Mortality is higher in patients with chronic kidney disease (CKD) than in the general population, but little information is available on CKD-related mortality that is representative of the Korean population. Our objective was to investigate mortality risk in Korean patients with CKD. We identified patients with incident CKD who had not undergone dialysis or kidney transplantation between January 1, 2003 and December 31, 2007 in Korea using the database of the Korean National Health Insurance Service-National Sample Cohort, and stratified the population into the following three groups: group 1 (n = 1,473), controls; group 2 (n = 2,212), patients with diabetes or hypertension, but without CKD; and group 3 (n = 2,212), patients with CKD. We then monitored them for all-cause mortality until December 2013. A total of 1,473 patients were included in this analysis. During the follow-up period, 941 patients in group 3 died (134 deaths/1,000 person-years) compared with 550 deaths in the group 2 (34 deaths/1,000 person-years) and 459 deaths in group 1 (30 deaths/1,000 person-years). The rate ratio for mortality rate was 4.5, and the hazard ratio for mortality was 4.88 (95% confidence interval [CI], 4.36-5.47, P < 0.001) in patients in group 3 compared with age- and sex-matched controls (group 1). The rate ratio for mortality rate was 4.0, and the hazard ratio for mortality was 4.36 (95% CI, 3.92-4.85, P < 0.001) in patients in group 3 compared with patients in group 2. In this nationally representative sample cohort, excess mortality was observed in Korean patients with incident CKD.

The autocrine and paracrine activation of the renin–angiotensin system (RAS) within cells of the kidney plays a role in the overall pathophysiology of the renal disease due to diabetes. In this study, we focus on components of the RAS in the podocyte as these cells are important in the pathogenesis of glomerulosclerosis and proteinuria. Immortalized mouse podocytes were exposed to media containing normal glucose (NG) or high glucose (HG) for in vitro studies. In vivo studies utilized kidney tissue obtained from rats treated for 3 months with streptozotocin to induce diabetes. Angiotensinogen (AGT) and the angiotensin II (AII) type 1 receptor mRNA and protein were significantly increased in the podocytes cultured under the high glucose conditions. Both angiotensins I and II levels were significantly higher in cell lysates and the conditioned media of cells grown in high glucose. There were no differences in renin activity, angiotensin-converting enzyme level, or AII type 2 receptor level. Glomerular AGT and AII type 1 receptor assessed by means of immunohistochemistry were increased in diabetic rats compared with the control rats. Other measured components of the RAS within the glomeruli were not different. We suggest that increased AGT, an attendant increase in AII and increased AII type 1 receptor in podocytes experiencing diabetic conditions play an important role in the pathogenesis of diabetic nephropathy.

Background and objectives Identifying the appropriate choice between hemodialysis (HD) and peritoneal dialysis (PD) is an unresolved issue in elderly patients with ESRD, who are at high risk for death but have a low chance of receiving kidney transplantation. Design, setting, participants, & measurements Data on 13,065 incident dialysis Korean patients (age≥65 years) receiving HD (n=10,675) or PD (n=2390) were obtained from the Korean Health Insurance dataset. Multiple statistical approaches, including the multivariate Cox model, were used to compare mortality between Korean patients receiving PD and those receiving HD. Subsequently, meta-analysis of previous comparison studies (published since the year 2000; population-based studies) and the Korean dataset was performed. Results During a mean duration of 1.8±1.3 years (maximum of 5 years), the Korean PD group had a higher mortality rate than the Korean HD group (hazard ratio [HR], 1.20 [95% confidence interval (95% CI), 1.13 to 1.28]; P631,421 elderly patients were reviewed. Compared with HD, the pooled HR with PD was 1.10 (95% CI, 1.01 to 1.20). When the meta-analysis was stratified by confounding factors, the survival benefit from HD was particularly strong in subgroups that had diabetes mellitus, had long dialysis duration (>1 year), or contained cohorts starting dialysis in the 1990s. Conclusions A meta-analysis that included results in Korean patients suggests a higher risk for death in elderly patients receiving PD than in those receiving HD.