Surgical vs Conventional Therapy for Weight Loss Treatment of Obstructive Sleep Apnea

Study Questions:

Is surgically induced weight loss more effective than conventional weight loss therapy in the management of obstructive sleep apnea (OSA)?


This was a randomized controlled trial of 60 obese patients (body mass index [BMI], >35 and <55 kg/m2) with recently diagnosed (<6 months) OSA and an apnea-hypopnea index (AHI) of 20 events/hour or more. These patients had been prescribed continuous positive airway pressure (CPAP) therapy to manage OSA and were identified via accredited community sleep clinics. The trial was conducted between September 2006 and March 2009. Patients were randomized to a conventional weight loss program that included regular consultations with a dietitian and physician, and the use of very low-calorie diets as necessary (n = 30), or to bariatric surgery (laparoscopic adjustable gastric banding; n = 30). The primary outcome measure was the change in AHI, as measured by polysomnography from baseline to 2 years.


Mean age was 48 years, 58% were male, mean BMI was 44 kg/m2, AHI was 61 events/hour, and 33% were diabetics. Patients lost a mean of 5.1 kg (95% confidence interval [CI], 0.8-9.3 kg) in the conventional weight loss program compared with 27.8 kg (95% CI, 20.9-34.7 kg) in the bariatric surgery group (p < 0.001). The AHI decreased by 14.0 events/hour (95% CI, 3.3-24.6 events/hour) in the conventional weight loss group and by 25.5 events/hour (95% CI, 14.2-36.7 events/hour) in the bariatric surgery group. The between-group difference was −11.5 events/hour (95% CI, −28.3 to 5.3 events/hour; p = 0.18). CPAP adherence did not differ between the groups. The bariatric surgery group had greater improvement in the Short Form-36 physical component summary score (mean, 9.3; 95% CI, 0.5-18.0; p = 0.04).


Among a group of obese patients with OSA, the use of bariatric surgery compared with conventional weight loss therapy did not result in a statistically greater reduction in AHI despite major differences in weight loss.


Considering the difference in weight loss over the 2 years of follow-up (12 lbs or 4% with conventional weight loss versus 60 lbs or 20% in the surgical group), the results don’t make sense, and suggest it was due to inadequate sample size. Further support of that conjecture is that an AHI of <15 events/hour, which indicates mild OSA, was achieved by eight in the surgical group (27%) and only two in the conventional group (7%) (p = 0.04). Against is that scatterplots of change in weight and AHI by absolute and percentage change demonstrated an attenuated benefit beyond the first 8-10% or 10 kg of weight loss. The latter suggests that if the only indication for weight loss is treatment of OSA, mild to moderate weight loss may be adequate.

Clinical Topics: Heart Failure and Cardiomyopathies, Prevention, Diet, Sleep Apnea

Keywords: Bariatric Surgery, Food Habits, Global Health, Weight Loss, Body Weight, Sleep Apnea Syndromes, Caloric Restriction, Body Mass Index, Weight Reduction Programs, Obesity, Morbid, Cardiology, Continuous Positive Airway Pressure, Diet, Nutritionists, Sleep Apnea, Obstructive, Diabetes Mellitus

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