The study found that the association between BMI and asthma was weaker for African Americans, a group that was previously known to have the highest prevalence of asthma, than for youth from other racial and ethnic groups. Researchers found the strongest association between BMI and asthma in Hispanic youth.

'This research contributes to the growing evidence that there is a relationship between childhood obesity and asthma, and suggests that factors related to race and ethnicity, particularly for Hispanic youth, may modify this relationship,' said study lead author Mary Helen Black, PhD, of the Kaiser Permanente Southern California Department of Research & Evaluation. 'The study's large and diverse population, which is broadly representative of the Southern California region, allowed us to examine a wide range of BMI categories in relation to asthma among youth from five racial/ethnic groups.'

Researchers also found that, among youths with asthma, being overweight or obese was associated with more frequent visits to the doctor or emergency department for asthma. In addition, overweight or obese youth with asthma used more inhaled and oral corticosteroid asthma drugs, compared to healthy-weight youth. The need for these medical treatments could have broader health implications as other studies have suggested a link between these medications and type 2 diabetes.

The cross-sectional, population-based study included youth from a racially and ethnically diverse population. Asthma was fairly common in this population, affecting about 18 percent of the youth in the study. Researchers used electronic health records to obtain height and weight measurements, asthma diagnoses, and dispensed prescriptions for asthma-specific medications for children and adolescents in the Kaiser Permanente Southern California integrated health plan from 2007 to 2009.

This study is part of the Kaiser Permanente Southern California Children's Health Study, and their ongoing work to better understand and prevent childhood obesity.

Last year, the Kaiser Permanente Southern California Children's Health Study found that 7 percent of boys and 6 percent of girls ages 2 to 19 in the population were extremely obese. This study also has used electronic health records to determine that children who were obese or overweight have a significantly higher prevalence of psoriasis, a chronic inflammatory disease of the skin.

Other study authors included Ning Smith, PhD, Steven Jacobsen, MD, and Corinna Koebnick, PhD, from the Department of Research & Evaluation, Kaiser Permanente Southern California; and Amy H. Porter, MD, from the Department of Pediatrics, Kaiser Permanente Los Angeles Medical Center.

About the Kaiser Permanente Department of Research & Evaluation
The Department of Research & Evaluation conducts high quality, innovative research into disease etiology, prevention, treatment and care delivery. Investigators conduct epidemiology, health sciences, and behavioral research as well as clinical trials. Areas of interest include diabetes and obesity, cancer, HIV/AIDS, cardiovascular disease, aging and cognition, pregnancy outcomes, women's and children's health, quality and safety, and pharmacoepidemiology. Located in Pasadena, Calif., the department focuses on translating research to practice quickly to benefit the health and lives of Kaiser Permanente Southern California members and the general population. Visit www.kp.org/research.

About Kaiser Permanente
Kaiser Permanente is committed to helping shape the future of health care. We are recognized as one of America's leading health care providers and not-for-profit health plans. Founded in 1945, our mission is to provide high-quality, affordable health care services and to improve the health of our members and the communities we serve. We serve approximately 8.9 million members in nine states and the District of Columbia. Care for members and patients is focused on their total health and guided by their personal physicians, specialists and team of caregivers. Our expert and caring medical teams are empowered and supported by industry-leading technology advances and tools for health promotion, disease prevention, state-of-the art care delivery and world-class chronic disease management. Kaiser Permanente is dedicated to care innovations, clinical research, health education and the support of community health. For more information, go to: www.kp.org/newscenter.