Relative risk for cardiovascular morbidity in hemodialysis patients regarding gene polymorphism for IL-10, IL-6, and TNF

Higher Muscle Mass and Higher Serum Prealbumin Levels Are Associated with Better Survival in Hemodialysis Patients during a Five-Year Observation Period

BACKGROUND

Dialysis is the most commonly used renal replacement therapy in patients with end-stage renal disease. The mortality rate of hemodialysis patients is 15-20%, with cardiovascular complications being the most common. There is an association between the severity of atherosclerosis and both the development of protein-calorie malnutrition and inflammatory mediators. The aim of this study was to assess the relationship between biochemical markers of nutritional status, body composition and survival in hemodialysis patients.

METHODS

Fifty-three hemodialysis patients were included in the study. Serum albumin, prealbumin, and IL-6 levels were measured, as well as body weight, body mass index, fat content and muscle mass. The five-year survival of patients was calculated using Kaplan-Meier estimators. The long-rank test was used for univariate comparison of survival curves, and the Cox proportional hazards model was used for multivariate analysis of survival predictors.

RESULTS

There were 47 deaths, 34 of which were due to cardiovascular disease. The hazard ratio (HR) for age in the middle-aged group (55-65 years) was 1.28 (confidence interval [CI] 0.58, 2.79) and 5.43 (CI 2.1, 14.07; statistically significant) for the oldest age group (over 65 years). A prealbumin level above 30 mg/dl was associated with an HR of 0.45 (CI 0.24, 0.84). Serum prealbumin (odds ratio [OR] = 5.23; CI 1.41, 19.43; p = 0.013) and muscle mass (OR = 7.5; CI 1.31, 43.03; p = 0.024) were significant predictors of all-cause mortality.

CONCLUSIONS

Prealbumin level and muscle mass were associated with increased mortality risk. Identification of these factors may improve the survival of hemodialysis patients.

Opportunities and Challenges for Genetic Studies of End-Stage Renal Disease in Canada

Purpose of review:

Genetic testing can improve diagnostic precision in some patients with end-stage renal disease (ESRD) providing the potential for targeted therapy and improved patient outcomes. We sought to describe the genetic architecture of ESRD and Canadian data sources available for further genetic investigation into ESRD.

Sources of information:

We performed PubMed searches of English, peer-reviewed articles using keywords “chronic kidney disease,” “ESRD,” “genetics,” “sequencing,” and “administrative databases,” and searched for nephrology-related Mendelian diseases on the Online Mendelian Inheritance in Man database.

Methods:

In this narrative review, we discuss our evolving understanding of the genetic architecture of kidney disease and ESRD, the risks and benefits of using genetic data to help diagnose and manage patients with ESRD, existing public Canadian biobanks and databases, and a vision for future genetic studies of ESRD in Canada.

Key findings:

ESRD has a polygenic architecture including rare Mendelian mutations and common small effect genetic polymorphism contributors. Genetic testing will improve diagnostic accuracy and contribute to a precision medicine approach in nephrology. However, the risk and benefits of genetic testing needs to be considered from an individual and societal perspective, and further research is required. Merging existing health data, linking biobanks and administrative databases, and forming Canadian collaborations hold great potential for genetic research into ESRD. Large sample sizes are necessary to perform the suitably powered investigations required to bring this vision to reality.

Limitations:

This is a narrative review of the literature discussing future directions and opportunities. It reflects the views and academic biases of the authors.

Implications:

National collaborations will be required to obtain sample sizes required for impactful, robust research. Merging established datasets may be one approach to obtain adequate samples. Patient education and engagement will improve the value of knowledge gained.

Polymorphism related to cardiovascular risk in hemodialysis subjects: a systematic review

Cardiovascular disease (CVD) is one of the leading causes of mortality in hemodialysis (HD) subjects. In addition to the traditional risk factors that are common in these individuals, genetic factors are also involved, with emphasis on single nucleotide polymorphs (SNPs). In this context, the present study aims to systematically review the studies that investigated the polymorphisms associated with cardiovascular risk in this population. In general, the SNPs present in HD individuals are those of genes related to inflammation, oxidative stress and vascular calcification, also able of interfering in the cardiovascular risk of this population. In addition, polymorphisms in genes related to recognized risk factors for CVD, such as dyslipidemia, arterial hypertension and left ventricular hypertrophy, also influence cardiovascular morbidity and mortality.

Cytokines Genotype-Phenotype Correlation in Nonalcoholic Steatohepatitis

NASH consists in lipid accumulation in hepatocytes that trigger oxidative stress, secretion of proinflammatory cytokines leading to steatohepatitis (NASH). The study aimed to investigate the levels of proinflammatory (TNF-α and IL-6) along with anti-inflammatory cytokine IL-10 in patients with NASH and to correlate the cytokines' level with their polymorphism. Sixty-six patients with NASH and 30 healthy volunteers were included in the study. The plasmatic level of IL-6, IL-10, and TNF-α were determined by ELISA. IL-10 -1082 G/A, IL-6 -174 G/C, and TNF-α -308 G/A polymorphisms were determined using the PCR-RFLP technique. IL-6, TNF-α, and CRP levels were significantly higher in patients with NASH. There was a positive correlation between proinflammatory cytokines and a negative correlation between IL-10 and proinflammatory markers. The G allele and GG genotype of IL-6 -174 G/C polymorphism were more frequently noticed in NASH patients. Regarding IL-10 -1082 G/A polymorphism, the AA genotype was correlated with NASH and with a low plasmatic level of IL-10. The A allele in position 308 of the TNF-α gene was associated with high level of cytokine. In conclusion, there was an imbalance between pro- and anti-inflammatory cytokines in NASH patients. IL-10 -1082 G/A and TNF-α -308 G/A genotypes were correlated with the plasmatic levels of cytokines.