Hyperinsulinemia in African-American Adolescents Compared With Their American White Peers Despite Similar Insulin Sensitivity: A reflection of upregulated [beta]-cell function?.
Hannon, Tamara S. MD 1; Bacha, Fida MD 1; Lin, Yan PHD 2; Arslanian, Silva A. MD 1
[Article] Diabetes Care. 31(7):1445-1447, July 2008.

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OBJECTIVE: African-American (AA) children are hyperinsulinemic and insulin resistant compared with American white (AW) children. Previously, we demonstrated that insulin secretion relative to insulin sensitivity was ~75% higher in AA compared with AW children, suggesting that hyperinsulinemia in AA children is not merely a compensatory response to lower insulin sensitivity. The aim of the present investigation was to assess whether glucose-stimulated insulin response is higher in AA versus AW adolescents who have comparable in vivo insulin sensitivity.

RESEARCH DESIGN AND METHODS: The hyperinsulinemic-euglycemic and hyperglycemic clamp techniques were utilized to assess first- and second-phase insulin secretion. Insulin secretion relative to insulin sensitivity was calculated as the glucose disposition index.

RESULTS: AA adolescents compared with their AW peers with comparable insulin sensitivity and body composition had higher first-phase insulin concentrations.

CONCLUSIONS: The quantitative relationship between insulin sensitivity and first-phase insulin appears to differ among AA and AW adolescents.

(C) 2008 by the American Diabetes Association, Inc.