Genetic and metabolic studies in diabetic neuropathy.

Forty-one diabetic patients with symptomatic diabetic neuropathy were studied together with an equal number of matched diabetic subjects without neuropathy. The acetylator status was determined and HLA-A, B, C and DR antigens were investigated. Metabolic control was assessed by measurement of glycosylated haemoglobin and by the mean of multiple random clinic blood glucose values. No significant difference was observed between the two groups in the proportion of fast and slow acetylators. The distribution of HLA frequencies was similar in subjects with and without neuropathy for both Type 1 (insulin-dependent) and Type 2 (non-insulin-dependent) diabetic patients. When compared with diabetic subjects without neuropathy, the neuropathy group had higher levels of both glycosylated haemoglobin (mean +/- SEM: 50.1 +/- 1.4 versus 57.5 +/- 1.8 mmol hydroxymethylfurfural/mol haemoglobin (10.5 +/- 0.3 versus 12.0 +/- 0.4% haemoglobin A1, p less than 0.01) mean blood glucose (9.3 +/- 0.4 versus 11.3 +/- 0.5 mmol/l, p less than 0.005). This study provides no evidence that genetic factors increase the susceptibility of diabetic patients to develop neuropathy. In contrast, the elevated glycosylated haemoglobin and blood glucose levels strengthen the association between hyperglycaemia and diabetic neuropathy.