Glomerular filtration function decline, mortality, and cardiovascular events: data from the Strong Heart Study.

Area of Science:

• Nephrology
• Cardiovascular Medicine
• Epidemiology

Background:

• Rapid kidney function decline is a significant predictor of mortality and cardiovascular disease (CVD), independent of chronic kidney disease (CKD).
• American Indians (AI) experience a disproportionately high burden of kidney disease, CVD, and stroke.
• This study investigates extreme loss of glomerular function in AI and its association with clinical outcomes.

Purpose of the Study:

• To examine the association between rapid decline in estimated glomerular filtration rate (eGFR) and clinical outcomes in American Indians.
• To determine if extreme eGFR loss predicts mortality and cardiovascular events in this population.
• To highlight the importance of monitoring kidney function changes over time.

Main Methods:

• Utilized data from the Strong Heart Study, a longitudinal cohort of adult AI participants (1989-1999).
• Calculated intraindividual regressions of eGFR to estimate linear changes in kidney function.
• Monitored mortality and cardiovascular events through physician-adjudicated surveillance until 2017.

Main Results:

• Mean eGFR decline was 6.8 mL/min over 10 years; the top 1% lost ~5.7 mL/min/year.
• Extreme eGFR loss (>20 mL/min) was independently associated with increased mortality (HR 3.5) and composite CVD events (HR 1.4).
• Diabetes and hypertension were more prevalent in participants with extreme eGFR loss.

Conclusions:

• This is the first study to examine eGFR decline in association with mortality and CVD in American Indians.
• Clinical evaluation should consider eGFR change over time, not just baseline eGFR or CKD status.
• Findings suggest that aspects of renal function not captured by CKD diagnosis may significantly impact long-term renal and vascular health.