肥胖与非肥胖阻塞性睡眠呼吸暂停低通气综合征患者心外膜脂肪厚度与疾病严重程度的关联研究

背景　肥胖是阻塞性睡眠呼吸暂停低通气综合征（OSAHS）发生与发展的一个重要诱发因素，多数OSAHS患者伴有中心性肥胖和内脏脂肪增加。心外膜脂肪厚度（EFT）是一种测量内脏脂肪的新型工具，目前探讨EFT与OSAHS疾病严重程度的研究仍鲜见报道。目的　探讨肥胖/非肥胖OSAHS患者EFT与疾病严重程度的相关性。方法　选择2015年10月—2017年10月航空总医院睡眠呼吸检测室行多导睡眠图（PSG）的OSAHS患者197例，同期选择体检健康者50例为对照组。依据体质指数（BMI）将OSAHS患者分为肥胖组（BMI≥28.0 kg/m2）111例和非肥胖组（BMI<28.0 kg/m2）86例。OSAHS患者根据呼吸暂停低通气指数（AHI）分为轻度OSAHS（5次/h≤AHI<15次/h）、中度OSAHS（15次/h≤AHI<30次/h）和重度OSAHS（AHI≥30次/h）。收集患者一般资料及PSG监测指标，所有受试者应用超声心动图检测EFT。结果　肥胖组与非肥胖组OSAHS患者年龄、AHI、氧减饱和指数（ODI）、平均血氧饱和度（MSaO2）、最低血氧饱和度（LSaO2）、EFT比较，差异均无统计学意义（P>0.05）；肥胖组OSAHS患者女性比例、BMI、颈围、腰围、血氧饱和度<90%时间占总睡眠时间比例（Ts90%）高于非肥胖组（P<0.05）。对照组根据BMI≥28.0 kg/m2分为肥胖14例，非肥胖36例。在肥胖人群中，对照组与不同疾病严重程度OSAHS患者颈围、腰围、AHI、Ts90%、ODI、MSaO2、LSaO2比较，差异均有统计学意义（P<0.05）；在非肥胖人群中，对照组与不同疾病严重程度OSAHS患者性别、颈围、AHI、Ts90%、ODI、MSaO2、LSaO2、EFT比较，差异均有统计学意义（P<0.05）。相关性分析显示，在肥胖OSHAS患者中，EFT与BMI、AHI、ODI呈正相关（P<0.05）。在非肥胖OSAHS患者中，EFT与BMI、颈围、AHI、Ts90%、ODI呈正相关，与LSaO2呈负相关（P<0.05）。多元线性回归分析结果显示，颈围〔β=0.747，95%CI（-0.106，1.820）〕、EFT〔β=3.375，95%CI（-1.783，7.938）〕是肥胖OSHAS患者AHI的独立预测因子（P<0.05），EFT〔β=4.346，95%CI（-0.081，8.771）〕是非肥胖患者AHI的独立预测因子（P<0.05）。结论　非肥胖不同疾病严重程度OSAHS患者间EFT有差异，EFT与BMI、AHI、ODI呈正相关，EFT可作为临床评估OSAHS疾病严重程度的一种客观指标，尤其是在非肥胖OSAHS人群。

Epicardial Fat Thickness and Severity of Obstructive Sleep Apnea-hypopnea Syndrome in Obese and Nonobese Patients

Background　Obesity is an important predisposing factor for the development and progression of obstructive sleep apnea-hypopnea syndrome （OSAHS）．Most OSAHS patients have central obesity and increased visceral fat.Epicardial fat thickness （EFT） is a new tool for measuring visceral fat.And its relationship with the severity of OSAHS has been rarely reported.Objective　To investigate the relationship between EFT and severity of OSAHS in obese and nonobese patients.Methods　A total of 197 OSAHS patients diagnosed by polysomnography （PSG） and 50 physical examinees （healthy controls） were enrolled from Aviation General Hospital from October 2015 to October 2017，among whom 111 OSAHS patients and 14 controls were obese，and 86 OSAHS patients and 36 controls were nonobese （obesity was defined as BMI≥28.0 kg/m2）．By the apnea-hypopnea index （AHI） per hour，OSAHS patients were stratified into mild OSAHS subgroup （5≤AHI <15），moderate OSAHS subgroup （15≤AHI <30），and severe OSAHS subgroup （AHI≥30）．Baseline and PSG characteristics of OSAHS patients were collected.EFT data of all the participants were obtained by echocardiography.Results　Compared with nonobese OSAHS patients，obese OSAHS patients showed similar mean age，AHI，oxygen desaturation index （ODI），mean oxygen saturation （MSaO2），lowest oxygen saturation （LSaO2） and EFT （P>0.05），but demonstrated higher female ratio，greater mean BMI，mean neck circumference，and waist circumference，and higher percentage of total sleep time with oxygen saturation <90% （Ts90%） （P<0.05）．Mean neck circumference，and waist circumference，AHI，Ts90%，ODI，MSaO2 and LSaO2 differed significantly between obese controls and obese patients with different severity of OSAHS （P<0.05）．Sex ratio，mean neck circumference，AHI，Ts90%，ODI，MSaO2，LSaO2，and EFT varied significantly between nonobese controls and nonobese patients with different severity of OSAHS（P<0.05）．Correlation analysis showed that EFT was positively correlated with BMI，AHI and ODI in obese OSHAS patients （P<0.05）．In nonobese OSHAS patients，it was positively correlated with BMI，neck circumference，AHI，Ts90%，and ODI，but negatively correlated with LSaO2 （P<0.05）．Multiple linear regression analysis suggested that neck circumference 〔β=0.747，95%CI（-0.106，1.820）〕，and EFT〔β=3.375，95%CI（-1.783，7.938）〕were independent predictors of AHI in obese OSHAS patients （P<0.05）．EFT 〔β=4.346，95%CI（-0.081，8.771）〕was an independent predictor of AHI in nonobese OSHAS patients （P<0.05）．Conclusion　EFT is different among nonobese patients with different severity of OSAHS，and it showed a positive correlation with BMI，AHI and OHI.EFT may be a valuable parameter in the objective evaluation of OSAHS severity，especially in nonobese patients.