Litonjua A A, Sparrow D, Celedon J C, DeMolles D, Weiss S T
Channing Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
Thorax. 2002 Jul;57(7):581-5. doi: 10.1136/thorax.57.7.581.
The rising prevalence of asthma in developed nations may be associated with the rising prevalence of obesity in these same nations. The relationship between body mass index (BMI) and the development of an objective marker for asthma, methacholine airway hyperresponsiveness (AHR), was investigated in adult men.
Sixty one men who had no AHR at initial methacholine challenge testing but who developed AHR about 4 years later and 244 matched controls participated in the study. The effects of initial BMI and change in BMI on development of AHR were examined in conditional logistic regression models.
Initial BMI was found to have a non-linear relationship with development of AHR. Compared with men with initial BMI in the middle quintile, men with BMI in the lowest quintile (BMI=19.8-24.3 kg/m(2)) and those with BMI in the highest quintile (BMI >29.4 kg/m(2)) were more likely to develop AHR: OR=7.0 (95% CI 1.8 to 27.7) and OR=10.0 (95% CI 2.6 to 37.9), respectively. These results remained significant after controlling for age, smoking, IgE level, and initial FEV(1). In addition, there was a positive linear relationship between change in BMI over the period of observation and the subsequent development of AHR.
In this cohort of adult men, both a low BMI and a high BMI were associated with the development of AHR. For men with a low initial BMI the increased risk for development of AHR appears to be partly mediated by a gain in weight. The effect of BMI on AHR may suggest mechanisms in the observed associations between obesity and asthma.
发达国家哮喘患病率的上升可能与这些国家肥胖率的上升有关。本研究在成年男性中调查了体重指数（BMI）与哮喘客观指标——乙酰甲胆碱气道高反应性（AHR）发展之间的关系。
61名在初次乙酰甲胆碱激发试验时无AHR但约4年后出现AHR的男性和244名匹配的对照者参与了本研究。在条件逻辑回归模型中检验了初始BMI和BMI变化对AHR发展的影响。
发现初始BMI与AHR的发展呈非线性关系。与初始BMI处于中间五分位数的男性相比，BMI处于最低五分位数（BMI = 19.8 - 24.3 kg/m²）和最高五分位数（BMI > 29.4 kg/m²）的男性更易发生AHR：比值比（OR）分别为7.0（95%置信区间1.8至27.7）和10.0（95%置信区间2.6至37.9）。在控制年龄、吸烟、IgE水平和初始第1秒用力呼气容积（FEV₁）后，这些结果仍然显著。此外，观察期内BMI的变化与随后AHR的发展呈正线性关系。
在这一成年男性队列中，低BMI和高BMI均与AHR的发展有关。对于初始BMI较低的男性，AHR发展风险增加似乎部分是由体重增加介导的。BMI对AHR的影响可能提示了肥胖与哮喘之间观察到的关联中的机制。
