Elevated blood glucose levels detected in routine outpatient tests, although well below diagnostic thresholds, have been shown to predict onset of diabetes within 5 years, according to researchers through the United States Department of Veterans Affairs (VA).
The study, published in PLOS ONE, shows that using plasma glucose levels in blood samples taken during regular doctor visits could signal the need for further testing, allow preventive intervention in high-risk individuals before onset of the disease, and lead to earlier identification of diabetes.
In the study, VA researchers examined data on routine blood tests to determine whether random plasma glucose levels could predict diabetes in patients without a diagnosis. They studied the data of more than 900,000 VA patients who did not have a diabetes diagnosis, all of whom received at least 3 random plasma glucose tests in a single year during the study.
Over a five-year follow-up, approximately 10% of the total study group developed diabetes. Although elevated random plasma glucose levels did not meet the diagnostic threshold for diabetes, they did accurately predict the development of the disease within five years. Patients with at least two random plasma glucose measurements of 115 mg/dL or higher within a 12-month period were highly likely to be diagnosed with diabetes within a few years, according to the study. Glucose levels of 130 mg/dL or higher were found to be even more predictive of diabetes.
Demographics and risk factors also predicted development of the disease, including age, sex, and race along with high body mass index, smoking, and high cholesterol. However, random plasma glucose tests were stronger predictors of diabetes than demographics and other risk factors.
Diabetes is a major health problem in the United States, yet according to the CDC, more than 7 million Americans with diabetes go undiagnosed. Screening for prediabetes and diabetes can allow for early detection and treatment; however, many at-risk individuals do not receive necessary screening. The American Diabetes Association currently has recommendations on diabetes testing, which include monitoring a fasting glucose level, oral glucose tolerance test, a HgbA1c level, or a random plasma glucose when accompanied by symptoms of high glucose levels.
The researchers suggest a cost-effective approach, through which patients receive follow-up diagnostic testing for diabetes, such as a fasting glucose or A1c test, if they have two random glucose tests showing levels 115 mg/dL or higher. The process could identify patients who have a higher risk, thereby leading to earlier intervention and prevention.