Abdominal obesity, waist circumference, body mass index, and echocardiographic measures in children and adolescents.

Background: Waist circumference (WC) may predict cardiovascular risk better than body mass index (BMI) in adults. The relationships between WC and echocardiographic measurements known to predict adult cardiovascular risk have not yet been explored in children.

Objective: This investigation sought to investigate whether WC predicts echocardiographic measures of cardiac structure and function and whether WC is a better predictor of these outcomes than BMI. If associations between WC and measures of diastolic function are found, are they due to increased left ventricular (LV) mass and whether WC and LV mass have synergistic or antagonistic effects on measures of diastolic function?

Methods: A total of 49 clinically normal children aged 3-19 years, including 17 with abdominal obesity, underwent detailed echocardiographic assessment to explore the associations between WC and various indices of systolic and diastolic function. Correlations, t-tests, and linear regressions were used for statistical testing. Results. Compared to subjects without abdominal obesity, those with abdominal obesity had increased left atrial dimensions, posterior wall thickness, and left ventricular (LV) mass index(2.7) (P < .05 for each comparison). Those with abdominal obesity also had altered LV filling patterns at the septal, lateral, and inferior wall by Doppler tissue imaging. WC was the sole predictor of, and was negatively associated with, the ratios of early peak velocity/late peak velocity at the septum, inferior wall, and right ventricle, and these associations were independent of LV mass (P < .001 for each comparison). Both BMI and WC were independent predictors of left ventricular mass index(2.7) (P= .001 and P= .05, respectively).

Conclusions: Otherwise normal children and adolescents with abdominal obesity had altered left ventricular diastolic function. These differences were often better predicted by WC than by BMI. Our findings suggest the importance of considering WC in future studies of the cardiovascular impact of childhood obesity.