One-year change in kidney function is associated with an increased mortality risk

Area of Science:

• Nephrology
• Public Health
• Epidemiology

Background:

• Serum creatinine is commonly used to estimate glomerular filtration rate (GFR).
• Long-term studies indicate death is more common than kidney failure progression.
• The relationship between short-term estimated GFR (eGFR) changes and mortality is not well understood.

Purpose of the Study:

• To investigate the association between short-term changes in eGFR over one year and subsequent all-cause mortality risk.
• To categorize changes in kidney function and assess their differential impact on mortality.

Main Methods:

• Utilized a large provincial laboratory registry (598,397 adults) with at least two eGFR measurements over a one-year period.
• Categorized kidney function changes into five groups: certain drop, uncertain drop, stable, uncertain rise, and certain rise (≥25% change).
• Employed Cox proportional hazards models, adjusting for baseline covariates, kidney function, and proteinuria.

Main Results:

• A certain drop in kidney function was associated with nearly double the mortality risk (HR 1.89).
• A certain rise in kidney function also showed an increased mortality risk (HR 1.51).
• These associations remained significant after adjusting for baseline eGFR, proteinuria, and other covariates.

Conclusions:

• A substantial change (≥25%) in kidney function, in either direction, over one year is linked to significantly increased mortality risk.
• Monitoring short-term kidney function fluctuations is important for predicting patient outcomes.