Hypertension Unit, University of Sao Paulo Medical School, São Paulo, Brazil.
Laboratory of Metabolism and Lipids, University of Sao Paulo Medical School, São Paulo, Brazil.
J Lipid Res. 2018 Jun;59(6):1027-1033. doi: 10.1194/jlr.M083436. Epub 2018 Apr 8.
This study aimed to explore lipoprotein metabolism in obstructive sleep apnea (OSA) and the effects of continuous positive airway pressure (CPAP). We studied 15 men with severe OSA [apnea-hypopnea index (AHI) ≥30 events/hour] and 12 age-, BMI-, and waist circumference-matched volunteers without OSA (AHI <5 events/hour). Carotid intima-media thickness (CIMT) was determined by a blind examiner. After 12 h fasting, a triglyceride-rich chylomicron-like emulsion, labeled with [C]cholesteryl oleate and [H]triolein, was injected intravenously followed by blood sample collection at preestablished times. Fractional clearance rate (FCR) of the radiolabeled lipids was estimated by compartmental analysis of radioisotope decay curves. Compared with controls, patients with OSA showed a significant delay in both cholesteryl ester FCR (0.0126 ± 0.0187 vs. 0.0015 ± 0.0025 min; = 0.0313) and triglycerides FCR (0.0334 ± 0.0390 vs. 0.0051 ± 0.0074 min; = 0.0001). CIMT was higher in the OSA group: 620 ± 17 vs. 725 ± 29 µm; = 0.004. Cholesteryl ester FCRs were inversely related to total sleep time <90% ( = -0.463; = 0.029) and CIMT ( = -0.601; = 0.022). The triglyceride FCR was inversely correlated with AHI ( = -0.537; = 0.04). In a subgroup of patients treated with CPAP for 3 months (n = 7), triglyceride FCR increased 5-fold ( = 0.025), but the cholesteryl ester FCR was unchanged. In conclusion, severe OSA decreased lipolysis of triglyceride-rich lipoproteins and delayed removal of remnants. CPAP treatment may be effective to restore the lipolysis rates.
本研究旨在探讨阻塞性睡眠呼吸暂停（OSA）中的脂蛋白代谢以及持续气道正压通气（CPAP）的作用。我们研究了 15 名患有严重 OSA（呼吸暂停低通气指数（AHI）≥30 次/小时）的男性和 12 名年龄、BMI 和腰围匹配的无 OSA 志愿者（AHI<5 次/小时）。通过盲法检查者确定颈动脉内膜中层厚度（CIMT）。禁食 12 小时后，静脉内注射富含甘油三酯的乳糜微粒样乳液，用 [C]胆固醇油酸酯和 [H]三油酸甘油酯标记，然后在预先设定的时间采集血样。通过放射性同位素衰减曲线的房室分析估算放射性标记脂质的分数清除率（FCR）。与对照组相比，OSA 患者的胆固醇酯 FCR（0.0126±0.0187 与 0.0015±0.0025 min；=0.0313）和甘油三酯 FCR（0.0334±0.0390 与 0.0051±0.0074 min；=0.0001）均显著延迟。OSA 组的 CIMT 更高：620±17 与 725±29 µm；=0.004。胆固醇酯 FCR 与总睡眠时间<90%（=-0.463；=0.029）和 CIMT（=-0.601；=0.022）呈负相关。甘油三酯 FCR 与 AHI 呈负相关（=-0.537；=0.04）。在接受 CPAP 治疗 3 个月的患者亚组（n=7）中，甘油三酯 FCR 增加了 5 倍（=0.025），但胆固醇酯 FCR 没有变化。总之，严重 OSA 降低了富含甘油三酯的脂蛋白的脂解作用并延迟了残基的清除。CPAP 治疗可能有效恢复脂解率。
