Analysis of the correlation between serum resistin and the variability of erythropoietin responsiveness in patients with chronic kidney disease

Beneficial and adverse effects of vitamin E on the kidney

This article reviews the beneficial and adverse effects of high-dose vitamin E supplementation on the vitamin E status and renal function in human and rodent studies. The high doses of vitamin E, which can cause renal effects, were compared to upper limits of toxicity (UL) as established by various authorities worldwide. In recent mice studies with higher doses of vitamin E, several biomarkers of tissue toxicity and inflammation were found to be significantly elevated. In these biomarker studies, the severity of inflammation and the increased levels of the biomarkers are discussed together with the need to re-evaluate ULs, given the toxic effects of vitamin E on the kidney and emphasizing oxidative stress and inflammation. The controversy in the literature about vitamin E effects on the kidney is mainly caused by the dose-effects relations that do not give a clear view, neither in human nor animals studies. In addition, more recent studies on rodents with new biomarkers of oxidative stress and inflammation give new insights into possible mechanisms. In this review, the controversy is shown and an advice given on the vitamin E supplementation for renal health.

Obesity and Chronic Kidney Disease A Current Review

Background

Obesity poses significant challenges to healthcare globally, particularly through its bi-directional relationship with co-morbid metabolic conditions such as type 2 diabetes and hypertension. There is also emerging evidence of an association between obesity and chronic kidney disease (CKD) which is less well characterized.

Methods

A literature search of electronic libraries was conducted to identify and present a narrative review of the interplay between obesity and CKD.

Findings

Obesity may predispose to CKD directly as it is linked to the histopathological finding of obesity-related glomerulopathy and indirectly through its widely recognized complications such as atherosclerosis, hypertension, and type 2 diabetes. The biochemical and endocrine products of adipose tissue contribute to pathophysiological processes such as inflammation, oxidative stress, endothelial dysfunction, and proteinuria. The prevention and management of obesity may prove critical in counteracting both the development and advancement of CKD. Moreover, measures of abdominal adiposity such as waist circumference, are generally associated with worse morbidity and mortality in individuals receiving maintenance hemodialysis.

Conclusion

Obesity is a risk factor for the onset and progression of CKD and should be recognized as a potential target for a preventative public health approach to reduce CKD rates within the general population. Future research should focus on the use of glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors in patients with CKD and obesity due to their multi-faceted actions on major outcomes.

The role of resistin and its relation to other pathogenetic factors of the chronic kidney disease development

Chronic kidney disease (CKD) is the leading cause of death from non-communicable diseases, and its prevalence in 2017 ranged from 8.5 to 9.8%. Depending on the stage of CKD, stage 1 was diagnosed in 3.5%, stage 2 in 3.2% and stage 3 in 7.6%, while stages 4 and 5 took place in 0.4 and 0.1% of the world’s population respectively. Obesity also contributes to the increase in the prevalence and severity of CKD, and their combination occurs in 3.1% of patients. Kidney damage and their structural and functional changes in patients with obesity are associated with high metabolic activity of adipose tissue, due to the synthesis of adipocytokines, including resistin.

The purpose of the work: to study changes of resistin level in the blood in patients with early stages of chronic kidney disease, its relation to the level of endothelin, markers of lipid metabolism and inflammation.

Materials and methods: 70 patients with stage 1 and 88 patients with stage 2 of CKD with different stages of obesity were examined. Glomerular filtration rate (GFR) was calculated by the formula CKD-EPI based on creatinine, cystatin C and their combination (CKD-EPIcysC / cr). The levels of cystatin C, resistin, tumor necrosis factor-alpha (TNF-α) and endothelin-1 were determined by enzyme-linked immunosorbent assay. Determination of total cholesterol and low-density lipoprotein cholesterol levels in the blood serum was performed by colorimetric method. Statistical analysis of the results was performed with the help of Statistica 6.0 statistical software package using Student’s t-test and Spearman’s rank correlation coefficient.

Results: an increase of the resistin level in the blood by 1.3 times in the patients with stage 1 CKD and by 1.6 times in the patients with stage 2 CKD and obesity was determined (p1.2 < 0.05), and there was a weak correlation between its concentration in the blood and body mass index. A significant average negative correlation between resistin and GFR was detected. Increased serum resistin level correlates with increased TNF-α. In patients of both groups, the level of resistin and LDL increases simultaneously, and the correlation between them increases as CKD progresses. Similar changes are observed with respect to increasing concentrations of resistin and endothelin-1. Thus, an increase of resistin level in the blood in patients with the early stages of CKD initiates a number of pathological changes, such as systemic inflammation, hyperlipidemia and endothelial dysfunction.

Association of genetic variants in RETN, NAMPT and ADIPOQ gene with glycemic, metabolic traits and diabetes risk in a Chinese population

Abnormal serum levels of adipokine have been established to be a strong predictor of developing several human diseases including type 2 diabetes mellitus (T2DM). Association studies have reported several genetic variants in genes coding adipokines with contributions to T2DM susceptibility as well as some glycemic and metabolic traits, of which the single nucleotide polymorphisms (SNPs) of RETN, NAMPT, and ADIPOQ gene were well documented. However, little is known about contributions of these SNPs to above phenotypes in Chinese. In the current study, with availably quantitative glycemic and metabolic data from a total of 185 T2DM patients and 191 healthy controls, we tested associations between four SNPs of RETN, NAMPT, ADIPOQ gene and 13 glycemic and metabolic traits. The results showed that the rs1862513 and rs34861192 of RETN gene were functional and negatively correlated with the levels of serum creatinine and cholesterol, respectively. The rs16861194 of ADIPOQ gene was positively correlated with the aspartate aminotransferase (AST) and AST/alanine aminotransferase level. Moreover, the rs34861192 and rs13237989 of NAMPT gene synergistically affected the levels of insulin and glycemic index. However, due to the limited sample size, only the rs16861194 exerted a significant increased risk on T2DM. These results underscore the contributions of SNPs in RETN, NAMPT, ADIPOQ gene to glycemic and metabolic traits as well as T2DM susceptibility in Chinese.