Impaired glucose tolerance and bone mineral content in overweight latino children with a family history of type 2 diabetes.

OBJECTIVE: Research on the skeletal status of pre-diabetic (type 2 diabetic) children is warranted. We examined the hypothesis that bone mineral content (BMC) and bone mineral density (BMD) will be lower in children with impaired glucose tolerance (IGT) versus normal glucose tolerance (NGT). RESEARCH DESIGN AND METHODS: Total body BMC and BMD of 184 overweight Latino children (106 boys, 78 girls, 11.9 +/- 1.7 years) with a family history of type 2 diabetes were measured using dual-energy X-ray absorptiometry. Glucose tolerance was assessed by 2-h glucose after an oral glucose tolerance test. Area under the insulin curve (AUC) assessed the cumulative insulin response to oral glucose. Acute insulin response to glucose (AIR) was determined by an intravenous glucose tolerance test.
RESULTS: Partial correlations revealed an inverse relationship between BMC and AIR (r = -0.29, P = 0.00), AUC (r = -0.28, P = 0.00), fasting insulin (r = -0.16, P = 0.04), and 2-h insulin (r = -0.16, P = 0.04). There was no significant difference in BMC or BMD between children with IGT (n = 46) or NGT (n = 138). Stepwise multiple linear regression revealed that 89% of the variance in BMC is attributed to lean mass (87%), age (1%), and AIR (1%). BMD was explained by lean mass (69%), Tanner stage (3%), and AUC (2%).
CONCLUSIONS: The findings of this study suggest that in overweight children, lean mass is the primary predictor of BMC and BMD, whereas age, Tanner stage, and the acute and cumulative insulin responses to oral glucose make subtle independent contributions to the total variances. In addition, poor glycemic control does not seem to be detrimental to bone mass of pre-diabetic children.