Overweight and obese children with sleep disordered breathing have elevated arterial stiffness.

BACKGROUND: The prevalence of obese children with sleep disordered breathing (SDB) is increasing. Obesity and SDB are independent cardiovascular risk factors, of which arterial stiffness is an early sign. Pulse wave velocity (PWV), is a marker of arterial stiffness and central systolic blood pressure (cSBP) is a better predictor of cardiovascular outcome than peripheral blood pressure. Therefore, we aimed to determine PWV and cSBP in overweight/obese or normal weight children with sleep disordered breathing (SDB), and non-snoring normal weight controls.

METHODS: Children (3-18 y) with SDB (overweight/obese [BMI z-scores ≥ 1.04], n = 48; normal weight n = 44) referred for clinical assessment of SDB and normal weight non-snoring controls recruited from the community (n = 38) underwent overnight polysomnography. PWV was calculated using photoplethysmography. cSBP was calculated using applanation tonometry in a subset of children older than 8 y (n = 55) who had usable waveforms.

RESULTS: Overweight/obese SDB group had higher PWV (mean cm/s (95% CI); wake: 366 (355-380); sleep: 340 (324-357)), than the normal-weight SDB group (wake: 257 (247-267), p = 0.002; sleep: 255 (242-269), p = 0.005), and non-snoring controls (wake: 238 (226-249), p = 0.002; sleep: 235 (220-250), p < 0.001). The normal-weight SDB group had higher PWV than controls (p = 0.03). Overweight/obese children with SDB had higher cSBP (105 (100-110) mmHg) compared with the normal weight children with SDB (96 (90-102)) and the non-snoring controls (97 (91-104); p < 0.05 for both).

CONCLUSION: This study suggests that overweight/obesity substantially worsens the cardiovascular sequelae of SDB, highlighting the imperative to treat obesity and SDB in children early in order to reduce future cardiovascular disease risk.