A diet and exercise program to improve clinical outcomes in patients with obstructive sleep apnea--a feasibility study

Abstract

Study objectives: To assess the feasibility and efficacy of a novel 16-week exercise and diet program for important clinical outcomes in obstructive sleep apnea (OSA).

Methods: Cohort study assessing sleep disordered breathing, cardiovascular risk factors, and neurobehavioral function prior to and following completion of the 16-week program. The program used a proprietary very low energy diet (Optifast, Novartis), and subjects participated in a supervised exercise schedule, which included both aerobic and resistance training. Follow-up contact was made at 12 months after program exit. Consecutive patients with newly diagnosed sleep apnea were approached who had an apnea-hypopnea index (AHI) of 10 to 50, a body mass index (BMI) of greater than 30 kg/m2, no significant comorbidities, and able to exercise.

Results: All data are presented as mean [SD]. Of 21 patients with OSA who were approached, 12 middle-aged (42.3 [10.4] years old), obese (BMI 36.1 [4.3] kg/m2), and predominantly female (75%) subjects with mild to moderate OSA were enrolled (AHI 24.6 [12.0]). Weight loss was significant (12.3 [9.6] kg, p <0.001), and 5 of the 10 who completed the program were able to independently maintain good weight loss at 12 months. At the 16-week assessment, there was a small nonsignificant fall in the AHI. Six of the 10 subjects had a reduction in sleep disordered breathing, and the AHI was less than 10 in 3 patients. There were significant improvements in neurobehavioral and cardiometabolic outcomes. Snoring improved in most subjects, but the improvement was clinically important (a score of < 2) in only 7.

Conclusions: A supportive diet and exercise program may be of benefit to obese patients with mild to moderate sleep apnea. The results of this feasibility study showed significant weight loss and improvement in clinically important neurobehavioral and cardiometabolic outcomes but no significant change in sleep disordered breathing. These promising preliminary results need confirmation with a larger randomized trial.

Figure 1

The diet consisted initially of 3 very low energy meals per day, reducing to 2 meals per day, and then provided as only breakfast as subjects were educated on the replacement of these meals with low-calorie home-prepared meals. The exercise program consisted of both resistance and aerobic training, a minimum of 5 sessions per week. Initially, 3 of these sessions were supervised in the hospital gymnasium; the number of supervised sessions was gradually reduced as subjects were educated about exercise in the community.

Figure 2

Weight loss was steady throughout the active program. Subjects gained some weight after exiting from the study, but overall weight loss was still significant.