Abstract
OBJECTIVE: To evaluate the cross-sectional relationship between asthma and pre-gravid body mass index (BMI), and to assess the risk of adult weight change among women with history of asthma diagnosed in childhood or adulthood, respectively. STUDY DESIGN: Study participants were 3737 pregnant women enrolled in a cohort study. Information on history of asthma, pre-gravid BMI, adult weight change (difference between BMI at age 18 and pre-gravid BMI), and other sociodemographic characteristics was collected using interviewer-administered questionnaires. Pre-gravid BMI was categorized into lean (BMI < 18.5 kg/m(2)), overweight (BMI = 25-24.9 kg/m(2)), and obese (BMI ≥ 30 kg/m(2)). Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Approximately 13.1% of study participants reported history of asthma. Compared with the reference group (BMI = 18.5-24.9 kg/m(2)), the odds of asthma was higher among overweight (OR = 1.51; 95% CI = 1.18-1.93) and obese (OR = 1.47; 95% CI = 1.06-2.03) women while it was lower among lean women (OR = 0.42; 95% CI = 0.21-0.84) (trend p-value <.001). Women who gained ≥20 kg compared with those who maintained their weight (±2.5 kg) had a 2.7-fold increased odds of asthma (95% CI = 1.02-7.00). CONCLUSIONS: Overweight and obese women were more likely to have a history of asthma. Adult weight gain was positively associated with asthma diagnosis. Longitudinal studies designed to prospectively assess patterns of adult weight change in relation to asthma are warranted.