Serum prolidase activity and oxidative status in patients with diabetic neuropathy.

We found no data in the literature related to oxidative stress index (OSI), total oxidative status (TOS) and prolidase activity in patients with diabetic neuropathy (DN). In this study, we aimed to evaluate the oxidative status of DN patients via measurement of TOS and serum total antioxidant status (TAS) and estimation of OSI using new automated methods. Thirty-eight healthy participants, 40 diabetic patients without neuropathy, and 39 patients with DN were included. Electrophysiological and neurological examinations were performed. The activity of prolidase and levels of TOS and TAS were determined in the serum of patients. The level of TAS was lower, while the levels of TOS and OSI, and activity of prolidase were higher in both DN and diabetic control groups compared with the healthy subjects (p < 0.05). Prolidase activity was found to be higher in the DN group than in the diabetic control group (p = 0.001). In conclusion, the presence of high TOS and OSI levels together with low levels of TAS in diabetic patients with or without neuropathy may support a role of oxidative stress in the pathogenesis of diabetes mellitus. In addition, increased serum prolidase activity in DN may be interpreted as evidence of increased collagen turnover.