睡眠呼吸暂停相关心率变异与晨起血压的关联性研究

目的 探讨迷走神经调节机制在阻塞性睡眠呼吸暂停低通气综合征(OSAHS)相关性高血压发生中的作用.方法 对104例OSAHS患者进行睡眠呼吸监测至少7 h,睡前和晨起测量血压,采用Pearson检验和Speammn检验分析体重指数(BMI)、呼吸暂停低通气指数(AHI)、夜间最低血氧饱和度(nSaO2%min)、SaO2<90%时间占总睡眠时间百分比(DT90%)、呼吸暂停期心率变异幅度(DHR)与睡前及晨起收缩压、舒张压、平均动脉压(MAP)及其差值的相关性,并对晨起收缩期高血压及舒张期高血压的危险因素进行多元逐步Logistic回归分析,计算各因素的优势比(OR)和95%可信区间(CI).结果 全组患者晨起收缩压、舒张压及MAP(mm Hg,1 mm Hg=0.133 kPa)分别为128.3±17.9、88.6±10.6和101.8±12.3,均较睡前(分别为123.5 4±17.8、82.0 4±9.6、95.8 4±11.5)升高(均P<0.01).血压满足高血压诊断者睡前为37例(35.6%),晨起为49例(47.1%).Spearman检验显示DHR与晨起舒张压相关(r=0.214,P<0.05).合并舒张期高血压患者的DHR大于不合并患者(P<0.05).排除年龄、BMI、AHI、nSaO2%min及DT90%的影响后,DHR是与晨起收缩期高血压相关的独立危险因素(OR=1.253,95%CI为1.057～1.486,P<0.01).结论 OSAHS患者呼吸暂停相关心率变异的程度与晨起舒张压相关,是晨起收缩期高血压的独立危险因素,提示迷走神经调节可能参与OSAHS相关性高血压的发生.

Relevance of sleep apnea-associated heart rate variability to morning blood pressure

Objective To explore the role of vagal nerve in obstructive sleep apnea hypopnea syndrome (OSAHS) associated hypertension. Methods A total of 104 patients were diagnosed OSAHS via polysomnngraphy for at least 7 hours. Their blood pressures were measured before and after sleep. Pearson's and Spearman's correlation test were applied to analyze the relevance of body mass index (BMI), apneahypopnea index (AHI), nocturnal minimum of arterial oxygen saturation (nSaO2% mira), percentage of dwell time of arterial oxygen saturation lower than 90% (DT90%), deviation between minimal heart rate and maximal heart rate during apnea (DHR) to systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial blood pressure (MAP) before and after sleep. Logistic regression was performed to examine the risk factors of morning diastolic hypertension and systolic hypertension. Moreover, odds ratio (OR) and 95% confidence interval (CI) of each risk factor were calculated. Results Morning SBP, DBP and MAP in 104 subjects were (128.3±17.9), (88.6± 10.6) and (101.8 ±12.3) mm Hg respectively. They were significantly elevated as compared with their pre-sleep levels (123.5 ± 17.8),(82.0 ±9.6) and (95.8 ± 11.5) mm Hg respectively, all P<0.01]. Thirty-seven eases (35.6%)met the diagnostic criteria of hypertension (SBP≥140 and/or DBP≥90 mm Hg) in their blood pressures before sleep while 49 cases (47. 1%) in their morning blood pressures. Spearman's correlation analysis shows that DBP after sleep was correlated with DHR (r =0.214, P<0.05). DHR in OSAHS patients with diastolic hypertension increased as compared with those without diastolic hypertension (P < 0.05). After adjusting for age, BMI, AHI, nSaO2% rain and DT90%, DHR was a predictor for the morning systolic hypertension (OR = 1. 253, 95% CI: 1. 057 - 1. 486, P < 0. 01). Conclusions Sleep apnea-associated heart rate variability is correlated with morning DBP in OSAHS patients. And it is also an independent predictive factor for morning systolic hypertension. This suggests that vagal regulation may be involved in OSAHS associated hypertension.