Study objectives: To evaluate the effects of a 2-year weight reduction program on respiratory disturbances, arousal index, daytime sleepiness, metabolic status, and quality of life in obese patients with obstructive sleep apnea syndrome (OSAS).
Methods: Prospective intervention study of 33 consecutive obese OSAS patients (24 men, 9 women); 19 subjects used continuous positive airway pressure and 4 used mandibular retaining device, except during nights with sleep recording. The program consisted of 8 weeks of low calorie diet followed by group meetings with behavioral change support.
Results: Seventy percent of the patients completed the program; 67% completed the sleep recordings. The success rate for the apnea-hypopnea index (AHI) (< 20 and reduction > or = 50%) was 15% in the intention to treat (ITT) analysis. The AHI showed a nonsignificant decrease in mean values, from 43 to 28. The oxygen desaturation index (ODI) decreased from 42 to 23 (p = 0.010), arousal index from 24 to 11 (p = 0.019), body mass index from 40 to 35 (p = 0.003) and the Epworth Sleepiness Scale (ESS) from 9 to 5 (p = 0.026), all ITT. Metabolic status, physical functioning, and vitality evaluations improved only in the per protocol analysis. Reduction in weight correlated significantly to reductions in ESS (p = 0.038) and insulin levels (p = 0.002), respectively. There were no differences based on gender or use/non-use of OSAS treatment device.
Conclusions: Our weight reduction program showed a limited success in reducing AHI. However, there were significant improvements in weight, ODI, arousal index, and subjective symptoms. We recommend the program as an adjunct treatment for well-motivated obese OSAS patients.