Respiratory Diseases Research Unit, Hospital Universitari Arnau de Vilanova, IRB Lleida, Lleida, Spain.
Sleep Breath. 2012 Sep;16(3):649-56. doi: 10.1007/s11325-011-0552-7. Epub 2011 Sep 13.
Obstructive sleep apnea syndrome (OSAS) is a common disorder characterized by excessive daytime sleepiness and repetitive upper airway obstruction episodes during sleep. Clinically, obesity is a major risk factor for developing OSAS. However, OSAS has been associated with hormonal and metabolic alterations that could predispose patients to obesity. The aim of this study was to investigate the independent role of apneas and obesity on plasma levels of metabolic hormones (adiponectin, ghrelin, and leptin) in patients with OSAS.
We have studied patients with OSAS and controls with and without obesity. All patients were male, had an apnea-hypopnea index of 20/h or greater, and were eligible for nasal continuous positive airway pressure (nCPAP) treatment. Patients were considered obese (n = 28) when their BMI was higher than 30 kg/m(2) and non-obese (n = 21) when it was lower than 27 kg/m(2). Non-obese control subjects (n = 20) were non-snorers with a normal cardiorespiratory sleep study, while obese control subjects (n = 10) were recruited from those obese subjects who were visited in our sleep unit and for whom OSAS was excluded by full polysomnography. A single blood sample was obtained from an antecubital vein in all participants after the completion of the nocturnal sleep laboratory recording. Plasma leptin, adiponectin, and ghrelin levels were determined by radioimmunoassay.
The adiponectin, ghrelin, and leptin plasma levels were similar in both patients and controls. There were differences in leptin and adiponectin plasma levels between the obese and non-obese in both patient and control groups. In the case of ghrelin, differences between obese and non-obese subjects were only seen in patients. There were no significant differences in hormone levels between the obese controls and obese patients or between non-obese controls and non-obese patients. After 3 months of nCPAP treatment, adiponectin levels decreased significantly both in obese and non-obese patients, and leptin levels decreased in obese patients. Finally, nCPAP did not reduce ghrelin in either obese or non-obese patients.
The basal levels of leptin, adiponectin, and ghrelin were mostly associated with obesity. We found that sleep apnea was not a determinant factor in leptin, adiponectin, and ghrelin hormonal levels. Interestingly, nCPAP treatment diminishes leptin in obese OSA patients and adiponectin levels in obese and non-obese patients with OSAS.
阻塞性睡眠呼吸暂停综合征（OSAS）是一种常见的疾病，其特征是白天过度嗜睡和睡眠期间反复出现上呼吸道阻塞。临床上，肥胖是导致 OSAS 的主要危险因素。然而，OSAS 与激素和代谢变化有关，这些变化可能使患者容易肥胖。本研究的目的是探讨呼吸暂停和肥胖对 OSAS 患者血浆代谢激素（脂联素、胃饥饿素和瘦素）水平的独立影响。
我们研究了 OSAS 患者和伴有或不伴有肥胖的对照组。所有患者均为男性，呼吸暂停-低通气指数（apnea-hypopnea index，AHI）≥20/h，符合接受持续气道正压通气（nasal continuous positive airway pressure，nCPAP）治疗的条件。当 BMI 高于 30kg/m² 时，患者被认为肥胖（n=28），当 BMI 低于 27kg/m² 时，患者被认为非肥胖（n=21）。非肥胖对照组（n=20）为非打鼾者，其心肺睡眠研究正常，而肥胖对照组（n=10）则招募于我院睡眠科就诊的肥胖患者，这些患者通过全睡眠多导图检查排除了 OSAS。所有参与者在夜间睡眠实验室记录完成后，均从前臂静脉采集单一血样。采用放射免疫法测定血浆瘦素、脂联素和胃饥饿素水平。
患者和对照组的脂联素、胃饥饿素和瘦素血浆水平相似。在患者和对照组中，肥胖组和非肥胖组之间的瘦素和脂联素血浆水平存在差异。在胃饥饿素方面，只有在患者中才观察到肥胖和非肥胖受试者之间的差异。肥胖对照组和肥胖患者之间、非肥胖对照组和非肥胖患者之间，激素水平无显著差异。接受 nCPAP 治疗 3 个月后，肥胖和非肥胖患者的脂联素水平均显著下降，肥胖患者的瘦素水平下降。最后，nCPAP 并未降低肥胖或非肥胖患者的胃饥饿素水平。
瘦素、脂联素和胃饥饿素的基础水平主要与肥胖有关。我们发现，睡眠呼吸暂停不是瘦素、脂联素和胃饥饿素激素水平的决定因素。有趣的是，nCPAP 治疗可降低肥胖 OSAS 患者的瘦素和肥胖及非肥胖 OSAS 患者的脂联素水平。
