Lipid peroxides in type 2 diabetic patients with neuropathy.

Diabetes and its metabolic changes in peripheral nerves contribute to cause a decrease of nitric oxide production and diminished nerve blood flow. Since lipid peroxides are thought to be formed by free radicals and may play an important role in the development of vascular disease, we have investigated the possible relationship between lipid peroxides (measured as thiobarbitouric acid reacting substances (TBARS) in diabetic patients with peripheral neuropathy. Seventy-seven patients with Type 2 diabetes (39 neuropathic and 38 non-neuropathic) and 38 control subjects were studied. The neuropathy study group had significantly lower levels of TBARS, 3.5micromol/l (2.2-5.6, 95% confidence limits) compared to controls 4.5microm/l (3.08-6.8), p < 0.001 and to diabetics without neuropathy 4.9micromol/l (3.09-8.05), p < 0.001. No differences were found in metabolic control between the two diabetic groups. In the neuropathy group there was a negative correlation between the score for nerve dysfunction with the TBARS levels (r = - 0.42, p < 0.01). In conclusion, in diabetic patients with neuropathy there are abnormalities of TBARS levels.