W eight loss significantly improved mild obstructive sleep apnea, according to results of a study of overweight adults.
Obesity is a risk factor for obstructive sleep apnea (OSA), but no randomized trials have addressed whether weight reduction improves the condition, noted Dr. Henri P.I. Tuomilehto of the University of Kuopio (Finland), and colleagues.
In the study, they randomized 72 overweight adults with mild OSA to a program that included a very-low-calorie diet and supervised lifestyle modification, or to lifestyle counseling.
The intervention included instructions for a very-low-calorie diet and 14 visits with a nutritionist during a 1-year period (including face-to-face meetings and group sessions), as well as recommendations for increasing physical activity. No specific exercise program was included in the intervention.
Improvements in OSA were objectively measured using the apnea-hypopnea index (AHI), and subjectively measured using a quality of life scale and patient reports of symptom changes. All participants had a body mass index between 28 and 40 kg/m
At 1-year, the intervention group achieved significantly greater weight loss on average, compared with the controls (11 kg vs. 2 kg). The average total AHI in the intervention group was 6 events per hour, which was significantly less than the average of 9.6 events per hour in the control group (Am. J. Respir. Crit. Care Med. 2009;179:320-7).
A 5-kg weight loss from baseline body weight was associated with a 2.0-unit reduction in AHI, and a 5-cm reduction in waist circumference was associated with a 2.5-unit reduction in AHI.
“Significant improvements were also found in symptoms related to OSA, insulin resistance, lipids, and cardiorespiratory variable, such as arterial oxygen saturation, in patients belonging to the intervention group,” they wrote.
The researchers had no financial conflicts to disclose.