Zeitschrift für Nephrologie und Therapeutik

Entity of Stage 4 CKD over 75 Years Old is Different from that of Less than 75 Years of Age: Characteristics of Elderly Patients with Stage 4 CKD

Abstract

Hiromichi Suzuki *,Inoue T ,Kikuta T ,Hamada Y ,Okada H

Background: Although age had a strong effect on the risk of development to end-stage renal disease (ESRD), it is reported that stage 4 CKD patients aged >75 years were less likely to subsequently commence renal replacement therapy (RRT) than those aged <75 years. In the present study, the longitudinal follow-up of elderly patients with stage 4 CKD was carried out in a single center in order to evaluate the prognosis of the patients >75 years in comparison with those between 74 and 65 years and to characterize patients with stage 4 CKD older than 75 years. Methods: This was a prospective, observational, single-center cohort study. Patients were recruited from specialist renal clinics from January 2004 to December 2005. All participating patients were followed for 5 years or until death, commencement of dialysis therapy, receiving renal transplantation, finding of neoplasm, or occurrence of a cardiovascular event. We utilized electronic databases to determine the incidence of RRT and morbidity. Results: The underlying renal disease of CKD included diabetic nephropathy (DM) (91 patients, 51%) chronic glomerulonephritis (GN) (41 patients, 23%), hypertensive nephrosclerosis (HT) (44 patients, 25%), and other diseases (3 patients, 1%) in the younger group (74 and 65 years)and DM (24 patients, 23%), GN (24 patients, 23%), HT(54 patients, 51%), and other diseases (4 patients, 4%) in the elderly population (older than 75 years). A proportion of the underlying renal diseases were significantly differences between the two groups. In the elderly group, the prevalence of diabetic nephropathy was significantly lower (P<0.01) and that of HT was significantly higher (P<0.01). The incidencefree rates at 1 year and 3 years were 90% and 81% in the elderly group and those were 90% and 57% in the younger group, respectively. In the patients without diabetic nephropathy, introduction to RRT was significantly lower compared with those with diabetic nephropathy in the younger group (P<0.05). The incidence-free rates at 1 year and 3 years were 88% and 80% in the patients without diabetic nephropathy and those were 87% and 38% in the patients with diabetic nephropathy, respectively. In the late referral patients, the prevalence of diabetic nephropathy were significantly higher and that of GN and HT were significantly lower compared with those of the non-late referral patients (P<0.01). Conclusions: From these findings, it is concluded that in the patients >75 years, the values of eGFR may be overestimated and a prognosis of diabetic nephropathy was poor. Besides, the early nephrology referral is encouraged.