Body fat mass distribution and interrupter resistance, fractional exhaled nitric oxide, and asthma at school-age

Abstract

Obesity and asthma often coexist. We hypothesized that detailed body fat distribution measures might be more strongly associated than body mass index (BMI) with childhood asthma. We examined the associations of total body and abdominal fat measures with respiratory resistance (Rint), fractional exhaled nitric oxide (Feno), and risks of wheezing and asthma in school-aged children. In a population-based prospective cohort study among 6178 children aged 6years, we measured BMI, fat mass index, android/gynoid ratio, and preperitoneal and subcutaneous fat mass by physical examinations, dual-energy x-ray absorptiometry, and ultrasound, respectively. We performed Rint and Feno measurements, and assessed physician-diagnosed wheezing and asthma by questionnaires. A higher BMI was associated with a higher Rint (Zscore [95% CI], 0.06 [0.01-0.12]) and increased risk of wheezing (odds ratio [95% CI], 1.07 [1.00-1.14], per Z score BMI increase), but not with Feno or asthma. Ahigh fat mass index was associated with a higher Rint (Z score [95% CI], 0.40 [0.13-0.68]). Ahigh android/gynoid fat mass ratio was associated with a lower Feno (Sym% [95% CI], -9.8 [-16.3 to -3.4]), whereas a high preperitoneal fat mass was associated with a higher Feno (Sym% [95% CI], 6.5 [0.1-12.9]). Subcutaneous fat mass was not associated with any respiratory outcome. Studying detailed body fat distribution measures might provide better insight into the obesity-asthma paradigm.