Differences in the in vivo insulin secretion and sensitivity of healthy black versus white adolescents

Fourteen black and 16 white healthy adolescents underwent a 2-hour hyperglycemic clamp (12.5 mmol/L) to investigate racial differences in insulin secretion and sensitivity. First-phase and second-phase insulin concentrations were higher in black subjects than in white subjects (first phase: 944 +/- 110 pmol/L vs. 462 +/- 52 pmol/L, p = 0.0003; second phase: 1050 +/- 146 pmol/L vs. 652 +/- 53 pmol/L, p = 0.0012). The insulin sensitivity index was lower in black adolescents (8.21 +/- 1.05) compared with white adolescents (12.55 +/- 1.42 mumol/kg per minute per picomole per liter, p = 0.02). These findings indicate that significant differences in insulin secretion and sensitivity are detectable in healthy black versus white adolescents.