Routine Blood Glucose Value Correlates with Diabetes Risk

Random glucose values obtained during routine blood tests are often overlooked, but could provide valuable insight into whether someone is at risk for having type 2 diabetes.

Random Blood Glucose (RBG) values in which the clinician is unaware of when the patient last ate account for the majority of glucose tests in clinical practice. Current guidelines do not call for using RBG values as a screening test for diabetes and do not consider higher levels an indicator of diabetes risk.


Scientists at the University of Texas Southwestern Medical Center (Dallas, TX, USA) analyzed data from 13,792 participants in the 2005-2010 National Health and Nutrition Examination Surveys, which tested participants for diabetes as part of the survey. The investigators examined the association between random blood glucose and a patient's diabetes status in patients without diagnosed diabetes. The study population consisted of non-pregnant adults, age18 and older.

Serum RBG measurements were determined using the Beckman Oxygen electrode, glucose oxidase method. Between 2007and 2012, one instrument change occurred as from 2008 the Beckman Unicel CxC800 Synchron (Beckman Coulter; Brea, CA, USA) was used. HbA1C assays were conducted using high-performance liquid chromatography (HPLC) methods mainly on the Tosoh HbA1C G7 (Tosoh Bioscience, Inc.; South San Francisco, CA, USA). Diabetes was defined as having an HbA1C ≥ 6.5% (48 mmol/mol) and prediabetes as having an HbA1C of 5.7–6.4% (39–46mmol/mol). Dysglycemia was defined as having an HbA1C ≥ 5.7% (39 mmol/mol).

The team found that those with even modest elevations in random blood glucose (RBG), between 100 to 119 mg/dL, were seven-times more likely to have diabetes, according to the study. As that number rose, so did the risk. Those with RBG values of 120 to 139 mg/dL were 30-times as likely to have undiagnosed diabetes. Individuals with values under 100 mg/dL served as a reference point and were not considered at risk.

Michael E. Bowen, MD, MPH, an assistant professor of Internal Medicine and lead author, said, “Our results provide compelling evidence that a single, elevated random blood glucose value is a strong risk factor for diabetes. After adjusting for traditional diabetes risk factors, we found that individuals with a single random glucose value greater than or equal to 100 mg/dL were 20-times more likely to have undiagnosed diabetes compared with those whose values were less than 100 mg/dL. We shouldn't ignore these values. If we do, we are missing an opportunity to identify patients at high risk for diabetes.” The study was published on February 4, 2015, in the Journal of Clinical Endocrinology and Metabolism.

Related Links:
University of Texas Southwestern Medical Center
Beckman Coulter 
Tosoh Bioscience