Obese May Carry Asthma Trait

A new study suggests obese patients may carry a specific trait or phenotype that causes them to have poorer asthma control than nonobese patients with asthma. Researchers from Quebec, Canada, compared pulmonary function changes, methacholine challenge scores, sputum induction cell counts, symptom perceptions, BMI/waist circumference, and waist-to-hip ratio between 44 obese patients with asthma and 44 nonobese patients with asthma. Compared with nonobese subjects, obese subjects had poorer asthma control and lower total lung capacity, expiratory reserve volume, functional residual capacity, and residual volume. Blood serum Creactive protein and fibrinogen levels also were higher in obese than nonobese subjects. Researchers speculate that bronchial and systemic inflammatory characteristic and patterns of pulmonary function changes suggest obese patients may have a different phenotype of asthma. This study is published in the August issue of the journal CHEST.