Relation between homocysteinaemia and diabetic neuropathy in patients withType 2 diabetes mellitus

Aims Limited data are available on determinants of diabetic neuropathy as i ts pathogenesis is multifactorial. Since homocysteine exhibits toxic effect s on vascular endothelial cells, the association between homocysteine and t he prevalence of neuropathy in Type 2 diabetes mellitus was investigated. Methods A total of 65 Type 2 diabetic patients were consecutively enrolled into the study. Neuropathy was diagnosed according to clinical symptoms, cl inical examination, electrophysiological sensory testing and autonomic func tion testing. With regard to homocysteine-related parameters, plasma homocy steine, folate, vitamin B12, vitamin B6 and renal function (creatinine, cer atinine clearance, cystatin C) were measured, and the C677T polymorphism of the methylenetetrahydrofolate reductase gene was determined. Results Forty-three of the Type 2 diabetic patients were classified as suff ering from neuropathy. Both patient groups were comparable with regard to d emographic data, blood pressure, glucose metabolism, renal function and hom ocysteine-related vitamins. In contrast, homocysteine levels (P = 0.04) and the frequency of hyperhomocysteinemia (greater than or equal to 15 mu mol/ l) (P = 0.01) were significantly increased in neuropathic patients. In a lo gistic regression model with neuropathy as dependent variable, homocysteine (adjusted for creatinine, homocysteine-related vitamins, HbA(1c) and durat ion of diabetes) was the only significant variable associated with the prev alence of neuropathy (odds ratio for homocysteine per 5 mu mol/l increase: 2.60 (95% confidence interval 1.07-6.33)). Conclusion The data indicate that homocysteine is independently associated with the prevalence of diabetic neuropathy in a collective of Type 2 diabet ic patients. A larger, prospective study would be desirable to clarify the role of homocysteine in the pathogenesis of diabetic neuropathy.