GENDER-SPECIFIC AND RACE-SPECIFIC EFFECTS OF ASTHMA AND WHEEZE ON LEVEL AND GROWTH OF LUNG-FUNCTION IN CHILDREN IN 6 US CITIES

The gender- and race-specific effects of asthma/wheeze on pulmonary fu nction level and annual growth velocity were studied in a cohort of 10 ,792 white and 944 black children 6 to 18 yr of age, examined annually between 1974 and 1989 in six U.S. cities. In comparison with white bo ys who never reported asthma or wheeze, FEV(1) levels were 5.7% lower and FEF(25-75) levels were 16.9% lower for white boys with a diagnosis of asthma who reported wheeze symptoms in the past year. White girls with asthma and wheeze had FEV(1) levels that were 3.4% lower and FEF( 25-75) levels that were 13.6% lower than white girls with never-asthma /wheeze. Asthma with wheeze was associated with a greater percent defi cit in FEV(1) level in boys than in girls (p < 0.01) and, particularly in preadolescence, with a significant percent increment in FVC level (1.6%) for girls but not for boys. The diagnosis of asthma with or wit hout wheeze in the past year was associated with a greater deficit in level of lung function than the reporting of wheeze symptoms in a chil d without the diagnosis of asthma. The prevalence of asthma and wheeze was higher among blacks, but no race differences were found in the ef fects of asthma or wheeze on level of FEV(1) and FEF(25-75). Compared with white adolescent female ever asthmatics with no medication use, F EV(1) level was 5.8% lower for those with routine medication use and 7 .8% lower for those with routine and additional medication use. Althou gh white girls with wheeze but no diagnosis of asthma had slightly slo wer growth of FEV(1) (0.3% per year) than did white girls without asth ma or wheeze, children with asthma did not have slower annual growth i n percent terms. In absolute terms, growth of FEV(1) was 14.7 ml/yr an d FEF(25-75) was 47 ml/s/yr slower for asthmatic white boys with wheez e than for those without asthma; for girls with asthma and wheeze grow th of FEF(25-75) was 29 ml/s/yr slower. We conclude that in absolute t erms, but not in percent terms, the pulmonary function deficits associ ated with asthma and wheeze increase throughout childhood. In the prea dolescent and adolescent years, the mechanical properties of the lungs and the inflammatory process in asthmatics may differ by gender, lead ing to gender differences in their pulmonary function. We also conclud e that lung function may not return to normal, even when asthmatics be come asymptomatic.