Glomerular filtration rate estimation and mortality in an elderly population

Area of Science:

• Gerontology
• Nephrology
• Epidemiology

Background:

• Limited research exists on the association between minor renal dysfunction and mortality in elderly populations.
• Assessing kidney function in older adults is crucial for predicting health outcomes.

Purpose of the Study:

• To compare three estimated glomerular filtration rate (eGFR) equations: Cockcroft-Gault (CG), abbreviated Modification of Diet in Renal Disease (MDRD), and Mayo Clinic.
• To evaluate the effectiveness of these eGFR equations in identifying renal dysfunction and predicting mortality in individuals aged 70 and above.

Main Methods:

• A longitudinal observational study involving 441 community-dwelling 70-year-olds from the Jerusalem Seventy Year Olds Longitudinal Study.
• Serum creatinine levels were measured to estimate GFR using CG, MDRD, and Mayo Clinic equations.
• The primary outcome measure was 12-year all-cause mortality.

Main Results:

• Prevalence of reduced eGFR varied significantly by equation: 51% (CG), 34% (MDRD), and 16% (Mayo Clinic).
• Only the Mayo Clinic equation significantly predicted mortality when eGFR was dichotomized by CKD definition (HR 1.56).
• All three equations predicted mortality when eGFR was analyzed in quartiles, with the lowest quartile showing substantially increased risk (HRs ranging from 5.48 to 7.47).

Conclusions:

• Reduced eGFR is prevalent in 70-year-old adults and is associated with increased mortality.
• The Mayo Clinic equation demonstrated the strongest association between reduced eGFR and mortality in this elderly cohort.