Insulin Resistance and Clustering of Cardiometabolic Risk Factors in Urban Teenagers in Southern India

Abstract

Objective To study the occurrence of cardiometabolic risk variables, their clustering and association with insulin resistance among healthy adolescents in urban south India.

Research Design and Methods School children aged 12 -- 19 years (n = 2640, Boys : Girls, 1323 : 1317) from diverse socio-economic background were studied. Demographic, social and medical details were obtained; anthropometry and blood pressure were measured. Fasting plasma glucose, insulin and lipid profile were measured. Clusters of risk variables were identified by factor analysis. Association of insulin resistance (Homeostasis Model Assessment (HOMA-IR)), with individual risk variables and their clusters were assessed.

Results One or more cardiometabolic abnormalities (i.e. low high density lipoprotein --cholesterol (HDL-C), elevated triglycerides, fasting plasma glucose or blood pressure) were present in 67.7%,64.8% among normal weight and in 85% of overweight children. Insulin resistance was associated with the above abnormalities except HDL-C. It also showed significant positive association with BMI, waist circumference (WC), body fat percentage and total cholesterol (p < 0.0001). Factor analysis identified three distinct clusters: (a) WC and blood pressure; (b) dyslipidemia, WC and insulin (c) WC, 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.

Conclusion Cardiometabolic abnormalities are present in nearly 68% of young healthy Asian Indian adoloscents, and even among children with normal weight. Insulin resistance is associated with individual cardiometabolic factors and plasma insulin showed association with clustering of some variables.