Diabet. Med. 29, e102–e105 (2012)
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 HbA1c as a screening test for impaired glucose tolerance in obese children and adolescents and identify the optimal HbA1c threshold.
Methods We studied 126 obese and overweight children (BMI > 85th percentile for age and gender) 4–17 years of age referred to the endocrine clinic at Ajou University Hospital in Korea. All subjects underwent HbA1c 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 HbA1c 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 HbA1c value of 40 mmol/mol (5.8%) should be used as a screening tool to identify children and adolescents with impaired glucose tolerance.