Using a combination of two blood sugar tests rather than a single test would improve detection of pre-diabetes in children and adults, according to a new study led by the Georgia State University in the US.

The researchers found that measuring both a person's fasting plasma glucose (FPG) and haemoglobin A1C (HbA1C) results in more accurate pre-diabetes detection across age, race/ethnicity and body mass than using only one of the tests.

Improving detection of pre-diabetes would save the American health care system and patient's money by motivating subjects with pre-diabetes to seek preventative care, said Ike S. Okosun, director of the Division of Epidemiology and Biostatistics.

The researchers noted that 24 million Americans have Type-2 diabetes -- a number that is projected to grow to 39 million by 2050. Another 65 million Americans have pre-diabetes, a figure that could double by 2030.

"Given the increasing prevalence of Type-2 diabetes, coming up with methods to catch the disease and stop it is a public health imperative," Okosun added.

The American Diabetes Association supports use of a different test, the haemoglobin A1C (HbA1C) test, to diagnose patients with Type-2 diabetes.

The research findings were based on analysis of data from the 2007-2008.

Most people being tested for pre-diabetes undergo either a fasting plasma glucose (FPG) test, which measures their blood sugar after a period of not eating -- usually a few hours -- or an oral glucose test (OGT), which measures their blood sugar soon after consuming a certain amount of carbohydrate.

Combining all three tests did not improve the overall detection of pre-diabetes beyond what was observed using the FBG test along with the HbA1C, the researchers found.

The study was published in the Frontiers in Public Health.