Pahkala R, Seppä J, Ikonen A, Smirnov G, Tuomilehto H
Institute of Dentistry, School of Medicine, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland,
Sleep Breath. 2014 May;18(2):275-82. doi: 10.1007/s11325-013-0878-4. Epub 2013 Jul 23.
Obesity is the most important risk factor for obstructive sleep apnea (OSA); however, the exact underlying mechanisms are still not fully understood. The aim of this study was to examine the morphology of upper airways in overweight habitual snorers and in mild OSA patients. Furthermore, the associations between weight loss, parapharyngeal fat pad area and OSA were assessed in a 1-year randomised, controlled follow-up study originally conducted to determine the effects of lifestyle changes with weight reduction as a treatment of OSA.
Thirty-six overweight adult patients with mild OSA [apnea-hypopnea index (AHI) 5-15 events/h] and 24 weight-matched habitual snorers (AHI < 5 events/h) were included in the study. All patients underwent nocturnal cardiorespiratory recordings and multislice computed tomography (CT) of parapharyngeal fat pad area, the smallest diameter and area in naso-, oro- and hypopharynx, the smallest diameter and area of the whole pharyngeal airway, the distance from the hyoid bone to the mandibular plane and to cervical tangent as well as the distance between mandibular symphysis and cervical spine. In addition, OSA patients were further randomised to receive either an active 1-year lifestyle intervention with an early weight loss programme or routine lifestyle counselling. After 1 year, the cardiorespiratory recordings and CT scans were repeated.
The pharyngeal fat pad area was significantly larger, and the distance from the hyoid bone to cervical spine was longer in patients with OSA than in habitual snorers (p = 0.002 and p = 0.018, respectively). The multiple regression analysis showed that besides a large pharyngeal fat pad area and a long distance from the cervical spine to hyoid bone, also a short distance from the mandibular symphysis to cervical tangent increased a risk to OSA. During the 1-year follow-up in OSA patients, the pharyngeal fat pad area and AHI decreased significantly in the intervention group (p = 0.003 and p < 0.001, respectively).
In the early stages of OSA, the pharyngeal fat pad seems to play an important role in the development of disease in overweight patients. Furthermore, weight reduction by lifestyle intervention-based programme reduces both central obesity and pharyngeal fat pads, resulting in an improvement of OSA.
肥胖是阻塞性睡眠呼吸暂停（OSA）最重要的危险因素；然而，确切的潜在机制仍未完全明确。本研究的目的是检查超重习惯性打鼾者和轻度OSA患者上气道的形态。此外，在一项为期1年的随机对照随访研究中评估了体重减轻、咽旁脂肪垫面积与OSA之间的关联，该研究最初旨在确定以减轻体重为OSA治疗手段的生活方式改变的效果。
本研究纳入了36名患有轻度OSA[呼吸暂停低通气指数（AHI）为5 - 15次/小时]的超重成年患者和24名体重匹配的习惯性打鼾者（AHI < 5次/小时）。所有患者均接受夜间心肺记录以及咽旁脂肪垫面积、鼻、口和下咽的最小直径和面积、整个咽气道的最小直径和面积、舌骨到下颌平面和颈椎切线的距离以及下颌联合与颈椎之间距离的多层计算机断层扫描（CT）。此外，OSA患者被进一步随机分为接受为期1年的积极生活方式干预及早期体重减轻计划或常规生活方式咨询。1年后，重复进行心肺记录和CT扫描。
OSA患者的咽脂肪垫面积显著更大，且舌骨到颈椎的距离比习惯性打鼾者更长（分别为p = 0.002和p = 0.018）。多元回归分析表明，除了咽脂肪垫面积大以及颈椎到舌骨的距离长之外，下颌联合到颈椎切线的距离短也增加了患OSA的风险。在OSA患者的1年随访期间，干预组的咽脂肪垫面积和AHI显著降低（分别为p = 0.003和p < 0.001）。
在OSA的早期阶段，咽脂肪垫似乎在超重患者疾病发展中起重要作用。此外，基于生活方式干预的计划减轻体重可减少中心性肥胖和咽脂肪垫，从而改善OSA。
