Influence of insulin resistance and body mass index at age 13 on systolic blood pressure, triglycerides, and high-density lipoprotein cholesterol at age 19.

The association of insulin resistance and body mass index (BMI) at age 13 years and change in insulin resistance and BMI from ages 13 to 19 years with systolic blood pressure, triglycerides, and high-density lipoprotein cholesterol at age 19 years was studied in black and non-Hispanic white children. Insulin clamps were conducted at mean ages 13 (N=357), 15 (N=309), and 19 (N=224) years with insulin resistance adjusted for lean body mass. A repeated-measures multiple regression model was used to predict the 3 risk factors and the clustering of the factors with fasting insulin (the insulin resistance [metabolic] syndrome score) at age 19 years from levels of insulin resistance and BMI at age 13 and their changes from ages 13 to 19 years. The tracking correlation between ages 13 and 19 was 0.85 for BMI and 0.42 for insulin resistance. It was 0.18 for fasting insulin (P=0.01) and P=0.11 after adjustment for BMI. In a multiple regression analysis, BMI at 13 years did not predict any of the risk factors at age 19; change in BMI predicted all 3 of the factors and score; insulin resistance at 13 years predicted systolic blood pressure, triglycerides, and score; change in insulin resistance predicted triglycerides and score. These results show an effect for insulin resistance that is independent of BMI, consistent with the hypothesis that reducing insulin resistance, in addition to weight, may be needed to reduce the prevalence of cardiovascular risk.