Peters Ubong, Hernandez Paul, Dechman Gail, Ellsmere James, Maksym Geoffrey
a School of Biomedical Engineering, Dalhousie University, 5981 University Avenue, Halifax, NS B3H 4R2, Canada.
b Department of Medicine, Dalhousie University, and Division of Respirology, Queen Elizabeth II Health Sciences Centre, Halifax, NS B3H 3A7, Canada.
Appl Physiol Nutr Metab. 2016 May;41(5):538-47. doi: 10.1139/apnm-2015-0473. Epub 2016 Jan 27.
Obesity is associated with respiratory symptoms that are reported to improve with weight loss, but this is poorly reflected in spirometry, and few studies have measured respiratory mechanics with oscillometry. We investigated whether early changes in lung mechanics following weight loss are detectable with oscillometry. Furthermore, we investigated whether the changes in lung mechanics measured in the supine position following weight loss are associated with changes in sleep quality. Nineteen severely obese female subjects (mean body mass index, 47.2 ± 6.6 kg/m(2)) were evaluated using spirometry, oscillometry, plethysmography, and the Pittsburgh Sleep Quality Index before and 5 weeks after bariatric surgery. These tests were conducted in both the upright and the supine position, and pre- and postbronchodilation with 200 μg of salbutamol. Five weeks after surgery, weight loss of 11.5 ± 2.5 kg was not associated with changes in spirometry and plethysmography, with the exception of functional residual capacity. There were also no changes in upright respiratory system resistance (Rrs) or reactance following weight loss. Importantly, however, in the supine position, weight loss caused a substantial reduction in Rrs. In addition, sleep quality improved significantly and was highly correlated with the reduction in supine Rrs. Prior to weight loss, subjects did not respond to the bronchodilator when assessed in the upright position with either spirometry or oscillometry; however, with modest weight loss, bronchodilator responsiveness returned to the normal range. Improvements in lung mechanics occur very early after weight loss, mostly in the supine position, resulting in improved sleep quality. These improvements are detectable with oscillometry but not with spirometry.
肥胖与据报道会随着体重减轻而改善的呼吸道症状相关，但这在肺功能测定中体现不佳，且很少有研究用振荡法测量呼吸力学。我们研究了振荡法是否能检测出体重减轻后肺力学的早期变化。此外，我们还研究了体重减轻后仰卧位测量的肺力学变化是否与睡眠质量变化相关。对19名严重肥胖女性受试者（平均体重指数，47.2±6.6kg/m²）在减肥手术前及术后5周进行了肺功能测定、振荡法、体积描记法和匹兹堡睡眠质量指数评估。这些测试在直立位和仰卧位进行，并在使用200μg沙丁胺醇进行支气管扩张前后进行。术后5周，体重减轻11.5±2.5kg，除功能残气量外，与肺功能测定和体积描记法的变化无关。体重减轻后直立位呼吸系统阻力（Rrs）或电抗也没有变化。然而，重要的是，在仰卧位，体重减轻导致Rrs大幅降低。此外，睡眠质量显著改善，且与仰卧位Rrs的降低高度相关。在体重减轻之前，受试者在直立位用肺功能测定或振荡法评估时对支气管扩张剂无反应；然而，随着体重适度减轻，支气管扩张剂反应性恢复到正常范围。体重减轻后肺力学的改善在很早的时候就出现了，主要在仰卧位，从而导致睡眠质量改善。这些改善可用振荡法检测到，但不能用肺功能测定法检测到。
