Methods: A total of 150 CKD patients and 64 non-CKD patients were enrolled. The type 2 diabetic patients in the recruited study participants were categorised based on their glycaemic control; poor glycaemic control (GC) with haemoglobin A1c (HbA1c) > 7% and good GC with HbA1c ≤ 7%. The levels or activities of GPx, SOD and sRAGE in plasma were measured. These biochemical parameters were analysed using Mann-WhitneyUtest and two-way analysis of variance (ANOVA).
Results: The activities of GPx and SOD as well as plasma level of sRAGE were not significantly different among the CKD patients with varying glycaemic control status. Irrespective of diabetes status and glycaemic control status, CKD patients also exhibited lower plasma SOD activities compared with non-CKD patients. Among the non-CKD patients, SOD activities were significantly higher in diabetic patients with good GC than diabetic patients with poor GC. Two-way ANOVA revealed that both CKD status and glycaemic control had an interaction effect on SOD activities in diabetic subjects with and without CKD. Follow-up analysis showed that SOD activities were significantly higher in non-CKD patients with good GC. There were no overall significant differences in GPx activities among the study participants. Furthermore, plasma sRAGE levels were higher in diabetic patients with CKD than those without CKD, regardless of glycaemic control status. There were no interaction effects between CKD status and glycaemic control status on GPx and sRAGE. Instead, CKD status showed significant main effects on these parameters, indicating significant differences between diabetic subjects with CKD and diabetic subjects without CKD.
Conclusion: Glycaemic control did not quantitatively alter GPx, SOD and sRAGE in diabetic CKD patients. Despite the advantages of good glycaemic control, a well-controlled diabetes in CKD did not modulate the activities of enzymatic antioxidants and sRAGE levels, therefore may not be the primary mechanism to handle oxidative stress.
MATERIALS AND METHODS: Six control and five DM Wistar rats were evaluated. DM was induced at 11 weeks of age using streptozotocin (STZ; 60 mg/kg, intraperitoneal). Animals were monitored up to 38 weeks of age, when plasma glucose, lipid profile, and markers specific for systemic inflammation, endothelial dysfunction, and oxidative stress were measured. The amount of fat within the aortic wall was assessed semiquantitatively using Oil Red O staining.
RESULTS: Diabetic rats presented significantly higher plasma glucose (p < 0.001), total cholesterol and triglycerides (both p = 0.02), high-sensitivity C-reactive protein (p = 0.01), and vascular endothelial growth factor (p = 0.04) levels, and significantly lower interleukin-10 (p = 0.04), superoxide dismutase (p < 0.01), and glutathione peroxidase (p = 0.01) levels than the control rats. Mild (grade 1) atherosclerotic lesions were observed in the aortic wall of 80% of the diabetic rats and in none of the control rats.
CONCLUSIONS: This study presents a STZ-induced type 1 DM rat model with one of the longest follow-ups in the literature. In this model, long-term DM created a highly pro-atherogenic environment characterised by hyperglycemia, dyslipidemia, systemic inflammation, endothelial dysfunction, and oxidative stress that resulted in the development of early aortic atherosclerotic lesions.
METHODS: Forty-one patients with thyroid disorders from University of Malaya Medical Centre were recruited. They were categorised into four groups: multinodular goitre (MNG) (n = 18), follicular thyroid adenoma (FTA) (n = 7), papillary thyroid cancer (PTC) (n = 10), and follicular thyroid cancer (FTC) (n = 6). Serum and RBC of patients were analysed for antioxidant activities, antioxidant enzymes, and biomarkers of oxidative stress. Alterations in genes encoding the antioxidant enzymes were analysed using whole exome sequencing and PCR-DNA sequencing.
RESULTS: Patients with thyroid disorders had significantly higher serum superoxide dismutase (SOD) and catalase (CAT) activities compared to control, but had lower activities in RBC. There were no significant changes in serum glutathione peroxidase (GPx) activity. Meanwhile, GPx activity in RBC was reduced in PTC and FTC, compared to control and the respective benign groups. Antioxidant activities in serum were decreased in the thyroid disorder groups when compared to the control group. The levels of malondialdehyde (MDA) were elevated in the serum of FTA group when compared to controls, while in the RBC, only the MNG and PTC groups showed higher MDA equivalents than control. Serum reactive oxygen species (ROS) levels in PTC group of both serum and RBC were significantly higher than control group. Whole exome sequencing has resulted in identification of 49 single nucleotide polymorphisms (SNPs) in MNG and PTC patients and their genotypic and allelic frequencies were calculated. Analyses of the relationship between serum enzyme activities and the total SNPs identified in both groups revealed no correlation.
DISCUSSION: Different forms of thyroid disorders influence the levels of antioxidant status in the serum and RBC of these patients, implying varying capability of preventing oxidative stress. A more comprehensive study with a larger target population should be done in order to further evaluate the relationships between antioxidant enzymes gene polymorphisms and thyroid disorders, as well as strengthening the minor evidences provided in literatures.