Patients on dialysis have numerous gastrointestinal problems related to uremia, which may represent concealed cholecystitis. We investigated the incidence and risk of acute cholecystitis in dialysis patients and used national health insurance data to identify acute cholecystitis in Korea. Methods: The Korean National Health Insurance Database was used, with excerpted data from the insurance claim of the International Classification of Diseases code of dialysis and acute cholecystitis treated with cholecystectomy. We included all patients who commenced dialysis between 2004 and 2013 and selected the same number of controls via propensity score matching. Results: A total of 59,999 dialysis and control patients were analyzed; of these, 3,940 dialysis patients (6.6%) and 647 controls (1.1%) developed acute cholecystitis. The overall incidence of acute cholecystitis was 8.04-fold higher in dialysis patients than in controls (95% confidence interval, 7.40–8.76). The acute cholecystitis incidence rate (incidence rate ratio, 23.13) was especially high in the oldest group of dialysis patients (aged ≥80 years) compared with that of controls. Dialysis was a significant risk factor for acute cholecystitis (adjusted hazard ratio, 8.94; 95% confidence interval, 8.19–9.76). Acute cholecystitis developed in 3,558 of 54,103 hemodialysis patients (6.6%) and in 382 of 5,896 patients (6.5%) undergoing peritoneal dialysis. Conclusion: Patients undergoing dialysis had a higher incidence and risk of acute cholecystitis than the general population. The possibility of a gallbladder disorder developing in patients with gastrointestinal problems should be considered in the dialysis clinic.

End-stage renal disease (ESRD) patients on hemodialysis have poor nutritional status and associated problems such as inflammation and sarcopenia. Blood urea nitrogen (BUN) is an important measure of uremic toxins, and urea reduction is a marker of hemodialysis efficacy. However, a low protein diet for lower BUN could aggravate malnutrition in patients, and optimal pre-dialysis BUN is not defined. We investigated the association of pre-dialysis BUN with patients’ comorbidities and the relationship between pre-dialysis BUN and serum albumin as a nutrient marker. Among the 67 patients, the average pre- and post-dialysis BUN were 59.2 and 15.0 mg/dL, respectively, serum creatinine was 10.1 mg/dL, and the average serum albumin was 4.0 g/dL. Patients’ age was negatively correlated with serum creatinine (r=−0.277, p<0.05) and albumin (r=−0.453, p<0.001). Predialysis BUN showed a significant positive correlation with serum albumin (r=0.287, p<0.05) and creatinine (r=0.454, p<0.001). However, the predialysis BUN was not significantly related to diabetes, coronary artery disease, congestive heart failure, or cerebrovascular disease. Hemodialysis patients with high pre-dialysis BUN and high serum creatinine could be regarded as having good nutritional status. The significance of this study lies in the potential utility of pre-dialysis blood urea nitrogen as an indicator of the nutritional status of patients. Liberal protein intake might be recommended to adequately dialyzed patients.

Background: We investigated the incidence and risk of retinal vein occlusion (RVO) in endstage renal disease (ESRD) patients on dialysis in Korea. Methods: In this nationwide cohort study, we used Korean National Health Insurance Service data between 2004 and 2013 for analysis. ESRD patients who started dialysis from 2004 to 2013 and an equal number of controls were selected through propensity score matching. RVO incidence in both cohorts were calculated for 2004–2013 using washout data from 2003. The multivariable Cox proportional hazards model was used to assess the risk of RVO in dialysis cohort. The Kaplan-Meier method was used to generate the cumulative RVO incidence curve.Whether the dialysis modality affects the development of RVO was also evaluated. Results: In this study, 74,551 ESRD patients on dialysis and the same number of controls were included. The incidence of RVO was significantly higher in the dialysis cohort than in the control cohort (dialysis = 7.3/1,000 person-years [PY]; control = 1.9/1,000 PY; P < 0.001). The cumulative-incidence of RVO was also significantly higher in the dialysis cohort than in the control cohort (P < 0.001; log-rank test). However, there was no significant difference in the incidence of RVO between the two dialysis methods (P = 0.550; log-rank test). Conclusion This study provided epidemiological evidence that receiving dialysis for ESRD could increase the risk of developing RVO. We also found a rapid increase in the incidence of RVO with a longer dialysis period. These results strengthen the relationship between retinal vascular disease and renal function.

Background: We investigated the incidence and risk of retinal vein occlusion (RVO) in endstage renal disease (ESRD) patients on dialysis in Korea. Methods: In this nationwide cohort study, we used Korean National Health Insurance Service data between 2004 and 2013 for analysis. ESRD patients who started dialysis from 2004 to 2013 and an equal number of controls were selected through propensity score matching. RVO incidence in both cohorts were calculated for 2004–2013 using washout data from 2003. The multivariable Cox proportional hazards model was used to assess the risk of RVO in dialysis cohort. The Kaplan-Meier method was used to generate the cumulative RVO incidence curve.Whether the dialysis modality affects the development of RVO was also evaluated. Results: In this study, 74,551 ESRD patients on dialysis and the same number of controls were included. The incidence of RVO was significantly higher in the dialysis cohort than in the control cohort (dialysis = 7.3/1,000 person-years [PY]; control = 1.9/1,000 PY; P < 0.001). The cumulative-incidence of RVO was also significantly higher in the dialysis cohort than in the control cohort (P < 0.001; log-rank test). However, there was no significant difference in the incidence of RVO between the two dialysis methods (P = 0.550; log-rank test). Conclusion This study provided epidemiological evidence that receiving dialysis for ESRD could increase the risk of developing RVO. We also found a rapid increase in the incidence of RVO with a longer dialysis period. These results strengthen the relationship between retinal vascular disease and renal function.

BACKGROUND: The numbers of patients on dialysis and their life expectancies are increasing. Reduced renal function is associated with an increased risk of cancer, but the cancer incidence and sites in dialysis patients compared with those of the general population require further investigation. We investigated the incidences of various cancers in dialysis patients in Korea and used national health insurance data to identify cancers that should be screened in dialysis clinics. METHODS: We accessed the Korean National Health Insurance Database and excerpted data using the International Classification of Disease codes for dialysis and malignancies. We included all patients who commenced dialysis between 2004 and 2013 and selected the same number of controls via propensity score matching. RESULTS: A total of 48,315 dialysis patients and controls were evaluated; of these, 2,504 (5.2%) dialysis patients and 2,201 (4.6%) controls developed cancer. The overall cancer risk was 1.54-fold higher in dialysis patients than in controls (adjusted hazard ratio, 1.71; 95% confidence interval, 1.61–1.81). The cancer incidence rate (incidence rate ratio [IRR], 3.27) was especially high in younger dialysis patients (aged 0–29 years). The most common malignancy of end-stage renal disease patients and controls was colorectal cancer. The major primary cancer sites in dialysis patients were liver and stomach, followed by the lung, kidney, and urinary tract. Kidney cancer exhibited the highest IRR (6.75), followed by upper urinary tract (4.00) and skin cancer (3.38). The rates of prostate cancer (0.54) and oropharyngeal cancer (0.72) were lower than those in the general population. CONCLUSION: Dialysis patients exhibited a higher incidence of malignancy than controls. Dialysis patients should be screened in terms of colorectal, liver, lung, kidney and urinary tract malignancies in dialysis clinics.
Colorectal Neoplasms ; Dialysis ; Epidemiology ; Humans ; Incidence ; International Classification of Diseases ; Kidney ; Kidney Failure, Chronic ; Kidney Neoplasms ; Korea ; Life Expectancy ; Liver ; Lung ; National Health Programs ; Oropharyngeal Neoplasms ; Propensity Score ; Prostatic Neoplasms ; Renal Dialysis ; Skin Neoplasms ; Stomach ; Urinary Tract

Severe eating disorders characterized by repetitive episodes of purging and vomiting can occasionally trigger acute kidney injury. However, interstitial nephritis induced by episodes of repeated vomiting has rarely been reported, and the pathophysiology of this entity remains unknown. A 26-year-old man was admitted to our hospital because of known hypokalemia. His serum electrolyte profile showed: sodium 133 mEq/L, potassium 2.6 mEq/L, chloride 72 mEq/L, total carbon dioxide 50 mEq/L, blood urea nitrogen/creatinine ratio (BUN/Cr) 21.9/1.98 mg/dL, and magnesium 2.0 mg/dL. Arterial blood gas analysis showed: pH 7.557, partial pressure of carbon dioxide 65.8 mmHg, and bicarbonate 58.5 mEq/L. His urinary potassium concentration was 73.2 mEq/L, and Cr was 111 mg/dL. Renal biopsy revealed acute tubular necrosis and tubulointerstitial nephritis with a few shrunken glomeruli. Repeated psychogenic vomiting may precipitate acute kidney injury and interstitial nephritis secondary to volume depletion and hypokalemia. Serum electrolyte levels and renal function should be carefully monitored in patients diagnosed with eating disorders to prevent tubular ischemia and interstitial nephritis.
Acute Kidney Injury ; Adult ; Anorexia Nervosa* ; Anorexia* ; Biopsy ; Blood Gas Analysis ; Carbon Dioxide ; Eating ; Humans ; Hydrogen-Ion Concentration ; Hypokalemia ; Ischemia ; Magnesium ; Male* ; Necrosis ; Nephritis, Interstitial* ; Partial Pressure ; Potassium ; Sodium ; Urea ; Vomiting

BACKGROUND: The converging epidemics of tuberculosis (TB) and end-stage renal disease (ESRD) have generated a significant public health burden, however, previous studies have been limited to a small number of patients. This nationwide cohort study aimed to assess the rate of developing active TB among patients receiving dialysis for ESRD. METHODS: The Korean national health insurance database was used to identify patients receiving dialysis for new-onset ESRD during 2004–2013, who were propensity score matched to an equivalent number of non-dialysis subjects from the general population. The incidences of active TB in the ESRD and control cohorts were calculated for 2004–2013, and multivariable Cox proportional hazards model was used to evaluate the ESRD-related risk of active TB. RESULTS: During 2004–2013, 59,584 patients received dialysis for newly diagnosed ESRD. In the dialysis and control cohorts, 457 (0.8%) and 125 (0.2%) cases of active TB were detected, respectively. Patients with ESRD were associated with a significantly higher risk of active TB compared to the controls (incidence rate ratio, 4.80). The ESRD cohort had an independently elevated risk of active TB (adjusted hazard ratio, 4.39; 95% confidence interval, 3.60–5.37). CONCLUSION: We found that patients receiving dialysis for ESRD had an elevated risk of active TB. These results highlight the need for detailed and well-organised guidelines for active TB screening among patients with ESRD.
Cohort Studies* ; Dialysis ; Humans ; Incidence ; Kidney Failure, Chronic* ; Korea ; Mass Screening ; National Health Programs ; Propensity Score ; Proportional Hazards Models ; Public Health ; Renal Insufficiency, Chronic ; Tuberculosis*

Familial renal glycosuria (FRG) is an inherited disorder characterized by persistent glycosuria in the absence of hyperglycemia. It is caused by mutations in the sodium-glucose co-transporter, leading to increase in the renal excretion of glucose and sodium. However, there have been no studies on the role of fasting and postprandial changes in the urinary sodium excretion in patients with FRG. We report a case of renal glycosuria, which was confirmed by a SLC5A2 mutation via gene sequencing, and compared the postprandial urinary glucose and sodium excretion. A 26-year-old man sometimes experienced glycosuria on routine screening; however, other laboratory findings were normal. His fasting and postprandial urinary glucose excretion levels were 295mg/dL and 2,170mg/dL, respectively. The fasting and postprandial urinary sodium excretion levels were 200mEq/L and 89mEq/L, respectively. In patients with FRG, excessive diuresis might be prevented by a compensatory mechanism that reduces postprandial sodium excretion.
Adult ; Diuresis ; Fasting ; Glucose ; Glycosuria* ; Glycosuria, Renal ; Humans ; Hyperglycemia ; Mass Screening ; Renal Elimination ; Sodium ; Sodium-Glucose Transport Proteins

BACKGROUND/AIMS: Podocytes play an important role in maintaining the glomerular filtration barrier and in formation of the slit diaphragm. Podocyte loss is associated with chronic kidney disease progression, but it is not clear whether urinary podocyte proteins in urine reflect the clinical extent of glomerular damage. We investigated the correlation between the amounts of urinary podocyte proteins and renal function and albuminuria. METHODS: The study enrolled 33 patients with diabetic kidney disease or glomerular disease and measured urinary podocytes proteins using Western blotting. Urinary podocyte proteins were measured according to the density of the bands on Western blotting. We measured serum creatinine and the spot urine albumin/creatinine ratio as markers of renal damage, and compared the correlation of urinary podocyte protein in the glomerular disease patients. RESULTS: The mean patient age was 49.3 ± 16.5 years, the mean serum creatinine level was 2.30 ± 1.76 mg/dL, and the mean albumin/creatinine ratio was 4.85 ± 3.52. Among the podocyte proteins, urine synaptopodin showed strong correlation with serum creatinine by multivariate regression analysis (p < 0.001) and showed linear correlation (r = 0.429, p < 0.01). Urine podocyte proteins were increased in patients with diabetes, and synaptopodin showed the greatest significant difference (7.68 ± 5.61 vs. 2.56 ± 3.11, p < 0.001), but this might be associated with renal impairment. The urine albumin excretion did not differ between the diabetics and non-diabetics (p = 0.73). CONCLUSIONS: Urine synaptopodin is associated with serum creatinine elevation in the patients with glomerulonephritis including diabetic kidney disease regardless of urine albumin excretion. We suggest that the urine synaptopodin level can predict glomerular damage independently of the urine albumin excretion.
Albuminuria ; Blotting, Western ; Creatinine ; Diabetic Nephropathies ; Diaphragm ; Disease Progression* ; Glomerular Filtration Barrier ; Glomerulonephritis ; Humans ; Podocytes ; Proteinuria ; Renal Insufficiency, Chronic

Anemia is common in patients with advanced chronic kidney disease (CKD). Though erythropoiesis-stimulating agents (ESAs) have been strongly endorsed in guidelines, it is of particular financial interest. Recently, the reimbursement of ESAs in non-dialytic patients was started by the Korean National Health Insurance System. Thus, we investigated the impact of the reimbursement of ESAs on the anemia care in non-dialytic CKD patients. Medical records of patients with advanced CKD (estimated GFR <30 mL/min/1.73 m2) were reviewed. Use of ESAs, blood transfusion, and hemoglobin concentrations were analyzed from one year prior to reimbursement to three years following. We used multivariable modified Poisson regression to estimate the utilization prevalence ratio (PRs). A total of 1,791 medical records were analyzed. The proportion of patients receiving ESAs increased from 14.8% before reimbursement to a peak 33.6% in 1 yr after reimbursement; thereafter, ESA use decreased to 22.4% in 3 yr after reimbursement (compared with baseline; PR, 2.19 [95% CI, 1.40-3.42]). In patients with Hb <10 g/dL, the proportion of receiving ESAs increased from 32.1% before reimbursement to 66.7% in 3 yr after reimbursement (compared with baseline; PR, 2.04 [95% CI, 1.25-3.32]). Mean hemoglobin concentrations were 10.06±1.54 g/dL before reimbursement and increased to 10.78±1.51 g/dL in 3 yr after the reimbursement change (P=0.001). However, the requirement of blood transfusion was not changed over time. With the reimbursement of ESAs, the advanced CKD patients were more likely to be treated with ESAs, and the hemoglobin concentrations increased.
Adolescent ; Adult ; Aged ; Anemia/complications/*drug therapy/epidemiology ; Blood Transfusion ; Female ; Glomerular Filtration Rate ; Hematinics/*therapeutic use ; Hematocrit ; Hemoglobins/analysis ; Humans ; Male ; Middle Aged ; National Health Programs ; Poisson Distribution ; Prevalence ; Renal Insufficiency, Chronic/complications/*drug therapy/epidemiology ; Republic of Korea/epidemiology ; Retrospective Studies ; Young Adult