More than 12 million people in the U.S. suffer from sleep apnea, most common among the overweight and obese. More than just loud snoring, it can lead to high blood pressure, stroke, cardiovascular disease and a poor quality of life. For years, doctors have told patients with sleep apnea that their best bet for alleviating it would be to lose weight, but there's been very little research-based evidence to prove that.
"Existing research has been limited by a number of factors, so there are very few studies that show whether the recommended amount of weight loss - about 10 percent - is enough to sufficiently improve sleep apnea," said Gary Foster, director of the Center for Obesity Research and Education.
Foster and colleagues from six other universities recently completed the largest randomized study on the effects of weight loss on sleep apnea in patients with type 2 diabetes. They found that among patients with severe sleep apnea, those who lost the recommended weight were three times more likely to nearly eliminate the number of sleep apnea episodes compared to those who did not lose weight. The results are published in the Sept. 28 issue of the Archives of Internal Medicine.
The new study, called Sleep AHEAD, looked at 264 obese patients with type 2 diabetes already enrolled in the Look AHEAD trial, an ongoing 16-site study investigating the long-term health impact of an intensive lifestyle intervention in 5,145 overweight or obese adults with type 2 diabetes. Participants were between 45 and 75 years old.
The 264 participants were broken into two randomized groups: the first received a group behavioral weight loss program developed especially for obese patients with type 2 diabetes, portion-controlled diets, and a prescribed exercise regimen of 175 minutes per week. The second attended three group informational sessions over a one-year period that focused on diabetes management through diet, physical activity and social support.
After one year, members of the first group lost an average of 24 pounds. More than three times as many participants in this group had complete remission of their sleep apnea (13.6 percent compared to 3.5 percent), and also had about half the instances of severe sleep apnea as the second group. Further, participants in the second group only lost about a pound, and saw significant worsening of their sleep apnea, which suggested to Foster and his team that without treatment, the disorder can progress rapidly.
"These results show that doctors as well as patients can expect a significant improvement in their sleep apnea with weight loss," said Foster, the study's lead author. "And a reduction in sleep apnea has a number of benefits for overall health and well-being."
Other authors on the study were Kelley Borradaile, from Temple; Mark Sanders, Anne Newman and David Kelley, from the University of Pittsburgh; Richard Millman and Rena Wing, from Brown University; Gary Zammit, from Clinilabs; Thomas Wadden and Samuel Kuna, from the University of Pennsylvania; F. Xavier Pi Sunyer, from Columbia University; David Reboussin, from Wake Forest University, and the Sleep AHEAD Research Group. Funding was provided by grants from the National Heart, Lung, and Blood Institute and the National Institute of Diabetes and Digestive and Kidney Diseases, both part of the National Institutes of Health.