Insulin sensitivity, insulin secretion and beta-cell function during puberty in overweight Hispanic children with a family history of type 2 diabetes.

OBJECTIVE

To examine cross-sectional differences in insulin sensitivity, insulin secretion and beta-cell function during puberty in overweight Hispanic boys and girls with a family history of type 2 diabetes.

STUDY DESIGN AND

PARTICIPANTS

This cross-sectional, observational study included 214 8-13-y-old Hispanic children with a BMI percentile > or = 85th percentile and family history of type 2 diabetes.

METHODS AND ANALYSES: Participants underwent a physical examination, body composition measures, oral glucose tolerance test (OGTT), and frequently-sampled intravenous glucose tolerance test. Unadjusted and adjusted general linear models (GLM) tested whether insulin/glucose dynamics differed by Tanner stage and gender.

RESULTS

Unadjusted group comparisons showed that fasting insulin increased whereas insulin sensitivity (SI) and the disposition index (DI) (a measure of pancreatic beta-cell function) decreased across Tanner stage groups (all P < 0.05). No differences in the acute insulin response to glucose (AIRg), fasting glucose or 2-h glucose were found. After adjusting for covariates, there was no independent effect of Tanner stage on SI (P = 0.9) or AIRg (P = 0.2), but DI was slightly lower in later Tanner stages suggesting decreased beta-cell function in the more mature groups (P = 0.10).

CONCLUSIONS

Overweight Hispanic children with a family history of type 2 diabetes may represent a unique population given that pubertal insulin resistance was not evident once analyses controlled for body composition. Longitudinal analyses are required to determine whether the slightly diminished beta-cell function in later Tanner stages plays a role in the development of type 2 diabetes.