Low Daily Protein Intake and Risk of Kidney Failure and Mortality in Chronic Kidney Disease

Importance: While protein restriction is a cornerstone of chronic kidney disease (CKD) management, its long-term benefits on clinical outcomes in Asian populations, who often have lower body mass and muscle reserves, remain unclear.

Objective

To investigate the association between daily protein intake (DPI) and the risk of kidney failure requiring replacement therapy (KFRT) and all-cause mortality in patients with non-dialysis-dependent CKD. Design, setting, and participants: This prospective cohort study used data from the Korean Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD). Participants with CKD at stages ranging from 1 to predialysis 5 were enrolled between 2011 and 2016 from 9 tertiary hospitals in South Korea. The study observation period ended on January 31, 2024. Data analysis was performed from February 2024 to May 2026. Exposures: DPI was objectively estimated using 24-hour urinary nitrogen excretion at baseline. The participants were categorized by DPI: less than 0.6, 0.6 to less than 0.8, 0.8 to less than 1.0, 1.0 to less than 1.2, and 1.2 or greater. Main outcomes and measures: The primary outcome was the onset of KFRT. Secondary outcomes included all-cause mortality and major adverse cardiovascular events (MACEs). Fine-Gray subdistribution hazard models were used to account for the competing risk of death.