INTRODUCTION: The profile of patients referred from primary to tertiary nephrology care is unclear. Ethnic Malay patients have the highest incidence and prevalence of kidney failure in Singapore. We hypothesised that there is a Malay predominance among patients referred to nephrology due to a higher burden of metabolic disease in this ethnic group. METHODS: This is a retrospective observational cohort study. From 2014 to 2018, a coordinator and physician triaged patients referred from primary care, and determined co-management and assignment to nephrology clinics. Key disease parameters were collated on triage and analysed. RESULTS: A total of 6,017 patients were studied. The mean age of patients was 64 ± 16 years. They comprised 57% men; 67% were Chinese and 22% were Malay. The proportion of Malay patients is higher than the proportion of Malays in the general population (13.4%) and they were more likely than other ethnicities to have ≥3 comorbidities, including diabetes mellitus, hypertension, hyperlipidaemia, coronary artery disease and stroke (70% vs. 57%, P < 0.001). Malay and Indian patients had poorer control of diabetes mellitus compared to other ethnicities (glycated haemoglobin 7.8% vs. 7.4%, P < 0.001). Higher proportion of Malay patients compared to other ethnicities had worse kidney function with estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m 2 on presentation (28% vs. 24%, P = 0.003). More ethnic Malay, Indian and younger patients missed appointments. CONCLUSION A disproportionately large number of Malay patients are referred for kidney disease. These patients have higher metabolic disease burden, tend to miss appointments and are referred at lower eGFR. Reasons underpinning these associations should be identified to facilitate efforts for targeting this at-risk population, ensuring kidney health for all.
Humans ; Male ; Female ; Retrospective Studies ; Middle Aged ; Singapore/epidemiology* ; Referral and Consultation/statistics & numerical data* ; Aged ; Nephrology ; Glomerular Filtration Rate ; Metabolic Diseases/epidemiology* ; Ethnicity ; Diabetes Mellitus/epidemiology* ; Malaysia/ethnology* ; Adult

BACKGROUND: Patients require risk stratification and preventive strategies for sudden cardiac death (SCD) based on the dialysis modality because the process of dialysis is a risk factor for SCD. This study aimed to compare the risk of SCD in patients undergoing hemodialysis (HD) versus peritoneal dialysis (PD).METHODS: Patients on HD and PD were included in the end-stage renal disease registry of the Korean Society of Nephrology between 1985 and 2017. The incidence and associated factors of SCD were analyzed based on the dialysis modalityRESULTS: Of 132,083 patients, 34,632 (26.2%) died during 94.8 ± 73.6 months of follow-up. In patients on HD and PD, 22.2% and 19.6% of total deaths were SCDs. In the propensity score-matched population, SCD accounted for 21.7% and 19.6% of total deaths in patients on HD and PD, respectively. HD was independently associated with SCD even after adjusting for age and significant comorbidities. Hypertension, coronary artery disease, and congestive heart failure, and age at the time of death < 65 years were independent risk factors for SCD in patients on HD but not in those on PD. Diabetes was significantly associated with SCD regardless of the dialysis modality.CONCLUSION: Compared with patients on PD, Korean patients on HD have a higher risk of SCD, which is attributable to cardiac comorbidities.
Comorbidity ; Coronary Artery Disease ; Death, Sudden, Cardiac ; Dialysis ; Follow-Up Studies ; Heart Failure ; Humans ; Hypertension ; Incidence ; Kidney Failure, Chronic ; Nephrology ; Peritoneal Dialysis ; Renal Dialysis ; Risk Factors

BACKGROUND: Unlike patterns observed in the general population, obesity is associated with better survival among hemodialysis patients, which could be explained by reverse causation or illness-related weight loss. However, the time-varying effect of body mass index (BMI) on hemodialysis survival has not been investigated. Therefore, this study investigated the time-varying effect of BMI on mortality after starting hemodialysis. METHODS: In the present study, we examined Korean Society of Nephrology data from 16,069 adult patients who started hemodialysis during or after the year 2000. Complete survival data were obtained from Statistics Korea. Survival analysis was performed using Cox regression and a non-proportional hazard fractional polynomial model. RESULTS: During the median follow-up of 8.6 years, 9,272 patients (57.7%) died. Compared to individuals with normal BMI (18.5–24.9 kg/m²), the underweight group (< 18.5 kg/m²) had a higer mortality hazard ratio (HR, 1.292; 95% confidence interval [CI], 1.203–1.387; P < 0.001) and the overweight group (25.0–29.9 kg/m²) had a lower mortality HR (0.904; 95% CI, 0.829–0.985; P = 0.022). The underweight group had increasing HRs during the first 3 to 7 years after starting hemodialysis, which varied according to age group. The young obese group (< 40 years old) had a U-shaped temporal trend in their mortality HRs, which reflected increased mortality after 7 years. CONCLUSION: The obese hemodialysis group had better survival during the early post-dialysis period, although the beneficial effect of obesity disappeared 7 years after starting hemodialysis. The young obese group also had an increased mortality HR after 7 years.
Adult ; Body Mass Index ; Follow-Up Studies ; Humans ; Korea ; Models, Statistical ; Mortality ; Nephrology ; Obesity ; Overweight ; Renal Dialysis ; Thinness ; Weight Loss

The End-stage Renal Disease Registry Committee of the Korean Society of Nephrology collects data on the dialysis therapy in Korea through an internet-based registry program and reports it annually. In this article, the method and clinical implications of the mortality hazard ratio analyses of various clinical parameters in the 2017 registry report have been described, with the inclusion of data on four additional parameters. The mortality risk based on clinical parameters was analyzed only for hemodialysis patients. The number of registered patients with laboratory data was 13,943 (8,446 male and 5,497 female patients), and death was reported in 3,139 patients. Analysis of the effects of various clinical parameters on mortality was performed using non-linear Cox proportional hazard model with the R statistics program. For all clinical parameters, univariate and adjusted multivariate hazard ratio analyses were performed. Analysis of the mortality hazard ratio showed that low body mass index, low hemoglobin, low serum albumin, low serum phosphorus, and low urea reduction ratio were associated with a significantly increased mortality risk, whereas paradoxically high serum creatinine levels were associated with low mortality risk.
Body Mass Index ; Creatinine ; Dialysis ; Female ; Humans ; Kidney Failure, Chronic ; Korea ; Male ; Methods ; Mortality ; Nephrology ; Phosphorus ; Proportional Hazards Models ; Renal Dialysis ; Serum Albumin ; Urea

BACKGROUND: Hyperuricemia is associated with the development and progression of chronic kidney disease (CKD) as well as cardiovascular diseases. However, there is no consistent recommendation regarding the treatment of asymptomatic hyperuricemia (AHU) in CKD patients. Here, we surveyed Korean physicians’ perceptions regarding the diagnosis and management of AHU in CKD patients. METHODS: Questionnaires on the management of AHU in CKD patients were emailed to regular members registered with the Korean Society of Nephrology. RESULTS: A total of 158 members answered the questionnaire. Among the respondents, 49.4%/41.1% were considered hyperuricemic in male CKD patients whereas 36.7%/20.9% were considered hyperuricemic in female CKD patients when defined by serum uric acid level over 7.0/8.0 mg/dL, respectively. A total of 80.4% reported treating AHU in CKD patients. The most important reasons to treat AHU in CKD patients were renal function preservation followed by cerebro-cardiac protection. Majority of respondents (59.5%) thought that uric acid-lowering agents (ULAs) were the most effective method for controlling serum uric acid levels. Approximately 80% chose febuxostat as the preferred medication. A total of 32.3% and 31.0%, respectively, initiated ULA treatment if the serum uric acid level was more than 8.0 or 9.0 mg/dL, respectively. In addition, 39.2% and 30.4% answered that target serum uric acid levels of less than 6.0 or 7.0 mg/dL, respectively, were appropriate. The two major hurdles to prescribing ULAs were concerns of adverse reactions and the existing lack of evidence (i.e., the absence of Korean guidelines). CONCLUSION: Most Korean physicians treat AHU in CKD patients to prevent CKD progression and cerebro-cardiovascular complications.
Cardiovascular Diseases ; Diagnosis ; Electronic Mail ; Febuxostat ; Female ; Humans ; Hyperuricemia ; Male ; Methods ; Nephrology ; Renal Insufficiency, Chronic ; Surveys and Questionnaires ; Uric Acid

BACKGROUND AND OBJECTIVES: In regenerative medicine, mesenchymal stem cells derived from adipose tissues (Ad-MSCs) are a very attractive target to treat many diseases. In relation to nephrology, the aim of the current study is to investigate the effects of Ad-MSCs for the amelioration of acute kidney injury and to explore the mechanism of renal parenchymal changes in response to allogeneic transplantation of Ad-MSCs. METHODS AND RESULTS: The nephrotoxicity was induced by cisplatin (CP) in balb/c mice according to RIFLE Class and AKIN Stage 3. PCR, qRT-PCR and fluorescent labeled cells infusion, histopathology, immunohistochemistry, functional analyses were used for genes and proteins expressions data acquisition respectively. We demonstrated that single intravenous infusion of 2.5×107/kg mAd-MSCs in mice pre-injected with CP recruited to the kidney, restored the renal structure, and function, which resulted in progressive survival of mice. The renal tissue morphology was recovered in terms of diminished necrosis or epithelial cells damage, protein casts formation, infiltration of inflammatory cells, tubular dilatation, and restoration of brush border protein; Megalin and decreased Kim-1 expressions in mAd-MSCs transplanted mice. Significant reduction in serum creatinine with slashed urea and urinary protein levels were observed. Anti-BrdU staining displayed enhanced tubular cells proliferation. Predominantly, downgrade expressions of TNF-α and TGF-β1 were observed post seven days in mAd-MSCs transplanted mice. CONCLUSIONS: Ad-MSCs exerts pro-proliferative, anti-inflammatory, and anti-fibrotic effects. Ad-MSCs transplantation without any chemical or genetic manipulation can provide the evidence of therapeutic strategy for the origin of regeneration and overall an improved survival of the system in functionally deprived failed kidneys.
Acute Kidney Injury ; Animals ; Cisplatin ; Creatinine ; Dilatation ; Epithelial Cells ; Immunohistochemistry ; Infusions, Intravenous ; Kidney ; Low Density Lipoprotein Receptor-Related Protein-2 ; Mesenchymal Stromal Cells ; Mice ; Microvilli ; Necrosis ; Nephrology ; Polymerase Chain Reaction ; Regeneration ; Regenerative Medicine ; Transplantation, Homologous ; Urea

An association between hypothyroidism and renal impairment has rarely been reported in the literature. We describe a case of hypothyroidism that was associated with otherwise unexplained acute kidney impairment, which was reversed with treatment. A 21-year-old female patient presented to her family physician with myalgia, and preliminary investigations revealed an elevated level of creatine kinase and poor renal function. Primary hypothyroidism was diagnosed and no other apparent etiology for renal failure could be identified despite extensive investigations by the Nephrology Department. Notably, the patient's renal impairment showed prompt resolution following thyroid hormone replacement.
Creatine Kinase ; Female ; Hashimoto Disease ; Humans ; Hypothyroidism* ; Kidney ; Myalgia ; Nephrology ; Physicians, Family ; Renal Insufficiency ; Thyroid Gland ; Young Adult

BACKGROUND/AIMS: Predialysis hyponatremia has been recently reported to be associated with mortality in incident hemodialysis patients. However, whether hyponatremia is associated with unfavorable outcomes in elderly patients remains unknown. We hypothesized that nephrology referral inf luences hyponatremia, and aimed to define how nephrology referral affects the association between hyponatremia and mortality in the elderly. METHODS: We retrospectively assessed mortality in 599 incident hemodialysis patients aged ≥ 70 at a tertiary university hospital, between 2000 and 2010. We analyzed 90-day and 1-year all-cause mortality (ACM) in relation to predialysis serum sodium (sNa). We divided the patients into two groups according to predialysis glucose-corrected sNa: hyponatremia (< 135 mmol/L) and normonatremia (135 to 145 mmol/L). RESULTS: Low estimated glomerular filtration rate, high phosphorus, low albumin, nonpreparation of arteriovenous fistula or graft, and late referral were associated with a low sNa in the elderly. Among 599 patients, 106 and 174 patients died at the 90-day and 1-year follow-ups, respectively. Each 10-mmol/L increase in predialysis sNa tended to be associated with lower 90-day and 1-year ACM. When patients were stratified by nephrology referral, hyponatremia was associated with increased mortality in early referral group (90-day ACM: hazard ratio [HR] = 2.335, p = 0.041; 1-year ACM: HR = 1.790, p = 0.024). However, hyponatremia was not associated with mortality in late referral group. CONCLUSIONS: Predialysis hyponatremia at hemodialysis initiation is associated with late referra
Aged* ; Arteriovenous Fistula ; Follow-Up Studies ; Glomerular Filtration Rate ; Humans ; Hyponatremia* ; Mortality* ; Nephrology ; Phosphorus ; Referral and Consultation ; Renal Dialysis* ; Retrospective Studies ; Sodium ; Transplants

BACKGROUND: We investigated the associations between mineral metabolism parameters and mortality to identify optimal targets in Korean hemodialysis patients. METHODS: Among hemodialysis patients registered in the end-stage renal disease registry of the Korean Society of Nephrology between March 2012 and June 2017, those with serum calcium, phosphorus, and intact parathyroid hormone (iPTH) measured at enrollment were included. Association of serum levels of calcium, phosphorus, and iPTH with all-cause mortality was analyzed. RESULTS: Among 21,433 enrolled patients, 3,135 (14.6%) died during 24.8 ± 14.5 months of follow-up. After multivariable adjustment, patients in the first quintile of corrected calcium were associated with lower mortality (hazard ratio [HR], 0.84; 95% confidence interval [95% CI], 0.71–0.99; P = 0.003), while those in the fifth quintile were associated with higher mortality (HR, 1.39; 95% CI, 1.20–1.61; P < 0.001) compared with those in the third quintile. For phosphorus, only the lowest quintile was significantly associated with increased mortality (HR, 1.24; 95% CI, 1.08–1.43; P = 0.003). The lowest (HR, 1.18; 95% CI, 1.02–1.36; P = 0.026) and highest quintiles of iPTH (HR, 1.24; 95% CI, 1.05–1.46; P = 0.013) were associated with increased mortality. For target counts achieved according to the Kidney Disease Outcomes Quality Initiative guideline, patients who did not achieve any mineral parameter targets hadhigher mortality than those who achieved all three targets (HR, 1.37; 95% CI, 1.12–1.67; P = 0.003). CONCLUSION: In Korean hemodialysis patients, high serum calcium, low phosphorus, and high and low iPTH levels were associated with increased all-cause mortality.
Calcium ; Follow-Up Studies ; Humans ; Kidney Diseases ; Kidney Failure, Chronic* ; Metabolism ; Miners* ; Mortality* ; Nephrology ; Parathyroid Hormone ; Phosphorus ; Renal Dialysis*

BACKGROUND: Urine culture is one of the most frequently requested tests in microbiology. Automated urine analyzers yield much infection-related information. The Sysmex UF-5000 analyzer (Sysmex, Japan) is a new flow cytometry urine analyzer capable of quantifying urinary particles, including bacteria, WBCs, and yeast-like cells (YLCs) and can provide a Gram stainability flag. In this work, we evaluated how many unnecessary urine cultures could be screened out using the UF-5000. METHODS: We compared the culture results of 126 urine samples among 453 requested urine cultures (from sources other than the Urology and Nephrology departments) with urinalysis results. Urine cultures were considered positive if bacterial or YLC growth was ≥104 CFUs/mL. RESULTS: We used urinalysis cut-off values of 50/µL and 100/µL for bacteria and YLC, respectively. Forty eight of the 126 (38.1%, or 10.6% of 453 requested) cultures were below these cut-off values and did not contain any culture-positive samples. CONCLUSION: Bacteria and YLC counts generated using the UF-5000 analyzer could be used to screen out negative cultures and reduce urine culture volume by ~10% without sacrificing detection of positive cultures.
Bacteria ; Flow Cytometry ; Nephrology ; Urinalysis ; Urinary Tract Infections ; Urology