One-hour post-load hyperglycemia: implications for prediction and prevention of type 2 diabetes

CONTEXT: Recently, a value of 1-h post-load glucose concentration (1-h-PG) ≥155 mg/dl (8.6 mmol/l) in individuals with normal glucose tolerance (NGT) has been found to be associated with an increased risk for future type 2 diabetes (T2DM). In this review, we analyze the implication of 1-h-PG determination in prediction of T2DM and cardiovascular disease. EVIDENCE ACQUISITION: A literature search was performed using MEDLINE. We included all English studies published up to February 2018 in peer-reviewed journals that examined the relationship between 1-h-PG and diabetes, cardio-metabolic alterations, organ damage, and cardiovascular disease. EVIDENCE SYNTHESIS: Several longitudinal studies have consistently shown that 1-h-PG ≥155 mg/dl can recognize individuals at increased risk for future T2DM amongst NGT subjects. Additionally, we describe the pathophysiological abnormalities associated with 1-h-PG ≥155 mg/dl including impaired insulin sensitivity, β-cell dysfunction, and increased glucose intestinal absorption, which are known to be involved in T2DM pathogenesis. Importantly, numerous studies have demonstrated that a value of 1-h-PG ≥155 mg/dl in NGT individuals is not only linked to an increased risk for future T2DM, but is also able to identify those having a worse cardiovascular phenotype and an increased risk of adverse cardiovascular outcomes. CONCLUSIONS: Although 1-h-PG determination is not currently recommended by the American Diabetes Association for identifying high-risk individuals, the available evidence indicates that a value of 1-h-PG ≥155 mg/dl may be a useful tool to recognize, among subjects with NGT, those at increased risk of T2DM and cardiovascular disease.