Does inflammation affect outcomes in dialysis patients?

Association of depressive symptoms with 25(OH) vitamin D in hemodialysis patients and effect of gender

BACKGROUND

Depression is common in chronic kidney disease (CKD) patients and associated with significant increase in morbidity and mortality. In recent years, a relationship between vitamin D deficiency and depression has been shown. The aim of this study is to investigate the relationship between 25-hydroxy (OH) vitamin D and depression in hemodialysis patients.

METHODS

A total of 140 patients were included in the study. Hamilton depression scale (HAM-D) was completed by all patients. 25(OH) vitamin D levels were compared between patients with and without depressive symptoms.

RESULTS

Patients who had depressive symptoms had significantly lower 25(OH) vitamin D levels (13.70 [24.3-8.25] vs. 18.20 [29.2-11.7] ng/mL, p = 0.016). HAM-D score showed significant association with gender (p = 0.011) and 25(OH) vitamin D level (p = 0.011). Univariate logistic regression analysis showed that males had lower risk of depression by a ratio of 61.1% (OR 0.389, p = 0.012) and vitamin D-deficient patients had 2.88 times greater risk of depression compared to non-deficient patients (OR 2.885, p = 0.013). Multivariate logistic regression analysis showed that males had 53.7% less risk of depression (OR 0.463, p = 0.046) and vitamin D-deficient patients had 2.39 times greater risk of depression (OR 2.397, p = 0.047). When evaluated by gender, univariate logistic regression analysis showed that 25(OH) vitamin D and other variables were not associated with depression in females (p > 0.05), while only vitamin D level had a significant effect on depression in males (OR 8.207, p = 0.008).

CONCLUSIONS

We found a significant association between vitamin D level and depressive symptoms in hemodialysis patients. When analyzed according to gender, this association was found to stand independent of other variables only in males.

Influence of dry weight reduction on anemia in patients undergoing hemodialysis

Objective

Volume load in patients undergoing hemodialysis correlates with renal anemia, with reductions in volume load significantly improving hemoglobin levels. We performed a prospective controlled study to assess the effect of post-dialysis dry weight reduction, resulting from the gradual enhancement of ultrafiltration, on renal anemia in this patient population.

Methods

Sixty-four patients with renal anemia on maintenance hemodialysis were randomized to an ultrafiltration group, in which dry weight was gradually reduced by slightly increasing the ultrafiltration volume while maintaining routine hemodialysis, and a control group, in which patients underwent conventional dialysis while routine ultrafiltration was maintained. After 28 weeks, post-dialysis weight and levels of hematocrit, hemoglobin, C-reactive protein, serum albumin, serum ferritin, and transferrin saturation were compared.

Results

All parameters were similar at baseline between the two groups and remained unchanged at week 28 in the control group compared with baseline. In contrast, the ultrafiltration group showed a significant reduction in post-dialysis weight and C-reactive protein concentration and a significant increase in hematocrit, hemoglobin, albumin, serum ferritin, and transferrin saturation.

Conclusions

Dry weight reduction resulting from enhanced ultrafiltration may improve renal anemia in patients undergoing hemodialysis.

Association of serum chromium levels with malnutrition in hemodialysis patients

BACKGROUND

Chromium is an essential trace metal that reduces oxidative stress and inflammation. In patients undergoing maintenance hemodialysis (MHD), a correlation among chromium exposure, inflammation, and malnutrition remains unclear. This study examined the possible effects of serum chromium levels (SCLs) in MHD patients.

METHODS

Initially, 732 MHD patients in dialysis centers were recruited. A total of 647 patients met the inclusion criteria and were stratified by SCL into four equal-sized groups: first quartile (< 0.29 μg/L), second quartile (0.29-0.56 μg/L), third quartile (0.57-1.06 μg/L), and fourth quartile (> 1.06 μg/L). Demographic, biochemical, and dialysis-related data were obtained for analyses. The analysis included nutritional and inflammatory markers.

RESULTS

As compared with the highest quartile group, more subjects in the lowest quartile group were of an older age; had lower hemoglobin and creatinine levels; had a higher prevalence of DM and malnutrition (serum albumin level < 3.6 g/dL); and higher serum transferrin saturation and ferritin levels. A stepwise multiple linear regression analysis revealed a significant negative correlation between malnutrition and SCL (β coefficient = - 0.129, p = 0.012) and negative associations among body mass index (β coefficient = - 0.010, p = 0.041), ferritin (β coefficient = - 0.107, p = 0.001) and SCL. A multivariate logistic regression analysis also demonstrated a negative correlation between malnutrition and SCL. With a 10-fold increase in SCL, the risk ratio of malnutrition was 0.49 (95% confidence interval: 0.25-0.96; p = 0.039).

CONCLUSIONS

SCL is significantly associated with malnutrition in MHD patients. Further evaluation of the relationship between clinical outcomes (morbidity/mortality) and SCL is necessitated.

The relationship of blood neutrophil-to-lymphocyte ratio with nutrition markers and health outcomes in hemodialysis patients

OBJECTIVE

Adverse outcomes in hemodialysis patients have been attributed, in part, to the pro-inflammatory state prevalent in this population. This study examines the relationship between blood neutrophil-to-lymphocyte ratio (NLR) with nutrition markers and health outcomes in hemodialysis (HD) patients.

DESIGN

This is a 12-month prospective cohort study that recruited 77 participants from May to Jun 2017.

SETTINGS AND SUBJECTS

Patients receiving maintenance hemodialysis.

MAIN OUTCOMES

Hospitalization, transplants and mortality.

RESULTS

Of the 77 participants, 63.8% were hospitalized, 10 (13%) died of cardiovascular diseases and 6 (7.8%) had a kidney transplant. Spearman correlations using baseline values showed an inverse significant correlation between the total number of hospitalizations and BMI kg/m2 (BMI rho = - 0.37, P <0.001); a significant inverse correlation between NLR and albumin (rho = - 0.22, P  = 0.028); and a significant direct correlation between baseline NLR and BMI kg/m2 (rho = 0.22, P  = 0.028). Participants were grouped by their NLR value into quartiles for outcomes analysis: quartile 1 (NLR ≤ 1.75), quartile 2 (NLR 1.76-2.6), quartile 3 (NLR 2.7-3.9) and quartile 4 (NLR ≥ 4). The percentage of patients with the lowest level of inflammation (NLR ≤ 1.75) was greater for not hospitalized patients than for hospitalized (39.3% vs 16.3%, P  = 0.025) and not hospitalized participants had higher BMI kg/m2 (mean ± SD) at baseline compared to those hospitalized (29.11 ± 5.4 vs 26.22 ± 5.34, P  = 0.026). In a multivariate cox regression analysis, participants in the lowest quartile (NLR ≤ 1.75) were compared to the rest on hospitalization, mortality and transplant. Years in dialysis, BMI kg/m2 and NLR ≤ 1.75 were significant predictors of hospitalization after adjustment (P  = 0.021, P  = 0.005, P  = 0.039; respectively) and we observed an association of low NLR with a hazard ratio (HR 0.44, 95% CI 0.20-0.96, P  =  0.039), BMI (HR 0.90, 95% CI 0.85-0.97, P  = 0.005) and years in dialysis (HR 0.90, 95% CI 0.83-0.98, P  = 0.021) for hospitalization in overall participants. In a further analysis comparing the effect of low NLR in the subgroup of diabetic vs non-diabetics, it was observed that BMI kg/m2 was a significant predictor for hospitalization in the non-diabetic subgroup (P  = 0.040) but not significant in the case of diabetics (P  = 0.128) after adjustments. Years in dialysis and NLR ≤ 1.75 were significant predictors of hospitalizations in the subgroup of diabetic before and after adjustment (P  = 0.049, P  = 0.044; respectively). Having a low NLR decreased 73% the risk for hospitalization (HR 0.27 95% CI 0.07-0.96, P  = 0.044) in this subgroup. Survival and hospitalization curves were analyzed by comparing all participants and the diabetic subgroup, in the lowest inflammation quartile vs the rest (NLR ≤ 1.75 vs NLR > 1.75). Participants with NLR ≤ 1.75 had 100% survival rate (log-rank test, P  = 0.059) and lower hospitalization rate (log-rank test, P  = 0.025); participants with diabetes had lower hospitalization rate (log-rank test, P  = 0.039).

CONCLUSION

NLR at baseline was associated with nutritional markers (albumin, BMI). Low NLR at baseline was a predictor of lower risk for hospitalizations in HD patients with diabetes.

Butyrate production in patients with end-stage renal disease

Background: Chronic kidney disease (CKD) is associated with a decreased intestinal barrier function, causing bacterial translocation over the intestinal wall and triggering a systemic inflammatory response. Butyrate, a short-chain fatty acid produced by certain bacterial strains, is considered instrumental to keep the intestinal barrier intact. There are indications that a decreased amount of these specific bacterial species is part of the cause of the decreased intestinal barrier function in CKD. The aim of this study is (i) to determine if Dutch patients with end-stage renal disease (ESRD) have a decreased amount of butyrate-producing species and butyrate-producing capacity and (ii) whether this correlates with systemic inflammation. Methods: We used qPCR to evaluate the most abundant butyrate-producing species F. prauznitzii, E. rectale and Roseburia spp. and the BCoAT gene, which reflects the butyrogenic capacity of the intestinal microbiota. Fecal samples were collected from healthy kidney donors (n=15), preemptive renal transplant recipients (n=4) and dialysis patients (n=31). Markers of inflammation (CRP and IL-6) and intestinal permeability (D-lactate) were measured in plasma. Results: Patients with ESRD did not have a significantly decreased amount F. prauznitzii, E. rectale and Roseburia spp. or the BCoAT gene. Neither was there a significant correlation with CRP, IL-6 or D-lactate. On the individual level, there were some patients with decreased BCoAT levels and increased levels of CRP, IL-6 and D-lactate. Conclusions: Patients with ESRD do not have a decreased amount of the most abundant butyrate-producing species nor a decreased butyrate-producing capacity.

Sudden Cardiac Death in Dialysis: Arrhythmic Mechanisms and the Value of Non-invasive Electrophysiology

Sudden Cardiac Death (SCD) is the leading cause of cardiovascular death in dialysis patients. This review discusses potential underlying arrhythmic mechanisms of SCD in the dialysis population. It examines recent evidence from studies using implantable loop recorders and from electrophysiological studies in experimental animal models of chronic kidney disease. The review summarizes advances in the field of non-invasive electrophysiology for risk prediction in dialysis patients focusing on the predictive value of the QRS-T angle and of the assessments of autonomic imbalance by means of heart rate variability analysis. Future research directions in non-invasive electrophysiology are identified to advance the understanding of the arrhythmic mechanisms. A suggestion is made of incorporation of non-invasive electrophysiology procedures into clinical practice. Key Concepts: - Large prospective studies in dialysis patients with continuous ECG monitoring are required to clarify the underlying arrhythmic mechanisms of SCD in dialysis patients. - Obstructive sleep apnoea may be associated with brady-arrhythmias in dialysis patients. Studies are needed to elucidate the burden and impact of sleeping disorders on arrhythmic complications in dialysis patients. - The QRS-T angle has the potential to be used as a descriptor of uremic cardiomyopathy. - The QRS-T angle can be calculated from routine collected surface ECGs. Multicenter collaboration is required to establish best methodological approach and normal values. - Heart Rate Variability provides indirect assessment of cardiac modulation that may be relevant for cardiac risk prediction in dialysis patients. Short-term recordings with autonomic provocations are likely to overcome the limitations of out of hospital 24-h recordings and should be prospectively assessed.

Hemoglobin targets for the anemia in patients with dialysis-dependent chronic kidney disease: a meta-analysis of randomized, controlled trials

BACKGROUND

Anemia is extremely common among dialysis patients and underlies some of the symptoms associated with reduced kidney function, including fatigue, depression, reduced exercise tolerance, and dyspnea.

OBJECTIVES

A clearer cognition of the prognosistic impact of hemoglobin (Hb) or hematocrit (Hct) target for the outcomes of dialysis patients is urgent. This article aims to establish the suitable hemoglobin in order to provide clinical guidance.

METHODS

MEDLINE, EmBase, the Cochrane Library and other databases were searched with both MeSH terms and keywords to gather randomized controlled trials that assessed all-cause mortality, cardiovascular events, fistula thrombosis, infectious diseases and transfusion among dialysis-dependent patients using erythropoiesis-stimulating agents. The meta-analysis was accomplished via Revman 5.3 version.

FINDINGS

Totally, nine eligible studies were included, with study subjects involving 3228 patients. There was a significantly higher risk of fistula thrombosis without heterogeneity (RR 1.34, 95% CI 1.15-1.55; p < 0.05) in the higher Hb target group than in the lower Hb target group in the fixed effects model. However, no significant difference was found in all-cause mortality in the fixed effects model (RR 1.09, 95% CI 0.93-1.27; p = 0.30), cardiovascular events (RR 0.77, 95% CI 0.31-1.92; p = 0.58), infectious diseases (RR 0.69, 95% CI 0.24-1.96; p = 0.49) and transfusion (RR 0.92, 95% CI 0.42-1.99; p = 0.82) in the random effects model between the higher Hb target group and the lower Hb target group.

DISCUSSION

The results favor lower Hb target. To target lower Hb target when treating dialysis patients with anemia may decrease the risk of fistula thrombosis without increasing the risk of death, cardiovascular events, infectious diseases and transfusion.