Obesity in teenagers is a risk factor for a number of conditions, including type 2 diabetes, high triglycerides, low HDL cholesterol, and hypertension, which places them at risk of developing heart disease as adults.

But they may not have to wait to face these devastating results. A study of 460 teenage American Indians found that heart abnormalities were already common in obese adolescents.

In the study, left ventricular hypertrophy (LVH, a thickening of the wall of the heart's left ventricle) was present in 12.4 percent of overweight teenagers and 33.5 percent of the obese teens, but in only 3.5 percent of adolescents whose weight was in the normal range.

In the study, LVH was accompanied by some heart abnormalities similar to those seen in heart failure, and a similar association between obesity and LVH has been identified in other adolescent populations.

High blood pressure and obesity are both important factors in the development of LVH in adults, and obesity in childhood predicts LVH in adults.

The increased heart size among the adolescents in this study could not be accounted for by high blood pressure and appeared to be greater than expected, probably due to the extra work the heart must do in a body of excessive weight.

The authors of an accompanying editorial suggested that the enlarged hearts of these teens may be due partly to growth-promoting effects of elevated insulin levels, which also are common in obese teenagers.

This finding of LVH in obese adolescents serves as yet another reason for parents to make every effort possible to control the weight of their children.

In my next entry, I'll discuss steps parents can take to help keep their children lean.