Nonfasting Screening Tests Evaluated for Dysglycemia

The performance of nonfasting tests to screen children for dysglycemia, either prediabetic or diabetic, has been appraised.

The screening tests included a random glucose test, fructosamine and the glycosalated hemoglobin test, HbA1c, following a formal glucose tolerance test (OGTT) performed on a previous visit.

Scientists at the University of Michigan (Ann Arbor, MI, USA) conducted a cross-sectional study of 254 overweight or obese children aged 10-17 years. Subjects came for two visits to a clinical research unit. They arrived fasting on the first visit and a glucose tolerance test and HbA1c and fructosamine testing were performed. For the second visit, they arrived nonfasting and had a random plasma glucose, a one hour 50-gram nonfasting glucose challenge test (1-h GCT), and urine dipstick performed. The primary end point was dysglycemia, that is a fasting plasma glucose of greater than 99 mg/dL or a two-hour postglucose greater than139 mg/dL. Approximately 50% of the children were female, 59% were white, and 30% were black.

The results of the study showed that there were 99 (39%) cases of prediabetes and 3 (1.2%) cases of diabetes. Urine dipstick, HbA1c, and fructosamine displayed poor discrimination for identifying children with dysglycemia. Both random glucose and 1-h GCT had better levels of test discrimination than HbA1c or fructosamine.

Glucose, fructosamine, and HbAlc were all measured using the Cobas Mira Plus Chemistry Analyzer (Roche; Basle, Switzerland). The urine dipstick test was performed using Chemstrip 10 strips also manufactured by Roche.

The authors concluded that they found reasonable test performance for the 1-h GCT and the random glucose, having systematically evaluated a variety of nonfasting screening tests used in the clinical setting for identifying dysglycemia in a population of overweight and obese adolescents, In contrast, test performance for HbAlc, fructosamine, and urinalysis was poor. Their findings have direct relevance for future recommendations for screening and diagnosis of dysglycemia among overweight and obese children and adolescents. The study was published the December 2011 issue of the journal Diabetes Care.

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