Relationship between asthma severity and obesity

The prevalence of both obesity and asthma has risen in recent years. We sought to investigate whether obesity may be related to asthma. We undertook a retrospective medical record review of patient records at an inner-city academic asthma center. Obesity was defined as a body mass index (BMI) greater than 30. Asthma severity was defined by using the National Heart Lung and Blood Institute 1997 guidelines. Adults with a history of cigarette smoking or other lung disease were excluded. A total of 143 individuals aged 18-88 with a mean age of 43.9 met the entry criteria. There were 113 females and 30 males. Seventy-two percent of the sample was obese. The Spearman correlation coefficient showed a linear relationship between asthma severity and BMI (r=0.40, p<0.0001). Females with asthma were significantly more overweight than males, mean BMI 35.9 vs. 32.14, respectively (p=0.01). The prevalence of obesity in the 13 patients on long-term oral corticosteroids was 100%. Prevalence of obesity increases with increasing asthma severity in adults. The association of asthma severity with obesity suggests that obesity may be a potentially modifiable risk factor for asthma or asthma-like symptoms.