Non-Fasting Glucose Measures and Their Clinical Significance in Diabetes Diagnosis and Cardiovascular and Cancer Risk Prediction: A Narrative Review

Several lipid-management guidelines now favor non-fasting lipid measurements for cardiovascular risk assessment. In parallel, this review evaluated the potential clinical utility of non-fasting glucose measures, which may better reflect real-world glycemic responses, capture postprandial dysregulation not detected by fasting glucose, and offer greater practicality in routine clinical settings. Postprandial plasma glucose measured 4–7.9 h after a meal (PPG4–7.9h) shows relative stability within this window and appears to be a promising marker for diagnosing diabetes and predicting mortality from cardiovascular disease (CVD) and cancer. Similarly, 2 h plasma glucose during an oral glucose tolerance test performed 4–7.9 h after a meal (2 h PGOGTT4–7.9h) demonstrates diagnostic and prognostic value, particularly for diabetes and cardiovascular mortality. Notably, the diagnostic and predictive performance of these non-fasting measures is not inferior to that of traditional fasting glucose assessments. Mechanistically, postprandial hyperglycemia may contribute to CVD through increased oxidative stress and inflammation, endothelial dysfunction, and promotion of atherogenesis and thrombogenesis. It may also increase cancer risk via oxidative stress, inflammation, and insulin-mediated cellular proliferation. In addition, it may enhance lipogenesis to form membrane lipids supporting tumor growth. Further research is required to establish the clinical applicability, optimal thresholds, and generalizability of these non-fasting glucose measures.