Effect of Obstructive Sleep Apnea on Cardiovascular Function in Obese Youth

The increasing prevalence of overweight or obese children and adolescents is a significant global health concern. Although the effect of obesity on cardiovascular function has been investigated, little is known on the impact of associated obstructive sleep apnea (OSA) in obese youth. The aim of the present study was to investigate the influence of OSA on cardiovascular functional parameters in obese youth. This is a prospective single-center observational cross-sectional study. Forty-four obese patients and 44 age- and gender-matched control subjects were included. All patients underwent polysomnography and cardiovascular assessment including functional echocardiography and carotid-femoral pulse wave velocity (PWV). Obese patients had higher left ventricular (LV) mass/height^2.7, preserved LV systolic parameters, differences in LV diastolic parameters, and increased PWV and systolic blood pressure at rest compared with control group. In obese youth, 14 of 44 (32%) had OSA. There was no correlation between obesity and the apnea-hypopnea index (AHI). LV mass/height^2.7 significantly correlated with body mass index z-score (r = 0.648, p <0.001) whereas PWV correlated with AHI (r = 0.352, p = 0.038). In obese patients, body mass index z-score was an independent predictor for LV mass/height^2.7 (r = 0.61, p <0.001) and AHI was an independent predictor for higher PWV (r = 0.352, p = 0.038). In conclusion, both obesity and OSA influence cardiovascular performance in obese youth. Although obesity is associated with increased LV mass and reduced LV diastolic function, OSA is associated with changes in arterial stiffness.