An American College of Cardiology study examines the effectiveness of weight reduction in reducing respiratory events in patients with obstructive sleep apnea.
Consecutive study subjects were recruited from patients referred for suspicion of sleep apnea. All were age 30-80 years, with moderate to severe OSA (apnea-hypopnea index [AHI] >15 events/hour) and body mass index (BMI) >25 kg/m2. Exclusions included coexisting sleep disorders, mild OSA, pregnant women, and history of surgery to treat OSA. OSA status was assessed with home sleep monitoring. Patients were randomized 1:1 to participate in a lifestyle modification program (LMP) or usual care for 1 year. The intervention group participated in a dietitian led LMP with weekly dietary consultation for 16 weeks. A 10-20% caloric reduction was set as a general initial goal. Control group patients received lifestyle advice from a clinician at baseline and 6 months.
A total of 185 Chinese patients were screened and 104 (61 intervention, 43 controls) were included in the final analysis. Baseline characteristics were similar in the two groups. The intervention group reduced AHI from baseline 16.9% versus 0.6% more events in the control group (p = 0.011). The intervention group also reduced BMI compared to controls (-1.8 kg/m2 vs. -0.6 kg/m2 of the initial BMI, p < 0.001) as well as reduced the Epworth Sleepiness Scale score (-3.5 vs. -1.1 intervention, control, p = 0.004).