Insulin resistance and clustering of cardiometabolic risk factors in urban teenagers in southern India

OBJECTIVE - We sought to study the occurrence of cardiometabolic risk variables, their clustering, and their association with insulin resistance among healthy adolescents in urban south India. RESEARCH DESIGN AND METHODS - School children aged 12-19 years (n = 2,640; 1,323 boys and 1,317 girls) from diverse socioeconomic backgrounds were studied. Demographic, social, and medical details were obtained; anthropometry and blood pressure were measured. Fasting plasma glucose, insulin, and lipid profiles were measured. Clusters of risk variables were identified by factor analysis. Association of insulin resistance (homeostasis model assessment) with individual risk variables and their clusters were assessed. RESULTS - One or more cardiometabolic abnormalities (i.e., low HDL cholesterol, elevated triglycerides, fasting plasma glucose, or blood pressure) was present in 67.7% of children (in 64.8% of normal weight and 85% of overweight children). insulin resistance was associated with the above abnormalities except HDL cholesterol. It also showed significant positive association with BMI, waist circumference, body fat percentage, and total cholesterol (P < 0.0001). Factor analysis identified three distinct clusters, with minor differences in the sexes: 1) waist circumference and blood pressure; 2) dyslipidemia, waist circumference, and insulin and 3) waist circumference, glucose, and plasma insulin, with minor differences in the sexes. Insulin was a component of the lipid and glucometabolic cluster. In girls, it was a component of all three clusters. CONCLUSIONS - Cardiometabolic abnormalities are present in nearly 68% of young, healthy, Asian-Indian adolescents and even among those with normal weight. Insulin resistance is associated with individual cardiometabolic factors, and plasma insulin showed association with clustering of some variables.