Estimated Glomerular Filtration Rate, Albuminuria, and Adverse Outcomes: An Individual-Participant Data Meta-Analysis

Area of Science:

• Nephrology
• Cardiovascular Medicine
• Epidemiology

Background:

• Chronic kidney disease (CKD) affects 14% of US adults, characterized by low estimated glomerular filtration rate (eGFR) or albuminuria.
• Early detection and risk assessment are crucial for managing CKD and its associated complications.

Purpose of the Study:

• To assess the association between lower eGFR (using creatinine alone or combined with cystatin C) and higher albuminuria with adverse kidney and cardiovascular outcomes.
• To evaluate the risk of other health outcomes, including all-cause mortality and hospitalizations.

Main Methods:

• An individual-participant data meta-analysis of over 27 million individuals from 114 global cohorts (eGFR by creatinine) and 720,736 individuals from 20 cohorts (eGFR by creatinine and cystatin C).
• Albuminuria was assessed using urine albumin-to-creatinine ratio (UACR).
• Random-effects meta-analyses were used to summarize risks for kidney failure, mortality, cardiovascular events, and hospitalizations.

Main Results:

• Lower eGFR and higher UACR were significantly associated with an increased risk of all 10 adverse outcomes studied.
• Even mild CKD categories showed significantly higher risks; for instance, an eGFR of 45-59 mL/min/1.73 m2 was linked to higher hospitalization rates compared to higher eGFR levels.
• Associations were consistent across different eGFR estimation methods and albuminuria levels.

Conclusions:

• Reduced eGFR and elevated UACR are independently associated with a substantially higher risk of adverse kidney outcomes, cardiovascular diseases, and hospitalizations.
• These findings underscore the importance of CKD screening and risk stratification, even in individuals with mildly reduced kidney function or albuminuria.
• The study emphasizes the predictive value of both eGFR and UACR for long-term health outcomes.