Hyperinsulinemia in African-American adolescents compared with their American white peers despite similar insulin sensitivity: a reflection of upregulated beta-cell function?
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 approximately 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.


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.
Hannon
Tamara S
TS
Division of Pediatric Endocrinology, Metabolism, and Diabetes, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA. tamara.hannon@chp.edu
Bacha
Fida
F
Lin
Yan
Y
Arslanian
Silva A
SA
D000273:Adipose Tissue / Q000033:anatomy & histology; D000293:Adolescent; D044383:Black People / Q000706:statistics & numerical data*; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition; D002648:Child; D005260:Female; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D006946:Hyperinsulinism / Q000453:epidemiology*; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D008297:Male; D044465:White People / Q000706:statistics & numerical data*; D001741:Black or African American
D001786:Blood Glucose; D007328:Insulin; D005947:Glucose