Objective: To evaluate the clinical characteristics of patients with obstructive sleep apnea hypopnea syndrome (OSAHS) combined with alveolar hypoventilation. Methods: This retrospective study included patients who were diagnosed as OSAHS by polysomnography (PSG) and underwent daytime awake transcutaneous carbon dioxide (PtcCO2) monitoring from November 2019 to February 2021 at the Sleep Center of the Second Affiliated Hospital of Soochow University. A total of 177 patients were enrolled in the analysis, including 167 males and 10 females, aged (40±8) years old. Patients with daytime awake PtcCO2>45 mmHg (1 mmHg=0.133 kPa) were diagnosed as daytime alveolar hypoventilation, with which participants were divided into the daytime alveolar hypoventilation group and non-daytime alveolar hypoventilation group. Body mass index (BMI) cut-off value predicting daytime alveolar hypoventilation was calculated and the patients were divided into the high BMI group and low BMI group. The continuous nocturnal PtcCO2 data was available for a subset of 128 patients, and the patients were divided into two groups according the daytime alveolar hypoventilation or not. Across-group differences were compared, respectively. Results: Compared with the non-daytime alveolar hypoventilation group (n=125), the BMI [27.57 (26.55, 30.33) vs 26.60 (25.06, 28.09) kg/m2], Epworth sleepiness score(ESS) score [9.50 (6.25, 12.00) vs 7.00 (4.00, 10.75)], higher oxygen desaturation index (ODI) [38.00 (15.23, 64.93) vs 26.80 (11.30, 44.30) events/h] and percentage of total time with oxygen saturation level<90% (TS90%) [11.24% (1.88%, 32.44%) vs 4.35% (0.72%, 9.87%)] of the daytime alveolar hypoventilation group(n=52) were significantly higher (P<0.05), and lowest arterial oxygen saturation (LSaO2) [74.50% (60.25%, 82.00%) vs 79.00% (73.00%, 84.50%)], mean arterial oxygen saturation (MSaO2) [94.00% (91.00%, 95.00%) vs 95.00% (94.00%, 96.00%)] were significantly lower (P<0.05). The BMI cut-off value for predicting daytime alveolar hypoventilation was 27.04 kg/m2. Of the 177 enrolled patients, 90 were in the high BMI group and 87 were in low group. Compared with the low BMI group, the proportion of daytime sleepiness, the ESS score, the prevalence of hypertension, AHI and daytime awake PtcCO2 in the high BMI group were significantly higher (P<0.05). Among the subset of 128 patients with nocturnal PtcCO2 data available, the BMI, daytime PtcCO2 level, the nocturnal CO2 level and the prevalence of sleep related alveolar hypoventilation in the daytime alveolar hypoventilation group (n=40) were significantly higher than those in the non-daytime alveolar hypoventilation group (n=88) (P<0.05). Conclusions: The OSAHS patients with alveolar hypoventilation have higher BMI and more severe nocturnal hypoxia. OSAHS patients with BMI>27.04 kg/m2 are more likely to develop sleep related alveolar hypoventilation disorder.
目的： 分析阻塞性睡眠呼吸暂停低通气综合征（OSAHS）合并肺泡低通气障碍患者的临床特征。 方法： 回顾性收集2019年11月至2021年2月在苏州大学附属第二医院睡眠中心就诊、经多导睡眠图（PSG）监测确诊为OSAHS且完成日间清醒期经皮二氧化碳（PtcCO2）监测的患者资料。共纳入患者177例，其中男167例，女10例，年龄为（40±8）岁。以日间清醒期PtcCO2>45 mmHg（1 mmHg=0.133 kPa）定义为日间肺泡低通气，分为日间肺泡低通气组、非日间肺泡低通气组；分析体质指数（BMI）预测日间肺泡低通气的临界值，并以BMI临界值进行分组；128例OSAHS患者进行了夜间持续PtcCO2监测，根据是否发生日间肺泡低通气进行分组；分别比较组间临床特征的差异。 结果： 日间肺泡低通气组（n=52）BMI［27.57（26.55，30.33）比26.60（25.06，28.09）kg/m2］、爱泼沃斯嗜睡量表（ESS）评分［9.50（6.25，12.00）比7.00（4.00，10.75）分］、氧减指数（ODI）［38.00（15.23，64.93）比26.80（11.30，44.30）次/h］、血氧饱和度<90%时间占总睡眠时间的百分比（TS90%）［11.24%（1.88%，32.44%）比 4.35%（0.72%，9.87%）］均高于非日间肺泡低通气组（n=125，均P<0.05）；夜间最低氧饱和度（LSaO2）［74.50%（60.25%，82.00%）比 79.00%（73.00%，84.50%）］、夜间平均氧饱和度（MSaO2）［94.00%（91.00%，95.00%）比 95.00%（94.00%，96.00%）］低于非日间肺泡低通气组（均P<0.05）。BMI预测日间肺泡低通气的临界值为27.04 kg/m2，据此将患者分为高BMI组（90例）、低BMI组（87例）。高BMI组主诉日间嗜睡的比例、ESS评分、高血压的患病率、呼吸暂停低通气指数（AHI）、日间清醒期PtcCO2水平均高于低BMI组（均P<0.05）。128例患者接受夜间持续PtcCO2监测的患者中，日间肺泡低通气组（n=40）的BMI、日间清醒期PtcCO2水平、睡眠期PtcCO2水平、发生睡眠相关肺泡低通气的比例均高于非日间肺泡低通气组（n=88）（均P<0.05）。 结论： OSAHS合并日间肺泡低通气的患者BMI较高，夜间缺氧更严重；BMI>27.04 kg/m2患者更易发生睡眠相关肺泡低通气障碍。.