Obesity Doubles Severe Asthma Risk

Vol. 20 •Issue 14 • Page 25
Inside Industry

Obesity Doubles Severe Asthma Risk

Obese people are significantly more likely to have persistent or severe asthma than are their thinner counterparts, according to a new study of more than 5,700 adult asthmatics.

Researchers from Emory Crawford Long Hospital in Atlanta presented their findings at the American Thoracic Society International Congress last month in San Francisco that people with a BMI of 30 or more are 66 percent more likely to have asthma symptoms than people with a lower BMI.

Furthermore, obese people were 47 percent less likely to be in remission from asthma, 52 percent more likely to have severe persistent asthma than non-overweight people and 36 percent more likely to miss more than two days of work annually due to asthma.

“There have been a number of studies on obesity and asthma prevalence, but until now there have been little data on obesity and asthma severity,” said lead researcher Brian Taylor, MD.

He noted this study took data from the National Asthma Survey, which includes 5,741 asthmatics, allowing the researchers with enough data to adjust for other factors such as gender, race, income and employment status and ensure that these factors were not playing a role in the results.

Like other studies, the Emory team found a strong relationship between asthma and obesity. “A big part of that is simply that 70 percent of the study subjects were women. We did find a statistically significant association between obesity and asthma severity in men too.”

It’s still not known why asthma and obesity are linked, but the hormone leptin may play a role. The hormone produces fat cells and regulates body weight.

A recent review of studies, which was published in the ATS’s own American Journal of Respiratory and Critical Care Medicine suggested that asthma incidence could be reduced by interventions targeting overweight and obesity.

Taylor et al. currently are studying whether patients who undergo bariatric surgery experience an improvement in airway function compared with obese patients.

OSA May Increase Risk of Diabetes

Just in case hypertension, obesity, heart disease and stroke weren’t enough, obstructive sleep apnea patients can add another disease to the list for which they face an increased risk–Type II diabetes.

Researchers at the Yale University School of Medicine in New Haven, Conn., followed 593 patients who were referred for evaluation of sleep-disordered breathing. The study was carried on over six years within the VA Connecticut Health Care System.

Those diagnosed with OSA had more than two-and-a-half times the risk of developing diabetes compared with those without the nighttime breathing disorder. The patients were then divided into groups based on the severity of their sleep apnea, and the more severe a patient’s sleep apnea, the greater the risk of developing diabetes.

“Our next step will be to determine whether the treatment of sleep apnea can improve an individual’s diabetic parameters and consequently the negative health effects of diabetes,” said researcher Nader Botros, MD. The Yale team presented its findings at the American Thoracic Society’s International Congress in San Francisco last month.

Although it is not known exactly what the link is between sleep apnea and diabetes, sleep apnea is thought to activate the body’s fight-or-flight response, including a production of high levels of the hormone cortisol that ultimately leads to insulin resistance and glucose intolerance, common pre-diabetic conditions.

“The impact of diabetes on public health is great,” Botros noted. “New approaches are needed to better understand the risk factors for diabetes in order to develop additional preventive strategies. Understanding the link between sleep-disordered breathing and diabetes may represent one such approach.”

Botros added that diet and exercise, along with medication, are the mainstays of treatment; but diabetes remains a major public health threat.