The association of overweight and obesity with spirometric values in minority children referred for asthma evaluation

Background. Overweight, obesity, and asthma are more prevalent in minority children; yet, the association of overweight and obesity with spirometric values in asthmatic minorities is not well characterized. Objective. To study the relationship between weight, ethnicity, and spirometric values in children referred for asthma evaluation to a large inner-city hospital in Bronx, NY. Methods. Retrospective review of spirometry done at the first pulmonary clinic visit of 980 asthmatic children, aged 7-20 years, was conducted. Linear regression analysis was performed to elucidate the association of overweight and obesity with pulmonary function among Whites, African Americans, and Hispanics compared with their normal weight counterparts. Results. More African Americans (58%) and Hispanics (65.4%) were overweight and obese than Whites (51.2%) (p < .05). Compared with their normal weight counterparts, percent forced expiratory volume in the 1st second (FEV1)/forced vital capacity (FVC) ratio was lower in both overweight and obese African Americans (2.99%, p < .05 and 3.56%, p < .01, respectively) and Hispanics (2.64%, p < .05 and 2.36%, p < .05, respectively); these differences were found in obese (3.73%, p < .05) but not in overweight (0.68%, p = .7) Whites. Conclusions. FEV1/FVC ratio was lower in both overweight and obese African American and Hispanic children, while this association was present only among obese Whites compared with their normal weight counterparts. These results suggest that spirometric measures of lower airway obstruction decrease with smaller weight increments in minority children when compared with White children. In the context of the higher prevalence of overweight and obesity among African Americans and Hispanics, our findings offer one potential explanation for increased asthma among minority children.