Sleep apnea after 1 year domiciliary nasal-continuous positive airway pressure and attempted weight reduction - Potential for weaning from continuous positive airway pressure

Study objective: To assess the effect of 1 year of therapy for sleep apnea syndrome (SAS) combining domiciliary nasal-continuous positive airway pressure (N-CPAP) and attempted weight loss on the severity of disease and to evaluate the potential for weaning from continuous positive airway pressure (CPAP). Methods and procedures: Ninety-five patients having a baseline apnea hypopnea index (AHI) greater than 10/h were prescribed N-CPAP at home. Weight loss was attempted by dietary counseling and by single ring vertical gastroplasty in those patients with a body mass index (BMI) greater than 40 kg/m(2). Subjects were asked to return after 1 year for a full-night polysomnography (PSG) without CPAP and the results were compared with baseline PSG. Results: Thirty-nine patients compliant to CPAP were evaluated. Weight had decreased from 108.3+/-29.0 to 99.7+/-17.7 kg as a result of dietary counseling (n=36) or gastroplasty (n=3). A significant improvement was found in AHI (66.5+/-28.7 --> 50.3+/-38.4/h; p<0.05), maximal duration of apnea or hypopnea (66+/-22 --> 47+/-18 s; p<0.001), minimal oxyhemoglobin saturation (62+/-16 --> 78+/-7%; p<0.001), and stage shift index (SSI) (76+/-29 --> 62+/-28/h; p<0.05). The drop in AHI correlated with the reduction in BMI (r=0.47; p<0.01) and with the decrease in SSI (r=0.50; p<0.001). Weaning from CPAP was proposed to six patients and succeeded in four (three with 29, 93, and 94 kg weight loss, respectively, and one subject with a normal unchanged weight). Conclusion: In 39 patients with SAS, 1-year domiciliary N-CPAP combined with weight loss resulted in a significant improvement in breathing during sleep and in sleep fragmentation, as judged from PSG without CPAP. Four subjects were successfully weaned, three of whom had in parallel a substantial decrease in weight.