Effect of obesity on clinical presentation and response to treatment in asthma.

Obesity is a risk factor for being diagnosed with asthma, but there is conflicting evidence on whether obesity is a risk factor for lung function abnormalities characteristic of asthma. We studied a cohort of 488 subjects, 47% of whom were obese. Obese and non-obese subjects with asthma had similar airflow limitation and bronchodilator responsiveness, but obese participants had increased sleep disturbance and gastroesophageal reflux disease, higher cytokine levels, and a trend towards increased exacerbations when treated with theophylline. Obese and non-obese asthmatics have similar lung function abnormalities, but comorbidities and altered responses to medications may significantly affect asthma control in obese people.