The impact of preload on 3-dimensional deformation parameters: principal strain, twist and torsion.

BACKGROUND: Strain analysis is feasible using three-dimensional (3D) echocardiography. This approach provides various parameters based on speckle tracking analysis from one full-volume image of the left ventricle; however, evidence for its volume independence is still lacking. METHODS: Fifty-eight subjects who were examined by transthoracic echocardiography immediately before and after hemodialysis (HD) were enrolled. Real-time full-volume 3D echocardiographic images were acquired and analyzed using dedicated software. Two-dimensional (2D) longitudinal strain (LS) was also measured for comparison with 3D strain values. RESULTS: Longitudinal (pre-HD: -24.57 ± 2.51, post-HD: -21.42 ± 2.15, P < 0.001); circumferential (pre-HD: -33.35 ± 3.50, post-HD: -30.90 ± 3.22, P < 0.001); and radial strain (pre-HD: 46.47 ± 4.27, post-HD: 42.90 ± 3.61, P < 0.001) values were significantly decreased after HD. The values of 3D principal strain (PS), a unique parameter of 3D images, were affected by acute preload changes (pre-HD: -38.10 ± 3.71, post-HD: -35.33 ± 3.22, P < 0.001). Twist and torsion values were decreased after HD (pre-HD: 17.69 ± 7.80, post-HD: 13.34 ± 6.92, P < 0.001; and pre-HD: 2.04 ± 0.86, post-HD:1.59 ± 0.80, respectively, P < 0.001). The 2D LS values correlated with the 3D LS and PS values. CONCLUSION: Various parameters representing left ventricular mechanics were easily acquired from 3D echocardiographic images; however, like conventional parameters, they were affected by acute preload changes. Therefore, strain values from 3D echocardiography should be interpreted with caution while considering the preload conditions of the patients.

The Natural Course of Biopsy-Proven Isolated Microscopic Hematuria: a Single Center Experience of 350 Patients.

The increasing interest in healthcare and health screening events is revealing additional cases of asymptomatic isolated microscopic hematuria (IMH). However, a consensus of the evaluation and explanation of the IMH prognosis is controversial among physicians. Here, we present the natural course of IMH together with the pathological diagnosis and features to provide supportive data when approaching patients with IMH. We retrospectively evaluated 350 patients with IMH who underwent a renal biopsy between 2002 and 2011, and the pathological diagnosis and chronic histopathological features (glomerulosclerosis, interstitial fibrosis, and tubular atrophy) were reviewed. Deterioration of renal function was examined during follow up. The patients with IMH were evaluated for a mean of 86 months. IgA nephropathy was the most common diagnosis in 164 patients (46.9%). Chronic histopathological changes were observed in 166 (47.4%) but was not correlated with proteinuria or a decline in renal function. Ten patients developed proteinuria, and all of them had IgA nephropathy. Three patients progressed to chronic kidney disease with an estimated glomerular filtration rate < 60 mL/min/1.73 m(2) but none progressed to end stage renal disease. In conclusion, IMH had a generally benign course during 7-years of observation, although IgA nephropathy should be monitored if it progresses to proteinuria. Future prospective randomized studies may help conclude the long-term prognosis and lead to a consensus for managing IMH.

Serum ß2-Microglobulin Predicts Mortality in Peritoneal Dialysis Patients: A Prospective Cohort Study.

BACKGROUND/AIMS: ß2-Microglobulin (ß2-M) is a surrogate marker of middle-molecule uremic toxins and is associated with mortality in chronic hemodialysis patients. However, the impact of serum ß2-M levels on mortality in peritoneal dialysis (PD) patients is uncertain. The purpose of this study was to examine the association of serum ß2-M levels with all-cause mortality in PD patients. METHODS: A total of 771 PD patients were selected from the Clinical Research Center registry for end-stage renal disease cohort in Korea. Patients were categorized into 3 groups by tertiles of serum ß2-M levels. The primary outcome was all-cause mortality. RESULTS: The median value of serum ß2-M was 23.6 mg/l (interquartile range 14.8-33.4 mg/l), and the median follow-up period was 39 months. The Kaplan-Meier analysis showed that the all-cause mortality rate was significantly different according to tertiles of serum ß2-M in PD patients (p=0.03, log-rank). Multivariate Cox proportional analysis showed that the hazards ratio for all-cause mortality was 1.02 (95% CI 1.01-1.04, p=0.006) per 1 mg/l increase in ß2-M after adjustment for multiple confounding factors that relate to malnutrition and inflammation marker. However, serum ß2-M was not associated with all-cause mortality after adjustment for residual renal clearance. CONCLUSIONS: These results are supportive of the potential role of the serum ß2-M level as a predictor of mortality in PD patients.

Effect of Pravastatin on Kidney Function in Patients with Dyslipidemia and Type 2 Diabetes Mellitus: A Multicenter Prospective Observational Study.

INTRODUCTION: Several studies have reported that pravastatin can mitigate the progression of kidney disease, but limited evidence exists regarding its effects on kidney function in Asian patients. This multicenter prospective observational study aimed to assess the effect of pravastatin on kidney function in Korean patients with dyslipidemia and type 2 diabetes mellitus (T2DM) in clinical practice. METHODS: This 48-week prospective multicenter study included 2604 of 2997 eligible patients with dyslipidemia and T2DM who had available estimated glomerular filtration rate (eGFR) measurements. The primary endpoint was eGFR percent change at week 24 from baseline. We also assessed secondary endpoints, which included percent changes in eGFR at weeks 12 and 48 from baseline, as well as changes in eGFR, metabolic profiles (lipid and glycemic levels) at 12, 24, and 48 weeks from baseline, and safety. RESULTS: We noted a significant improvement in eGFR, with mean percent changes of 2.5%, 2.5%, and 3.0% at 12, 24, and 48 weeks, respectively (all adjusted p < 0.05). The eGFR percent changes significantly increased in subgroups with baseline eGFR 30-90 mL/min/1.73 m2, glycated hemoglobin (HbA1c) ≥ 7 at baseline, no hypertension history, T2DM duration > 5 years, or previous statin therapy. Lipid profiles were improved and remained stable throughout the study, and interestingly, fasting glucose and HbA1c were improved at 24 weeks. CONCLUSION: Our findings suggest that pravastatin may have potential benefits for improving eGFR in Korean patients with dyslipidemia and T2DM. This could make it a preferable treatment option for patients with reduced kidney function. TRIAL REGISTRATION NUMBER: NCT05107063 submitted October 27, 2021.

The role of autophagy in unilateral ureteral obstruction rat model.

AIM: Autophagy is a cellular process of degradation of damaged cytoplasmic components and regulates cell death or proliferation. Unilateral ureteral obstruction (UUO) is a model of progressive renal fibrosis in the obstructed kidney. And UUO is followed by compensatory cellular proliferation in the contralateral kidney. We investigate the role of autophagy in the obstructed kidney and contralateral kidney after UUO. METHODS: To obtain the evidence and the patterns of autophagy during UUO, the rats were sacrificed 3, 7 and 14 days after UUO. To examine the efficacy of the autophagy inhibitors, 3-methyladenine (3-MA), the rats were treated daily with intraperitoneal injection of 3-MA (30 mg/kg per day) for 7 days. RESULTS: After UUO, autophagy was induced in the obstructed kidney in a time-dependent manner. Inhibition of autophagy by 3-MA enhanced tubular cell apoptosis and tubulointerstitial fibrosis in the obstructed kidney after UUO. In the contralateral kidney, autophagy was also induced and prolonged during UUO. Inhibition of autophagy by 3-MA increased the protein expression of proliferating cell nuclear antigen significantly in the contralateral kidney after UUO. The Akt-mammalian target of rapamycin (mTOR) signalling pathway was involved in the induction of autophagy after UUO in both kidneys. CONCLUSION: Our present results support that autophagy induced by UUO has a renoprotective role in the obstructed kidney and regulatory role of compensatory cellular proliferation in the contralateral kidney through Akt-mTOR signalling pathway.

Relationship of visceral and subcutaneous adiposity with renal function in people with type 2 diabetes mellitus.

BACKGROUND: Obesity and diabetes mellitus (DM) are established risk factors for the development of chronic kidney disease. Visceral adiposity (VAT) and subcutaneous adiposity (SAT) may be associated with the differential metabolic risk. Our study was performed to determine whether VAT or SAT was associated with the decrease of renal function in people with type 2 DM. METHODS: Nine hundred and twenty-nine people with type 2 DM and who had undergone abdominal computed tomography assessment of the SAT and VAT areas were included. The estimated glomerular filtration rate (eGFR) was calculated using the Cockcroft-Gault equation and the Modification of Diet in Renal Disease (MDRD) four-variable equation at the time of the assessment of the SAT and VAT areas. RESULTS: VAT was negatively associated with eGFR using the MDRD equation after adjustment for the clinical variables (ß-coefficient = - 0.075, P = 0.034), while SAT was not significantly associated with eGFR. There was no significant association between the abdominal adiposity measurements and the eGFR using the Cockcroft-Gault formula. When stratifying the individuals by the body mass index groups, VAT was negatively associated with eGFR by the MDRD equation and the Cockcroft-Gault formula in the overweight and obese subjects after adjustment for the clinical variables, while there was no significant association between the VAT and the eGFR in the normal weight subjects. SAT was not significantly associated with eGFR in the normal weight, overweight and obese subjects. CONCLUSIONS: Our data suggest that VAT may be an additional prognostic factor for the decrease of renal function especially in the overweight or obese subjects with type 2 DM.

Posttraumatic Embitterment Disorder in Patients with Chronic Kidney Disease.

OBJECTIVE: Posttraumatic embitterment disorder (PTED), a subgroup of an adjustment disorder, is a feeling with anger and helplessness. Hemodialysis may be a trigger event leading to PTED. We investigated the prevalence of PTED in patients with each categorized stages of chronic kidney disease (CKD) and the association between PTED and depression and functional impairment. METHODS: Patients were categorized into three groups according to the stages of CKD (stage I-II, III-IV, and V). CKD (I-II) group was defined as estimated glomerular filtration rate (eGFR) ＞60 ml/min/1.73 m2, CKD (III-IV) group as eGFR ＜60 ml/min/1.73 m2, and CKD (V) group as CKD stage V including patients ongoing hemodialysis. Patients were assessed for the prevalence of PTED, depression, and decreased quality of life by using the scale of PTED, Patient Health Questionnaire-9 (PHQ-9), and EuroQol Five Dimensional Questionnaires, Visual Analogue Scale (EQ-5D-VAS), respectively. RESULTS: A total of 445 patients were analyzed. The number of patients in CKD (I-II) was 166, CKD (III-IV) was 172, and CKD (V) was 107. Multivariate analysis by binomial logistic regression demonstrated that CKD (V) was significantly associated with the prevalence of PTED (odds ratio, 4.13; 95% confidence interval, 1.56-15.6; p =0.006) after adjustment for age, gender, and diabetes mellitus. Also, a significant correlation existed between PTED and EQ-5D-VAS in all stages, but the correlation was nonsignificant between PTED and PHQ-9 score in group CKD (V). CONCLUSION: The findings suggest that PTED is underdiagnosed in CKD patients. Acknowledgment and diagnosis of PTED in CKD patients may lead to a better quality of life.

The impact of high serum bicarbonate levels on mortality in hemodialysis patients.

BACKGROUND/AIMS: The optimal serum bicarbonate level is controversial for patients who are undergoing hemodialysis (HD). In this study, we analyzed the impact of serum bicarbonate levels on mortality among HD patients. METHODS: Prevalent HD patients were selected from the Clinical Research Center registry for End Stage Renal Disease cohort in Korea. Patients were categorized into quartiles according to their total carbon dioxide (tCO2) levels: quartile 1, a tCO2 of < 19.4 mEq/L; quartile 2, a tCO2 of 19.4 to 21.5 mEq/L; quartile 3, a tCO2 of 21.6 to 23.9 mEq/L; and quartile 4, a tCO2 of ≥ 24 mEq/L. Cox regression analysis was used to calculate the adjusted hazard ratio (HR) and confidence interval (CI) for mortality. RESULTS: We included 1,159 prevalent HD patients, with a median follow-up period of 37 months. Kaplan-Meier analysis revealed that the all-cause mortality was significantly higher in patients from quartile 4, compared to those from the other quartiles (p = 0.009, log-rank test). The multivariate Cox proportional hazard model revealed that patients from quartile 4 had significantly higher risk of mortality than those from quartile 1, 2 and 3, after adjusting for the clinical variables in model 1 (HR, 1.99; 95% CI, 1.15 to 3.45; p = 0.01) and model 2 (HR, 1.82; 95% CI, 1.03 to 3.22; p = 0.04). CONCLUSIONS: Our data indicate that high serum bicarbonate levels (a tCO2 of ≥ 24 mEq/L) were associated with increased mortality among prevalent HD patients. Further effort might be necessary in finding the cause and correcting metabolic alkalosis in the chronic HD patients with high serum bicarbonate levels.

Calcitriol regresses cardiac hypertrophy and QT dispersion in secondary hyperparathyroidism on hemodialysis.

BACKGROUND: Sudden cardiac death is common in patients on hemodialysis (HD), and its rate is as high as 25% of all cardiac deaths associated with left ventricular hypertrophy (LVH) and secondary hyperparathyroidism. A prolonged QT interval on standard electrocardiography is related to an increase in sudden death in various patient groups. It is also well known that LVH has been noted in uremic patients with high parathyroid hormone levels. METHODS: To evaluate the response of intravenous calcitriol treatment on the QT interval and LVH in HD patients with secondary hyperparathyroidism (intact parathyroid hormone, iPTH, > 450 ng/ml), echocardiographic, electrocardiographic (ECG), and biochemical assessments were performed over a 15-week period in 25 HD patients before and after intravenous calcitriol treatment. We also evaluated 25 age-, sex-, HD duration-, and BMI-matched HD control patients with secondary hyperparathyroidism. RESULTS: In patients receiving intravenous calcitriol, a significant reduction in iPTH levels (p < 0.05) and alkaline phosphatase levels (p < 0.01) was found without changes in values of serum calcium and ionized Ca2+, phosphorus, Na+, K+, Mg2+, hematocrit, blood pressure, or other hemodynamic changes. Echocardiograms showed significant decreases in the thickness of the interventricular septum (p < 0.05), left posterior wall thickness (p < 0.05), and left ventricle mass index (LVMi, p < 0.01). In addition, sequential ECG measurement in patients with calcitriol treatment showed significant reductions in QTcmax (QTmax interval corrected for heart rates, p < 0.01) and QTc dispersion (QT dispersion corrected for heart rates, p < 0.01). However, in the control patients, biochemical, hemodynamic, and ECG changes, as well as myocardial structural and functional changes were not seen. Multiple regression analysis in all patients indicated that iPTH and LVMi levels were independent predictors of QTcmax while the LVMi level was the only independent predictor of QTc dispersion (p < 0.05). CONCLUSIONS: Our study showed a significant correlation between LVMi and QT dispersion in HD patients with secondary hyperparathyroidism. Intravenous calcitriol treatment, to be used for the control of secondary hyperparathyroidism, was found to cause regression of myocardial hypertrophy and a reduction in the QTc interval and dispersion, without biochemical and hemodynamic changes. These findings suggest that an active vitamin D metabolite has a cardioprotective action in HD patients.

The impact of blood flow rate during hemodialysis on all-cause mortality.

BACKGROUND/AIMS: Inadequacy of dialysis is associated with morbidity and mortality in chronic hemodialysis (HD) patients. Blood flow rate (BFR) during HD is one of the important determinants of increasing dialysis dose. However, the optimal BFR is unclear. In this study, we investigated the impact of the BFR on all-cause mortality in chronic HD patients. METHODS: Prevalent HD patients were selected from Clinical Research Center registry for end-stage renal disease cohort in Korea. We categorized patients into two groups by BFR < 250 and ≥ 250 mL/min according to the median value of BFR 250 mL/min in this study. The primary outcome was all-cause mortality. RESULTS: A total of 1,129 prevalent HD patients were included. The number of patients in the BFR < 250 mL/min was 271 (24%) and in the BFR ≥ 250 mL/min was 858 (76%). The median follow-up period was 30 months. Kaplan-Meier analysis showed that the mortality rate was significantly higher in patients with BFR < 250 mL/min than those with BFR ≥ 250 mL/min (p = 0.042, log-rank). In the multivariate Cox regression analyses, patients with BFR < 250 mL/min had higher all-cause mortality than those with BFR ≥ 250 mL/min (hazard ratio, 1.66; 95% confidence interval, 1.00 to 2.73; p = 0.048). CONCLUSIONS: Our data showed that BFR < 250 mL/min during HD was associated with higher all-cause mortality in chronic HD patients.

Comparison of uremic pruritus between patients undergoing hemodialysis and peritoneal dialysis.

BACKGROUND: Uremic pruritus is a common, but unpleasant, complication of end-stage renal disease. The uremic burden may differ between hemodialysis (HD) and peritoneal dialysis (PD) patients. This difference may also change the clinical characteristics of uremic pruritus between the 2 modalities. In this study, we investigated the uremic pruritus between patients on HD and PD. METHODS: A total of 425 HD and 223 PD patients from the Clinical Research Center registry in Korea were included. Patients were assessed for pruritus intensity, scratching activity, pruritus distribution, and frequency of pruritus-related sleep disturbance using the visual analog scale and questionnaire. RESULTS: The prevalence of uremic pruritus was higher in PD patients than that in HD patients (62.6% vs. 48.3%, P = 0.001). In the multivariable logistic analysis, PD treatment was significantly associated with the prevalence of uremic pruritus (odds ratio, 1.76; 95% confidence interval, 1.20-2.57, P = 0.004) after adjustment for clinical variables. The visual analog scale score, representing a subjective intensity of itchiness, was significantly higher in PD patients (PD 2.11 ± 2.32 vs. HD 1.65 ± 2.28, P = 0.013) compared with HD patients. The intensity of uremic pruritus was independently related with serum albumin levels (ß = -0.143, P = 0.006) in HD patients and total weekly Kt/V (ß = -0.176, P = 0.028) in PD patients. CONCLUSION: Our data demonstrate the difference in prevalence, intensity, and risk factors of uremic pruritus between HD and PD patients. These findings suggest that careful consideration for uremic pruritus might be needed in end-stage renal disease patients according to the dialysis modality.

Serum Alkaline Phosphatase Levels Predict Infection-Related Mortality and Hospitalization in Peritoneal Dialysis Patients.

BACKGROUND: Serum alkaline phosphatase (ALP) levels have been reported to be associated with all-cause and cardiovascular mortality in peritoneal dialysis (PD) patients. However, it is unclear whether serum ALP levels predict infection-related clinical outcomes in PD patients. The aim of this study was to determine the relationships between serum ALP levels, infection-related mortality and hospitalization in PD patients. METHODS: PD patients from the Clinical Research Center registry for end-stage renal disease, a multicenter prospective observational cohort study in Korea, were included in the present study. Patients were categorized into three groups by serum ALP tertiles as follows: Tertile 1, ALP <78 U/L; Tertile 2, ALP = 78-155 U/L; Tertile 3, ALP >155 U/L. Tertile 1 was used as the reference category. The primary outcomes were infection-related mortality and hospitalization. RESULTS: A total of 1,455 PD patients were included. The median follow-up period was 32 months. The most common cause of infection-related mortality and hospitalization was PD-related peritonitis. Multivariate Cox regression analyses showed that patients in the highest tertiles of serum ALP levels were at higher risk of infection-related mortality (HR 2.29, 95% CI, 1.42-5.21, P = 0.008) after adjustment for clinical variables. Higher tertiles of serum ALP levels were associated with higher risk of infection-related hospitalization (Tertile 2: HR 1.56, 95% CI, 1.18-2.19, P = 0.009, tertile 3: HR 1.34, 95% CI, 1.03-2.62, P = 0.031). CONCLUSIONS: Our data showed that elevated serum ALP levels were independently associated with a higher risk of infection-related mortality and hospitalization in PD patients.

The Association of Visual Impairment With Clinical Outcomes in Hemodialysis Patients.

Visual impairment limits people's ability to perform daily tasks and affects their quality of life. We evaluated the impact of visual impairment on clinical outcomes in hemodialysis (HD) patients.HD patients were selected from the Clinical Research Center registry a prospective cohort study on dialysis patients in Korea. Visual impairment was defined as difficulty in daily life due to decreased visual acuity or blindness. The primary outcome was all-cause mortality and the secondary outcomes were cardiovascular and infection-related hospitalization.A total of 3250 patients were included. Seven hundred thirty (22.5%) of the enrolled patients had visual impairment. The median follow-up period was 30 months. The Kaplan-Meier curve and log-rank test showed that all-cause mortality rates (P < 0.001) as well as cardiovascular and infection-related hospitalization rates (P < 0.001 and P < 0.001) were significantly higher in patients with visual impairment than in patients without visual impairment. In the multivariable analysis, visual impairment had significant predictive power for all-cause mortality (Hazard ratio [HR], 1.77, 95% confidence interval [CI], 1.21-2.61, P = 0.004) and cardiovascular hospitalization (HR 1.45 [1.00-1.90], P = 0.008) after adjusting for confounding variables. Of these 3250 patients, 634 patients from each group were matched by propensity scores. In the propensity score matched analysis, patients with visual impairment had independently significant associations with increased all-cause mortality (HR 1.69 [1.12-2.54], P = 0.01) and cardiovascular hospitalization (HR 1.48 [1.08-2.02], P = 0.01) compared with patients without visual impairment after adjustment for confounding variables.Our data demonstrated that visual impairment was an independent risk factor for clinical adverse outcomes in HD patients.

Serum Gamma-Glutamyltransferase Levels Predict Clinical Outcomes in Hemodialysis Patients.

BACKGROUND: Gamma-glutamyltransferase (GGT) is a biomarker of liver injury. GGT has also been reported to be a marker of oxidative stress and a predictor of mortality in the general population. Hemodialysis (HD) patients suffer from oxidative stress. The aim of our study was to investigate the relationship between serum GGT levels and clinical outcomes in HD patients. METHODS: A total of 1,634 HD patients were enrolled from the Clinical Research Center registry for end-stage renal disease, a prospective cohort in Korea. Patients were categorized into three groups by tertiles of serum GGT levels. The primary outcome was all-cause, cardiovascular, or infection-related mortality and hospitalization. RESULTS: During the median follow-up period of 30 months, the highest tertile of serum GGT levels had a significantly higher risk for all-cause mortality (hazard ratio (HR) 2.39, 95% confidence interval (CI), 1.55-3.69, P<0.001), cardiovascular mortality (HR 2.14, 95% CI, 1.07-4.26, P = 0.031) and infection-related mortality (HR 3.07, 95% CI, 1.30-7.25, P = 0.011) using tertile 1 as the reference group after adjusting for clinical variables including liver diseases. The highest tertile also had a significantly higher risk for first hospitalization (HR 1.22, 95% CI, 1.00-1.48, P = 0.048) and cardiovascular hospitalization (HR 1.42, 95% CI, 1.06-1.92, P = 0.028). CONCLUSIONS: Our data demonstrate that high serum GGT levels were an independent risk factor for all-cause, cardiovascular, and infection-related mortality, as well as cardiovascular hospitalization in HD patients. These findings suggest that serum GGT levels might be a useful biomarker to predict clinical outcomes in HD patients.

Impact of Dialysate Calcium Concentration on Clinical Outcomes in Incident Hemodialysis Patients.

The association between dialysate calcium (DCa) concentration and mortality in hemodialysis (HD) patients is controversial. In this study, we evaluated the impact of DCa concentration on mortality in incident HD patient. Incident HD patients were selected from the Clinical Research Center registry-a prospective cohort study on dialysis patients in Korea. Patients were categorized into 3 groups according to the prescribed DCa concentration at the time of enrollment. High DCa was defined as a concentration of 3.5 mEq/L, mid-DCa as 3.0 mEq/L, and low DCa as 2.5 to 2.6 mEq/L. The primary outcome was all-cause mortality and secondary outcomes were cardiovascular or infection-related hospitalization. A total of 1182 patients with incident HD were included. The number of patients in each group was 182 (15.4%) in high DCa group, 701 (59.3%) in the mid-DCa group, and 299 (25.3%) in the low DCa group. The median follow-up period was 16 months. The high DCa group had a significantly higher risk of all-cause mortality compared with the mid-DCa group (hazard ratio [HR] 2.23, 95% confidence interval [CI] 1.28-3.90, P = 0.005) and the low DCa group (HR 3.67, 95% CI 1.78-7.55, P < 0.001) after adjustment for clinical variables. The high DCa group was associated with higher risk of cardiovascular and infection-related hospitalization compared with the low DCa group (HR 3.25, 95% CI 1.53-6.89, P = 0.002; and HR 2.77, 95% CI 1.29-5.94, P =  .009, respectively). Of these 1182 patients, 163 patients from each group were matched by propensity scores. In the propensity score matched analysis, the high DCa group had a significantly higher risk of all-cause mortality compared with the mid-DCa group (HR 2.52, 95% CI 1.04-6.07, P = 0.04) and the low DCa group (HR 4.25, 95% CI 1.64-11.03, P = 0.003) after adjustment for clinical variables. Our data showed that HD using a high DCa was a significant risk factor for all-cause mortality and cardiovascular or infection-related hospitalization in incident HD patients.

The Impact of Timing of Dialysis Initiation on Mortality in Patients with Peritoneal Dialysis.

UNLABELLED: ♦ BACKGROUND: The impact of timing of dialysis initiation on mortality is controversial in patients with peritoneal dialysis (PD). In this study, we analyzed the impact of timing of dialysis initiation on mortality in the incident PD population. ♦ METHODS: Incident patients with PD were selected from the Clinical Research Center (CRC) registry for end-stage renal disease (ESRD), a prospective cohort study on dialysis in Korea. Patients were categorized into 3 groups according to the estimated glomerular filtration rate (eGFR) at the initiation of PD using the Modification of Diet in Renal Disease (MDRD) equation. Group A was defined as eGFR < 5 mL/min/1.73m(2), group B as eGFR 5 - 10 mL/min/1.73m(2), and group C as eGFR > 10 mL/min/1.73m(2). Cox regression analysis was used to calculate the adjusted hazard ratio (HR) of mortality with group B as the reference. The primary outcome was all-cause mortality. ♦ RESULTS: A total of 495 incident PD patients were included. The number of patients in group A was 109, group B was 279, and group C was 107. The median follow-up period was 23 months. Multivariate Cox regression analysis showed that group A had a significantly higher risk of all-cause mortality compared with group B (HR 4.13, 95% confidence interval [CI], 1.55 - 11.03, p = 0.005) after adjustment for age, gender, cause of ESRD, serum albumin level, diabetes mellitus, and cardiovascular disease. There was no significant difference in mortality between group C and group B (HR 1.50, 95% CI, 0.59 - 3.80, p = 0.398) after adjustment for clinical variables. ♦ CONCLUSION: An eGFR < 5 mL/min/1.73m(2) at the initiation of PD was a significant risk factor for death, while an eGFR >10 mL/min/1.73m(2) at the initiation of PD was not associated with improved survival compared with an eGFR of 5 - 10 mL/min/1.73m(2) at the initiation of PD.

Serum Gamma-Glutamyltransferase Levels Predict Mortality in Patients With Peritoneal Dialysis.

Serum gamma-glutamyltransferase (GGT) level has been considered marker of oxidative stress as well as liver function. Serum GGT level has been reported to be associated with the mortality in hemodialysis patients. However, it is not well established whether serum GGT level is associated with all-cause mortality in peritoneal dialysis (PD) patients. The aim of this study was to determine the association between serum GGT levels and all-cause mortality in PD patients.PD patients were included from the Clinical Research Center registry for end-stage renal disease cohort, a multicenter prospective observational cohort study in Korea. Patients were categorized into 3 groups by tertile of serum GGT levels as follows: tertile 1, GGT < 16 IU/L; tertile 2, GGT = 16 to 27 IU/L; and tertile 3, GGT > 27 IU/L. Primary outcome was all-cause mortality.A total of 820 PD patients were included. The median follow-up period was 34 months. Kaplan-Meier analysis showed that the all-cause mortality rate was significantly different according to tertiles of GGT (P = 0.001, log-rank). The multivariate Cox regression analysis showed that higher tertiles significantly associated with higher risk for all-cause mortality (tertile 2: hazard ratio [HR] 2.08, 95% confidence interval [CI], 1.17-3.72, P = 0.013; tertile 3: HR 1.83, 95% CI, 1.04-3.22, P = 0.035) in using tertile 1 as the reference group after adjusting for clinical variables.Our study demonstrated that high serum GGT levels were an independent risk factor for all-cause mortality in PD patients. Our findings suggest that serum GGT levels might be a useful biomarker to predict all-cause mortality in PD patients.

Association of Erythropoietin-Stimulating Agent Responsiveness with Mortality in Hemodialysis and Peritoneal Dialysis Patients.

Erythropoiesis-stimulating agent (ESA) responsiveness has been reported to be associated with increased mortality in hemodialysis (HD) patients. ESA requirement to obtain the same hemoglobin (Hb) level is different between HD and peritoneal dialysis (PD) patients. In this study, we investigated the impact of ESA responsiveness on mortality between both HD and PD patients. Prevalent HD and PD patients were selected from the Clinical Research Center registry for end-stage renal disease, a prospective cohort study in Korea. ESA responsiveness was estimated using an erythropoietin resistant index (ERI) (U/kg/week/g/dL). Patients were divided into three groups by tertiles of ERI. ESA responsiveness was also assessed based on a combination of ESA dosage and hemoglobin (Hb) levels. The primary outcome was all-cause mortality. A total of 1,594 HD and 876 PD patients were included. The median ESA dose and ERI were lower in PD patients compared with HD patients (ESA dose: 4000 U/week vs 6000 U/week, respectively. P<0.001, ERI: 7.0 vs 10.4 U/kg/week/g/dl, respectively. P<0.001). The median follow-up period was 40 months. In HD patients, the highest ERI tertile was significantly associated with higher risk for all-cause mortality (HR 1.96, 95% CI, 1.07 to 3.59, P = 0.029). HD patients with high-dose ESA and low Hb levels (ESA hypo-responsiveness) had a significantly higher risk of all-cause mortality (HR 2.24, 95% CI, 1.16 to 4.31, P = 0.016). In PD patients, there was no significant difference in all-cause mortality among the ERI groups (P = 0.247, log-rank test). ESA hypo-responsiveness was not associated with all-cause mortality (HR = 1.75, 95% CI, 0.58 to 5.28, P = 0.319). Our data showed that ESA hypo-responsiveness was associated with an increased risk of all-cause mortality in HD patients. However, in PD patients, ESA hypo-responsiveness was not related to all-cause mortality. These finding suggest the different prognostic value of ESA responsiveness between HD and PD patients.

Comparison of the impact of high-flux dialysis on mortality in hemodialysis patients with and without residual renal function.

BACKGROUND: The effect of flux membranes on mortality in hemodialysis (HD) patients is controversial. Residual renal function (RRF) has shown to not only be as a predictor of mortality but also a contributor to ß2-microglobulin clearance in HD patients. Our study aimed to determine the interaction of residual renal function with dialyzer membrane flux on mortality in HD patients. METHODS: HD Patients were included from the Clinical Research Center registry for End Stage Renal Disease, a prospective observational cohort study in Korea. Cox proportional hazards regression models were used to study the association between use of high-flux dialysis membranes and all-cause mortality with RRF and without RRF. The primary outcome was all-cause mortality. RESULTS: This study included 893 patients with 24 h-residual urine volume ≥100 ml (569 and 324 dialyzed using low-flux and high-flux dialysis membranes, respectively) and 913 patients with 24 h-residual urine volume <100 ml (570 and 343 dialyzed using low-flux and high-flux dialysis membranes, respectively). After a median follow-up period of 31 months, mortality was not significantly different between the high and low-flux groups in patients with 24 h-residual urine volume ≥100 ml (HR 0.86, 95% CI, 0.38-1.95, P = 0.723). In patients with 24 h-residual urine volume <100 ml, HD using high-flux dialysis membrane was associated with decreased mortality compared to HD using low-flux dialysis membrane in multivariate analysis (HR 0.40, 95% CI, 0.21-0.78, P = 0.007). CONCLUSIONS: Our data showed that HD using high-flux dialysis membranes had a survival benefit in patients with 24 h-residual urine volume <100 ml, but not in patients with 24 h-residual urine volume ≥100 ml. These findings suggest that high-flux dialysis rather than low-flux dialysis might be considered in HD patients without RRF.