(RxWiki News) Patients who have obstructive sleep apnea are at higher risk for a range of health concerns. If the patient is obese, one way to improve symptoms of sleep apnea may be to lose weight.
A recent study found that patients with sleep apnea who lost weight saw their sleep apnea symptoms improve.
In fact, about one in five of the patients who lost weight no longer had sleep apnea four years after the study began.
The research group gained back about half the weight they had lost during the four-year study. However, their sleep apnea improvements remained.
"Lose weight to live healthy."
The study, led by Samuel T. Kuna, MD, of the University of Pennsylvania in Philadelphia, looked at whether long-term weight loss improves obstructive sleep apnea symptoms.
The researchers followed 264 obese adults, who had both type 2 diabetes and obstructive sleep apnea, for four years.
The participants underwent sleep studies so researchers could measure their sleep apnea symptoms at one year, two years and four years after the study began.
One group of 125 participants went through an in-depth behavioral weight loss program aimed at obese patients with type 2 diabetes.
They were told to restrict the portion sizes in their diets, including using liquid meal replacements and snack bars as diet aids.
They were also instructed to exercise three hours a week. They received regular lessons on how to adjust their behavior to lose weight through diet and exercise, and they received reminders twice a month in the second through fourth years of the study.
The other group of 139 participants attended three group sessions each year that provided information on a healthy diet, physical activity and social support. They were not provided with behavior strategies.
At the one-year follow-up, the group in the intensive program had lost an average 23.6 pounds.
They were still 16.3 pounds lighter than when they started at the two-year follow-up and 11.5 pounds lighter at the four-year follow-up.
Meanwhile, at all three follow-ups, the control group of participants who only attended the three annual sessions were less than 2 pounds lighter than they were at the start of the study.
The sleep apnea symptoms of the participants were measured with the apnea-hypopnea index (AHI). This index measures how many times patients stop breathing or slow their breathing considerably while asleep.
The score a person receives represents the number of times they stop breathing for at least 10 seconds or have a severe drop in blood oxygen for at least 10 seconds during one hour of sleep.
A score of 5 to 15 means the person has mild obstructive sleep apnea while a score of 15 to 30 is moderate and over 30 is severe.
The group who lost weight averaged 9.7 fewer points (better) on their AHI than the control group at the one-year follow-up.
At two years, the group in the intensive behavioral program had AHI scores an average 8 fewer points (better) than those who received only three annual sessions.
At four years, the group that lost weight still had an AHI of an average 7.7 fewer points (better) than the group who did not lose more than a pound or two.
The participants who experienced the intensive lifestyle intervention were five times more likely than the control group not to have sleep apnea anymore four years later.
At the four-year follow-up, 20.7 percent of the patients who were in the high weight loss group no longer had obstructive sleep apnea, compared to only 3.6 percent of the control group.
"Among obese adults with type 2 diabetes and obstructive sleep apnea, intensive lifestyle intervention produced greater reductions in weight and apnea-hypopnea index over a 4 year period than did diabetes support and education," the authors wrote.
Even though the participants in the behavioral intervention group gained back about half the weight they had lost, they continued to have better symptoms of sleep apnea.
The study was published in the May issue of the journal Sleep. The research was funded by the National Institutes of Health.
Seven authors reported links to various industry and pharmaceutical companies, including Philips Respironics, which manufactures machines for patients with sleep apnea. The other authors declared no potential conflicts of interest.