Those who lost the weight also saw a substantial reduction in the number of sleep apnea episodes they experienced, with more than three times as many people in the intensive group experiencing complete remission (13.6 percent versus 3.5 percent).
"The greatest benefit was seen in men and those with severe apnea," Foster said.
Any amount of weight loss brought on an improvement, but those who lost about 10 percent of their original body weight saw the greatest effect. "Any weight loss is good," Foster said.
Most experts recommend 10 percent as the weight loss needed to improve sleep apnea.
However, the study also found that people whose weight remained stable experienced a worsening in their sleep apnea. Just why that occurred remains unclear.
"This is one of the first and certainly the largest study ever conducted so we're at the point in the field, unfortunately, where we're just describing the effect," Foster said.
The study, published Sept. 28 in the Archives of Internal Medicine, does seem to confirm what common sense and experience have shown.
"We've seen that when patients gain five to 10 pounds, their sleep apnea is much worse. If they lose five to 10 pounds, the sleep apnea is much better," said Dr. Hormoz Ashtyani, director of pulmonary critical care and sleep medicine at Hackensack University Medical Center in New Jersey. "It's usually not a resolution, but it's a significant improvement."
The U.S. National Heart, Lung and Blood Institute has more on sleep apnea.
SOURCES: Gary Foster, Ph.D., director, Center for Obesity Research and Education, and professor, medicine and p
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