Insulin sensitivity in African-American children with and without family history of type 2 diabetes.
OBJECTIVE
African-Americans are at increased risk for type 2 diabetes. We have previously demonstrated that African-American children are hyperinsulinemic and insulin resistant compared with their white American peers. The aim of the present investigation was to assess the impact of family history of type 2 diabetes on insulin sensitivity in African-American children.


METHODS
A total of 13 prepubertal healthy children with negative family history (FH-) and 9 with positive family history (FH+) of type 2 diabetes underwent a 3-h hyperinsulinemic (40 mU x m(-2) x min(-1))-euglycemic clamp study to assess insulin sensitivity. The groups were comparable for age, pubertal status, total body adiposity determined by dual-energy X-ray absorptiometry, abdominal adiposity assessed by computed tomography scan at the level of L4-5 lumbar vertebra, and physical fitness measured by maximal oxygen consumption (VO2max).


RESULTS
The FH+, compared with the FH-, group had lower insulin-stimulated glucose disposal (10.9+/-1.2 vs. 14.2+/-0.9 mg x kg(-1) x min(-1), P = 0.035) and lower nonoxidative glucose disposal (5.7+/-0.8 vs. 8.3+/-0.6 mg x kg(-1) x min(-1), P = 0.015), with no differences in rates of glucose oxidation, fat oxidation, or insulin-mediated free fatty acid suppression. Fasting hepatic glucose production assessed with [6,6-2H2]glucose and basal rates of glucose and fat oxidation were not different between the two groups.


CONCLUSIONS
These data suggest that in African-American children, family history of type 2 diabetes is a risk factor for insulin resistance. These children manifest important metabolic alterations, including impaired insulin-stimulated total and nonoxidative glucose disposal early in the first decade of life. We propose that this familial tendency, combined with environmental influences, could lead to type 2 diabetes decades later.
Danadian
K
K
Division of Pediatric Endocrinology, Metabolism and Diabetes Mellitus, University of Pittsburgh, Pennsylvania, USA.
Balasekaran
G
G
Lewy
V
V
Meza
M P
MP
Robertson
R
R
Arslanian
S A
SA
D001481:Basal Metabolism; D044383:Black People / Q000235:genetics*; D002648:Child; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D005192:Family Health; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D006946:Hyperinsulinism / Q000235:genetics; D007333:Insulin Resistance; D008297:Male; D008487:Medical History Taking; D001741:Black or African American