Glucose tolerance and insulin sensitivity markers in children and adolescents with excess weight

Type 2 diabetes mellitus (T2DM) and obesity are alarmingly increasing in children and adolescents. Hence, predictors for early metabolic abnormalities in childhood are urgently needed. We investigated glucose tolerance in children and adolescents with obesity, markers of insulin sensitivity between males and females and the potential association between the parameters measured during an OGTT (glucose, insulin, c-peptide) and prediabetes or stages of puberty.

Glucose tolerance in 89 children and adolescents with excess weight, aged 4-19 years, from Western Greece was studied. A 3-hour OGTT was performed and fasting glucose (FG), fasting insulin (FI), 1/FI, FG/FI, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), Quantitative insulin sensitivity check index (QUICKI), ISI Matsuda index and Insulinogenic index (IGI30), were also calculated.

No significant differences were observed in glucose values between males and females. Insulin and c-peptide concentrations were higher in the girls at several time points. FG/FI was significantly higher in the boys. Girls with obesity may be at higher risk for future insulin resistance.

Better surveillance of pubertal girls with obesity is crucial and can be achieved using additional information provided by an OGTT, since they appear to be at a higher risk for beta-cell exhaustion. During the OGTT, not only are the baseline and 2-hour glucose and insulin measurements useful for predicting future metabolic risks and development of T2DM in children and adolescents with obesity, but additional time measurements may also be helpful.