High-flux Hemodialysis Does Not Increase Vitamin B Loss Compared With Low-flux Hemodialysis.

OBJECTIVES: A consistent effect of hemodialysis (HD) on vitamin B loss has not been fully demonstrated and the effect of high-flux hemodialysis (HFHD) is also inconclusive. The aim of this study was to identify the loss of vitamin B1, B3, B5, and B6 in a single HD session and to evaluate the effect of HFHD on vitamin B removal. METHODS: Patients on maintenance HD were enrolled in this study. They were divided into low-flux hemodialysis (LFHD) group and HFHD group. Vitamin B1, B3, B5, and B6 (pyridoxal 5'-phosphate [PLP]) concentrations in blood pre- and post-HD sessions, as well as in the spent dialysate were measured. Loss of vitamin B was calculated and the difference in vitamin B loss between the 2 groups was compared. The association between HFHD and vitamin B loss was estimated using multivariable linear regression analysis. RESULTS: Seventy-six patients were included, of whom 29 were on LFHD and 47 were on HFHD. The median reduction ratio of serum vitamins B1, B3, B5, and B6 after a single HD session was 38.1%, 24.9%, 48.4%, and 44.7%, respectively. The median concentration of vitamins B1, B3, B5, and B6 in the dialysate was 0.3 µg/L, 2.9 µg/mL, 2.0 µg/L, and 0.4 ng/mL. There was no difference in either the reduction ratio of vitamin B in blood, or the concentration in dialysate between LFHD and HFHD groups. After adjusting for covariates by multivariable regression, HFHD had no effect on vitamin B1, B3, B5, or B6 removal. CONCLUSIONS: Vitamins B1, B3, B5, and B6 can be removed by HD and HFHD does not increase the loss.

There is no association of serum vitamin B levels with all-cause and cardiovascular mortality in hemodialysis patients.

INTRODUCTION: The impact of vitamin B metabolic disorders on hemodialysis (HD) patients' survival is unknown. This study is to investigate the association of serum vitamin B1, B3, B5, and B6 with all-cause and cardiovascular (CV) mortality in HD patients. METHODS: Patients' baseline serum vitamin B1, B3, B5, and B6 levels were collected, and they were followed up for the occurrence of all-cause and CV death. Kaplan-Meier analysis and Cox proportional hazards model were used to examine the association of vitamin B with mortality. RESULTS: Seventy-six HD patients were included. The median follow-up time was 99 months. Kaplan-Meier analysis showed that baseline vitamin B5 < 69.0 nmol/L and vitamin B6 < 8.1 ng/ml were associated with a higher risk of CV mortality, but these associations were nullified after adjustment. CONCLUSIONS: Serum vitamins B1, B3, B5, and B6 were not associated with all-cause or CV mortality in HD patients. CLINICAL TRIAL REGISTRY: ChiCTR2200057078 (Chinese Clinical Trial Registry, https://www.chictr.org.cn/).

The Influence of Altitude on Erythropoietin Resistance Index in Maintenance Hemodialysis Patients: Data from Tibetan Plateau.

BACKGROUND: It is known that hypoxia influences many of the biologic processes involved in erythropoiesis; therefore, the high-altitude hypoxia may affect erythropoietin (EPO) responsiveness in maintenance hemodialysis (MHD) patients. This study aimed to evaluate the impact of altitude on EPO responsiveness in MHD patients. METHODS: In this retrospective study, MHD patients from Tibet Autonomous Region People's Hospital (3,650 m above sea level) and Peking University People's Hospital (43.5 m above sea level) were recruited between May 2016 and December 2018. Patients were divided into 2 groups according to altitude. Variables including age, sex, dialysis vintage, dialysis modality, duration of EPO use, EPO doses, and laboratory tests were collected and analyzed. EPO responsiveness was measured in terms of the EPO resistance index (ERI). ERI was defined as the weekly weight-adjusted dose of EPO (IU/kg/week) divided by hemoglobin concentration (g/dL). The association between ERI and altitude was estimated using a multivariable linear regression model. RESULTS: Sixty-two patients from Tibet Autonomous Region People's Hospital (high-altitude [HA] group) and 102 patients from Peking University People's Hospital (low-altitude [LA] group) were recruited. The ERI for HA group and LA group was 6.9 ± 5.1 IU w-1 kg-1 (g/dL)-1 and 11.5 ± 6.4 IU w-1 kg-1 (g/dL)-1, respectively. After adjusting for covariates by multivariable regression, altitude was independently associated with ERI (R2 = 0.245, p < 0.001). CONCLUSION: Altitude had an independent negative correlation with ERI. This result supported the hypothesis that altitude-associated hypoxia improved EPO responsiveness in MHD patients.

Relationship of sRANKL level and vascular calcification score to cardiovascular events in maintenance hemodialysis patients.

BACKGROUND: Vascular calcification and cardiovascular events are common in hemodialysis patients. Receptor activator of nuclear factor-kappaB ligand (RANKL) plays an important role in vascular calcification and bone remodeling. This study investigates the effects of soluble RANKL (sRANKL) on cardiovascular events in hemodialysis patients. METHODS: Serum sRANKL levels of 47 patients were tested by ELISA. Vascular calcification was radiographically measured and patients were followed up for 2 years. RESULTS: After 2 years, 10 (36.6%) patients had experienced cardiovascular events. Seventy-five percent (6/9) of mortality was due to cardiovascular disease. Patients experiencing cardiovascular events showed significantly higher vascular calcification scores (VCS) (3.20 +/- 2.74 vs. 1.19 +/- 1.60; t = 2.999; p < 0.05). Multivariate regression analysis showed that serum sRANKL levels, vascular calcification scores and phosphorus were independent determinants of cardiovascular events. CONCLUSION: Serum sRANKL levels and VCS are independent risk factors, and hemodialysis patients with low serum sRANKL levels have a risk of cardiovascular events.

Vascular calcification in maintenance hemodialysis patients.

BACKGROUND: The objective was to investigate the status of vascular calcification, and to explore factors influencing vascular calcification in maintenance hemodialysis patients. METHODS: Vascular calcification was quantitatively evaluated using radiographic films of the abdomen, pelvis and hands. Plasma fetuin-A and other parameters related to calcification were examined. RESULTS: 33/50 cases of vascular calcification were identified by radiographic film. Calcifications of the abdominal aorta and peripheral muscular arteries were seen in 90.9 and 36.4%. Patients with moderate to severe calcification were older, more likely to be male, had lower diastolic blood pressure and fetuin-A levels, and a higher incidence of diabetes than those with mild calcification. Logistic regression analysis showed that diabetes and plasma fetuin-A were independent risk factors for vascular calcification. CONCLUSIONS: Vascular calcification was present in a large proportion of maintenance hemodialysis patients, most frequently in the abdominal aorta. Diabetes and plasma fetuin-A levels were independent risk factors for vascular calcification in maintenance hemodialysis patients.

[Effects of low molecular weight heparin on vascular endothelial growth factor expression of early diabetic nephropathy].

OBJECTIVE: To investigate the effects of low molecular weight heparin (LMWH) on vascular endothelial growth factor (VEGF) expression of early diabetic nephropathy. METHODS: Ninety-five male SD rats were randomly divided into three groups: normal control rats, STZ-induced diabetic rats and diabetic rats treated with LMWH. The renal tissues were subjected to immunohistochemical staining after 1, 2, 4, 6, and 8 weeks' treatment respectively to quantify the VEGF expression. RESULTS: Immunohistochemical staining demonstrated an increasing in VEGF positive cells in diabetic rats. It was found that there were significant differences in VEGF staining intensity between diabetic rats and normal control rats and between LMWH treated rats and untreated diabetic rats after two weeks treatment. CONCLUSION: The inhibition of VEGF expression may be one of the mechanisms of LMWH's renal protective effects on early diabetic nephropathy.