Effect of obesity on echocardiographic parameters in children.

We studied the effect of obesity on echocardiographic parameters in Japanese children. The subjects were 341 children: 106 first graders (age 6 years), 166 seventh graders (age 12 years), and 69 tenth graders (age 15 years). They were assigned to six groups according to school grade and sex. Echocardiographic parameters included thickness of the interventricular septum and of the posterior wall, end diastolic left ventricular internal dimension, and left ventricular mass. Left ventricular parameters were normalized for height, and for height to the power of 2.7. The obesity index as well as the body mass index were used to estimate obesity, because the obesity index is frequently used in Japan. There were significant correlations between the indices of obesity and left ventricular internal dimension or left ventricular mass in each group. The obesity index was more strongly correlated than the body mass index with posterior wall thickness and left ventricular internal dimension. For normalization of left ventricular parameters, correction for height was better for the first graders, whereas correction for height to the power of 2.7 was better for seventh and tenth graders. The most important finding was that the effect of obesity on left ventricular parameters was evident at 6 years of age.