The study found that obese adults were 66% more likely than adults of normal weight to have asthma. Current smokers were 29% more likely than people who never smoked to have asthma, while former smokers were 36% more likely to have asthma than those who never smoked.
The study, from the Centers for Disease Control and Prevention, using data from the 2000 Behavioral Risk Factor Surveillance System, also found that women were 94% more likely than men to have asthma.
“This study adds to the evidence that obesity and smoking are risk factors that play an important role in the prevalence of asthma,” said Charon Gwynn, Ph.D., Epidemic Intelligence Service Officer for the CDC. “Since these are also risk factors for a number of other diseases including heart disease and diabetes, this study provides even more incentive to maintain a normal weight and not smoke.”
Dr. Gwynn said that women were found to be at higher risk of having asthma if they were overweight or obese, or if they were current or former smokers.
“There are several possible theories as to why women are more likely to have asthma,” she said. “Hormonal factors may play a role in differences in asthma prevalence between men and women, or it may be due to the fact that women have smaller lungs and airways than men.”
The study also found that people in lower socioeconomic groups were 30 percent more likely to have asthma compared with those in higher socioeconomic groups. A state-by-state analysis of asthma prevalence found that overall, asthma prevalence was 7.2%, and ranged from 5% in Louisiana to 8.9% in Maine, with no discernable regional patterns.
Asthma is the one of the leading chronic conditions in the United States and one of the most common chronic illnesses of children in the U.S. It is also responsible for an estimated 14 million school days lost annually. Asthma is the third-ranking cause of hospitalization among children under the age of 15.
An estimated 26.3 million Americans have been diagnosed with asthma by a health professional within their lifetime. Overall, an estimated 10.5 million Americans (3.8 million children under 18) had an asthma attack in 1999.