جستجوی مقالات مرتبط با کلیدواژه "اکسیداسیون لیپیدها" در نشریات گروه "پزشکی"

Subclinical hyperthyroidism is defined by the suppressed level of TSH and normal values of T4 and T3. The effect of this status on lipid metabolism is not well recognized this study was done to address this issue. Methods and Materials: In this case-control study, 41 patients with subclinical hyperthyroidism and 36 euthyroid subjects were recruited. Subclinical hyperthyroidism was difined as TSH<0. 3 and normal T3 and T4 values, and confirmed with the TRH test. Questionnaires for clinical data and drug history were completed for all patients and blood samples were obtained for laboratory tests. In this study the markers of lipid oxidation, antioxidants, paraoxonase enzyme activity, serum lipid levels, vit A, E and B-carotene were measured and the parameters were analysed using the appropriate statistical methods. There were no significant changes between the two groups regarding age (46±13 vs 47±13, years old), sex (30/11 vs 14/12 male/female), weight (79±14 vs 77±13 kg), body mass index and hypertension. Significantly lower serum TSH (0.16±0.1 vs 1.1±1.0, mIU/L p<0. 001) was found in the subclinically hyperthyroid group. Significantly lower level of paraoxonase enzyme activity, vit A, B caroten, oxidized LDL-C, TAC, total cholesterol, triglyceride, LDL-C and Pon/LDL ratio were found in patients with subclincal hyperthyroidsim as compared with the control group. Significant differences in lipid levels and lipid oxidation and antioxidants seen in these patients show a change in the basal methobolism of this group.

Paraoxonase (an HDL-associated enzyme) is believed to protect lipoproteins against peroxidation. Patients with end stage renal failure on hemodialysis are exposed to oxidative stress. In this study we investigated the status of paraoxonase activity, TAC and oxidized LDL in a population of diabetic and non-diabetic ESRD patients. The study population consisted of 46 patients with diabetes and 46 non diabetics and 46 control participants. Patients were selected from hemodialysis centers of Shaheed Beheshti University of Medical Sciences. Individuals with thyroid dysfunction, Cerebrovascular accident, recent coronary event, recent hospitalization or under treatment with lipid-lowering agents were excluded. A fasting predialysis sample was obtained. Paraoxonase activity was measured by spectrophotometer, measuring P-nitrophenol paraoxon after adding paraoxon to the sera and TAC by adding 20µL serum to PBS (80µmol/L, PH=7.4) and 6.1 µmol/L metmyoglobin and ABTS (as a chromogen and substrate) and hydrogen peroxide as a substrate. The decrease in blue-green color was measured by Elisa reader. 46 diabetic patients, 26 men and 20 women, aged 61.8±10 and 46 non diabetic ESRD patients, 25 men and 21 women, aged 61.5±9.9, and 46 healthy controls, 24 men and 22 women, aged 60.8±10.0 were studied. Significant reduction in serum paraoxonase activity in non diabetic ESRD and diabetic patients compared with control group was present (47.2±32.2 VS 9.5±48.6 VS 86.4±62.5 IU/mL, respectively). While these groups showed no significant change in oxidized LDL and TAC. Paraoxonase activity was significantly lower in non diabetic ESRD patients than diabetics. It has been shown that there is enhanced oxidative stress in patients with diabetes mellitus and chronic renal failure. Reduction in paraoxonase activity may have a role in this process.