Distal symmetric diabetic neuropathy (DPN) occurs in both type 1 and type 2 diabetes mellitus (T1DM and T2DM, respectively), but a recent study has shown that the predominant type of nerve lesion differs between the two conditions. T2-weighted magnetic resonance neurography of the sciatic nerve in 120 patients with DPN and 36 controls without DPN revealed a greater volume of hypointense lesions in patients with T2DM than in patients with T1DM. Conversely, the volume of hyperintense lesions was greater in patients with T1DM than in those with T2DM. Correlations between the lesion types, blood levels of glycated haemoglobin and lipids suggest that lesions in T1DM result from poor glycaemic control, whereas lesions in T2DM are associated with changes in lipid metabolism. The findings suggest that different approaches are needed for the prevention and treatment of DPN in the two types of diabetes.