Study Suggests Non-Fasting Blood Test Can Help Screen Youth for Prediabetes, Diabetes

A blood test that does not require overnight fasting was found to be an accurate screening tool for identifying youth at risk for type 2 diabetes and heart disease risk later in life, according to a recent study from the Johns Hopkins Bloomberg School of Public Health.

The results of the study suggest that the blood test, or hemoglobin A1c (HbA1c), should be used more frequently to screen youth for diabetes and related health risks.

The researchers analyzed a national survey and medical exam data on more than 14,000 youth aged 10 to 19 years. Further, 1 of the study objectives was to see how closely a positive result on different tests for high blood sugar is related to risk factors for diabetes and heart disease, such as obesity and high blood cholesterol.

Hyperglycemia was strongly associated with cardiometabolic risk factors compared with hyperglycemia defined by the traditional fasting glucose test, according to the researchers. Among youth with HbA1c-defined hyperglycemia, 51% were obese compared with 29% of youth with hyperglycemia defined by the fasting glucose test.

The HbA1c test measures the degree to which sugar molecules have linked irreversibly to molecules in red blood cells in the previous few months, according to the study. However, this test does not require compliance with overnight fasting before the test, and compared with the fasting plasma glucose test, is less complicated to administer and can be less prone to error, according to the researchers.

“Our study demonstrates that HbA1c is a useful non-fasting test for identifying high-risk youth who could benefit from lifestyle interventions to prevent diabetes and cardiovascular disease later in life,” said study senior author Elizabeth Selvin, PhD, MPH, in a press release.

The study examined data from screening tools for diabetes and cardiometabolic risk on 14,119 youth aged 10 to 19 years from the US National Health and Nutrition Examination Surveys conducted between 1999 and 2016. These data include results of blood tests that are commonly used to detect hyperglycemia.

Another objective of the study was to evaluate how often the youth who are eligible for screening by these criteria actually have hyperglycemia at the moderate level, or the prediabetes level. The current analysis suggests that the current screening criteria, despite covering approximately one-quarter of US children and adolescents, do not capture many youths with hyperglycemia.

“Current screening criteria miss a lot of children who are at high risk for diabetes,” said study lead author Amelia Wallace, a PhD student in the department of epidemiology at the Bloomberg School.

The researchers also evaluated the dataset to see how closely different measures of hyperglycemia were linked to cardiometabolic risk factors.

The HbA1c blood test was particularly useful as a screening tool, showing stronger associations with the risk factors examined compared with the fasting glucose test. For example, having hyperglycemia as defined by the HbA1c test was associated with a 4.1 times greater prevalence of obesity, whereas having hyperglycemia defined by the fasting glucose test was associated with an only 1.8 times greater prevalence of obesity.

REFERENCE

Non-fasting blood test can help screen youth for prediabetes and diabetes. John Hopkins Bloomberg School of Public Health. https://www.jhsph.edu/news/news-releases/2020/non-fasting-blood-test-can-help-screen-youth-for-prediabetes-and-diabetes.html. Published August 10, 2020. Accessed August 12, 2020.