BACKGROUND: The clinical importance of hypokalemia is likely underrecognized in Chinese dialysis patients, and whether its clinical effect was mediated by serum albumin is not fully elucidated. This study aimed to explore the association between serum potassium and mortality in dialysis patients of a Chinese nationwide multicenter cohort, taking albumin as a consideration. METHODS: This was a prospective nation-wide multicenter cohort study. Restricted cubic splines were used to test the linearity of serum potassium and relationships with all-cause (AC) and cardiovascular (CV) mortality and a subsequent two-line piecewise linear model was fitted to approach the nadir. A mediation analysis was performed to examine relations of albumin to potassium and mortalities. RESULTS: A total of 10,027 patients were included, of whom 6605 were peritoneal dialysis and 3422 were hemodialysis patients. In the overall population, the mean age was 51.7 ± 14.8 years, 55.3%(5546/10,027) were male, and the median dialysis vintage was 13.60 (4.70, 39.70) months. Baseline serum potassium was 4.30 ± 0.88 mmol/L. After a median follow-up period of 26.87 (14.77, 41.50) months, a U-shape was found between potassium and mortality, and a marked increase in risk at lower potassium but a moderate elevation in risk at higher potassium were observed. The nadir for AC mortality risk was estimated from piecewise linear models to be a potassium concentration of 4.0 mmol/L. Interestingly, the significance of the association between potassium and mortality was attenuated when albumin was introduced into the extended adjusted model. A subsequent significant mediation by albumin for potassium and AC and CV mortalities were found ( P < 0.001 for both), indicating that hypokalemia led to higher mortality mediated by low serum albumin, which was a surrogate of poor nutritional status and inflammation. CONCLUSIONS Associations between potassium and mortalities were U-shaped in the overall population. The nadir for AC mortality risk was at a potassium of 4.0 mmol/L. Serum albumin mediated the association between potassium and AC and CV mortalities.
Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; East Asian People ; Hypokalemia/etiology* ; Kidney Failure, Chronic/mortality* ; Potassium/blood* ; Prospective Studies ; Renal Dialysis ; Serum Albumin/analysis*

Diabetic kidney disease is a microvascular complication of diabetes mellitus and the leading cause of end-stage renal disease resulting in renal replacement therapy. Approximately 30% to 40% of diabetic patients have diabetic kidney disease, which contributes to a significant increase in morbidity and mortality. Microalbuminuria is considered the gold standard for diabetic kidney disease diagnosis; however, its predictive value is restricted. Although blood glucose control, blood pressure control, and angiotensin converting enzyme inhibitors have been the primary treatment strategies, there are no definitive treatment modalities capable of inhibiting the progression of kidney dysfunction in these patients. This study was undertaken to answer seven questions regarding the various aspects of diabetic kidney disease. Why does it develop? what kind of factors affect its development? How is it diagnosed? What are its possible biomarkers? When is a kidney biopsy necessary? What are the preventive and therapeutic options? And what are the novel treatments?
Angiotensin-Converting Enzyme Inhibitors ; Biomarkers ; Biopsy ; Blood Glucose ; Blood Pressure ; Diabetes Mellitus ; Diabetic Nephropathies ; Diagnosis ; Humans ; Kidney ; Kidney Failure, Chronic ; Mortality ; Renal Replacement Therapy

Adult ; Aged ; Alkaline Phosphatase ; blood ; Female ; Humans ; Kaplan-Meier Estimate ; Kidney Failure, Chronic ; blood ; mortality ; therapy ; Male ; Middle Aged ; Peritoneal Dialysis ; Retrospective Studies

BACKGROUND: Kidney transplantation is an effective renal replacement therapy for patients with end-stage renal disease (ESRD). In this study, we assessed the impact of the baseline characteristics and comorbidities of ESRD patients on the probability of deceased donor kidney transplantation (DDKT) and evaluated the morbidity and mortality during the time spent waiting. METHODS: The study population consisted of 544 ESRD patients on the waiting list for DDKT at Chungnam National University Hospital in South Korea between February 2000 and October 2015. The patients were observed from the date of transplantation list registration to the date of transplantation. Baseline characteristics and comorbidities were investigated together with new-onset comorbidities that occurred during the waiting time. RESULTS: Diabetes mellitus (39.0%), hypertension (25.2%), and glomerulonephritis (21.3%) were the three most common causes of ESRD in this study, and coronary artery disease (9.4%) was the most common comorbidity. The 115 patients (19.3%) who underwent DDKT had a mean waiting time of 1,711 days (768–2,654 days or 4.68 years [2.10–7.27]). Blood groups other than type O, peritoneal dialysis, and nondiabetic ESRD were significantly associated with a higher likelihood of DDKT. Infection was the leading cause of death and the most common comorbidity that arose during the waiting time. Patients who experienced cardiovascular events during the waiting time showed a lower transplant rate compared with those who did not. CONCLUSION: The prevalence of comorbidities was high in renal transplantation candidates. During the often-long waiting time, new comorbidities may occur, with long-term sequelae limiting access to kidney transplantation or resulting in death.
Blood Group Antigens ; Cause of Death ; Chungcheongnam-do ; Comorbidity ; Coronary Artery Disease ; Diabetes Mellitus ; Glomerulonephritis ; Humans ; Hypertension ; Kidney Failure, Chronic ; Kidney Transplantation ; Kidney ; Korea ; Mortality ; Peritoneal Dialysis ; Prevalence ; Renal Replacement Therapy ; Tissue Donors ; Waiting Lists

Hypertension affects the majority of patients with chronic kidney disease (CKD) and increases the risk of cardiovascular disease, end-stage renal disease and mortality. Previously, many hypertension guidelines have suggested blood pressure targets in patients with CKD. Recently, the American College of Cardiology/American Heart Association 2017 Guideline for Hypertension suggests a new definition for hypertension and therapeutic targets, which were equally applicated to patients with CKD. These changes reflect the results of the Systolic Blood Pressure Intervention Trial (SPRINT) study, but the renal outcome of intensive blood pressure control was not good. Furthermore, the majority of hypertension guidelines including those of the Korean Society of Hypertension and the European Society of Hypertension have retained the traditional definition. Herein, we intend to analyze in detail the effect of intensive blood pressure control on kidney through the post-hoc analyses of the SPRINT study.
Blood Pressure ; Cardiovascular Diseases ; Diagnosis ; Heart ; Humans ; Hypertension ; Kidney ; Kidney Failure, Chronic ; Mortality ; Renal Insufficiency, Chronic

BACKGROUND: Diabetic nephropathy is a leading cause of end stage renal disease and is associated with an increased risk of cardiovascular mortality. It manifests as albuminuria or impaired glomerular filtration rate (GFR), and the prevalence of diabetic nephropathy varies with ethnicity. The prevalence of diabetic nephropathy and its determinants in Korean adults have not previously been studied at the national level. This cross-sectional study was undertaken to ascertain the prevalence and determinants of albuminuria and chronic kidney disease (CKD) in Korean patients with diabetes. METHODS: The Korea National Health and Nutrition Examination Survey (KNHANES) V, conducted in 2011, was used to define albuminuria (n=4,652), and the dataset of KNHANES IV-V (2008-2011) was used to define CKD (n=21,521). Selected samples were weighted to represent the entire civilian population in Korea. Albuminuria was defined as a spot urine albumin/creatinine ratio >30 mg/g. CKD was defined as a GFR <60 mL/min/1.73 m2. RESULTS: Among subjects with diabetes, 26.7% had albuminuria, and 8.6% had CKD. Diabetes was associated with an approximate 2.5-fold increased risk of albuminuria, with virtually no difference between new-onset and previously diagnosed diabetes. Only systolic blood pressure was significantly associated with albuminuria, and old age, high serum triglyceride levels, and previous cardiovascular disease (CVD) were related with CKD in subjects with diabetes. CONCLUSION: Korean subjects with diabetes had a higher prevalence of albuminuria and CKD than those without diabetes. Blood pressure was associated with albuminuria, and age, triglyceride level, and previous CVD were independent determinants of CKD in subjects with diabetes.
Adult ; Albuminuria ; Blood Pressure ; Cardiovascular Diseases ; Cross-Sectional Studies ; Dataset ; Diabetes Mellitus ; Diabetic Nephropathies* ; Glomerular Filtration Rate ; Humans ; Kidney Failure, Chronic ; Korea ; Mortality ; Nutrition Surveys* ; Prevalence* ; Renal Insufficiency, Chronic ; Triglycerides

Although oxidized low-density lipoprotein (LDL) and lysophosphatidylcholine (LPC) have been proposed as important mediators of the atherosclerosis, the long-term contribution to the risk of cardiovascular disease (CVD) in hemodialysis patients has not been evaluated. This study investigated the relation between oxidized LDL and LPC levels with long term risk of CVD. Plasma oxidized LDL and LPC levels were determined in 69 Korean hemodialysis patients as a prospective observational study for 5 yr. During the observation period, 18 cardiovascular events (26.1%) occurred including 6 deaths among the hemodialysis patients. The low LPC level group (< or = 254 microM/L, median value) had much more increased risk of CVD compared to the high LPC level group (> 254 microM/L) (P = 0.01). However, serum levels of oxidized LDL were not significantly different between groups with and without CVD. In adjusted Cox analysis, previous CVD, (hazard ratio [HR], 5.68; 95% confidence interval [CI], 1.94-16.63, P = 0.002) and low LPC level (HR, 3.45; 95% CI, 1.04-11.42, P = 0.04) were significant independent risk factors for development of CVD. It is suggested that low LPC, but not oxidized LDL, is associated with increased risk of CVD among a group of Korean hemodialysis patients.
Adult ; Aged ; Asian Continental Ancestry Group ; Cardiovascular Diseases/*diagnosis/etiology/mortality ; Case-Control Studies ; Female ; Follow-Up Studies ; Humans ; Kidney Failure, Chronic/blood/complications/diagnosis ; Lipoproteins, LDL/*blood ; Lysophosphatidylcholines/*blood ; Male ; Middle Aged ; Proportional Hazards Models ; Prospective Studies ; Renal Dialysis ; Republic of Korea ; Risk Factors

This study evaluated the significance of aortic calcification index (ACI), an estimate of abdominal aortic calcification by plain abdominal computed tomography (CT), in terms of left ventricular (LV) diastolic dysfunction, mortality, and nonfatal cardiovascular (CV) events in chronic hemodialysis patients. Hemodialysis patients who took both an abdominal CT and echocardiography were divided into a low-ACI group (n = 64) and a high-ACI group (n = 64). The high-ACI group was significantly older, had a longer dialysis vintage and higher comorbidity indices, and more patients had a previous history of CV disease than the low-ACI group. The ACI was negatively correlated with LV end-diastolic volume or LV stroke volume, and was positively correlated with the ratio of peak early transmitral flow velocity to peak early diastolic mitral annular velocity (E/E' ratio), a marker of LV diastolic function. The E/E' ratio was independently associated with the ACI. The event-free survival rates for mortality and nonfatal CV events were significantly lower in the high-ACI group compared with those in the low-ACI group, and the ACI was an independent predictor for all-cause deaths and nonfatal CV events. In conclusion, ACI is significantly associated with diastolic dysfunction and predicts all-cause mortality and nonfatal CV events in hemodialysis patients.
Adult ; Age Factors ; Aged ; Aged, 80 and over ; Aorta, Abdominal ; Blood Flow Velocity ; Blood Pressure ; Calcinosis/*etiology ; Cardiovascular Diseases/*complications ; Disease-Free Survival ; Echocardiography ; Female ; Follow-Up Studies ; Humans ; Kaplan-Meier Estimate ; Kidney Failure, Chronic/*complications/mortality ; Male ; Middle Aged ; Predictive Value of Tests ; Prognosis ; Regression Analysis ; Renal Dialysis ; Risk Factors ; Tomography, X-Ray Computed ; Ventricular Dysfunction, Left/complications/*physiopathology

Malnutrition and inflammation are related to high rates of morbidity and mortality in hemodialysis patients. Resistin is associated with nutrition and inflammation. We attempted to determine whether resistin levels may predict clinical outcomes in hemodialysis patients. We conducted a prospective evaluation of 100 outpatients on hemodialysis in a single dialysis center (male, 46%; mean age, 53.7 +/- 16.4 yr). We stratified the patients into 4 groups according to quartiles of serum resistin levels. During the 18-month observational period, patients with the lowest quartile of serum resistin levels had poor hospitalization-free survival (log rank test, P = 0.016). After adjustment of all co-variables, patients with the lowest quartile of serum resistin levels had poor hospitalization-free survival, compared with reference resistin levels. Higher levels of interleukin-6 were an independent predictor of poor hospitalization-free survival. In contrast, serum resistin levels were not correlated with interleukin-6 levels. The current data showed that low resistin levels may independently predict poor hospitalization free survival in hemodialysis patients.
Adult ; Aged ; Diabetes Complications ; Female ; Hospitalization ; Humans ; Interleukin-6/blood ; Kidney Failure, Chronic/blood/*mortality ; Male ; Middle Aged ; Proportional Hazards Models ; Prospective Studies ; *Renal Dialysis ; Resistin/*blood ; Survival Analysis

PURPOSE: Cardiac troponin T (cTnT), a useful marker for diagnosing acute myocardial infarction (AMI) in the general population, is significantly higher than the usual cut-off value in many end-stage renal disease (ESRD) patients without clinically apparent evidence of AMI. The aim of this study was to evaluate the clinical usefulness of cTnT in ESRD patients with acute coronary syndrome (ACS). MATERIALS AND METHODS: Two hundred eighty-four ESRD patients with ACS were enrolled between March 2002 and February 2008. These patients were followed until death or June 2009. Medical records were reviewed retrospectively. The cut-off value of cTnT for AMI was evaluated using a receiver operating characteristic (ROC) curve. We calculated Kaplan-Meier survival curves, and potential outcome predictors were determined by Cox proportional hazard analysis. RESULTS: AMIs were diagnosed in 40 patients (14.1%). The area under the curve was 0.98 in the ROC curve (p<0.001; 95% CI, 0.95-1.00). The summation of sensitivity and specificity was highest at the initial cTnT value of 0.35 ng/mL (sensitivity, 0.95; specificity, 0.97). Survival analysis showed a statistically significant difference in all-cause and cardiovascular mortalities for the group with an initial cTnT > or =0.35 ng/mL compared to the other groups. Initial serum cTnT concentration was an independent predictor for mortality. CONCLUSION: Because ESRD patients with an initial cTnT concentration > or =0.35 ng/mL have a poor prognosis, it is suggested that urgent diagnosis and treatment be indicated in dialysis patients with ACS when the initial cTnT levels are > or =0.35 ng/mL.
Acute Coronary Syndrome/blood/complications/*diagnosis/mortality ; Aged ; Biological Markers/blood ; Female ; Humans ; Kidney Failure, Chronic/blood/complications/*diagnosis/mortality ; Male ; Middle Aged ; Prognosis ; Retrospective Studies ; Sensitivity and Specificity ; Troponin T/*blood