Oxidative stress in type I diabetic patients with and without macrovascular disease

The aim of the present work was to determine whether, and to what degree, oxidative stress occurs in type I diabetes with and without macrovascular disease and to assess the prooxidant/antioxidant balance in relation to other metabolic control parameters of the disease. The study was carried out on twenty type I diabetic patients without macrovascular disease [group I] and twenty diabetic patients with macrovascular disease [group II].A control group composed of 10 healthy volunteers was also included in this study. All patients and controls were subjected to the following: determination of blood pressure, fasting and postprandial plasma glucose [FPG, PPG], Glycosylated hemoglobin [HbAlc], serum triglycerides [TG], serum total cholesterol [TC], serum high density lipoprotein cholesterol [HDL-C], serum low density lipoprotein cholesterol [LDL-C], plasma malondialdehyde [MDA], whole blood glutathione [GSH], Erythrocyte glutathione peroxidase [GPx] and superoxide dismutase [SOD], plasma vitamins E and C, serum vitamin A and beta-carotene, serum uric acid, plasma transferrin, ceruloplasmin and iron, and serum copper, zinc and selenium. There was a statistically significant increase in systolic and diastolic blood pressure, FPG, PPG, HbAlc, serum TG, TC, and LDL-C, atherogenicity ratio, plasma MDA, and serum iron and copper in group II than in group I and the control group and also in group I than in the control group [P<0.0001]. There was a statistically significant decrease in whole blood GSH, erythrocyte GPx and SOD, plasma vitamin C, transferrin, ceruloplasmin and iron, serum HDL-C, ;vitamin A, beta-carotene, uric acid, copper, zinc and selenium levels in group II than in group I and the control group and also in group I than in the control group [P<0.0001]. As regards vitamin E levels, there was no significant difference among the three studied groups, however, when vitamin E values were normalized by total lipids [so called vitamin E status], there was significant decrease in group II than in group I and also in group I than the control group [P<0.0001]. Oxidative stress is an outstanding feature of type I diabetes and is attributed to imbalance between prooxidants and antioxidants in favor of the former. Such oxidative stress appears to be an important component in the complex pathophysiology of diabetes as well as diabetes related macrovascular disease. Supplementation of antioxidants to diabetic patients with and without macrovascular disease may restore prooxidants/antioxidant balance and may be of a benefit to abort the process of oxidative stress

Calcium regulating hormones in children with insulin dependent diabetes mellitus [IDDM]

Recent studies have revealed that altered mineral metabolism is observed in diabetic patients with the complication of osteopenia. In order to elucidate the role of calcium regulating hormones on calcium homeostasis and whether they are linked to glycemic control, we have designed this study. The study included 20 children with insulin dependent diabetes mellitus [IDDM] aged from 5.8 - 13 years and 20 age and sex matched normal children who served as control. Serum level of parathyroid hormone, 1,25 dihydroxy vitamin D, calcitonin, serum total and ionized calcium, phosphorus and magnesium were measured. The study included also measurement of biochemical bone remodeling markers [serum alkaline phophatase and osteocalcin]. Glycemic control was assessed in diabetic children by measurement of fasting blood sugar level and glycosylated hemoglobin. The levels of serum calcium, and magnesium were significantly lower in diabetic patients than control and they were significantly correlated with the fasting blood sugar level. In parallel, significant lower levels of 1,25 dihydroxy vitamin D were observed in diabetic patients than control group and were significantly correlated to glycosylated hemoglobin This may indicate that poor control of diabetes significantly affects the level of this active metabolite of Vitamin D. Serum level of calcitonin was slightly higher in diabetic children than control but this was not statistically significant. The levels of serum osteocalcin were significantly lower in diabetic patients than control and they were significantly correlated with the level of glycosylated hemoglobin This may indicate that the degree of metabolic control and duration of disease affected it. It was concluded that, in IDDM, an osteoblastic deficit appears to exist with decreased bone turnover and increased bone resorption. This deficit is aggravated by lower level of 1,25 dihydroxy vitamin D, increased levels of calcitonin and failure of activation of parathyroid hormone. Glucosuric induced osmotic diuresis may also be responsible for the negative calcium balance observed in these patients