The Decrease in Serum Total Cholesterol and Low-Density Lipoprotein (LDL) Concentrations With the Initiation of Hemodialysis Despite a Concomitant Increase in Serum Albumin Concentrations

Background and objective Hemodialysis patients often have lower serum low-density lipoprotein (LDL) and total cholesterol concentrations compared to the general population. It is unclear if this is due to a persistent decline in the values due to kidney disease or if the hemodialysis itself is contributing to the lower values. It is often assumed that malnutrition and anorexia are the main causes of the low lipid concentration in hemodialysis patients. In this study, we aimed to determine the association between hemodialysis initiation and serum lipid and albumin concentrations. Methodology The medical records of all patients initiating hemodialysis over an 11-year period at a single center were retrospectively reviewed. The data of 145 patients who had all the required lab values available were ultimately included in the study. Serum lipid levels at the initiation of hemodialysis were compared to values obtained mostly 6-18 months later. In order to determine if poor nutritional status is the reason for the decline in serum lipid levels, the serum albumin concentration at the initiation of hemodialysis was compared to that obtained during follow-up labs. Results We observed that serum cholesterol concentration declined from an average of 147 mg/dL to 137 mg/dL, while LDL decreased from an average of 78 mg/dL to 68 mg/dL, and serum albumin concentration increased from 3.4 g/dL to 3.8 g/dL after an average follow-up period of 10.8 months. Conclusions Based on our findings, the decline in serum LDL and total cholesterol concentrations with the initiation of hemodialysis may not be attributed to poor nutritional intake.

Proteomics investigation of the changes in serum proteins after high- and low-flux hemodialysis

PURPOSE

This study aimed to use proteomics methods to investigate the changes in serum protein levels after high- and low-flux hemodialysis (HD).

METHODS

Before and after HD, serum samples were obtained from two selected patients who were treated with a Polyflux 140 H high-flux dialyzer and a Polyflux 14 L low-flux dialyzer during two continuous therapy sessions. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was performed to identify the proteins.

RESULTS

A total of 212 and 203 serum proteins were identified after high-flux and low-flux HD, respectively. After high-flux HD, 21 proteins increased, and 132 proteins decreased. After low-flux HD, 87 proteins increased, and 45 proteins decreased. High-flux HD led to a significantly greater reduction in protein levels than low-flux HD (0.73 ± 0.13 vs. 0.84 ± 0.18, p = .00). Among the increased and decreased proteins, the isoelectric point (pI) values mainly ranged from 5 to 7, and the molecular weights (Mws) were mostly smaller than 30 kDa. The serum proteins showed no difference in pI or Mw for high- and low-flux HD. Gene ontology (GO) analysis showed that the detected proteins were related to immune system processes and complement activation.

CONCLUSIONS

Serum protein levels differentially changed after high- and low-flux HD. Long-term effects should be observed in future studies.

Improving Erythropoiesis Stimulating Agent Hyporesponsiveness in Hemodialysis Patients: The Role of Hepcidin and Hemodiafiltration Online

Hyporesponsiveness to erythropoietin stimulating agents (ESAs) is a condition associated with increased mortality. Even after identifying the condition, the causes are difficult to treat and only partially reversible in end-stage renal disease patients. Thus, the role of more recent hemodialysis (HD) techniques in improving such conditions is an emerging issue. However, major randomized clinical trials have not confirmed the results of smaller observational studies in which online hemodiafiltration has shown some efficacy in improving patients' response to ESAs. In our interpretation, these findings are not in contrast, but they can be explained by a better understanding of the interactions between HD and ESAs on iron mobilization, first of all through the role of hepcidin. The kinetics of hepcidin removal through HD combined with the action of selected ESAs may help the clinician in prescribing the best association between HD treatment and ESAs to overcome hyporesponsiveness.

The relationship between hemodialysis modality and insulin resistance in non-diabetic hemodialysis patients

BACKGROUND

Although various modalities of hemodialysis (HD) are presumed to have different effects on insulin resistance (IR), the relationship between hemodiafiltration (HDF) and IR has not been fully evaluated.

METHODS

In a cross-sectional study, 82 non-diabetic HD patients were enrolled. The patients were divided into two groups according to the median homeostasis model assessment index (HOMA-IR) value of 1.685. Clinical and biochemical data were compared, and multivariate logistic regression analysis was performed to identify the independent factors associated with higher HOMA-IR.

RESULTS

The higher HOMA-IR group had increased body mass index (BMI), decreased HDL cholesterol, and lower beta-2 microglobulin reduction rate (β2-MG RR) compared to the lower HOMA-IR group. HOMA-IR was significantly correlated with β2-MG RR. In addition, HDF patients had lower HOMA-IR levels compared with low flux hemodialysis patients. On multivariate logistic regression analysis, BMI and HDF treatment were independent factors associated with higher and lower HOMA-IR, respectively.

CONCLUSION

This study suggests that HDF treatment may reduce IR in non-diabetic HD patients.