Plasma Lipid Peroxidation Zinc And Erythrocyte Cu-Zn Superoxide Dismutase Enzyme Activity In Patients With Type 2 Diabetes Mellitus In Gorgan City (South East Of The Caspian Sea)

摘要

Diabetes mellitus is a chronic metabolic disorder, which may be associated with the imbalance between protective effect of antioxidants and increased free radical production. Diabetes mellitus can alter the nutritional status of the individual. The aim of this study was to determine the changes of plasma lipid peroxidation , zinc and erythrocyte cu-zn superoxide dismutase activity in patients with type 2 diabetes mellitus and healthy control in Gorgan city. Fifty type 2 patients with diabetes mellitus and 50 people without diabetes were included in this randomized study. None of patients studied had any diabetic complications. The levels of plasma malondialdehyde and zinc from type 2 diabetes mellitus patients (6.24 ± 0.85 nmol / ml and 116.78± 5.51 mg / dl) and control groups (3.63 ± 0.97 nmol / ml and 146.86 ± 9.06 mg / dl) were determined. Erythrocyte Cu-Zn superoxide dismutase activity from patients with diabetes ( 675.34± 60.89 U / g Hb) and control groups (1052.70± 52.76 U / g Hb) were determined. The increased plasma lipid peroxidation and decreased plasma zinc and erythrocyte Cu-Zn superoxide dismutase activity that we observed in patients with type 2 diabetes mellitus may predispose to the development of cardiovascular complications.We propose that diabetic patients may have elevated requirement for antioxidants. Supplementation with zinc and vitamin or dietary free radical scavengers such as vitamins E and C or tomato, orange and etc. have a potential role in boosting antioxidant-related defences and maybe important in patients with diabetes. Introduction Free radicals are highly reactive molecules generated by biochemical redox reactions that occur as a part of normal cell metabolism (1). These unstable species may cause oxidative damage to DNA, carbohydrate, proteins and lipids that are normally counteracted by protective antioxidants. Oxidative defense is provided by a number of enzymes and vitamins, including the vitamin E, vitamin C and glutathione (2,3,4). In times of increased free radical production, individuals may become deficient in these antioxidants. Excessive free radical production or low antioxidant level leads to oxidation of cellular lipids, proteins and nucleic acids, which results in fragmentation and cross-linking. This may ultimately lead to cell death with widespread pathological consequences (5) The imbalance between protective antioxidants (antioxidant defense) and increased free radical production, leading to oxidative damage, is known as oxidative stress. Oxidative stress is caused by a relative overload of oxidants, i.e., reactive oxygen species. This impairs cellular functions and contributes to the pathophysiology of many diseases. Evidence has accumulated suggesting that complications of diabetes seem to be partially mediated by oxidative stress (6,7,8). The function of zinc in the body metabolism is based on its enzymatic affinity, such as a zinc-enzyme complex or Zinc metalloenzyme. In humans and animals, diabetes maybe results in disturbance of these vital trace elements (9). In most mammals, insulin is stored as zinc crystals and is likely secreted in zinc form. Zinc has important role in modulating the immune system, and its dysfunction in diabetes mellitus may be related in part to the status of zinc (10). Lack or inadequate supply of such nutrients produces functional impairment and can result in disease. The clinical significance and evaluation of zinc in regard to different diseases, including diabetes mellitus remains conflicting as well as controversial. Many questions still remain unanswered. Several reports underscore the role of micronutrient status in patients with type 1 or 2 diabetes mellitus (11,12,13,14,15,16,17). Zinc maybe act in normalizing glycemia, and a restored zinc status in patients with type 2 diabetes mellitus may counteract the deleterious effects of oxidative stress, helping to prevent many complications associated with diabetes. Diabetes mellitus is a ma