持续气道正压通气治疗对阻塞性睡眠呼吸暂停低通气综合征患者血管内皮功能及自主神经调制的影响

Effects of CPAP on endothelial function and autonomic modulation in OSAHS patients

目的探讨即时及长期持续气道正压通气（continuous positive airway pressure，CPAP）治疗对于阻塞性睡眠呼吸暂停低通气综合征（obstructive sleep apnea hypopnea syndrome，OSAHS）患者血管内皮功能及自主神经调制的影响。方法共有23例呼吸暂停／低通气指数（apnea／hypopnea index，AHI）≥15次／h的OSAHS患者[AHI（58．8±28．4）次／h]纳入该研究。所有受试者均为男性，年龄为（43．2±10．7）岁，体质量指数为（33．7±8．3）kg／m2。该研究采用动脉增加指数（AAI）作为血管内皮功能的测量指标、心率变异（HRV）及血压变异（BPV）的各频谱成分作为自主神经调制的评价指标，对纳入研究的受试者接受整夜及长期（6个月）的CPAP治疗后其血管内皮功能及自主神经的变化进行评价。结果整夜CPAP治疗时：睡眠前后AAI、HRV及BPV各成分均无显著改变；与无CPAP治疗时相比，睡眠后的HRVLF（60．8±10．4vs69．8±13．8，P〈0．001）、HRV LF／HF（2．4±1．1vs3．8±1．8，P〈0．001）及BPVLF（66．5±11．6vs78．5±14．8，P〈0．001）有显著降低，HRVHF（29．5±11．7vs20．7±9．7，P〈0．05）有显著升高，而AAI无显著变化。6个月CPAP治疗后：与治疗前相比，睡眠前的AAI（8．1±1．8vs12．8±2．3，P〈0．001）显著降低，HRVLF（58．3±9．7vs63．4±11．5，P〈0．05）、HRVLF／HF（2．0±0．8vs2．5±1．2，P〈0．05）及BPVLF（60．5±12．1vs67．7±13．2，P〈0.05）显著降低，HRVHF（35．5±9．8vs28．8±10．1，P〈0．05）显著升高；但若停止CPAP治疗1个晚上，则晨起血压升高、自主神经功能紊乱仍会发生，但与6个月前未CPAP治疗时相比均有所减缓。结论整夜CPAP治疗除了可降低OSAHS患者的晨起血压升高，还可显著改善晨起自主神经紊乱，而长期有效CPAP治疗可显著改善基础内皮功能及自主神经调制，并可减缓OSAHS患者对阻塞性呼吸事件的心血管反应，因而可降低心血管疾病发生率、改善心血管预后。

Objective To investigate the effects of overnight and long term continuous positive airway pressure （CPAP）treatment on endothelial function and autonomic modulation in normotensive men with obstructive sleep apnea. Methods 23 normotensive men with moderate-severe obstructive sleep apnea hypopnea syndrome （OSAHS） [（AHI （58.8± 28.4） times/hi were recruited. The mean age of the subjects was （43.2±10.7） year-old,and body mass index was （33.7±8.3） kg/m2. ECG and beat- to-beat blood pressure were continuously recorded from the radial artery by applanation tonometry for 15 mins before and after overnight sleep. Endothelial function was measured by arterial augmentation index （AAI）. Spectral analysis of heart rate variability （HRV） and blood pressure variability （BPV） were computed for cardiac parasympathetic modulation （high frequency power, HF）, sympathetic modulation （low frequency power, LF）, sympatho vagal balance （LF/HF power of R-R variability, LF/HF） and BPV sympathetic modulation （BPV LF） in normalized units （[total power of the components]/[total power-very low frequency power] ×100）. The changes of endothelial function and autonomic modulation after overnight and long term CPAP treatment were evaluated. Results With overnight CPAP treatment, there was no significant difference in endothelial function and autonomic modulation between before and after sleep, compared to that of no-CPAP, HRV LF（60.8±10.4 vs 69.8±13.8, P 〈0.001）, HRV LF/ HF（2.4±1.1 vs 3.8±1.8, P〈0. 001） and BPV LF （66.5±11.6 vs 78.5±14.8, P〈0. 001）after sleep were decreased significantly, HRV HF （29.5 ± 11.7 vs 20.7±9.7, P〈0.05） increased significantly, while no change in AAI. After 6 months of CPAP treatment., compared to that of the baseline （before treatment）, AAI （8.1±1.8 vs 12.8±2.3, P〈0.001）,HRV LF （58.3±9.7 vs 63.4±11.5, P〈 0.05）,HRV LF/HF（2.0±0.8 vs 2.5±1.2, P〈0.05）and BPV LF （60.5±12.1 vs 67.7±13.2, P〈0.05） decreased significantly respectively, with HRV HF（35.5 ± 9.8 vs 28.8 ± 10.1, P 〈0.05） increased significantly,while the blood pressure would increase significantly and autonomic modulation would get disordered significantly in the morning if the CPAP treatment was suspended for a single night, but the change in blood pressure and autonomic modulation were alleviated compared to that of baseline before CPAP treatment. Conclusions Overnight CPAP treatment not only can decrease the morning increasing of blood pressure, but also improve the morning disorder Of autonomic modulation in OSAHS patients. Long term effective CPAP treatment can improve the baseline endothelial function and autonomic modulation, and also can alleviate the cardiovascular response to obstructive breathing events in OSAHS patients.