Relation of insulin resistance and body size in adolescence to birthweight

Abstract

P04 A relationship between birthweight (BW) and the insulin resistance syndrome has been reported in adults but has not been defined in adolescents. Data were analyzed in 287 children (124 girls, 163 boys) mean age 15.0 ±1.2 yrs undergoing euglycemic insulin clamp studies (intravenous administration of 1mU/kg/min of insulin balanced by a variable infusion of 20% glucose to maintain blood glucose at 100 mg/dl). Insulin sensitivity (M) was determined by glucose uptake during the final 40 minutes of the 3 hr clamp per kg body weight. BW was reported by parents. BW ranged from 1021-4848g (mean, 3403 ±573), with 5.4% of BW < 2500g. Height increased with BW (r=0.3, p<0.0001). Fat mass and BMI had U-shaped relations with BW after adjustment for ethnicity, age, sex, and blood pressure, but lean body mass was not signficantly different between BW quartiles ( Table). Fasting insulin was positively, and M inversely, related to fat mass (r=0.55,and r=-0.45 respectively p<0.0001). After further adjustment for body weight, fasting insulin was highest (p= 0.009) and M lowest (p=0.17) in the lowest BW quartile. Triglycerides, HDL-C, LDL-C and blood pressure were unrelated to BW. In these data, insulin resistance in adolescence is higher with low BW and increased body fat. In addition, fat mass is increased in both high and low BW in adolescence. Thus both high and low BW are potential risk factors for the development of adult cardiovascular disease and insulin resistance syndrome. Table 1.