“Is Prediabetes a Risk Factor or Is It a Disease?"

Prediabetes is a heterogeneous condition with variable risk of progression to type 2 diabetes. Individuals with prediabetes have abnormal glucose regulation and increased risk for developing diabetes mellitus (DM) type 2 and its complications. The diagnostic thresholds for DM are based on the bimodal distribution of impaired fasting glucose (IFG) and 2-h plasma glucose during an oral glucose tolerance test and the glycemic thresholds for the development of microvascular complications, specifically retinopathy. In epidemiologic studies, isolated impaired glucose tolerance consistently has a higher prevalence than isolated IFG. The prevalence of retinopathy is significantly higher in subjects with DM, but retinopathy can develop in subjects with prediabetic range dysglycemia. Multiple studies suggest that prediabetic-range hyperglycemia is associated with higher rates of nephropathy. There is also an increased prevalence of cardiovascular disease, cardiovascular mortality, and all-cause mortality in patients with prediabetes compared to those with normal glucose metabolism.