0897 SLEEP-DISORDERED BREATHING, SLEEP ARCHITECTURE AND CARDIOMETABOLIC RISKS: EFFECTS OF WEIGHT LOSS INDUCED BY LONG-TERM EXERCISE TRAINING AND MODIFIED FOOD HABITS IN OBESE YOUTH

Abstract

Introduction: The relationships between sleep-disordered breathing (SDB) and cardiometabolic comorbidities in paediatric population are currently of major interest. It is well accepted that lifestyle modification based on an increased physical activity and healthy diet is useful as therapeutic treatment to manage obesity and its cardiometabolic risks (CMR). However, it remains unknown whether a weight reduction, achieved by both long-term exercise training and modified dietary habits improves sleep architecture, decreases SDB and CMR. The aim of this study was therefore to assess in obese adolescents; (i) the association between SDB and CMR and (ii) the effects of a 9-month lifestyle intervention (physical activity and balanced diet) on these parameters and sleep architecture. Method(s): Twenty-nine subjects (14.6 +/- 1.3 years, BMI zscore = 4.7 +/- 0.9) were studied. Before and after the lifestyle intervention, several assessments were performed: (i) standard overnight ambulatory polysomnography during which total sleep time (TST), %REM, %NREM stages, apnea-hypopnea index (AHI) and respiratory-disturbance index (RDI) have been recorded; (ii) MetScore, a CMR predictor, calculated from the average of the zscore of fasting insulin, glucose, triglycerides, HDL cholesterol, waist-circumference and blood pressures; (iii) CRP concentration; and (iv) fat mass. Result(s): The subjects were divided in two groups: G1: AHI < 2 (33.3%) and G2: AHI >= 2 (66.7%). At baseline, MetScore was higher in G2 (0.25) than G1 (-0.26). AHI and RDI were correlated with MetScore (r = 0.46 and r = 0.50, p < 0.05, respectively). Furthermore, CRP was associated with MetScore (r = 0.44, p < 0.05). At the end of the intervention, AHI and RDI were not decreased in G2 despite a decline of BMI z-score and fat mass. Conversely, MetScore and CRP were lower (-0.65, p < 0.001 and -4 mg/L, p < 0.05). In both group, TST was longer (G1: 479 min, G2: 489 min) than recorded during baseline night (G1: 455 min, G2: 450 min) with an increase of %REM and a decrease of %N3. Conclusion(s): This study showed a strong relation between SDB and CMR in adolescents with severe obesity. A combination of supervised aerobic exercises and a balanced diet lead to weight, CMR and systemic inflammation reduction without changes in SDB. Further investigations will be necessary to understand the association between changes in sleep architecture and weight loss.