Impact of CPAP on Activity Patterns and Diet in Patients with Obstructive Sleep Apnea (OSA)

Study Objectives: Patients with severe OSA consume greater amounts of cholesterol, protein, and fat as well as have greater caloric expenditure. However, it is not known whether their activity levels or diet change after treatment with CPAP. To investigate this issue, serial assessments of activity and dietary intake were performed in the Apnea Positive Pressure Long-term Efficacy Study (APPLES); a 6-month randomized controlled study of CPAP vs. sham CPAP on neurocognitive outcomes.

Methods: Subjects were recruited into APPLES at 5 sites through clinic encounters or public advertisement. After undergoing a diagnostic polysomnogram, subjects were randomized to CPAP or sham if their AHI was ≥ 10. Adherence was assessed using data cards from the devices. At the Tucson and Walla Walla sites, subjects were asked to complete validated activity and food frequency questionnaires at baseline and their 4-month visit.

Results: Activity and diet data were available at baseline and after 4 months treatment with CPAP or sham in up to 231 subjects (117 CPAP, 114 Sham). Mean age, AHI, BMI, and Epworth Sleepiness Score (ESS) for this cohort were 55 ± 13 [SD] years, 44 ± 27 /h, 33 ± 7.8 kg/m(2), and 10 ± 4, respectively. The participants lacking activity and diet data were younger, had lower AHI and arousal index, and had better sleep efficiency (p < 0.05). The BMI was higher among women in both CPAP and Sham groups. However, compared to women, men had higher AHI only in the CPAP group (50 vs. 34). Similarly, the arousal index was higher among men in CPAP group. Level of adherence defined as hours of device usage per night at 4 months was significantly higher among men in CPAP group (4.0 ± 2.9 vs. 2.6 ± 2.6). No changes in consumption of total calories, protein, carbohydrate or fat were noted after 4 months. Except for a modest increase in recreational activity in women (268 ± 85 vs. 170 ± 47 calories, p < 0.05), there also were no changes in activity patterns.

Conclusion: Except for a modest increase in recreational activity in women, OSA patients treated with CPAP do not substantially change their diet or physical activity habits after treatment. .