Obese People with Asthma Have Nearly 5 Times Greater Risk of Hospitalization for Asthma

04/09/08 Obese people who have asthma are nearly five times more likely to be hospitalized for the condition than non-obese people with asthma, according to a Kaiser Permanente study published in the September issue of the Journal of Allergy and Clinical Immunology.

This is the first study to control for the risk factors – smoking, use of oral or inhaled corticosteroid medications, gastroesophageal reflux disorder, and demographics – that might explain the obesity-asthma association. Previous studies have shown that obese people are more likely to suffer asthma than non-obese people, and that obese patients often have more severe asthma than their non-obese counterparts.

More than 20 million Americans have been diagnosed with asthma. Nearly a third of adults with asthma are also obese, according to researchers. The Centers for Disease Control and Prevention defines obesity as having a Body Mass Index of 30 or higher.

Researchers at Kaiser Permanente Center for Health Research in Portland, Ore., and the Kaiser Permanente Institute for Health Research in Denver surveyed 1,113 patients in Oregon, Washington, and Colorado, age 35 and older, who have persistent asthma. The researchers asked the patients about their weight, height, smoking habits, other illnesses, treatment and their asthma-specific quality of life, asthma control and asthma-related hospitalizations.

"The big finding here is that even after adjusting for risk factors, obese adults were nearly five times more likely to be hospitalized for their asthma," said study lead author David M. Mosen, Ph.D., MPH, of the Kaiser Permanente Center for Health Research. "Given that nearly 30 percent of our country is obese, this study is yet another example of the long-term dangers of obesity, along with heart disease, diabetes, stroke and dementia."

The study uncovered these findings:
• Obese people with asthma had significantly worse asthma control, lower asthma-related quality of life, and had 4.6 times higher risk for asthma-related hospitalizations than non-obese asthmatics
• Obese people with asthma were younger and less educated than non-obese people with asthma
• Obese people with asthma used more oral corticosteroids
• Obese people with asthma had a higher incidence of gastroesophageal reflux disorder.

"The take-home message of this study for clinicians is that obese people with asthma need to be followed more carefully because it's harder to control their asthma, so they are more likely to end up in the hospital," said study co-author Dr. Michael Schatz, Chief of Allergy at Kaiser Permanente San Diego Medical Center. "My advice for obese asthmatics is: be vigilant to keep your asthma symptoms in check, make sure you know what to do when your symptoms worsen, and do whatever you can to lose weight."

Funded by the Centers for Disease Control and Prevention, the study was authored by David M. Mosen, Ph.D., MPH of the Kaiser Permanente Center for Health Research; Michael Schatz, MD, MS, of Kaiser Permanente San Diego Medical Center; David J. Magid, MD, of the Kaiser Permanente Institute for Health Research in Denver; and Carlos A. Camargo, Jr, MD, DrPH, of the Department of Emergency Medicine, Massachusetts General Hospital and Harvard Medical School.