Persistent overweight or obesity, lung function, and asthma exacerbations in Puerto Rican youth

Background: Whether persistent overweight or obesity affects lung function or asthma morbidity in youth is unclear.

Objective: To evaluate overweight or obesity that persists between school age and adolescence and change in lung function and total immunoglobulin (Ig)E and severe asthma exacerbations in Puerto Rican youth.

Methods: Prospective study of 340 Puerto Rican youth assessed at 2 visits, the first at ages 6 to 14 years and the second at ages 9 to 20 years. Persistent overweight or obesity was defined as a body mass index z-score greater than or equal to 85th percentile at both visits. Outcomes of interest were change in percent predicted (%pred) lung function measures and total IgE between study visits and severe asthma exacerbations in the year before visit 2. Logistic or linear regression was used for multivariable analysis.

Results: In multivariable analysis, persistently overweight or obese subjects had changes in %pred forced expiratory volume in 1 second (FEV1) (β = -5.07%; 95% confidence interval, -1.51% to -8.62%; P < .01) and %pred FEV1 to forced vital capacity (FVC) ratio (β = -2.85%; 95% confidence interval, -0.18% to -5.51%; P = .04) which were lower than those observed in subjects with normal weight at both study visits (control subjects). Compared with control subjects, those who were persistently overweight or obese and those who became overweight or obese at visit 2 had increased odds of more than or equal to 1 severe asthma exacerbation in the year before visit 2. There was no significant association between persistent overweight or obesity and change in %pred FVC or total IgE (P > .20 for both instances).

Conclusion: In a prospective study of Puerto Rican youth, persistently overweight or obese subjects had lower changes in FEV1 or FEV1 to FVC ratio and higher odds of severe asthma exacerbations than subjects of normal weight.