Random Plasma Glucose Tests Could Predict Diabetes

Diabetes is a major health problem in the USA, yet over seven million Americans with diabetes go undiagnosed. Diabetes is the major cause of kidney failure, blindness, and non-traumatic leg amputations in adults in the USA and a leading cause of stroke and heart disease.

Early diagnosis allows the use of lifestyle changes or medications that could help prevent or delay the progression from prediabetes to diabetes and help keep diabetes from worsening. When diagnosis is delayed, diabetes-related complications could develop before treatment starts.


A team of scientists working with the Emory University School of Medicine (Atlanta, GA, USA) conducted a retrospective analysis of the association of outpatient random plasma glucose (RPG) levels with the subsequent clinical diagnosis of diabetes. Study subjects were veterans with data in the Veterans Administration (VA) Informatics and Computing Infrastructure (VINCI) Corporate Data Warehouse (CDW).

The team selected veterans who (a) did not have a diabetes diagnosis during a baseline year (365 days) in 2002–2007; (b) had three or more measurements of random plasma/serum glucose (RPG) during the baseline year, along with assessments of other demographic variables and cardiovascular disease (CVD) risk factors; and (c) had subsequent continuity of primary care [≥1 primary care provider (PCP) visit per year for five years immediately following the baseline year].

The scientists reported that over a five-year follow-up, about 10% of the total study group developed diabetes. Elevated random plasma glucose levels, though not meeting the diagnostic threshold for diabetes, accurately predicted the development of diabetes within the following 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. Glucose levels of 130 mg/dL or higher were even more predictive of diabetes. Development of diabetes was infrequent in subjects whose highest random plasma glucose levels were below 110 mg/dL.

The authors recommended that patients receive follow-up diagnostic testing for diabetes, such as a fasting glucose or HbA1c test, if they have two random glucose tests showing levels of 115 mg/dL or higher. This approach would very likely be cost-effective, they say, because clinicians can use testing that is already being done during routine outpatient visits. Using random glucose levels for screening could identify patients at higher risk for diabetes, leading to earlier intervention to prevent or control the disease. The study was published on July 19, 2019, in the journal PLOS ONE.”

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Emory University School of Medicine