The more you weigh, the less you may be able to breathe. New research suggests that overweight and obese individuals in Dallas, Houston and throughout Texas are 50 percent more likely to develop asthma than normal-weight men and women. Public health efforts to control asthma should therefore emphasize the importance of healthy weight management, the study researchers reported.
“The bottom line is that being overweight appears to significantly increase the risk of asthma,” said study co-author Dr. E. Rand Sutherland, of the National Jewish Medical and Research Center (NJMRC) in Denver. “But the caveat is that, until further studies are done, it won’t be clear exactly what type or severity of asthma is present in obese people.”
According to the U.S. National Institutes of Health, asthma is an incurable but usually controllable chronic disease involving inflammation and narrowing of the airways that carry oxygen into and out of the lungs. The disease, which affects approximately 20 million Americans, including 9 million children, typically provokes recurrent wheezing, coughing, and a hypersensitivity to allergies.
A recent national survey found that about 65 percent of Americans are either obese or overweight, and research has long suggested links between asthma and obesity. In this study, researchers pored over prior data on the body mass indices (BMI) — measurements of body fat based on the height and weight — of adult asthma patients. They looked at data from seven prior studies conducted between 1966 and 2006 in the United States, Canada, and Europe. Together, these studies had looked at the relationship between BMI and asthma in more than 333,000 severely asthmatic patients.
During data review, the study adopted standard BMI yardsticks, which define “normal weight” as having a BMI of under 25, “overweight” as a BMI between 25 and 29, and “obese” as a BMI more than 30. For example, a person who is 5 feet 6 inches tall and weighs 145 pounds has a BMI of 22.
The odds of developing asthma grew by 50 percent among patients with a BMI of 25 and up, and the risk climbed as the pounds piled on, the study found. Women and men appeared to be equally susceptible to the weight-asthma association, they added.
Based on the findings, the researchers believe asthma should be added to the long list of diseases — including diabetes, sleep apnea, stroke, cardiovascular illness, and arthritis — for which excess weight is a risk factor.
And, because two-thirds of the U.S. adult population is now thought to be obese or overweight, that means millions more Americans may be at risk of developing asthma than was previously thought, the study reported. On the up side, “significant weight loss” could potentially reduce asthma cases by as many as 250,000 each year, the researchers noted.
Not every overweight person with respiratory symptoms necessarily has asthma, however. The experts noted that excess weight can cause lung volume reduction, chest wall restriction, and breathlessness unrelated to the disease.