Raviv Stacy, Dixon Anne E, Kalhan Ravi, Shade David, Smith Lewis J
Department of Pulmonary and Critical Care Medicine, Northshore University Health System, Evanston, IL, USA.
J Asthma. 2011 Feb;48(1):98-104. doi: 10.3109/02770903.2010.534220. Epub 2010 Nov 22.
We recently reported that obese and non-obese patients with asthma have similar airflow limitation and bronchodilator responsiveness, but obese patients have more symptoms overall. There is limited information on the effect of obesity on asthmatics of varying severity measured by objective physiological parameters. Understanding how obesity affects asthmatics of differing severity can provide insights into the pathogenesis of asthma in the obese and a rationale for the therapeutic approach to such patients.
Participants with asthma from two American Lung Association--Asthma Clinical Research Center (ALA-ACRC) studies were grouped by tertiles of airflow obstruction (forced expiratory volume in one second (FEV(1)%) predicted, FEV(1)/forced vital capacity (FVC)) and methacholine reactivity (PC(20)FEV(1)). Within each tertile, we examined the independent effect of body mass index (BMI), divided into normal weight, overweight, and obese categories, on lung function, airway reactivity, and symptoms.
Overall, both FEV(1) and FVC decreased and symptoms worsened with increasing BMI; airway reactivity was unchanged. When stratified by the degree of airflow obstruction, higher BMI was not associated with greater airway reactivity to methacholine. Higher BMI was associated with more asthma symptoms only in the least obstructed FEV(1)/FVC tertile. When stratified by degree of airway reactivity, BMI was inversely associated with FVC in all PC(20)FEV(1) tertiles. BMI was directly associated with asthma symptoms only in those with the least airway reactivity.
Obesity does not influence airway reactivity in patients with asthma and it is associated with more symptoms only in those with less severe disease.
我们最近报道，肥胖和非肥胖哮喘患者具有相似的气流受限和支气管扩张剂反应性，但肥胖患者总体症状更多。关于肥胖对通过客观生理参数测量的不同严重程度哮喘患者的影响，相关信息有限。了解肥胖如何影响不同严重程度的哮喘患者，有助于深入了解肥胖患者哮喘的发病机制，并为这类患者的治疗方法提供理论依据。
来自两项美国肺脏协会哮喘临床研究中心（ALA-ACRC）研究的哮喘参与者，根据气流阻塞三分位数（一秒用力呼气容积（FEV(1)%）预计值、FEV(1)/用力肺活量（FVC））和乙酰甲胆碱反应性（PC(20)FEV(1)）进行分组。在每个三分位数内，我们研究了体重指数（BMI）分为正常体重、超重和肥胖类别后，对肺功能、气道反应性和症状的独立影响。
总体而言，随着BMI增加，FEV(1)和FVC均下降，症状加重；气道反应性未改变。按气流阻塞程度分层时，较高的BMI与对乙酰甲胆碱的气道反应性增加无关。仅在FEV(1)/FVC阻塞程度最低的三分位数中，较高的BMI与更多哮喘症状相关。按气道反应性程度分层时，在所有PC(20)FEV(1)三分位数中，BMI与FVC呈负相关。仅在气道反应性最低的患者中，BMI与哮喘症状呈正相关。
肥胖不影响哮喘患者的气道反应性，仅在病情较轻的患者中与更多症状相关。
