Role of neutrophil extracellular traps in vascular access thrombosis in hemodialysis patients

BACKGROUND

A patent vascular access (VA) is a lifeline for hemodialysis (HD) patients. However, vascular access is prone to thrombosis, which, if left untreated, can lead to permanent VA loss and increased mortality. Neutrophil extracellular traps (NETs) are known to be involved in intravascular thrombosis. We evaluated the relationship between NETs and VA thrombosis and their impact on VA prognosis.

METHODS

A total of 189 patients with VA flow problems were enrolled. Among these, 93 patients underwent percutaneous transluminal angioplasty (PTA) for stenosis, and 96 patients underwent PTA with thrombectomy for thrombosis. Plasma nucleosome, myeloperoxidase-DNA complex, and von Willebrand factor (vWF) were measured as markers of circulating NETs and thrombosis risk, respectively. The primary outcome was permanent VA loss and the secondary outcome was recurrent thrombotic occlusion within 6 months. In addition, the presence of NETs in thrombi was evaluated by histopathological analysis.

RESULTS

Circulating nucleosome levels were closely associated with plasma vWF levels (r = 0.172, p = 0.025), and both were higher in thrombectomy cases than in PTA alone cases (nucleosome; 0.83 ± 0.70 vs. 0.35 ± 0.26, p < 0.001, vWF: 9.0 ± 7.6 vs. 7.3 ± 6.2, p = 0.038). The highest quartile of nucleosomes (Q4) was associated with an 18-fold increased rate of access thrombotic occlusion (p < 0.001). In addition, multivariate analysis showed that the rates of permanent access loss (HR 2.77, 95 % CI 1.35-5.77) and recurrent thrombosis (HR 2.35, 95 % CI 1.22-4.54) were much higher in patients with the Q4 nucleosome group than in those with Q1-3. In addition, higher neutrophil infiltration and NET expression in thrombi were also associated with poor VA prognosis.

CONCLUSIONS

Higher levels of circulating NETs and the amount of NET expression in thrombi may be associated with VA thrombosis and poor VA outcomes.

Exploring the Link between Chronic Kidney Disease and Alzheimer's Disease: A Longitudinal Follow-Up Study Using the Korean National Health Screening Cohort

Chronic kidney disease (CKD) and Alzheimer's disease (AD) are common chronic diseases in the elderly population. Although a relationship between CKD and the occurrence of AD has been proposed, previous research results have been disputed, and further investigation is necessary to confirm this relationship. In this longitudinal follow-up study, we examined data from the Korean National Health Insurance Service-Health Screening Cohort, consisting of 15,756 individuals with CKD and 63,024 matched controls aged ≥40 years who received health check-ups between 2002 and 2019. Overlap-weighted Cox proportional hazard regression models were exploited to calculate hazard ratios (HRs) for the association between CKD and AD. During the monitoring period, individuals with CKD had a greater incidence of AD than those without CKD (15.80 versus 12.40 per 1000 person years). After accounting for various factors, CKD was significantly associated with a 1.14-fold increased likelihood of developing AD, with a 95% confidence interval ranging from 1.08 to 1.20. In subgroup analysis, this relationship persisted irrespective of age (≥70 or <70), sex, income, smoking status, alcohol consumption, place of residence, or fasting blood glucose level. Additionally, the association between CKD and AD was still evident among patients who were overweight or obese, those with normal blood pressure or cholesterol levels, and those without any other health conditions or with a CCI score of ≥2. These results suggest that CKD could increase the probability of developing AD in the Korean adult population irrespective of demographic or lifestyle conditions. This may make it challenging to predict AD in patients with CKD, emphasizing the importance of frequent AD screening and management.

Elevated Ferritin Levels Associated with High Body Fat Mass Affect Mortality in Peritoneal Dialysis Patients

Obesity is a common health problem in peritoneal dialysis (PD) patients and causes high serum ferritin levels. However, mixed results have been reported on whether serum ferritin levels affect the prognosis of PD patients. We investigated the effect of increased adiposity on ferritin levels and its association with mortality in 350 well-nourished PD patients. Body composition was measured using a portable whole-body bioimpedance spectroscope, and clinical determinants of high ferritin levels were evaluated. High ferritin levels (≥600 ng/mL) were observed in 63 (18.0%) patients. Patients with high ferritin levels had a significantly higher body fat percentage and a lower lean tissue index than patients with low or normal ferritin levels. During a median follow-up of 30 months, there were 65 deaths. Ferritin ≥ 600 ng/mL was associated with significantly higher all-cause mortality compared with 200-600 ng/mL of ferritin. Multivariate analysis showed that high ferritin levels were significantly associated with a higher percentage of body fat after adjustment for lean tissue index and volume status. High ferritin increased all-cause mortality in PD patients, and increased fat mass was an important determinant of the high ferritin. Our results support that adiposity may lead to an adverse clinical outcome in PD patients.

High-field magnetization and electronic spin resonance study in the twisted honeycomb latticeα-Mn2V2O7

We report the single-crystal growth of Mn₂V₂O₇and the results of magnetic susceptibility, high-field magnetization up to 55 T and high-frequency electric spin resonance (ESR) measurements for its low-temperatureαphase. Two antiferromagnetic (AFM) ordering at 17.5 K and 3 K and obvious magnetic anisotropy are observed inα-Mn₂V₂O₇upon cooling. In pulsed high magnetic fields, the compound reaches the saturation magnetic moment of ∼10.5μ_Bfor each molecular formula at around 45 T after two undergoing AFM phase transitions atH_c1≈ 16 T,H_c2≈ 34.5 T forH//[11-0] andH_sf1= 2.5 T,H_sf2= 7 T forH//[001]. In these two directions, two and seven resonance modes are detected by ESR spectroscopy, respectively. Theω₁andω₂modes ofH//[11-0] can be well described by two-sublattice AFM resonance mode with two zero-field gaps at 94.51 GHz and 169.28 GHz, indicating a hard-axis feature. The seven modes forH//[001] are partially separated by the critical fields ofH_sf1andH_sf2, displaying the two signs of spin-flop transition. The fittings ofω_c1andω_c2modes yield zero-field gaps at 69.50 GHz and 84.73 GHz forH//[001], confirming the axis-type anisotropy. The saturated moment and gyromagnetic ratio indicate the Mn²⁺ion inα-Mn₂V₂O₇is in a high spin state with orbital moment completely quenched. A quasi-one-dimensional magnetism with a zig-zag-chain spin configuration is suggested inα-Mn₂V₂O₇, due to the special neighbor interactions caused by a distorted network structure with honeycomb layer.

Impact of needle type on substitution volume during online hemodiafiltration: plastic cannulae versus metal needles

BACKGROUND

Plastic cannulae have attracted increasing interest as an alternative to traditional metal needles with the aim of reducing cannulation-related complications. We investigated whether the substitution volumes during hemodiafiltration differ using these two types of needles in dialysis patients.

METHODS

An intervention study involving 26 hemodialysis patients was conducted in Korea between March and September in 2021. Patients first received online hemodiafiltration using traditional metal needles, and thereafter plastic cannulae were used in a stepwise protocol. Repeated-measures design and linear mixed-effect models were used to compare substitution volumes between the two needle types with the same inner diameter.

RESULTS

The mean patient age was 62.7 years, and their mean dialysis vintage was 95.2 months. Most patients (92.3%) had an arteriovenous fistula as the vascular access. The substitution volume increased as blood flow and needle size increased for both plastic cannulae and metal needles. The substitution volume was significantly higher with 17-gauge (G) plastic cannulae than with 16-G metal needles at blood flow rates of 280, 300, and 330 mL/min. Similar results were obtained for 15-G metal needles and 16-G plastic cannulae at a blood flow rate of 330 mL/min. However, the patient ratings of pain on a visual analogue scale were higher for plastic cannulae.

CONCLUSION

Higher substitution volumes were obtained at the same prescribed blood flow rate with plastic cannulae than with metal needles during online hemodiafiltration. Plastic cannulae are an option for achieving high-volume hemodiafiltration for patients with low blood flow rates.

Effect of once-weekly dulaglutide on renal function in patients with chronic kidney disease

Background

Dulaglutide is associated with improved cardiovascular and kidney outcomes and can be a good therapeutic option for patients with type 2 diabetes with chronic kidney disease (CKD). In this study, the effects of dulaglutide on glucose-lowering efficacy and changes in renal function were analyzed.

Methods

This retrospective study involved 197 patients with type 2 diabetes with mild-to-severe CKD treated with dulaglutide for at least 3 months between January 2017 and December 2020 at two tertiary hospitals in Korea. Changes in the creatinine-based estimated glomerular filtration rate (eGFR) and HbA1c were compared before and after the use of dulaglutide in each patient.

Results

The number of patients and mean eGFR (mL/min/1.73 m²) in CKD 2, 3a, 3b, and 4 were 94 (75.0 ± 8.5), 46 (54.8 ± 6.3), 31 (38.8 ± 4.4), and 26 (22.5 ± 5.4), respectively. Mean HbA1c level and body mass index (BMI) at the initiation of dulaglutide were 8.9% ± 1.4% and 29.1 ± 3.6 kg/m², the median duration of the use of dulaglutide was 16 months. The use of dulaglutide was associated with a mean decrease in HbA1c by 0.9% ± 1.5% and the glucose-lowering efficacy was similar across all stages of CKD. Also, it was associated with a reduced decline in the eGFR; the mean eGFR change after the use of dulaglutide was –0.76 mL/min/1.73 m² per year, whereas it was –2.41 mL/min/1.73 m² before use (paired t-test, P = 0.003). The difference was more pronounced in patients with an eGFR < 60 mL/min/1.73 m². Subgroup analysis showed that the renal protective effect was better in patients with proteinuria, age ≤ 65 years, and HbA1c < 9.0%, but showed no association with BMI.

Conclusions

The use of dulaglutide provided adequate glycemic control irrespective of CKD stage and was associated with a reduced decline in the eGFR in the CKD population.

High-flow arteriovenous fistula and myocardial fibrosis in hemodialysis patients with non-contrast cardiac magnetic resonance imaging

Background

The role of high-flow arteriovenous fistula (AVF) in cardiovascular morbidity in hemodialysis (HD) patients is very likely under-recognized. We assessed the relationship between high access flow (Qa) and myocardial fibrosis in HD patients.

Methods

Myocardial fibrosis was assessed by native T1 relaxation times on non-contrast cardiac magnetic resonance imaging and a potential marker of fibrosis. Serum levels of galectin-3, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and monocyte chemoattractant protein 1 (MCP-1) were measured in 101 HD patients who underwent regular monitoring of AVF Qa. A high-flow AVF was defined as a Qa >2 L/min.

Results

Hemodialysis patients showed significantly higher galectin-3 value and increased T1 relaxation time compared to healthy volunteers, suggesting increased myocardial fibrosis in uremic cardiomyopathy. In HD patients, 20 (19.8%) had a Qa > 2L/min, and they had significantly higher cardiac output, cardiac index, left ventricular mass, and increased T1 times than those with a Qa ≤ 2 L/min. Also, serum galectin-3 and NT-proBNP levels were much higher in the high Qa group, indicating a close relationship between the high Qa, increased myocardial fibrosis, and the risk of heart failure (HF) in HD patients. It is interesting that a higher AVF Qa for myocardial fibrosis was independent of several traditional cardiovascular risk factors as well as serum levels of NT-proBNP and MCP-1.

Conclusions

A supra-physiologically high Qa can be related to myocardial fibrosis and increased risk of HF in HD patients. Regular Qa monitoring could allow early detection of a high-flow AVF that could arise cardiac complications.

Serum cystatin C to creatinine ratio is associated with sarcopenia in non-dialysis-dependent chronic kidney disease

Background

Methods

Results

Conclusion

When and why to start continuous renal replacement therapy in critically ill patients with acute kidney injury

Acute kidney injury (AKI) is a common condition in critically ill patients, and may contribute to significant medical, social, and economic consequences, including death. Although there have been advances in medical technology, including continuous renal replacement therapy (CRRT), the mortality rate of AKI is high, and there is no fundamental treatment that can reverse disease progression. The decision to implement CRRT is often subjective and based primarily on the clinician’s judgment without consistent and concrete guidelines or protocols regarding when to initiate and discontinue CRRT and how to manage complications. Recently, several randomized controlled trials addressing the initiation of renal replacement therapy in critically ill patients with AKI have been completed, but clinical application of the findings is limited by the heterogeneity of the objectives and research designs. In this review, the advantages and disadvantages of CRRT initiation, clinical guideline recommendations, and the results of currently published clinical trials and meta-analyses are summarized to guide patient care and identify future research priorities.

Neutrophil extracellular traps and heparin-induced antibodies contribute to vascular access thrombosis in hemodialysis patients

Background

Anti-heparin/platelet factor 4 (PF4) antibodies may trigger severe thrombotic complications in hemodialysis (HD) patients. Tetrameric PF4 has a high affinity for extracellular DNA, which is a key component of neutrophil extracellular traps (NETs); therefore, the interactions between anti-heparin/PF4 antibodies and NETs can contribute to prothrombotic events.

Methods

Anti-heparin/PF4 antibody levels were measured by enzyme-linked immunosorbent assay and an optical density > 1.8 was regarded as clinically significant. We additionally measured serum nucleosome levels as representative markers of NETs, and the contributions of anti-heparin/PF4 and increased serum nucleosome levels to the primary functional patency loss of vascular access was assessed.

Results

The frequency of anti-heparin/PF4 antibodies was significantly higher in incident HD patients compared to prevalent HD patients (23.6% vs. 7.7%). Serum nucleosome levels, as well as the white blood cell counts, neutrophil counts, and high- sensitivity C-reactive protein levels, were significantly higher in anti-heparin/PF4 antibody-positive patients compared to the control. Platelet counts tended to be lower in the patients with anti-heparin/PF4 of >1.8 than in the controls. Relative risk calculations showed that the presence of anti-heparin/PF4 antibodies increased the risk of primary functional patency failure by 4.28-fold, and this risk increased further with higher nucleosome levels. Furthermore, in the anti-heparin/PF4 antibody-positive group, the time to first vascular intervention was much shorter, and the risk of repeated intervention was higher, compared to the controls.

Conclusion

In incident HD patients, the presence of anti-heparin/PF4 antibodies was associated with increased NET formation; this could be a strong predictor of vascular access complications

Efficacy and Safety of Plastic Cannulae Compared with Metal Needles in the Initial Use of an Arteriovenous Fistulae in Incident Hemodialysis Patients: A Randomized Controlled Study

INTRODUCTION

Successful cannulation of an arteriovenous fistula (AVF) is important in patients starting hemodialysis (HD). Metal needles have been used for decades, but the usefulness of plastic cannulae has recently been demonstrated as a new technique.

METHODS

This was a prospective, randomized, open-label study of incident HD patients. Eligible patients were randomized into 2 groups in a 1:1 ratio (n = 45/group). Maturation of the AVF was confirmed using Doppler ultrasound prior to first needling, and 2 well-trained nurses implemented the AVF cannulation. The primary endpoint was the initial cannulation failure rate, defined as the failure of successful completion of 3 consecutive dialysis sessions. The secondary endpoints were time for hemostasis at the end of HD, degree of patients' pain, degree of cannulation difficulty felt by the nursing staffs, and achieving optimal HD adequacy.

RESULTS

The mean elapsed time from AVF creation to the first cannulation was 48.1 ± 16.7 days. A total of 17 cases of cannulation failure occurred, and the failure risk tended to be higher in the metal needle group than the plastic cannula group (hazard ratio 2.6, 95% confidence interval 0.95-7.41) after adjusting for age, gender, comorbidities, and AVF location. The overall incidence of vessel injury was higher and time for hemostasis was significantly longer in the metal group than the plastic group. The use of plastic cannula was associated with a better HD adequacy compared to a metal needle. However, the patients' pain score (p = 0.004) and nursing staff's cannulation difficulty score (p = 0.084) were higher in the plastic group, emphasizing the great importance of practice using plastic cannulae.

CONCLUSION

The vascular outcomes of plastic cannulae were much favorable compared to metal needles in incident HD patients. The use of plastic cannulae could be a new and innovative way to improve the quality of dialysis.

Effectiveness of Flow Volume Measurement Training Using a Custom-Made Doppler Flow Simulator

INTRODUCTION

This study was conducted to analyze the effectiveness of a custom-made Doppler ultrasound (DUS) flow simulator, vascular phantom, and Doppler test fluid in the training of dialysis staff in flow volume (FV) measurements for arteriovenous (AV) access in hemodialysis (HD) patients.

METHODS

A DUS flow simulator was constructed using a continuous renal replacement therapy machine. Vascular phantoms were constructed using a rubber enema tube and keyboard cleaning gel. The Doppler test fluid consisted of freeze-dried instant coffee granules and 0.9% saline. This easy and affordable simulator was used to train 12 dialysis staff members, with no previous experience in DUS FV measurement. After a 3-day lecture course, the staff members performed DUS analyses on the AV access of HD patients. Thereafter, they underwent a 3-day training course using the simulator and then performed the DUS analyses of the AV access again. Each staff member assessed the FV 3 times, and the mean values of the measurements pretraining and posttraining were analyzed using paired t tests.

RESULTS

The difference in the mean value of FV measurements and the reference value decreased from 131.6 mL/min to 62.5 mL/min (95% confidence interval = 30.0-108.0, P = 0.002), and the standard deviation of the FV measurements decreased from 96.9 mL/min to 47.0 mL/min (95% confidence interval = 7.9-91.8, P = 0.023) after DUS training with the simulator.

CONCLUSIONS

The accuracy and reproducibility of FV measurements markedly improved after training with the simulator; it may be helpful for medical practitioners involved in AV access for HD treatment.

Serum levels of protein carbonyl, a marker of oxidative stress, are associated with overhydration, sarcopenia and mortality in hemodialysis patients

Background

Increased oxidative stress in end-stage renal disease is regarded as one of the important mechanisms in the atherosclerosis and muscle wasting. However, studies examining the clinical significance of oxidative stress by direct measurement of these markers and its association with volume status and sarcopenia are limited.

Methods

A follow-up cross-sectional study was performed in stable hemodialysis (HD) patients and serum protein carbonyl levels were measured as a biomarker of oxidative stress. Additionally, multi-frequency body composition analysis, handgrip strength (HGS) and nutritional assessments were performed at baseline.

Results

Eighty-eight patients undergoing HD were included and 30 (34.1%) patients died during a mean follow-up of 5.2 years. The mean patient age was 60.6 ± 13.5 years, and the mean HD duration was 50.8 ± 41.3 months. In total, 16 patients (18.2%) were overhydrated, 49 (55.7%) had low HGS and 36 (40.9%) had low muscle mass. Serum protein carbonyl levels were associated with serum levels of albumin, prealbumin and transferrin, hydration status and low HGS. Overhydration (odds ratio [OR] 7.01, 95% CI 1.77–27.79, p = 0.006), prealbumin (OR 0.91, 95% CI 0.83–0.99, p = 0.030), subjective global assessment (OR 3.52, 95% CI 1.08–11.46, p = 0.037) and sarcopenia (OR 3.41, 95% CI 1.02–11.32, p = 0.046) were significantly related to increased serum protein carbonyl levels. Multivariate analysis showed that the serum levels of protein carbonyl (Hazard ratio [HR] 2.37, 95% CI 1.02–5.55, p = 0.036), albumin (HR 0.17, 95% CI 0.06–0.46, p = 0.003), prealbumin (HR 0.86, 95% CI 0.80–0.92, p = 0.001), overhydration (HR 2.31, 95% CI 1.26–8.71, p = 0.015) and sarcopenia (HR 2.72, 95% CI 1.11–6.63, p = 0.028) were independent determinants of all-cause mortality.

Conclusions

Serum protein carbonyl was significantly associated with overhydration, nutritional status and sarcopenia, and could be a new predictor of mortality in patients undergoing HD.

P0762THE SERUM URIC ACID HAS A INDEPENDENT ASSOCIATION WITH 1-YEAR RENAL OUTCOMES IN CHRONIC KIDNEY DISEASE PATIENT WITH HYPERTENSION

Background and Aims

Serum uric acid (UA) is associated with renal disease. Hyperuricemia can be a risk of hypertension, intrarenal vascular disease and renal injury. We investigate the serum UA has an association with renal disease progression in patients with chronic kidney disease (CKD) with hypertension.

Method

We recruited 270 CKD patients with hypertension from 4 centers in Korea through the APrODiTe study and followed for 1 year. Serum UA was evaluated as a continuous value and groups divided by quartiles. The renal outcomes were an increase in random urine protein/creatinine ratio (PCR) than baseline value or estimated glomerular filtration rate (eGFR) deterioration which means a decrease in eGFR ≥ 5 (ml/min/1.73m2).

Results

Baseline serum UA was 6.58 ± 1.73 mg/dl and 6.52 ± 3.59 mg/dl after 1 year. For proteinuria progression, a 1 mg/dl higher serum UA has independent correlation in multivariate regression (odds ratio (OR): 1.272; 95% confidence interval (CI): 1.031-1.568; P = 0.024). The higher quartile of serum UA showed a correlation with the odd ratio than lower quartile (OR: 2.243; 95% CI: 0.862-5.837; P = 0.098, OR:3.417; 95% CI: 1.275-9.152; P= 0.015, OR: 2.754; 95% CI: 1.013-7.488; P &lt; 0.047). In subgroup analysis, the patients with late CKD stage (3-5) showed serum UA has a positive correlation with proteinuria progression (OR: 1.311; 95% CI: 1.022-1.682; P= 0.033) and the top quartile group was correlated with the increased odds ratio compared to lower quartile (OR: 3.811; 95% CI: 1.153-12.59; P = 0.028). For eGFR deterioration, the higher quartile of UA was positively correlated with the odd ratio in only univariate analysis.

Conclusion

Serum UA level has an independent correlation with proteinuria progression in especially late CKD patient with hypertension. Whereas for eGFR deterioration, serum UA did not show a significant correlation.

Fat-to-muscle ratio as a predictor of insulin resistance and metabolic syndrome in Korean adults

BACKGROUND

The present study evaluated the associations of the fat-to-muscle ratio (FMR) with metabolic syndrome (MetS) and insulin resistance (IR) in Korean adults using nationally representative survey data.

METHODS

A two-stage stratified sampling method was reflected in a cross-sectional study involving a total of 13 032 participants aged ≥ 19 years who participated in the fourth and fifth Korea National Health and Nutrition Examination Surveys. The homeostasis model assessment for IR (HOMA-IR) was used to evaluate IR and was calculated as follows: [fasting plasma glucose level (mg/dL) × fasting plasma insulin level (uIU/mL)]/405. MetS was defined using the 2006 International Diabetes Federation criteria, and FMR was measured using whole-body dual-energy X-ray absorptiometry and calculated as follows: total fat mass (kg) divided by total lean mass (kg). In addition, the optimal FMR cut-off values for detecting MetS and the odds ratios (ORs) for MetS risk were determined according to the FMR quartile and sex.

RESULTS

Among all participants, the proportion of women was 58.4%, and the mean age was 44.22 ± 0.26 years. The FMR significantly differed between men and women (0.30 ± 0.002 vs. 0.53 ± 0.003, respectively, P < 0.001), and the prevalence of MetS and IR gradually increased as FMR increased (P for trend: <0.001). The optimal FMR cut-off value for detecting MetS was higher in women than in men (0.555 vs. 0.336, respectively). The negative predictive value was the highest in normal-weight participants (0.9992 in women and 0.9986 in men), while the positive predictive value was the highest in obese participants (0.5994 in women and 0.5428 in men). Based on the derived cut-off FMR, a high FMR was associated with poor outcomes in terms of cardiometabolic risk markers (P < 0.001). The multivariable-adjusted ORs for MetS, abdominal obesity, and IR (HOMA-IR ≥ 3) were 5.35 [95% confidence interval (CI): 4.39-6.52], 7.67 (95% CI: 6.33-9.30), and 3.25 (95% CI: 2.70-3.92), respectively, in men and 5.59 (95% CI: 4.66-6.72), 7.48 (95% CI: 6.35-8.82), and 2.55 (95% CI: 2.17-3.00), respectively, in women.

CONCLUSIONS

In the present study, a high FMR was significantly associated with the prevalence of MetS and IR. The present findings also showed that FMR can be a novel indicator for detecting the absence or presence of MetS, particularly in metabolically healthy normal-weight individuals and metabolically obese obese-weight individuals.

P1580LONGITUDINAL CHANGES IN BODY COMPOSITION ARE ASSOCIATED WITH ALL-CAUSE MORTALITY IN PATIENTS ON PERITONEAL DIALYSIS

Background and Aims

Peritoneal dialysis (PD) is associated with a number of adverse body compositional changes, including fat gain and muscle wasting. Whether body compositional changes are associated with the long-term prognosis is uncertain. The purpose of this study was to analyze the effects of longitudinal changes in body composition on all-cause mortality in PD patients.

Method

PD patients were subjected to bioimpedance spectroscopy (BIS) and handgrip strength (HGS) at baseline and after 2 years. Among 160 patients, 131 patients were tested with a repeat BIS and HGS. Lean tissue index (LTI) loss and fat tissue index (FTI) gain were defined as a 10% decline in LTI and a 10% gain in FTI, respectively after 2 years.

Results

The prevalence of sarcopenia at baseline was 13.8%. After 2 years, LTI loss and FTI gain were observed in 40 (30.5%) and 58 (44.3%) patients, respectively. Baseline clinical factors did not predict longitudinal body compositional changes, and there was a negative association between changes in the LTI and FTI (r = –0.574, p &lt; 0.001). Low LTI and low HGS at baseline were significant predictors of all-cause mortality after adjusting for demographic and biochemical parameters, but not when cardiovascular factors were included in the multivariate analysis. However, LTI loss and FTI gain were independent risk factors for all-cause mortality after adjusting for demographic, biochemical, and cardiovascular parameters.

Conclusion

In PD patients, longitudinal changes in LTI and FTI were more strongly associated with all-cause mortality than single values in LTI and FTI.

Comparison of dynamic arterial and venous pressure between metal needles and plastic cannulas in incident hemodialysis patients with arteriovenous graft

Background and objects:

We hypothesized that plastic cannulae with 17-gauge inner needle compared to 16-gauge metal needles can have stable dynamic venous and arterial pressure maintaining prescribed blood flow safely during a hemodialysis treatment.

Design, setting, participants, and measurements:

A single-center, prospective, randomized, open-label clinical trial was conducted involving 16 incident hemodialysis patients who had arteriovenous graft placed as their first arteriovenous access. Subjects were randomized to metal needle group (n = 8) versus plastic cannula group (n = 8). We measured serial dynamic pre-pump arterial and venous pressure under five different blood pump flow rates (150, 200, 250, 300, and 350 mL/min).

Results:

The mean age of patients was 67.6 ± 8.5 (range: 51–81) years, and six patients (37.5%) were male. Patients with plastic cannula showed less negative arterial pre-pump pressures and lower venous pressures than those with metal needles at all prescribed blood flow rates, and the difference was statistically significant (P < 0.001).

Conclusion:

The plastic cannula had more stable arterial and venous pressures at prescribed blood pump flow rates than those pressures of the metal needle in incident patients with arteriovenous graft during hemodialysis.

Role of peribrachial fat as a key determinant of brachial artery dilatation for successful arteriovenous fistula maturation in hemodialysis patients

The functional quality of the inflow artery is one of the most important determinants of arteriovenous fistula (AVF) success. We evaluated the association of early optimal brachial arterial dilatation with a successful AVF maturation and assessed the role of peribrachial adipose tissue in determining brachial arterial distensibility. All patients underwent a preoperative vascular mapping with Doppler ultrasound (US), and only patients who had suitable vessels for AVF creation were enrolled (n = 162). Peribrachial fat thickness was measured using US. To evaluate the degree of brachial dilatation, follow-up US was performed at 1 month after surgery, and early brachial artery dilation was defined as the change in postoperative arterial diameter compared to the preoperative value. The primary outcome was failure to achieve a clinically functional AVF within 8 weeks. Nonfunctional AVF occurred in 21 (13.0%) patients, and they had a significantly lower brachial dilatation than patients with successful AVF during early period after surgery (0.85 vs. 0.43 mm, p = 0.003). Patients with a brachial dilatation greater than median level showed a 1.8-times higher rate of achieving a successful AVF than those without. Interestingly, the early brachial dilatation showed significant correlations with diabetes (r = −0.260, p = 0.001), peribrachial fat thickness (r = −0.301, p = 0.008), and the presence of brachial artery calcification (r = −0.178, p = 0.036). Even after adjustments for demographic factors, comorbidities, and baseline brachial flow volume, peribrachial fat thickness was an independent determinant for early brachial dilatation (β = −0.286, p = 0.013). A close interplay between the peri-brachial fat and brachial dilatation can be translated into novel clinical tools to predict successful AVF maturation.

Association of Blood Pressure at Specific Time-Points with 1-Year Renal Outcomes in Patients with Diabetic Chronic Kidney Disease

Background

The 24-hour mean blood pressure (mBP) is the best predictor of organ damage; however, it is not easily applicable in clinical practice. The APrODiTe study suggested that systolic blood pressure (SBP) values at 7:00 AM and 9:30 PM were associated with the 24-hour mSBP in patients with chronic kidney disease (CKD). We investigated the association of the SBP values at these time-points with the renal outcomes in patients with diabetic CKD during 1-year follow-up.

Methods

Ninety-six patients with diabetic CKD were included at 1-year follow-up. The renal outcomes were an increase in the random urine protein/creatinine ratio or estimated glomerular filtration rate (eGFR) deterioration, which means a decrease in eGFR ≥5 mL/min/1.73 m² compared to the baseline values.

Results

The baseline SBP values at 7:00 AM, and 9:30 PM, and the 24-hour mSBP were 135.6±24.9 mmHg, 141.7±25.6 mmHg, and 136.4±20.7 mmHg, respectively. The SBP values measured at the same time-points after 1 year were similar to those at baseline. The SBP at 7:00 AM was significantly associated with eGFR deterioration in the univariate and multivariate analyses (odds ratio [OR]: 1.032; 95% confidence interval [CI]: 1.006-1.059; p=0.016). The SBP at 7:00AM and 24-hour mSBP did not show a concordant association with sustained proteinuria in the linear and logistic analyses. In the subgroup analysis, the association between the SBP at 7:00 AM and eGFR deterioration persisted in patients with CKD stage 3-5 (OR: 1.041; 95% CI: 1.010-1.073; p=0.010).

Conclusion

The SBP at 7:00 AM, in addition to the 24-hour mSBP, is also associated with eGFR deterioration in patients with diabetic CKD, particularly in those with CKD stage 3-5.

Outcomes of vascular access in hemodialysis patients: Analysis based on the Korean National Health Insurance Database from 2008 to 2016

Background

Controversies exist whether arteriovenous fistula (AVF) placement is preferred over arteriovenous graft (AVG) for elderly patients. Current guidelines did not offer specific recommendations. Thus, this study was conducted to analyze the all-cause mortality and primary patency associated with various vascular access (VA) types according to age group.

Methods

This retrospective observational study investigated the Korean insurance claims data of chronic kidney disease patients who began hemodialysis between January 2008 and December 2016. We investigated all-cause mortality associated with initial VA in incident hemodialysis patients and primary patency between AVF and AVG according to age group.

Results

The proportion of patients with a tunneled dialysis catheter (TDC) that was first placed for VA increased from 18.4% in 2008 to 52.3% in 2016. Incident hemodialysis patients with a TDC or AVG for the initial VA had significantly higher mortality risk than patients with an AVF, except for patients over 85 years, who showed no significant difference in all-cause mortality regardless of VA type. In the patency analysis on initial AV access, AVG had significantly poorer primary patency than AVF in all age groups.

Conclusion

AVF had better patency than AVG in all age groups; however, the benefit of AVF attenuated in the older age groups. The mortality rate between AVF and AVG was not significantly different in patients over 85 years. Therefore, a “patient-first” approach should be emphasized over a “fistula-first” approach in AV access creation for incident hemodialysis patients older than 85 years.

Custom-made Doppler ultrasound flow simulator for dialysis access using continuous renal replacement therapy machine

The purpose of this article was to introduce an easy and inexpensive way of making a simulator for training in Doppler ultrasound flow rate measurement using a continuous renal replacement therapy machine and home-made phantoms. A Doppler ultrasound flow simulator was made using a continuous renal replacement therapy machine and vascular phantoms for flow rate assessment of dialysis access with readily accessible components including rubber tube, keyboard cleaning gel, and freeze-dried instant coffee granules. The simulator is an affordable and easy method of Doppler ultrasound flow rate measurement training for dialysis staff using materials readily available in dialysis centers.

Impact of sarcopenia on long-term mortality and cardiovascular events in patients undergoing hemodialysis

BACKGROUND/AIMS

A high body mass index (BMI) is known to correlate with better survival in patients on hemodialysis (HD). However, the impacts of body composition and sarcopenia on survival have not been well studied in this population.

METHODS

One hundred and forty-two prevalent HD patients were recruited and followed prospectively for up to 4.5 years. Low muscle mass (measured using a portable, whole-body, bioimpedance spectroscopic device) was defined as a lean tissue index (LTI) two standard deviations (SD) or more below the normal gender-specific mean for young people. Low muscle strength was a handgrip strength (HGS) of less than 30 kg in males and less than 20 kg in females. Sarcopenia was considered present when both LTI and HGS were reduced.

RESULTS

The mean age was 59.8 ± 13.1 years; 57.0% were male and 47.2% had diabetes. Forty-seven patients (33.1%) had sarcopenia. During follow-up, 28 patients (19.7%) died, and low LTI (adjusted hazard ratio [HR], 2.77; 95% confidence interval [CI], 1.10 to 6.97) and low HGS (HR 5.65; 95% CI, 1.99 to 16.04) were independently associated with mortality. Sarcopenia was a significant predictor for death (HR, 6.99; 95% CI, 1.84 to 26.58; p = 0.004) and cardiovascular events (HR, 4.33; 95% CI, 1.51 to 12.43; p = 0.006).

CONCLUSION

Sarcopenia was strongly associated with long-term mortality and cardiovascular events in HD patients. Assessment of muscle strength and muscle mass may provide additional prognostic information to survival in patients with end-stage renal disease.

Effects of Excessive Body Fat Accumulation on Long-Term Outcomes During Peritoneal Dialysis

Background:Significant body fat accumulation is an inevitable but potentially serious problem in peritoneal dialysis (PD) patients. Whether excessive fat gain predicts long-term outcomes in these patients remains unknown.Methods:In this prospective cohort study (n = 297), the associations of excessive fat accumulation with patient survival and PD failure rate were examined. Based on dialysis duration at the time of study enrollment, patients were divided into short- (< 2 years) and long-term (> 2 years) groups. Body weight (BW) and body composition were measured twice, 12.8 ± 4.6 months apart. Excessive fat accumulation was defined as a 1-year change in the percentage of body fat (ΔPBF) over the highest quartile (5.0% for men, 5.4% for women).Results:Substantial 1-year increases in BW and PBF were observed only in the short-term group (p < 0.001 and p = 0.027, respectively); changes were insignificant in the long-term group. In the short-term group, the ΔPBF was associated closely with unfavorable baseline metabolic profiles, including old age, diabetes, obesity, elevated blood pressure, and edema. Accordingly, the mortality rate was significantly higher in patients with, than in those without, excessive fat accumulation (hazard ratio [HR] 3.26, 95% confidence interval [CI], 1.05 - 10.26). It also increased the incident risk of PD failure 2.22-fold (95% CI, 1.08 - 4.54), even after adjustment for diabetes, obesity, and fluid status. In the long-term group, fat gain had no impact on long-term prognosis.Conclusions:Excessive fat accumulation during the early period of PD was associated with baseline unhealthy metabolic profiles, a higher mortality rate, and a higher PD failure rate, independent of baseline obesity and fluid status.

Current treatment status and medical costs for hemodialysis vascular access based on analysis of the Korean Health Insurance Database

BACKGROUND/AIMS

The Republic of Korea is a country where the hemodialysis population is growing rapidly. It is believed that the numbers of treatments related to vascular access-related complications are also increasing. This study investigated the current status of treatment and medical expenses for vascular access in Korean patients on hemodialysis.

METHODS

This was a descriptive observational study. We inspected the insurance claims of patients with chronic kidney disease who underwent hemodialysis between January 2008 and December 2016. We calculated descriptive statistics of the frequencies and medical expenses of procedures for vascular access.

RESULTS

The national medical expenses for access-related treatment were 7.12 billion KRW (equivalent to 6.36 million USD) in 2008, and these expenses increased to 42.12 billion KRW (equivalent to 37.67 million USD) in 2016. The population of hemodialysis patients, the annual frequency of access-related procedures, and the total medical cost for access-related procedures increased by 1.6-, 2.6-, and 5.9-fold, respectively, over the past 9 years. The frequency and costs of access care increased as the number of patients on hemodialysis increased. The increase in vascular access-related costs has largely been driven by increased numbers of percutaneous angioplasty.

CONCLUSION

The increasing proportion of medical costs for percutaneous angioplasty represents a challenge in the management of end-stage renal disease in Korea. It is essential to identify the clinical and physiological aspects as well as anatomical abnormalities before planning angioplasty. A timely surgical correction could be a viable option to control the rapid growth of access-related medical expenses.

Anatomical variants of upper arm veins on preoperative mapping venography for hemodialysis access in Korean adults

INTRODUCTION

The number of elderly patients requiring hemodialysis has increased, along with the need for multiple vascular access placements. Thus, the frequency of access creation using the upper arm veins, including transposed basilic arteriovenous fistula, has also increased. The purpose of this study was to identify the prevalence of anatomical variations in the upper arm veins on preoperative mapping venography and to investigate the implications of such variants on access creation.

METHODS

A total of 494 venograms were performed on 251 patients for primary access creation from June 2014 to June 2017 in this single-center, retrospective study. The venograms were classified into eight subtypes, based on the anatomical relationship between the basilic and brachial veins. The presence of bifid cephalic arches and brachial-basilic ladders was also examined.

RESULTS

The presence of bifid cephalic arches and brachial-basilic ladders was identified in 8.7% and 14.0% of cases, respectively. Paired brachial veins joined separately with the basilic vein in 67.4% of venograms, whereas these veins merged into a common brachial vein before connecting to the basilic vein in 13.1% of cases. A single brachial vein was present in 19.3% of cases. 15.7% of cases were considered unsuitable for basilic vein transposition due to the early confluence of the brachial-basilic vein, posing a risk of obliterating the deep venous drainage if transposed.

CONCLUSION

There are significant anatomical variations of upper arm veins, and the recognition of certain variants can affect surgical planning and outcomes of access placement. It is important to identify anatomical variants of the upper arm veins during preoperative vein mapping.

The relationship between autophagy, increased neutrophil extracellular traps formation and endothelial dysfunction in chronic kidney disease

In chronic kidney disease (CKD), the number of circulating neutrophils are increased, and this is usually accompanied by an increased basal activation state. However, the possible association between neutrophil extracellular traps (NETs) with vascular complications has not been evaluated. We assessed the relationship between NETs, autophagy and endothelial dysfunction in maintenance hemodialysis (MHD) patients. NET formation, neutrophil elastase (NE) activities, and serum nucleosome levels were measured in MHD (n = 60) and controls (n = 20). Basal NET formation were markedly increased in MHD patient compared to controls. After PMA stimulation, MHD neutrophils showed significantly increased NETs formation response than controls. The degree of NETs was strongly associated with lower flow-mediated dilatation(%) of brachial artery even after adjustment for cardiovascular risk factors and uremic toxins. Moreover, MHD neutrophils showed increased basal autophagy activity. Interestingly, the levels of NETs were markedly augmented after autophagy inhibition, suggesting a protective role of autophagy in excessive NET formation.

Fat-to-Lean Mass Ratio Can Predict Cardiac Events and All-Cause Mortality in Patients Undergoing Hemodialysis

BACKGROUND

Although higher body mass index (BMI) is associated with better survival in patients undergoing dialysis, BMI is not an adequate obesity indicator. We hypothesized that the fat-to-lean (F/L) mass ratio could be a suitable marker of nutritional status and evaluated its prognostic impact on long-term outcomes in patients undergoing hemodialysis (HD).

METHODS

In total, 131 patients undergoing HD were recruited and monitored prospectively for up to 5 years. Body composition was analyzed, and other nutritional and inflammatory parameters were measured.

RESULTS

The mean age of the cohort was 60.7 ± 13.6 years, and 65 patients were diabetic. Age, sex, diabetes, comorbidity, and inflammation were associated significantly with the F/L mass ratio. During the follow-up period, 21 patients experienced cardiac events and 22 patients died. Patients with higher F/L mass ratios had significantly higher risks of all-cause death (hazard ratio [HR] 3.61, 95% CI 1.07-12.13; p = 0.038) and cardiac events (HR 3.54, 95% CI 1.05-11.94; p = 0.041) than those with lower F/L mass ratios.

CONCLUSIONS

The F/L mass ratio was a useful surrogate marker of nutritional and inflammatory status, and an independent predictor of cardiac events and all-cause mortality, in patients undergoing HD.

Comparison of tolvaptan treatment between patients with the SIADH and congestive heart failure: a single-center experience

BACKGROUND/AIMS

Tolvaptan is a very effective treatment for hypervolemic or euvolemic hyponatremia. We compared the clinical efficacy of and response to tolvaptan in patients with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and congestive heart failure (CHF).

METHODS

We retrospectively reviewed the medical records of 50 patients (SIADH, n = 30; CHF, n = 20) who were prescribed tolvaptan between July 2013 and October 2015. Tolvaptan was prescribed when the serum sodium level was < 125 mmol/L and the standard treatment failed. Normonatremia was defined as a serum sodium level of > 135 mmol/L.

RESULTS

After the initiation of tolvaptan therapy, there was an immediate response in the urine volume and serum sodium level in all patients. The improvements in the urine volume and serum sodium concentration were highest within the first 24 hours of treatment. In addition, the mean change in the serum sodium level during the first 24 hours was significantly higher in patients with SIADH than in those with CHF (∆Na, 9.9 ± 4.5 mmol/L vs. 6.9 ± 4.4 mmol/L, respectively; p = 0.025). Also, the mean maintenance dose was lower, and the total duration of tolvaptan use was slightly shorter in the SIADH group than CHF group (21.5 ± 14.9 days vs. 28.0 ± 20.1 days, p = 0.070).

CONCLUSIONS

The early response to tolvaptan treatment was better in patients with SIADH than in those with CHF. Thus, the tolvaptan treatment strategy should be differed between patients with SIADH and those with CHF.

Repeated Bioimpedance Measurements Predict Prognosis of Peritoneal Dialysis Patients

BACKGROUND

Fluid overload is a major risk factor for mortality in patients undergoing peritoneal dialysis (PD). However, few studies have investigated the effect of chronic exposure to sustained fluid overload on long-term outcomes.

METHOD

A total of 284 prevalent PD patients were included in this prospective study. Repeated multifrequency body composition analysis was performed 12 months apart, and 1-year cumulative chronic fluid overload were used to predict all-cause mortality and the risk for transfer to hemodialysis (HD) during the ensuing 15.6 ± 9.1 months.

RESULTS

The prevalence of fluid overload was approximately 27%. Interestingly, a substantial number of hypervolemic patients at first test were persistently hypervolemic at their second test. With this, chronic fluid overload was observed in 18.3% (n = 52). Notably, most of chronic fluid overload patients had diabetes (86.5%), and it was accompanied by concomitant changes in peritoneal membrane characteristics, a higher progression rate to high transporter. The risk of transfer to HD increased 2.8 times in patients with chronic fluid overload than in those without. Also, it significantly increased the risk of mortality (p = 0.038). Surprisingly, subgroup analysis found that patients with euvolemic status at follow-up experienced no mortality despite being in a fluid overload state at baseline.

CONCLUSIONS

One-year chronic exposure to fluid overload is a strong independent risk factor for transfer to HD and death in prevalent PD patients. Although the fluid status of most PD patients is not easily changed over time, becoming euvolemic during the entire PD treatment period seems to be very important.

Long-term prognosis of end-stage renal disease patients with normal myocardial perfusion as determined by single photon emission computed tomography

BACKGROUND/AIMS

Normal myocardial perfusion is closely associated with very low rates of cardiac events and better long-term outcomes; however, little is known about its prognostic value in patients with end-stage renal disease (ESRD).

METHODS

A total of 286 incident patients underwent baseline cardiac evaluations using echocardiography and stress-rest single-photon emission computed tomography. Perfusion scans for 177 patients (61.9%) who had a summed stress score (SSS) < 4 were normal.

RESULTS

During the 4-year follow-up period, 79 cardiac events occurred. Patients with a SSS < 4 had significantly lower annual rates of cardiac events than did those with a SSS ≥ 4 (6.4% vs. 13.2%; hazard ratio, 0.54; 95% confidence interval, 0.31 to 0.94). Among patients with a SSS < 4, however, cardiac event rates significantly differed according to the presence of comorbid conditions such as old age, diabetes, history of coronary artery disease, and elevated C-reactive protein levels. In addition, the presence of left ventricular (LV) systolic dysfunction and LV hypertrophy at the start of hemodialysis strongly influenced future cardiac events.

CONCLUSIONS

In patients with ESRD, normal perfusion scans usually indicate a significantly low risk of adverse cardiac events. However, even in patients with normal perfusion scans, the cardiovascular prognosis is largely dependent on baseline inflammation levels and comorbidities.

Physician perceptions of blood pressure control in patients with chronic kidney disease and target blood pressure achievement rate

Background

Blood pressure (BP) control is the most-established method for the prevention of chronic kidney disease (CKD) progression. However, the ideal BP target for CKD patients is still under debate.

Methods

We performed a survey of regular registered members of the Korean Society of Nephrology to determine physician perceptions of BP control in patients with CKD. In addition, we evaluated the target BP achievement rate using data from the APrODiTe-2 study.

Results

Two-thirds of physicians considered the target BP for CKD to be < 130/85 mmHg. The systolic BP (SBP) thresholds for diabetic CKD, proteinuria ≥ 300 mg/day, 30 ≤ glomerular filtration rate (GFR) < 60 mL/min/1.73 m², age < 60 years, and the presence of atherosclerotic (ASO) complications were significantly lower than the SBP thresholds of the opposite parameters. The three major hurdles to controlling BP were non-compliance with lifestyle modification and medications, and self-report of well-controlled home BP. Most physicians prescribed home and ambulatory BP monitoring to less than 50% of their patients. The target BP achievement rates using the SBP thresholds in this survey were as follows: non-diabetic (69.3%); diabetic (29.5%); proteinuria < 300 mg/day (72.3%); proteinuria > 300 mg/day (33.7%); GFR ≥ 60 (76.4%); GFR < 30 (47.8%); no evidence of ASO (67.8%); and the presence of ASO (42.9%).

Conclusion

The target BP was lower in patients with higher cerebro-cardiovascular risks. These patient groups also showed lower target BP achievement rates. We also found a relatively lower application and clinical reflection rate of home or ambulatory BP monitoring.

Acute kidney injury can predict in-hospital and long-term mortality in elderly patients undergoing hip fracture surgery

Background

Hip fracture is a common health problem in the elderly that is associated with increased mortality. Acute kidney injury (AKI) is a frequent complication in elderly patients undergoing surgery and is associated with the clinical outcome. We evaluated the incidence and risk factors of AKI in elderly patients undergoing hip fracture surgery and the impact of AKI on short- and long-term clinical outcomes.

Methods

We performed a retrospective cohort study of 450 elderly patients who underwent hip fracture surgery between January 2010 and December 2012. We defined AKI according to the Acute Kidney Injury Network (AKIN) criteria and investigated the effect of AKI on the duration of hospital stay and in-hospital and long-term mortality.

Results

Of the 450 patients, 95 (21.1%) developed AKI during hospitalization and 178 (39.6%) died, with a mean follow-up of 3.6 ± 1.0 years. The baseline serum creatinine level, use of angiotensin-converting enzyme inhibitors or angiotensin-II receptor antagonists, red blood cell transfusion volume, and history of coronary artery disease were independent risk factors for AKI. Patients with AKI during hospitalization had significantly longer hospital stays and higher in-hospital and long-term mortality than those without AKI. Multivariate analysis revealed that age, history of coronary artery disease, serum albumin level, and AKI were independent predictors of long-term mortality.

Conclusions

AKI is a frequent complication in elderly patients undergoing hip fracture surgery and is independently associated with increased in-hospital and long-term mortality.

Vitamin D: a possible modifying factor linking obesity to vascular calcification in hemodialysis patients

Background

Obesity is a risk factor for increased cardiovascular disease. Whether vitamin D deficiency modifies this association is unclear. Here, we examined the association of obesity and vitamin D deficiency with vascular calcification score (VCS) in incident end-stage renal disease (ESRD) patients.

Methods

A cross-sectional study was conducted with 213 ESRD patients. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D (25(OH)D) levels below 10 ng/mL, and obesity was defined as a percentage of body fat (PBF) higher than the sex-specific median value in the cohort (>26.8% for men, >36.2% for women). VCS was measured by plain radiographic film of the lateral abdomen in the standing position.

Results

Most ESRD patients (76.6%) had 25(OH)D deficiency at the start of dialysis. The prevalence of 25(OH)D deficiency was much higher in obese patients than non-obese patients, and it had significant inverse association with PBF (r = −0.315, p < 0.001). Abdominal aortic calcification was identified in 104 (48.9%) patients. VCS was significantly higher in obese population; 2.6 (0–23) for all patients, 4.2 (0–23) for obese and 1.0 (0–12) for non-obese patients (p < 0.001). Interestingly, vitamin D deficiency was associated with greater risk of a high VCS, especially in obese population [odds ratio (OR) 3.02, 95% confidence interval (CI) 1.09-9.38)], but not with non-obese patients (OR 1.82, 95% CI 0.56-5.60).

Conclusion

The magnitude and direction of the association between obesity and the risk of vascular calcification may depend on an individual’s 25(OH)D level, a possible representative marker of cardiometabolic disturbance in ESRD patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12986-017-0181-7) contains supplementary material, which is available to authorized users.

Impact of rapid ultrafiltration rate on changes in the echocardiographic left atrial volume index in patients undergoing haemodialysis: a longitudinal observational study

OBJECTIVE

Optimal fluid management is essential when caring for a patient on haemodialysis (HD). However, if the fluid removal is too rapid, the resultant higher ultrafiltration rate (UFR) disadvantageously promotes haemodynamic instability and cardiac injury. We evaluated the effects of a rapid UFR on changes in the echocardiographic left atrial volume index (LAVI) over a period of time.

DESIGN

Longitudinal observational study.

SETTING AND PARTICIPANTS

A total of 124 new patients on HD.

INTERVENTIONS

Echocardiography was performed at baseline and repeated after 19.7 months (range 11.3-23.1 months). Changes in LAVI (ΔLAVI/year, mL/m²/year) were calculated. The UFR was expressed in mL/hour/kg, and we used the mean UFR over 30 days (∼12-13 treatments).

MAIN OUTCOME MEASURES

The 75th centile of the ΔLAVI/year distribution was regarded as a 'pathological' increment.

RESULTS

The mean interdialytic weight gain was 1.73±0.94 kg, and the UFR was 8.01±3.87 mL/hour/kg. The significant pathological increment point in ΔLAVI/year was 4.89 mL/m²/year. Correlation analysis showed that ΔLAVI/year was closely related to the baseline blood pressure, haemoglobin level, residual renal function and UFR. According to the receiver operating characteristics curve, the 'best' cut-off value of UFR for predicting the pathological increment was 10 mL/hour/kg, with an area under the curve of 0.712. In multivariate analysis, systolic blood pressure, a history of coronary artery disease, haemoglobin <10 g/dL and high UFR were significant predictors. An increase of 1 mL/hour/kg in the UFR was associated with a 22% higher risk of a worsening LAVI (OR 1.22, 95% CI 1.05 to 1.41).

CONCLUSIONS

An increased haemodynamic load could affect left atrial remodelling in incident patients on HD. Thus, close monitoring and optimal control of UFR are needed.

Leptin, pre-existing vascular disease, and increased arteriovenous fistula maturation failure in dialysis patients

BACKGROUND

The adipocytokine leptin is an independent cardiovascular risk factor and exerts proatherogenic effect. Pre-existing vascular disease is an important cause of arteriovenous fistula (AVF) maturation failure. We explored the association between serum leptin, pre-existing vascular disease, and AVF maturation failure in incident hemodialysis patients.

METHODS

Vein samples from 62 patients were collected at the time of AVF creation. Pre-existing vascular disease was evaluated with histologic changes and immunohistochemical characteristics of cellular phenotypes in intima. AVF maturation failure was defined as an AVF that could not be used successfully by the third month after its creation.

RESULTS

The prevalence of body mass index ≥30 kg/m² was 17%, and AVF maturation failure occurred in 28 (45%) patients. Patients within the highest leptin tertile showed significantly higher maturation failure rate, independent of age, gender, diabetes, and body mass index. On histologic examination, significant differences in intimal hyperplasia (13.3 ± 4.5 vs 18.2 ± 5.2 vs 30.3 ± 14.3 μm) and medial thickening (76.8 ± 23.7 vs 103.9 ± 33.6 vs 109.3 ± 36.5 μm) were observed across leptin tertiles. Similarly, medial fibrosis was most severe in the highest tertile. According to the immunohistochemical staining, most intimal cells were α-smooth muscle actin-positive, vimentin-positive, desmin-negative myofibroblasts. However, in the lowest tertile, desmin-positive contractile smooth muscle cells were also frequently observed, suggesting relatively slow phenotypic changes in this group. Furthermore, as leptin tertiles increased, the expression of leptin receptor in the luminal border of intima was significantly decreased.

CONCLUSIONS

Obesity-related higher fistula maturation failure rate may be partly mediated by higher leptin level-associated pre-existing vascular diseases in end-stage renal disease patients. Decreased expression of leptin receptor may be related to this association.

Sex differences in the association between obesity and albuminuria among Korean adults: a cross-sectional study using the Korea National Health and Nutrition Examination Survey data

Background

The association between obesity and albuminuria in the general population remains unclear. We aimed to identify the association between obesity and albuminuria as well as sex differences regarding the associations using several obesity indices, including waist circumference (WC), body mass index (BMI), and waist-to-height ratio (WHR).

Methods

This study included 3841 subjects (1730 males and 2111 females; age 20–80 years) who participated in the Fifth Korea National Health and Nutrition Examination Survey conducted in 2011. Subjects with hypertension, diabetes, renal failure, or a malignant tumor and those who were pregnant or menstruating were excluded. Albuminuria was defined as a urinary albumin-to-creatinine ratio ≥30 mg/g. Anthropometric parameters were categorized into sex-specific quartiles. Logistic regression models were used to assess the associations between each anthropometric parameter and albuminuria.

Results

All of the obesity indices of the fourth quartile group of females showed a twofold higher risk for albuminuria than the second quartile group, and it was persistently significant after adjusting for age, smoking, and physical activity. After further adjustment for high blood pressure and impaired fasting glucose and triglyceride levels, WC and BMI of the fourth quartile group of females still showed a significantly higher risk for albuminuria than the second quartile group (odds ratios 1.96 and 2.24; 95 % confidence intervals 1.03–3.74 and 1.15–4.37). None of the associations between albuminuria and the obesity indices were significant in males.

Conclusion

Higher WC and BMI were significantly associated with the risk of albuminuria among females, but not males.

Electronic supplementary material

The online version of this article (doi:10.1007/s10157-016-1238-z) contains supplementary material, which is available to authorized users.

Overhydration Negatively Affects Quality of Life in Peritoneal Dialysis Patients: Evidence from a Prospective Observational Study

Backgound: This study evaluated whether the hydration status affected health-related quality of life (HRQOL) during 12 months in peritoneal dialysis (PD) patients.

METHODS

The hydration status and the HRQOL were examined at baseline and after 12 months using a bioimpedance spectroscopy and Kidney Disease Quality of Life-Short Form, respectively in PD patients. Four hundred eighty-one patients were included and divided according to the baseline overhydration (OH) value; normohydration group (NH group, -2L≤ OH ≤+2L, n=266) and overhydration group (OH group, OH >+2L, n=215). Baseline HRQOL scores were compared between the two groups. The subjects were re-stratified into quartiles according to the OH difference (OH value at baseline - OH value at 12 months; <-1, -1 - -0.1, -0.1 - +1, and ≥+1L). The relations of OH difference with HRQOL scores at 12 months and the association of OH difference with the HRQOL score difference (HRQOL score at baseline - HRQOL score at 12 months) were assessed.

RESULTS

The OH group showed significantly lower baseline physical and mental health scores (PCS and MCS), and kidney disease component scores (KDCS) compared with the NH group (all, P<0.01). At 12 months, the adjusted PCS, MCS, and KDCS significantly increased as the OH difference quartiles increased (P<0.001, P=0.002, P<0.001, respectively). In multivariate analysis, the OH difference was independently associated with higher PCS (β = 2.04, P< .001), MCS (β=1.02, P=0.002), and KDCS (β=1.06, P<0.001) at 12 months. The OH difference was independently associated with the PCS difference (β = -1.81, P<0.001), MCS difference (β=-0.92, P=0.01), and KDCS difference (β=-0.90, P=0.001).

CONCLUSION

The hydration status was associated with HRQOL and increased hydration status negatively affected HRQOL after 12 months in PD patients.

Excessive Weight Gain during the First Year of Peritoneal Dialysis Is Associated with Inflammation, Diabetes Mellitus, and a Rapid Decrease in Residual Renal Function

OBJECTIVES

Significant weight gain is a potential problem in most patients starting peritoneal dialysis (PD); however, few studies have explored the clinical effects of increased body weight (BW) in these patients. We evaluated the effect of excess weight gain during the first year after PD on residual renal function (RRF).

METHODS

A total of 148 incident PD patients were analyzed in a longitudinal observational study. The mean duration of follow-up was 23.8 months. RRF was measured at baseline (within 1 month of starting PD) and thereafter at 6-month intervals for 2-3 years or until loss of RRF. BW was measured at the time of RRF measurement, and excess weight gain was defined as a BW increase over the median value (3.0%).

RESULTS

The median 1-year increase in BW was 2.3kg (IQR, 1.01-4.58) or 3.0% (IQR, 1.13-5.31). The mean slope of RRF decline was -0.068 ± 0.053 mL/min/month/1.73m2, and RRF loss developed in 48 patients at a mean follow-up time of 19.4 ± 6.8 months. Patients with BW increases > 3.0% showed significantly increased RRF decline rate compared to those without excess weight gain (p<0.001), and the BW increase (%/year) correlated significantly with higher hs-CRP levels and RRF decline rate. High systolic blood pressure, diabetes, large amount of proteinuria and excess BW gain significantly influenced the RRF decline rate. Also, it increased the risk of RRF loss by 4.17-fold (95% confidence intervals, 1.87-9.28; p<0.001).

CONCLUSIONS

Excess weight gain during the first year of PD was closely linked to systemic inflammation, diabetes and rapid decline in RRF.

Specific alterations in plasma proteins during depressed, manic, and euthymic states of bipolar disorder

Bipolar disorder (BD) is a common psychiatric mood disorder affecting more than 1-2% of the general population of different European countries. Unfortunately, there is no objective laboratory-based test to aid BD diagnosis or monitor its progression, and little is known about the molecular basis of BD. Here, we performed a comparative proteomic study to identify differentially expressed plasma proteins in various BD mood states (depressed BD, manic BD, and euthymic BD) relative to healthy controls. A total of 10 euthymic BD, 20 depressed BD, 15 manic BD, and 20 demographically matched healthy control subjects were recruited. Seven high-abundance proteins were immunodepleted in plasma samples from the 4 experimental groups, which were then subjected to proteome-wide expression profiling by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight tandem mass spectrometry. Proteomic results were validated by immunoblotting and bioinformatically analyzed using MetaCore. From a total of 32 proteins identified with 1.5-fold changes in expression compared with healthy controls, 16 proteins were perturbed in BD independent of mood state, while 16 proteins were specifically associated with particular BD mood states. Two mood-independent differential proteins, apolipoprotein (Apo) A1 and Apo L1, suggest that BD pathophysiology may be associated with early perturbations in lipid metabolism. Moreover, down-regulation of one mood-dependent protein, carbonic anhydrase 1 (CA-1), suggests it may be involved in the pathophysiology of depressive episodes in BD. Thus, BD pathophysiology may be associated with early perturbations in lipid metabolism that are independent of mood state, while CA-1 may be involved in the pathophysiology of depressive episodes.