The Risk Factors For Diabetic Complications

The major late complications of diabetes mellitus can be classified into those attributable to atherosclerosis (heart attacks, stroke, and peripheral vascular disease) and to microvascular disease (diabetic polyneuropathy [DPN], retinopathy, and nephropathy). The risk factors for diabetic polyneuropathy had not previously been adequately assessed by: 1) assessing representative population-based cohorts; 2) assessing DPN comprehensively and quantitatively; 3) expressing nerve tests as a percentile and normal deviate value correcting for anthropometric characteristics as based on study of a randomly selected normal subject cohort from which neurologic disease had been excluded; 4) assessing risk factors serially over time; and 5) performing multivariate analysis of risk factors. For DPN we have found that the risk factors are: 1) markers of diabetic microvessel disease (diabetic retinopathy, 24-hour proteinuria, or 24-hour microalbuminuria); 2) chronic hyperglycemic exposure; and 3) type of DM. Excluding markers of microvessel disease and type of DM we found that the highest correlation coefficients were obtained by glycated hemoglobin (GH) × duration of DM 1/2 × 18/age of onset DM (lowest score = 1) × total plasma antioxidant activity. Similarly, major determinants for diabetic retinopathy and nephropathy also are GH × duration of DM. These results provide strong supportive evidence that the product of chronic hyperglycemic (especially GH) exposure × duration of DM are the main determinants of the diabetic complications of retinopathy, nephropathy, and neuropathy.