This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Mounting evidence points to obesity as a risk factor for asthma, but little is known about the effects of obesity on the health status of patients with asthma. To understand the relationship between obesity and asthma, it is important to measure both the percent of body fat and the fat distribution. It is also important to measure blood levels of substances such as leptin that are related to obesity and inflammation. The ACE Weight Study is an observational study of the relationship of obesity, percent body fat, fat distribution, and blood biomarkers to asthma morbidity among children and adolescents with asthma participating in the ACE study. The ACE participants will be interviewed regarding their physical activity and diet. Bioelectrical impedance analysis (a measure of percent body fat and regional body fat) and Dual Energy X-ray Absorptiometry (a routine test for bone density that also measures body fat) will be performed. A blood sample will be collected for measurement of inflammatory markers. These activities will be performed once. These measurements will be studied in relation to measures of asthma morbidity including symptom frequency, asthma exacerbation frequency, acute health care utlilization, and pulmonary function. Research subjects participating in the ACE study, protocol H23758 will be invited to participate in this ancillary weight study that was added to the ACE protocol in October 2005.