Overweight women have an increased risk of developing asthma and allergy. Previous reports have linked asthma and obesity in women, but it was unclear if this association resulted from confusion between real asthma or breathing symptoms caused by being overweight. Researchers from the University of Otago in Dunedin, New Zealand, analysed the data on airway function and allergies in a group of 1000 subjects between the ages of 9 and 26 years. It was found that the body mass index (weight in relation to height) in women is directly related to the risk of developing asthma or wheezing, needing asthma treatment, having allergies, and poorer lung function. There was little evidence that BMI was associated with asthma or allergies in men. The researchers estimate that 28 per cent of asthma developing in women after age 9 is due to overweight. Why is BMI linked to asthma in females could be partially explained by the fact that for a given BMI, women had a greater percentage of body fat than men. This suggests that hormones might be involved in susceptibility to asthma.
American Journal of Respiratory and Critical Care Medicine,
March 2005