Abstract
The objective of this study was to examine the differences in glucose and insulin responses between African–American and Caucasian youths and to determine the associations of between‐group differences with sex, body mass index (BMI) and pubertal status using a noncompartmental pharmacokinetic approach. Sixteen African–American and 22 Caucasian healthy adolescents were tested using the frequently sampled intravenous glucose tolerance test. Longitudinal t‐tests across each observation revealed that (1) African–American youths have higher insulin concentrations between 4 to 19 min; (2) insulin levels remained similar as subjects were grouped according to sex and pubertal status; (3) for glucose, the only difference was found as it approached steady‐state basal level (>100 min) between groups with different BMIs. Linear regression showed that insulin concentrations between 4 to 19 min are associated with BMI in Caucasians. African–American youths were found to have higher insulin responses after glucose stimulation and the insulin concentrations were more related to BMI in Caucasians compared with African–Americans. BMI also has a significant effect on the glucose steady state basal level. The acute insulin response to glucose (AIR~g~) extended to 20 min resulted in a more significant racial difference (p<0.0006) compared with the calculation done over 10 min suggested in the past (p<0.001). Copyright © 2009 John Wiley & Sons, Ltd.