Prevalence of Chronic Kidney Disease in Korea: the Korean National Health and Nutritional Examination Survey 2011-2013

Chronic kidney disease is a leading public health problem related to poor quality of life and premature death. As a resource for evidence-informed health policy-making, we evaluated the prevalence of chronic kidney disease using the data of non-institutionalized adults aged ≥ 20 years (n = 15,319) from the Korean National Health and Nutrition Examination Survey in 2011-2013. Chronic kidney disease was defined as a urine albumin-to-creatinine ratio ≥ 30 mg/g or an estimated glomerular filtration rate < 60 mL/min/1.73 m2 using the Chronic Kidney Disease-Epidemiology Collaboration equation. The total prevalence estimate of chronic kidney disease for adults aged ≥ 20 years in Korea was 8.2%. By disease stage, the prevalence of chronic kidney disease was as follows: stage 1, 3.0%; stage 2, 2.7%; stage 3a, 1.9%; stage 3b, 0.4%; and stages 4-5, 0.2%. When grouped into three risk categories according to the 2012 Kidney Disease: Improving Global Outcomes guidelines, the proportions for the moderately increased risk, high risk, and very high risk categories were 6.5%, 1.2%, and 0.5%, respectively. Factors including older age, diabetes, hypertension, cardiovascular disease, body mass indexes of ≥ 25 kg/m2 and < 18.5 kg/m2, and rural residential area were independently associated with chronic kidney disease. Based on this comprehensive analysis, evidence-based screening strategies for chronic kidney disease in the Korean population should be developed to optimize prevention and early intervention of chronic kidney disease and its associated risk factors.

Predictors of early neurological deterioration in patients with acute ischaemic stroke with special reference to blood urea nitrogen (BUN)/creatinine ratio & urine specific gravity.

Background & objectives: Early neurological deterioration (END) occurs in about 20 to 40 per cent of patients with acute ischaemic stroke and results in increased mortality and functional disability. In recent studies relative dehydration has been found to be associated with END in patients with acute ischaemic stroke. This study was conducted to identify factors useful for predicting END and to assess the role of blood urea nitrogen/creatinine ratio (BUN/creatinine) and urine specific gravity (USG) as predictors of END in patients with acute ischaemic stroke. methods: The present study was an observational prospective study. Various parameters comprising demographic, clinical, laboratory and radiological variables along with stroke severity were assessed and studied as predictors of early neurological deterioration in 114 consecutive patients presenting to the Emergency department during 2012. BUN/creatinine >15 and USG >1.010 were studied as markers of relative dehydration contributing to END. results: of the 114 patients enrolled in the study, END was observed in 25 (21.9%) patients. National Institutes Health Stroke Scale score (NIHSS) ≥ 12 at admission was found to be an independent risk factor for END. Amongst markers of relative dehydration, BUN/creatinine >15 at admission was found to be an independent risk factor for END, as also USG >1.010. Also, cerebral oedema and size of hypodensity >1/3rd of the middle cerebral artery territory on cranial CT were observed to be independent risk factors for END. Interpretation & conclusions: Our study findings highlighted a possible association of relative dehydration, as indicated by BUN/creatinine ratio >15, with END along with other parameters like stroke severity at presentation, extent of hypodensity >1/3rd of the middle cerebral artery (MCA) territory and cerebral oedema. Dehydration being a treatable condition, the use of BUN/creatinine >15 as a marker of relative dehydration, can be helpful in detecting patients with dehydration early and thus play a role in preventing END.

Estimación de la función renal mediante creatinina sérica y fórmulas predictivas en población litiásica cubana / Stimation of renal function from serum creatinine and predictive formulas in Cuban population with lithiasic

Introducción: la función renal puede ser estimada mediante la creatinina sérica o por fórmulas predictivas, de ahí que resulte importante evidenciar el valor de estos métodos. Objetivo: determinar la validez de la creatinina sérica y la fiabilidad de las fórmulas de estimación de la función renal en población litiásica cubana. Métodos: se realizó un estudio transversal. Se estudiaron 6 290 pacientes con litiasis urinarias que se realizaron estudio metabólico en el Instituto de Nefrología entre 2006 y 2011, 4 133 (65,7 por ciento) del sexo masculino y 2 157 (34,3 por ciento), del femenino. La información fue procesada utilizando el paquete estadístico SPSS 15.0. Para evaluar la capacidad diagnóstica de la creatinina sérica se emplearon curvas ROC y en el análisis de la fiabilidad de las fórmulas, diagramas de Bland y Altman. Resultados: las fórmulas con menor diferencia promedio con respecto al aclaramiento de creatinina fueron en la ERC (TFG ≤ 90 mL/min/1,73 m²): Cockcroft-Gault (3,81 mL/min/1,73 m²; DE 19,20 mL/min/1,73 m²), Salazar-Corcoran (-4,47 mL/min/1,73 m²; DE 18,40 mL/min/1,73 m²) y Levey (MDRD) (4,69 mL/min/1,73 m²; DE 13,75 mL/min/1,73 m²) y en IRC (TFG < 60 mL/min/1,73 m ²): Levey (MDRD) (1,39 mL/min/1,73 m²; DE 10,22 mL/min/1,73 m²), Jelliffe 1 973 (2,15 mL/min/1,73 m²; DE 10,87 mL/min/1,73 m²) y Salazar-Corcoran (-4,47 mL/min/1,73 m²; DE 18,40 mL/min/1,73 m²). La ecuación de Baracskay tuvo la mayor diferencia promedio (-9,67 mL/min/1,73m²; DE 17,04 mL/min/1,73 m²). El valor óptimo de corte para la creatinina sérica en ERC fue 1,07 mg/dLy 0,89 mg/dL, en hombres y mujeres, respectivamente. Conclusiones: los resultados de este estudio sugieren que la fiabilidad de las fórmulas predictivas es alta, con excepción de la de Baracskay, utilizada en ancianos...

Introduction: renal function may be estimated from serum creatinine or with prediction formulas. Hence the importance of being aware of the usefulness of these methods. Objective: determine the validity of serum creatinine and the reliability of renal function estimation formulas. Methods: a cross-sectional study was conducted of 6 290 patients with urolithiasis (4 133 male and 2 157 female -65.7% and 34.3 percent, respectively-) undergoing metabolic studies at the Institute of Nephrology from 2006 to 2011. Data were processed with the statistical software SPSS version 15.0. ROC curves were used to evaluate the diagnostic capacity of serum creatinine. Reliability of the formulas was assessed with Bland-Altman plots. Results: the formulas with the smallest mean difference with respect to creatinine clearance were the following: for ERC (GFR ≤ 90 mL/min/1.73 m²): Cockcroft-Gault (3.81 mL/min/1.73 m²; DE 19.20 mL/min/1.73 m²), Salazar-Corcoran (-4.47 mL/min/1.73 m²; DE 18.40 mL/min/1.73 m²) and Levey (MDRD) (4.69 mL/min/1.73 m²; DE 13.75 mL/min/1.73 m²) and for IRC (GFR < 60 mL/min/1.73 m ²): Levey (MDRD) (1.39 mL/min/1.73 m²; DE 10.22 mL/min/1.73 m²), Jelliffe 1 973 (2.15 mL/min/1.73 m²; DE 10.87 mL/min/1.73 m²) and Salazar-Corcoran (-4.47 mL/min/1.73 m²; DE 18.40 mL/min/1.73 m²). The Baracskay formula showed the greatest mean difference (-9.67 mL/min/1.73m²; DE 17.04 mL/min/1.73 m²). Optimal cutoff value for serum creatinine in ERC was 1.07 mg/dL and 0.89 mg/dL for men and women, respectively. Conclusions: results suggest that the reliability of prediction formulas is high, except for Baracskay's, which is used in elderly patients...

Urinary Sodium Excretion Has Positive Correlation with Activation of Urinary Renin Angiotensin System and Reactive Oxygen Species in Hypertensive Chronic Kidney Disease

It is not well described the pathophysiology of renal injuries caused by a high salt intake in humans. The authors analyzed the relationship between the 24-hr urine sodium-to-creatinine ratio (24HUna/cr) and renal injury parameters such as urine angiotensinogen (uAGT/cr), monocyte chemoattractant peptide-1 (uMCP1/cr), and malondialdehyde-to-creatinine ratio (uMDA/cr) by using the data derived from 226 hypertensive chronic kidney disease patients. At baseline, the 24HUna/cr group or levels had a positive correlation with uAGT/cr and uMDA/cr adjusted for related factors (P or =200 mEq/g cr was higher than in patients with or =200 mEq/g cr (P=0.016). During the 16-week follow-up period, an increase in urinary sodium excretion predicted an increase in urinary angiotensinogen excretion. In conclusion, high salt intake increases renal renin-angiotensin-system (RAS) activation, primarily, and directly or indirectly affects the production of reactive oxygen species through renal RAS activation.

Estimated Amount of 24-Hour Urine Sodium Excretion Is Positively Correlated with Stomach and Breast Cancer Prevalence in Korea

Stomach cancer is one of the most common cancers in Korea. The aim of this study was to identify the association between the prevalence of cancer, particularly stomach cancer, and the amount of 24-hr urine sodium excretion estimated from spot urine specimens. The study included 19,083 subjects who took part in the Korean National Health and Nutritional Examination Survey between 2009 and 2011. The total amount of urine sodium excreted in a 24-hr period was estimated by using two equations based on the values for spot urine sodium and creatinine. In subjects who had an estimated 24-hr urine sodium excretion of more than two standard deviations above the mean (group 2), the prevalence of stomach cancer was higher than in subjects with lower 24-hr sodium excretion (group 1). By using the Tanaka equation to estimate it, the prevalence of stomach cancer was 0.6% (114/18,331) in group 1, whereas it was 1.6% (9/568) in group 2 (P=0.006). By using the Korean equation, the prevalence was 0.6% (115/18,392) in group 1, and 1.6% in group 2 (8/507) (P=0.010). By using the Tanaka equation, breast cancer in women is more prevalent in group 2 (1.9%, 6/324) than group 1 (0.8%, 78/9,985, P=0.039). Higher salt intake, as defined by the estimated amount of 24-hr urine sodium excretion, is positively correlated with a higher prevalence of stomach or breast cancer in the Korean population.

Microalbuminuria in Normal Korean Children

PURPOSE: Although microalbuminuria is known as a predictor of clinical nephropathy and cardiomyopathy, few studies have investigated the incidence and reference range of microalbuminuria in healthy children. This study aimed to establish a reference range and to study the age-related trend for spot urine microalbumin/creatinine ratio in a Korean pediatric population. MATERIALS AND METHODS: 352 healthy children were studied from July 2007 through March 2010. Height, weight, serum creatinine, spot urine microalbumin/creatinine ratio, and glomerular filtration rate (GFR) were obtained for each subject. We divided the study population into 5 groups according to age, and compared the spot urine microalbumin/creatinine ratio with other variables using one-way analysis of variance (ANOVA), regression analysis and Pearson's correlation analysis. RESULTS: In this study, the data showed that the spot urine microalbumin/creatinine ratio decreased with age: 1-12 months, 22.72+/-13.80 mg/mmol (2SD: 3.33-54.40 mg/mmol); 13-28 months, 16.34+/-9.58 mg/mmol (2SD: 3.16-35.19 mg/mmol); 29-48 months, 13.12+/-9.74 mg/mmol (2SD: 3.01-41.57 mg/mmol); 4-6 years, 10.58+/-8.13 mg/mmol (2SD: 0.00-30.19 mg/mmol); and 7-19 years, 5.13+/-5.44 mg/mmol (2SD: 0.45-14.45 mg/mmol). The spot urine microalbumin/creatinine ratio showed correlation with age, height, height z-score, weight, weight z-score, GFR, body mass index (BMI) and body surface area (BSA). CONCLUSION: The spot urine microalbumin/creatinine ratio in normal Korean children decreased with age. This ratio could potentially be used to establish reference ranges and cutoff values for Korean children and to predict nephropathy and cardiomyopathy.

[Rando urinary proteinuria to creatinine ratio for predict of 24 hours proteinuria in women preeclampsia]

Preeclampsia occurs in approximately 5-12% of pregnancies, and its aetiology remains unknown. The most prevalent quantitative assessment of the amount of protein excreted in the urine for the diagnosis of preeclampsia is a 24-hour urine collection. However, the collection and analysis of 24-hour urine specimens is cumbersome and time consuming for both the patient and the laboratory. This study was undertaken to validate the prediction of 24-hour urine protein excretion by a single voided urine protein-to-creatinine [p:c] ratio in a hospitalized pregnant population at our institution. This study was an analytical observation study investigation and was performed on 30 hospitalized pregrant women who were diagnosed as preeclampsia at 22 Bahman Hospital from 1382-1383. Pregnant patients who were admitted to the antepartum unit at 22-Bahman Hospital, and who were undergoing a 24-hour urine collection for the quantitation of proteinuria, were recruited. A single urine specimen was obtained after the completion of 24- hour urine collection and analyzed for the protein- to- creatinine ratio. Multiple linear regression was used to determine the correlation between the 24-hour urine protein excretion and spot urine protein-to-creatinine ratio. The strength of the association was assessed with the Pearson correlation coefficient. The correlation of the 24-hour urine protein and protein-to-creatinine ratio with other variables [including maternal age, gestational age, parity, blood pressure and weight] were assessed. Multiple linear regression was used to detect any confonuding effects. Thirty patients completed the study. There was a significant correlation between the 24-hour urine protein and the protein-to-creatinine ratio [r=85%, p<0/001]. The associations of maternal age, gestational age, weight, parity and blood pressure at the time of collection with protein-to-creatinine ratio and 24- hour urine protein were weak and not significant. On the basis of multiple linear regression, there was no confunding effect of maternal age, gestational age, parity, weight and blood pressure.Our data supports the use of single protein-to-creatinine ratio in hospitalized pregnant patients to predict the 24- hour urine protein result

Tratamiento de la hipercalciuria idiopática con solución oral de fosfatos / Treatment of idiopatic hypercalciuria with an oral phosphate solution

Objetivo: evaluar la respuesta de pacientes con hipercalciuria idiopática y concentraciones indetectables de paratohormona en el plasma al suministro de fosfato oral. Pacientes y método: en seis pacientes con hipercalciuria idiopática de 8 a 13 años de edad, tres varones, con concentraciones sanguíneas basales indetectables de hormona paratiroidea, se administró una solución oral de fosfatos por durante nueve meses. El desenlace primario esperado fue la normalización de la relación Ca/creatina en la orina y el secundario la disminución de la eliminación urinaria de Ca a menos de 4 mg por kg de peso corporal al día. Resultados: el promedio de la relación Ca/Cr al comienzo del estudio era 0,356. Al cabo de tres meses de tratamiento era 0,18 en 5 casos y 0,09 al cabo de 9 meses postratamiento en 4 casos: (p<0,003 y 0,001) al tercer y noveno mes de tratamiento, como también a los 3 meses de suspendida la terapia (p<0,003). Conclusión: en algunos pacientes de hipercalciuria idiopática con disminución basal de paratohormona (que puede deberse a pérdida primaria renal de fosfato) la terapia oral con fosfatos pudiese representar una alternativa terapéutica

Efectos cardiovasculares del acortamiento del intervalo AV mediante estimulación eléctrica del corazón en miocardiopatía dilatada / Cardiovascular effects of AV interval shortening with heart electric stimulation in dilated cardiomyopathy

Patients and methods: Nine patients with dilated cardiomyopathy were studied. Hemodynamic and tissular perfusion values, echocardiographic and radioisotopic ventricular function parameters were measured before and after six hours of AV interval shortening with electrical stimulation of the heart. Results: After electrical stimulation, cardiac output increased from 3.38 ñ 0.8 to 32.87 ñ 0.79 l/min (p < 0.05). Pulmonary capillary pressure decreased from 23.8 ñ 8.9 to 19.8 ñ 9.2 mm Hg (p = NS). There were no significant changes in ventricular function parameters or in systemic and pulmonary pressures. Conclusions: Electrical shortening of AV interval in patients with dilated cardiomyopathy increases cardiac output but does not change ventricular function parameters

Seasonal variations in urinary calcium and sodium excretion.

Serum levels and urinary excretion of calcium, sodium and creatinine have been studied in 25 male subjects in summer and winter seasons. In contrast to the reports from the West, urinary calcium excretion was significantly less in summer than in winter. Urinary sodium excretion too was decreased in summer. The mechanisms possibly responsible for the observed seasonal variations have been discussed.