Risk factor for progression to kidney failure with replacement therapy in elderly patients with chronic kidney disease: A retrospective single-centre cohort study

Abstract

Background: Although the number of elderly patients with chronic kidney disease (CKD) has increased, few studies have examined their prognosis.

Methods: The study design was a retrospective cohort study at a single centre. We evaluated 301 patients aged ≥75 years old with CKD stage G3a to G5. The primary endpoint was kidney failure with replacement therapy (KFRT) and secondary endpoints were all-cause mortality and annual decline rates of estimated glomerular filtration rate (eGFR). The incidence of KFRT was estimated using the cumulative incidence method considering the competing risk of death. To identify the independent risk factors related to KFRT, multivariate Fine-Gray regression model analysis were performed.

Results: The median age of the patients was 79 years and the median eGFR was 24.0 mL/min/1.73 m² at baseline. Urinary protein was positive in 70% of patients. With a median follow-up of 24.5 months, 35% of the patients developed KFRT and 9% died. Kidney survival significantly decreased according to the CKD stage at baseline. In patients without proteinuria, the cumulative incidence of KFRT increased in CKD stage G5 patients, while in patients with proteinuria, the incidence of KFRT increased from patients with CKD stage G3b. Multivariate Fine-Gray regression model revealed that less aged, CKD stage G5, baseline data such as proteinuria, hypoalbuminemia, hyperphosphatemia, and hyperuricemia were independent risk factors for KFRT.

Conclusion: Elderly CKD patients with proteinuria need to be carefully monitored even at an early CKD stage because of the risk of developing KFRT.

Keywords: chronic kidney disease; competing risk model; elderly; prognosis; proteinuria.