact of apnea severity on autonomic cardiac function remains unclear. The aim of this study was to evaluate the relationship between the severity of sleep apnea and heart rate turbulence (HRT) and heart rate variability (HRV) in OSA. DESIGN AND SETTING: Observational cross-sectional study conducted in the Departments of Cardiology and Pulmonary Diseases, Afyon Kocatepe University, Turkey. METHODS: 106 patients with OSA and 27 healthy volunteers were enrolled. Based on apnea hypopnea index (AHI) values, obstructive sleep apnea severity was classified as follows: mild OSA (AHI ≥ 5 and 30). HRV and HRT parameters were assessed via 24-hour digital Holter electrocardiogram recordings for all subjects. RESULTS: HRV and HRT results were significantly lower among OSA patients than among control subjects (P

研究背景与目标：心脏自主神经功能受损是阻塞性睡眠呼吸暂停（obstructive sleep apnea, OSA）的重要临床并发症。此类功能损害主要由呼吸暂停引发的间歇性低氧发作所致。然而，呼吸暂停严重程度对心脏自主神经功能的影响仍不明确。本研究旨在评估阻塞性睡眠呼吸暂停患者的睡眠呼吸暂停严重程度与心率震荡（heart rate turbulence, HRT）、心率变异性（heart rate variability, HRV）之间的关联。
研究设计与实施场景：本研究为观察性横断面研究，在土耳其阿菲永科恰泰佩大学心脏病学与肺病学教研室开展。
研究方法：共纳入106例阻塞性睡眠呼吸暂停患者与27名健康志愿者。根据呼吸暂停低通气指数（apnea hypopnea index, AHI）数值，阻塞性睡眠呼吸暂停严重程度分级如下：轻度阻塞性睡眠呼吸暂停（AHI≥5且30）。所有受试者均通过24小时数字化动态心电图（Holter）记录评估心率变异性与心率震荡参数。
研究结果：阻塞性睡眠呼吸暂停患者的心率变异性与心率震荡指标均显著低于健康对照组（P