Waist circumference can significantly predict asthma, even for people who aren't technically overweight, according to a study in Thorax. Of the more than 88,000 female schoolteachers in California surveyed, 7.5% reported having asthma. Of those, women with waist circumferences of 35.2 inches or larger but body mass indexes below 25 -- the official cutoff for 'overweight' -- were over one-third more likely than other 'normal' weight women to have asthma. （Women with large waists who were also obese were even more likely to have asthma.） The findings suggest that abdominal fat may contribute to asthma independently of overall body fat, the researchers said. While the specific pathways aren't crystal clear, excess fat tissue in the abdomen is thought to increase the risk for asthma by restricting and inflaming airways.

    Caveat: Because it used a one-time survey, originally intended to track breast cancer, the study's researchers were unable to follow patients as their diagnoses changed over time, and thus couldn't conclude that obesity or abdominal fat definitively led to asthma.

    根據《胸腔》（Thorax）雜志上的一項研究，腰圍可以有效預測哮喘，甚至是對那些理論上并不超重的人。對加利福尼亞88,000多名女教師的調查發現，7.5%的人患有哮喘。其中，腰圍為35.2英寸或更粗，但體重指數低于25（"超重"的公認分界線）的女性患哮喘的概率比其他"正常"體重的女性高出三分之一強。（腰粗而肥胖的女性患哮喘的概率更高。）研究人員稱，這一發現表明，腹部脂肪對哮喘的影響可能獨立于全身脂肪的影響。盡管具體作用方式尚不完全明了，但研究人員認為，腹部的多余脂肪組織限制了氣道并使其發炎，從而增加了罹患哮喘的風險。

    注意：由于這項研究使用的是一次性調查，最初目的是追蹤乳腺癌，因此研究人員無法在病人的診斷結果隨時間的推移發生變化時對其進行跟蹤，因此不能得出肥胖或腹部肥胖必定導致哮喘的結論。