Purpose of the Study
The prevalence of both asthma and obesity have been increasing over recent years, and are higher among minorities. The aim of this study was to observe whether the weight status of inner-city minority asthmatic children differed from that of their nonasthmatic peers, and to determine if overweight asthmatic children experienced more severe asthma.
The study group was composed of 209 black and Hispanic children between the ages of 2 and 18 who carried the single diagnosis of asthma, and who had not received chronic oral steroids or more than 4 short courses of oral steroids within the past year. The control group consisted of 1017 black and Hispanic children enrolled in New York City schools.
Information obtained from the patient record and an interview was used to determine asthma severity. This information included peak expiratory flow (PEF) records, number of medications used, number of emergency visits or hospitalizations, number of school days missed, and ability to participate in play or sports activities. PEF rate was measured at enrollment in patients who were at least 6 years old and could perform a good effort. Standing height and weight were measured in the patients. Height and weight measurements for the control group were available for comparison. Body mass index (BMI) was calculated and used as the indicator of weight status. Differences in BMI between the asthmatic children and their peers were determined, and the relationship between high BMI and the various measures of asthma severity was examined.
The percentile distribution of BMI for the children with asthma was compared with that of the control group as well as the established reference population. The BMI distribution for the asthmatic patients as well as the controls was skewed towards the higher percentiles compared with the reference population, but was skewed to a greater extent for the asthmatics. The asthmatic children had a relative risk of 1.34 of having a BMI at 85th percentile or greater compared with the peer group (P = .06). The relative risk for asthmatics of having a BMI at 95th percentile or greater was 1.51 (P = .03). The risk of being overweight (based on a BMI of 85th percentile or greater) was found to be significantly associated with days of school missed (30 days or more missed per year), PEF rate of ≤60% predicted, and three or more prescribed asthma medications. The risk of being overweight was not significantly associated with number of hospitalizations, number of emergency visits, or level of sports participation.
The prevalence of being overweight was significantly higher in asthmatic children compared with their peers. Being overweight was significantly associated with severity of asthma as measured by PEF rate, days of school missed, and number of asthma medications.
The authors mention that the findings of this study do not allow us to determine whether asthmatic children are more overweight because of a decreased activity level, or if being overweight actually leads to increased severity of asthma. Asthmatic children may be held back from participating in sports by their parents and thus become overweight because of inactivity. Alternatively, overweight children might spend more time indoors, thereby being exposed to greater amounts of indoor allergens, leading to increased asthma. The latter explanation might be more of an issue in inner-city environments.