Myelinated fibers diameter distributions on acute (A) and chronic (B) treated and untreated diabetic groups and respective controls. All fibers from all nerves are represented. For all experimental groups, myelinated fibers distributions are bimodal in shape, with a clear point of separation between small and large fibers at 6.0 μm. The acute control group shows an homogeneous distribution of the small fibers while both diabetic groups, treated and untreated showed a larger percentage of small myelinated fibers, shifting the histograms to the left (One Way ANOVA on Ranks, p < 0.001). The chronic diabetic group also shows a shift of the distribution towards the small fibers, with a disorganization of the large fibers distribution (One Way ANOVA on Ranks, p < 0.001). The chronic treated group showed a reduced percentage of both small and large myelinated fibers (One Way ANOVA on Ranks, p < 0.001).