Medline ® Abstracts for References 14,29

STUDY OBJECTIVES: To examine whether the initial benefit of weight loss on obstructive sleep apnea (OSA) severity at 1 year is maintained at 4 years.

DESIGN: Randomized controlled trial with follow-up at 1, 2, and 4 years.

SETTING: 4 Look AHEAD clinical centers.

PARTICIPANTS: Two hundred sixty-four obese adults with type 2 diabetes and OSA.

INTERVENTIONS: Intensive lifestyle intervention with a behavioral weight loss program or diabetes support and education.

MEASUREMENTS: Change in apnea-hypopnea index on polysomnogram.

RESULTS: The intensive lifestyle intervention group's mean weight loss was 10.7±0.7 (standard error), 7.4±0.7, and 5.2±0.7 kg at 1, 2, and 4 years respectively, compared to a less than 1-kg weight loss for the control group at each time (P<0.001). Apnea-hypopnea index difference between groups was 9.7±2.0, 8.0±2.0, and 7.7±2.3 events/h at 1, 2 and 4 years respectively (P<0.001). Change in apnea-hypopnea index over time was related to the amount of weight loss (P<0.0001) and intervention, independent of weight loss (P = 0.001). Remission of OSA at 4 years was 5 times more common with intensive lifestyle intervention (20.7%) than diabetes support and education (3.6%).

CONCLUSIONS: Among obese adults with type 2 diabetes and OSA, intensive lifestyle intervention produced greater reductions in weight and apnea-hypopnea index over a 4 year period than did diabetes support and education. Beneficial effects of intensive lifestyle intervention on apneahypopnea index at 1 year persisted at 4 years, despite an almost 50% weight regain. Effect of intensive lifestyle intervention on apnea-hypopnea index was largely, but not entirely, due to weight loss.