Left ventricular hypertrophy in children from the upper five percent of the blood pressure distribution--the Odense Schoolchild Study.

Left ventricular structural dimensions were assessed by echocardiography in a group of 64 children aged 9-11 years with a mean blood pressure at or above the 95th percentile (HC-group) and in a group of 66 children randomly selected from the rest of the population (NC-group). Children in the HC-group were heavier, more obese, and less fit. Parental history of hypertension was more frequent in the HC-group. Calculated left ventricular mass (LVM), and LVM corrected for body surface area (LVMI), were significantly greater in the HC-group and in boys. Repeated echocardiographic examination in 57 of the children following 8 months of physical training revealed significant increases in posterior wall thickness and the posterior-wall-thickness-to-radius ratio. LVM increased significantly in the NC-group. Neither physical fitness nor change in physical fitness contributed independently to the variability in LVM following the training period. In children aged 9-11 years at increased risk of developing essential hypertension left ventricular hypertrophy is present.