The Relationship Between Body Weight and Objective Measures of Airway Obstruction in Children

Objective: The purpose of this study was to describe the effects of obesity (body mass index 95 th percentile) on objective measures of airway obstruction as determined by spirometry. Design: Prospective cross-sectional study. Methods: Two hundred ninty six (Age: 13.6 ± 1.5 Years) children from two middle schools were enrolled. The standing heights and weights in bear-feet were measured, and body mass index (BMI) was calculated. Spirometry was performed according to the American Thoracic Society guidelines. The definition of reversible airway obstruction was based on the following criteria: forced expiratory volume in one second (FEV1) < 80% predicted, and FEV1/forced vital capacity (FVC) > 5% lower than predicted for age and sex. Results: Two-hundred-twenty-six children (76%) were African-American and 71 children (24%) were white. 138 (46%) children were obese. 36/296 (12%) children met the criteria for reversible airway obstruction, of which 29/296 (9.7%) were obese. Baseline FEV1 percent predicted (88 ± 6 vs 84 ± 7 %, p = 0.03), FEV1 /FVC(94 ± 6 vs 86 ± 8, p < 0.001), and FEV1 percent predicted following albuterol administration (95 ± 7 vs 88 ± 7 %, p = 0.03) were all lower in children who were obese. Conclusions: There is an association between obesity and reversible airway obstruction as demonstrated by spirometry in