In population studies of Olmsted County, Minnesota, inhabitants, prevalence of typical DPN, retinopathy, and nephropathy was significantly increased only in subjects with new diabetes—not in subjects with IG as defined by American Diabetes Association (ADA) criteria of abnormality of Impaired Fasting Glucose(IFG), Impaired Glucose Tolerance(IGT), or Impaired A1C (IA1C). For atypical DPN, such an increase was not observed even in subjects with new diabetes.

The authors mention that their findings might have several implications. "By showing that IG alone does not cause diabetic microvessel complications, our results support present [American Diabetes Association] criteria for the diagnosis of diabetes, based on the idea that the lowest level of chronic hyperglycaemia that induces micro vessel complications should be the minimal criteria for the diagnosis of diabetes."