The Effect of Continuous Positive Airway Pressure on Basal Metabolism Rate in Patients with Severe Obstructive Sleep Apnoea Syndrome

Objective: To assess the effect of the continuous positive airway pressure (CPAP) treatment on basal metabolism rate (BMR) in patients with severe obstructive sleep apnoea syndrome (OSAS). Methods: Demographic characteristics, body mass index (BMI), apnoea-hypopnoea index (AHI) and smoking history of the patients were recorded. Basal metabolism rate was measured via indirect calorimetry in the morning following nights of polysomnography and CPAP titration. Basal metabolism rate, oxygen consumption (VO2) and carbon dioxide output (VCO2) levels were compared before and after CPAP administration. Results: A total of 25 patients with a mean age of 51.4 +/- 13.7 years were included in the study: 6 (24%) female and 19 (76%) male. A significant reduction in the BMR (p = 0.049), VO2 (p = 0.042) and VCO2 (p = 0.008) values were observed after a single night administration of CPAP as compared to before treatment. Furthermore, it was detected that this reduction provided by CPAP treatment was more significant in current smokers, patients with AHI > 60 and BMI >= 30. Conclusion: It is suggested that there is a correlation between BMR and the severity of OSAS, and it is possible to provide a significant reduction in BMR with single night administration of CPAP depending on the patient's smoking history, degree of obesity and disease severity.