Background  

With positive results from diabetes prevention studies, there is interest in convenient ways to incorporate screening for glucose intolerance into routine care and to limit the need for fasting diagnostic tests.

Objective  

The aim of this study is to determine whether random plasma glucose (RPG) could be used to screen for glucose intolerance.

Design  

This is a cross-sectional study.

Participants  

The participants of this study include a voluntary sample of 990 adults not known to have diabetes.

Measurements  

RPG was measured, and each subject had a 75-g oral glucose tolerance test several weeks later. Glucose intolerance targets included diabetes, impaired glucose tolerance (IGT), and impaired fasting glucose₁₁₀ (IFG₁₁₀; fasting glucose, 110–125 mg/dl, and 2 h glucose < 140 mg/dl). Screening performance was measured by area under receiver operating characteristic curves (AROC).

Results  

Mean age was 48 years, and body mass index (BMI) was 30.4 kg/m²; 66% were women, and 52% were black; 5.1% had previously unrecognized diabetes, and 24.0% had any “high-risk” glucose intolerance (diabetes or IGT or IFG₁₁₀). The AROC was 0.80 (95% CI 0.74–0.86) for RPG to identify diabetes and 0.72 (0.68–0.75) to identify any glucose intolerance, both highly significant (p < 0.001). Screening performance was generally consistent at different times of the day, regardless of meal status, and across a range of risk factors such as age, BMI, high density lipoprotein cholesterol, triglycerides, and blood pressure.

Conclusions  

RPG values should be considered by health care providers to be an opportunistic initial screening test and used to prompt further evaluation of patients at risk of glucose intolerance. Such “serendipitous screening” could help to identify unrecognized diabetes and prediabetes.