The haemoglobin A1c (HbA1c) test is not effective in diagnosing diabetes in children, according to a new study by University of Michigan's CS Mott Children's Hospital in the US.

The HbA1c test is used to diagnose diabetes in patients without symptoms, and it does not require patients to fast overnight.

In a study, researchers analysed the testing results of 1,156 obese and overweight adolescents, ages 12-18.

The study results showed that HbA1c was not reliable for identifying children with diabetes and pre-diabetes compared to adults, and could lead to missed cases in children.

According to guidelines released by American Diabetes Association, individuals without symptoms would be classified as having diabetes if HbA1c values reach 6.5% and as having pre-diabetes if HbA1c values reach between 6 and 6.4% on two separate tests.

The study authors suggest that the cut off point may need to be lower for kids.

Study lead author Joyce Lee said based on the study findings, a fasting blood glucose test should still be used for diagnosing diabetes in children.