Objective: In this study, we aimed to evaluate the possible effects of leptin and oxidative stress on the pathogenesis of type 1 and type 2 diabetes mellitus.

Material and Methods: Subjects were assigned to four groups: type 1 diabetes group (n=20), type 2 diabetes group (n=40), young co ntrol (n=10; control group of type 1diabetes), adult control (n=10; control group of type 2 diabetes). The uric acid and albumin levels were measured in serum samples by otoanalyzer, leptin; hormone for the energy homeostasis were determined by Elisa method, serum copper and zinc levels were determined by atomic absorption spectrophotometer, antioxidant status were determined by superoxide dismutase enzyme activities (SOD) and MDA and ROOH levels were measured for the markers of lipid peroxidation.

Results: One of the main findings of our recent study was that the increased levels of serum MDA and ROOH and the decreased levels of SOD levels were observed when type 1 diabetes group was compared with its control group. Also the statistically increased levels of ROOH, statistically not increased levels of MDA and statistically decreased levels of SOD were determined when the type 2 diabetes group was compared with its control group. There were not any statistical significant differences were observed in both groups for leptin levels when compared with their control groups. However there were a significant correlation between leptin levels and body mass indexes in all groups.

Conclusion: The observations in our study suggest the idea that the relationship between the diabetes, leptin and oxidative stress seem to be a complex combination which is not easy to explain it by metabolic pathways. We need really increased number of patients and data to conclude on those relationships.