Sleep-disordered breathing and metabolic dysregulation in obese children before and after weight loss

Introduction: A high prevalence of sleep-disordered breathing (SDB) is found in childhood obesity. SDB is a known risk factor for developing the metabolic syndrome. Weight loss has been suggested to be the treatment of choice in obese children. Aim: In this study we focused on the effects of weight loss and SDB on common metabolic parameters. Methods: Consecutive obese children between 10 and 18 years were recruited. They followed a treatment program with diet, increased physical activity and psychological support. All children underwent a baseline sleep screening and a control study after 4-6 months of treatment in case of diagnosed SDB. A fasting blood assay was performed baseline and after 4-6 months. Results: 84 children and adolescents with a median age of 15.1 years (9.5-18.9) were included. Mean BMI z-score was 2.73±0.41. 44% of the subjects had SDB. Respiratory disturbance index correlated with HDL-cholesterol (r=-0.34; P =0.002), ASAT (r=0.33; P =0.003) and ALAT (r=0.35; P =0.001). No correlations were found for glucose, triglycerides and total cholesterol. After weight loss treatment all metabolic parameters improved and only 8% of the patients had residual SDB. Improvements in ASAT and ALAT were mediated by improvements in BMI. Improvements in oxygen desaturation index (ODI) were associated with an increase in HDL-cholesterol (r=0.49; P =0.003). Conclusion: This study confirms the link between ASAT, ALAT, HDL-cholesterol and SDB baseline. HDL-cholesterol improved after weight loss in association with improvements in ODI.