HbA1c and glucose intolerance in obese children and adolescents

Abstract

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.