A Randomized Controlled Study to Examine the Effect of a Lifestyle Modification Program inOSA

Susanna S. S. Ng, MBChB, FCCP; Ruth S. M. Chan, PhD; Jean Woo, MD; Tat-On Chan, MPhil; Bernice H. K. Cheung, RD; Mandy M. M. Sea, PhD; Kin-Wang To, MBChB; Ken K. P. Chan, MBChB; Jenny Ngai, MBChB; Wing-Ho Yip, MBChB; Fanny W. S. Ko, MD, FCCP; David S. C. Hui, MD, FCCP

BACKGROUND: Obesity is an important risk factor for OSA. This study aimed to assess the effect of weight reduction through a lifestyle modification program (LMP) on patients with moderate to severe OSA.

METHODS: This was a parallel group, randomized controlled trial. Altogether, 104 patients with moderate to severe OSA diagnosed on portable home sleep monitoring were randomized to receive a dietician-led LMP or usual care for 12 months. The primary outcome was reduction of apnea-hypopnea index (AHI) at 12 months as assessed by portable home sleep monitoring.

RESULTS: In the intention-to-treat analysis (ITT), LMP (n = 61) was more effective in reducing AHI from baseline (16.9% fewer events in the LMP group vs 0.6% more events in the control group, P = .011). LMP was more effective in reducing BMI (−1.8 kg/m2, 6.0% of the initial BMI; −0.6 kg/m2, 2.0% of the initial BMI in control group; P < .001). The reduction in daytime sleepiness as assessed by Epworth Sleepiness Scale was not significant in ITT but was more in the LMP group (−3.5 in the LMP group vs −1.1 in the control group, P = .004) by treatment per protocol analysis. There was modest improvement in mental health in the Short Form Health Survey. Eating behavior was improved with increased intake of protein and fiber. These changes were observed 4 months after the initial intensive diet counseling and persisted at 12 months.

CONCLUSIONS: LMP was effective in reducing the severity of OSA and daytime sleepiness. The beneficial effect was sustained in 12 months.

Chest. 2015;148(5):1193-1203. doi:10.1378/chest.14-3016