The Influence of the Severity of Early Chronic Kidney Disease on Oxidative Stress in Patients with and without Type 2 Diabetes Mellitus

Abstract

Early Chronic Kidney Disease (CKD) is a condition that tends to progress to End-Stage Kidney Disease (ESKD). Early diagnosis of kidney disease in the early stages can reduce complications. Alterations in renal function represent a complication of diabetes mellitus (DM). The mechanisms underlying the progression of CKD in diabetes could be associated with oxidative and inflammatory processes. This study aimed to evaluate the state of inflammation and oxidative stress (OS) on the progression of CKD in the early stages in patients with and without type 2 diabetes mellitus (T2DM). An analytical cross-sectional study was carried out in patients with CKD in early stages (1, 2, 3) with and without T2DM. The ELISA method determined the expression of pro-inflammatory cytokines IL-6 and TNF-α as well as lipoperoxides (LPO), nitric oxide (NO), and superoxide dismutase activity (SOD). Colorimetric methods determined glutathione peroxidase (GPx) and total antioxidant capacity (TAC). Patients with CKD and T2DM had significantly decreased antioxidant defenses for SOD (p < 0.01), GPx (p < 0.01), and TAC (p < 0.01) compared to patients without T2DM. Consequently, patients with T2DM had higher concentrations of oxidant markers, NO (p < 0.01), inflammation markers, IL-6 (p < 0.01), and TNF-α than patients without T2DM. CKD stages were not related to oxidative, antioxidant, and inflammatory marker outcomes in T2DM patients. Patients without T2DM presented an increase in SOD (p = 0.04) and a decrease in NO (p < 0.01) when the stage of CKD increased. In conclusion, patients with T2DM present higher levels of oxidative and inflammatory markers accompanied by a decrease in antioxidant defense. However, these oxidative status markers were associated with CKD stage progression in patients without T2DM. Thus, NO and SOD markers could help detect the early stages of CKD in patients who have not yet developed metabolic comorbidities such as T2DM.

The Effect of the Extra Virgin Olive Oil Minor Phenolic Compound 3′,4′-Dihydroxyphenylglycol in Experimental Diabetic Kidney Disease

“…One of the biochemical pathways of cellular damage that induce high glucose levels is cellular oxidative stress, a mechanism recognized in almost all tissues of the organism in uncontrolled diabetes mellitus. Oxidative stress was shown to induce glomerular inflammation, which increases glomerular volume; moreover, oxidative stress leads to glomerular function failures, especially an increase in urinary protein excretion and a decrease in glomerular filtration fraction [ 8 , 9 ].…”

Special Issue IJMS—Molecular Mechanisms of Diabetic Kidney Disease

“…A significant increase in the pro-inflammatory cytokines IL-6 and TNF-α was observed in the T2DM group. The authors concluded that in the patients with type 2 DM, oxidative imbalance was characterized by an increase in oxidative markers and a decrease in antioxidant defenses (SOD, TAC, and GPx) [7].…”