Backgrounds and aims Several studies have stated the association between higher left ventricular mass and impaired systolic and diastolic function in obese adults. However, little is known in paediatric population. The aim of this study is to assess how early changes appear in obese and normotensive patients.

Methods Anthropometric and biochemical measurements were taken in 130 normotensive children, 88 with obesity (age 11.0 ± 2.8 years) and 42 with normal weight (age 11.1 ± 2.7 years). The function and left ventricular (LV) mass was assessed according to the formula of Devereux and indexed for height^2.7 to obtain left ventricular mass index (LVMI). The E/E’ value, quotient between transmitral early filling wave (E) and the average of the diastolic anular velocity (E’) was calculated for estimating the left ventricular filling pressure, therefore diastolic function.

Results The obese group showed higher levels of LVMI than control group (43.6 ± 14.2 g/m^2.7 vs 36.3 ± 13.3 g/m^2.7, p = 0.020), and higher levels of ratio E/E´ (6.03 ± 0.97 vs 7.24 ± 1.09, p < 0.001). The areas under the curve are 0.679 for LVMi and 0.757 for E/E’. Therefore, E/E’ parameter is more valid than LVMi with respect the excess of BMI. The cut-off point to E/E’ between obese and normal weight children was 6.55.

Conclusion In order to select one of the two main cardiac alterations found, diastolic function is a more sensitive/early finding than increased LV mass in obese normotensive children.