Background. Obstructive sleep apnea (OSA) was highly prevalent in patients with type 2 diabetes (T2D). Cathepsin S (CTSS), a cysteine protease, is involved in the inflammatory activity in T2D and hypoxia conditions. The aim of the study was to evaluate whether CTSS could be involved in the inflammatory reaction of OSA in patients with T2D. Methods. We included 158 participants in this study matched for age, gender, and body mass index in 4 groups (control, non-OSA&T2D, OSA&non-T2D, and OSA&T2D). After overnight polysomnography, we collected the clinical data including anthropometrical characteristics, blood pressure, and fasting blood samples in the morning. Plasma CTSS concentration was evaluated using the human Magnetic Luminex Assay. Results. Compared with the control group, both the non-OSA&T2D group and the OSA&non-T2D group showed higher CTSS levels. Plasma CTSS expression was significantly increased in subjects with OSA&T2D compared to subjects with non-OSA&T2D. The OSA&T2D group had higher CTSS levels than the OSA&non-T2D group, but there were no statistically significant differences. Plasma CTSS levels showed significant correlation with the apnea-hypopnea index (AHI) (, ) and plasma fasting blood glucose (, ). After adjusting confounding factors, plasma CTSS levels were independently associated with the AHI (Beta: 0.386, 95% confidence intervals (CI): 21.988 to 57.781; ). Furthermore, we confirmed the higher pinpoint accuracy of plasma CTSS in the diagnosis of OSA (area under the curve: 0.868). Conclusions. Plasma CTSS expression was significantly elevated in the OSA&T2D group and was independently associated with the AHI; it could be a biomarker with a positive diagnostic value on diagnosing OSA among patients with T2D.

中文翻译：

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组织蛋白酶 S 对预测 2 型糖尿病患者阻塞性睡眠呼吸暂停风险的有用性

背景。阻塞性睡眠呼吸暂停 (OSA) 在 2 型糖尿病 (T2D) 患者中非常普遍。组织蛋白酶 S (CTSS) 是一种半胱氨酸蛋白酶，参与 T2D 和缺氧条件下的炎症活动。该研究的目的是评估 CTSS 是否可能参与 T2D 患者 OSA 的炎症反应。方法。我们在 4 组（对照组、非 OSA&T2D、OSA&non-T2D 和 OSA&T2D）中纳入了年龄、性别和体重指数匹配的 158 名参与者。经过一夜的多导睡眠图，我们收集了包括人体测量学特征、血压和早上空腹血样在内的临床数据。使用人 Magnetic Luminex Assay 评估血浆 CTSS 浓度。结果. 与对照组相比，非OSA&T2D组和OSA&non-T2D组CTSS水平均较高。与非 OSA&T2D 受试者相比，OSA&T2D 受试者的血浆 CTSS 表达显着增加。OSA&T2D组CTSS水平高于OSA&非T2D组，但差异无统计学意义。血浆 CTSS 水平与呼吸暂停低通气指数（AHI）显着相关（, )和血浆空腹血糖 (, ）。调整混杂因素后，血浆 CTSS 水平与 AHI 独立相关（Beta：0.386，95% 置信区间 (CI)：21.988 至 57.781；）。此外，我们证实了血浆 CTSS 在诊断 OSA 中的更高精确度（曲线下面积：0.868）。结论。OSA&T2D 组血浆 CTSS 表达显着升高，且与 AHI 独立相关；它可能是一个对诊断 T2D 患者 OSA 具有阳性诊断价值的生物标志物。