Increase in Oxidative Stress but Not in Antioxidant Capacity with Advancing Stages of Chronic Kidney Disease

Abstract

Background/Aims: Increased oxidative stress in chronic kidney disease (CKD) was suggested to be both a cause and an effect of renal injury. However, the evolution of oxidant stress from early stages of renal function decline is not fully clear. This study aimed to determine the oxidant-antioxidant balance across the whole range of renal function. Methods: A total of 116 patients with CKD (85 predialysis patients divided into groups according to CKD stage, and 31 patients with end-stage renal disease (ESRD) on hemodialysis treatment), as well as 29 healthy subjects were evaluated. Plasma levels of 15-F_2t-isoprostane (15-F_2t-IsoP), a valid marker of oxidant stress, as well as total antioxidant capacity (TAC) and serum levels of vitamin E were measured in all participants. Results: Plasma 15-F_2t-IsoP levels were higher in predialysis and ESRD patients compared to healthy subjects and were progressively increasing with advancing CKD stages (p < 0.001). In contrast, plasma TAC was similar between healthy subjects and predialysis patients, and presented a small reduction in ESRD patients (p < 0.001). Vitamin E levels were higher in healthy subjects compared to any other group (p < 0.001) and slightly higher in ESRD patients compared to predialysis patients (p < 0.01), but did not differ significantly between the groups of predialysis patients. Plasma 15-F_2t-IsoP levels were inversely correlated with estimated glomerular filtration rate in predialysis patients (r = –0.65, p < 0.001). Conclusions: This study shows that 15-F_2t-IsoP levels increase progressively with advancing CKD stages, whereas TAC and vitamin E levels remain rather stable with the loss of renal function and change only in patients with ESRD.

Relationship between glyco-oxidation, antioxidant status and microalbuminuria in type 2 diabetic patients

“…Aslan et al found lower serum levels of antioxidants in type 2 diabetic patients with microalbuminuria, but provided no data on glyco-oxidation [38]. Other authors found that serum levels of antioxidants were much the same and tended to remain stable in various stages of non-metabolic kidney disease (changing only in patients with end-stage renal disease) despite a progressive increase in oxidative stress [39]. Our data from the PCA analysis suggest that microalbuminuria in type 2 diabetic patients might be promoted by an insufficient counter-regulation of the antioxidant system in the event of increased glycooxidation/glycation.…”

Bardoxolone Methyl Decreases Megalin and Activates Nrf2 in the Kidney

“…[1][2][3][4][5] Indeed, oxidative stress and impaired antioxidant capacity intensify with progression of CKD, 6,7 and production of reactive oxygen species and oxidative stress result in activation of the transcription factor nuclear factor kB (NFkB). NFkB regulates expression of proinflammatory cytokines and chemokines, and its pathologic activation is a hallmark of many inflammatory disorders, including CKD.…”

Antioxidants deficiency: a sensitive indicator of cardiometabolic risk in chronic renal failure

“…They proposed that vitamin E supplementations could increase the levels of vitamin E as well as vitamin C. 22 Ioannis Karamouzis et al (2008) and Mehri Kadkhodaee et al (2008) observed lower values of plasma vitamin E in CRF patients as compared to controls. 23,24 Francesco Galli et al also observed decreased vitamin E levels in patients of chronic renal failure patients on hemodialysis. 25 In contrast, some studies have indicated normal or higher values of vitamin E in the chronic renal failure patients.…”