This report supports the growing body of data linking glomerulosclerosis directly to a reduction in relative podocyte number [increased glomerular area per podocyte (GAPP)]. It raises important questions related to the mechanisms of podocyte loss, strategies for prevention of podocyte depletion, and the prevention of progression of glomerular diseases.

BackgroundThe progression and complications of chronic kidney disease should differ depending on the cause (C), glomerular filtration rate category (G), and albuminuria (A). The KNOW-CKD (KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease), which is a prospective cohort study, enrolls subjects with chronic kidney disease stages 1 to 5 (predialysis).Methods/DesignNine nephrology centers in major university hospitals throughout Korea will enroll approximately 2,450 adults with chronic kidney disease over a 5-year period from 2011 to 2015. The participating individuals will be monitored for approximately 10 years until death or until end-stage renal disease occurs. The subjects will be classified into subgroups based on the following specific causes of chronic kidney disease: glomerulonephritis, diabetic nephropathy, hypertensive nephropathy, polycystic kidney disease, and others. The eligible subjects will be evaluated at baseline for socio-demographic information, detailed personal/family history, office BP, quality of life, and health behaviors. After enrollment in the study, thorough assessments, including laboratory tests, cardiac evaluation and radiologic imaging, will be performed according to the standardized protocol. The biospecimen samples will be collected regularly. A renal event is defined by >50% decrease in estimated GFR (eGFR) from the baseline values, doubling of serum creatinine, or end-stage renal disease. The primary composite outcome consists of renal events, cardiovascular events, and death. As of September 2013, 1,470 adult chronic kidney disease subjects were enrolled in the study, including 543 subjects with glomerulonephritis, 317 with diabetic nephropathy, 294 with hypertensive nephropathy and 249 with polycystic kidney disease.DiscussionAs the first large-scale chronic kidney disease cohort study to be established and maintained longitudinally for up to 10 years, the KNOW-CKD will help to clarify the natural course, complication profiles, and risk factors of Asian populations with chronic kidney disease.Trial registrationNo. NCT01630486 at http://www.clinicaltrials.gov.

Chronic kidney disease (CKD) is a worldwide problem. This study was designed to survey the prevalence and risk factors for CKD in Korea. The 2,356 subjects were selected in proportion to age, gender, and city. Subjects 35 yr of age or older were selected from 7 cities. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease (MDRD) Study equation, with albuminuria defined as a urine albumin to creatinine ratio of 30 mg/g or more. The overall prevalence of CKD was 13.7%. The prevalences of CKD according to stage were 2.0% stage 1, 6.7% stage 2, 4.8% stage 3, 0.2% stage 4, and 0.0% stage 5. The prevalences of microalbuminuria and macroalbuminuria were 8.6% and 1.6%, respectively. The prevalence of eGFR less than 60 mL/min/1.73 m2 was 5.0%. Age, body mass index (BMI), hypertension, diabetes mellitus, systolic blood pressure (SBP), diastolic blood pressure (DBP), and fasting blood glucose were independent factors related to the presence of CKD. In conclusions, Korea, in which the prevalence of CKD is increasing, should prepare a policy for early detection and appropriate treatment of CKD. The present data will be helpful in taking those actions.

Anemia is a common and significant complication of chronic kidney disease (CKD). However, its prevalence and current management status has not been studied thoroughly in Korea. We examined the prevalence of anemia, its association with clinical and laboratory factors, and utilization of iron agents and erythropoiesis stimulating agents using the baseline data from the large-scale CKD cohort in Korea. We defined anemia when hemoglobin level was lower than 13.0 g/dL in males and 12.0 g/dL in females, or received by erythropoiesis stimulating agents. Overall prevalence of anemia was 45.0% among 2,198 non-dialysis CKD patients from stage 1 to 5. Diabetic nephropathy (DN) as a cause, CKD stages, body mass index (BMI), smoking, leukocyte count, serum albumin, iron markers, calcium, and phosphorus concentration were identified as independent risk factors for anemia. Considering the current coverage of Korean National Health Insurance System, only 7.9% among applicable patients were managed by intravenous iron agents, and 42.7% were managed by erythropoiesis stimulating agents.

Prescription of low GDP, pH-neutral PD solutions has rapidly increased in Korea. This change has resulted in a significant improvement in patient and technique survival without any measurable change in peritonitis incidence or rate. Reasons for the improved patient survival cannot be determined from this analysis and require further study.