Does a Link Exist Between Obesity and Asthma?

By Clement A. Maccia, M.D.

Each of these disorders has a significant public health impact and most recently there has been significant literature suggesting the association between the two. Childhood obesity has become a significant problem in the United States along with the increase in asthma. In addition to the asthma epidemic there is an obesity epidemic in the United States. Statistics reveal that one third of all 16-year-old children in the United States are overweight, and 15% are obese. Studies indicate an increased prevalence of asthma in the obese. Possible explanations are that there is a decrease in exercise in these individuals however longitudinal studies have shown that obesity predates the development of asthma. Epidemiological data reveals the impact of obesity on asthma is much stronger in females than males. The incident of asthma after age 11 years is 5 to 7 times higher in females who are obese versus lean females. No such relationship exists for males.

The relationship between obesity and asthma is reasonably clear, however the relationship between obesity and airway responsiveness is not clear. It is possible that in- utero events are contributing to the relationship between obesity and asthma in children. Low birthweight is known to be associated with an increased incidence of asthma and high birthweight is associated with a higher subsequent incidence of obesity. There is very little information in regards to maternal caloric intake during pregnancy and hyperinsulinemia during pregnancy on the development of obesity.

The systemic inflammatory state in obesity can lead to metabolic and cardiovascular complications. It is not known positively whether this inflammatory environment alters asthma risk or phenotype. Most of literature has concentrated on the effect of leptin, a hormone produced by adipocytes which increases basal metabolic rate and signals the brain that the individual has reached satiety. Animal studies have indicated that airway inflammatory response to both allergenic and nonallergenic exposures is enhanced by both endogenous and exogenous leptin. Studies have shown in humans a modest overall incidence of asthma and prevalence in the obese, although body mass index does not appear to be a significant modifier of asthma severity.

Asthma and obesity are common conditions and both are major public health problems. Obesity appears to increase the risk of asthma and both conditions may share common genetic and environmental causes. There are mechanical, developmental, hormonal, signal transduction, and immunological reasons for their effects. Ongoing research including genetic understanding of these complex traits and elucidation of genes to specific asthma phenotypes should enhance our understanding of the common genetic basis of these disorders.

Yes, there is an association between the two, however a many studies and questions must be answered before we can directly relate obesity and asthma.

Clement A. Maccia MD

Dr. Maccia is Board certified in Pediatrics and Allergy and Immunology. Presently he is Clinical Professor of Pediatrics at the UMDNJ-Robert Wood Johnson Medical School. Dr. Maccia is the Director of the Allergy Clinic. He is the author of numerous articles and has been selected for the past eight years into the Best Doctors in the New York-New Jersey Metropolitan Area by Castle Connolly. In 2007, he was included in the edition Top Doctors in the New York Metro Area.

He was elected by the residents in Medicine and Pediatrics at UMDNJ-Robert Wood Johnson Medical School for a teaching award in 2001and in 2005 for his excellence as a clinician, teacher and role model. Dr. Maccia was Chief of Pediatrics at Muhlenberg Regional Medical Center, an affiliate of UMDNJ- Robert Wood Johnson Medical School, from 1991-1999.

He presently serves on the Medical Advisory Board of ‘nPLAY A Childhood Obesity Foundation (www.nplayfoundation.org). In addition, he serves on the Board of Governors for Conventus Medical Malpractice Insurance Company. In the past he served on the Board of Governors for Muhlenberg Hospital and the Solaris Health System.

For more information or questions please feel free to write to clement.maccia@gmail.com.