HbA1c and glucose intolerance in obese children and adolescents.

AIMS

Childhood obesity is associated with an increased likelihood for having impaired glucose tolerance, dyslipidaemia and diabetes. The aim of the study was to evaluate HbA(1c) as a screening test for impaired glucose tolerance in obese children and adolescents and identify the optimal HbA(1c) threshold.

METHODS

We studied 126 obese and overweight children (BMI > 85 th percentile for age and gender) 4-17 years of age referred to the endocrine clinic at Ajou University Hospital in Korea. All subjects underwent HbA(1c) and oral glucose tolerance test.

RESULTS

Thirty-four patients (27%) out of 126 had impaired glucose tolerance. Silent diabetes was diagnosed in 10 adolescents (7.9%). Based on the receiver operating characteristic curve, the optimal cut point of HbA(1c) related to impaired glucose tolerance diagnosed by oral glucose tolerance test was 40 mmol/mol (5.8%), which was associated with a 64.7% sensitivity and 61.6% specificity, with an area under the receiver operating characteristic curve of 0.651 (95% CI 0.529-0.772).

CONCLUSIONS

Obesity is associated with an increased risk of impaired glucose tolerance. An HbA(1c) value of 40 mmol/mol (5.8%) should be used as a screening tool to identify children and adolescents with impaired glucose tolerance.