Estimating glomerular filtration in young people.

Area of Science:

• Nephrology
• Clinical Chemistry
• Epidemiology

Background:

• Creatinine-based equations are standard for estimating glomerular filtration rate (eGFR).
• Key equations include the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), re-expressed Lund-Malmö Revised (r-LMR), and European Kidney Function Consortium (EKFC).
• The performance of EKFC and r-LMR in young adults is debated.

Purpose of the Study:

• To compare the performance of EKFC, r-LMR, and CKD-EPI equations in estimating GFR in young adults.
• To determine if EKFC and r-LMR offer improved accuracy in this demographic.

Main Methods:

• Data from 2366 young adults (18-25 years) from Europe and the USA were analyzed.
• Measured GFR (exogenous marker clearance) served as the reference method.
• Serum creatinine, age, and sex were used for eGFR calculations.

Main Results:

• In European cohorts, EKFC and r-LMR showed significantly better bias and accuracy (P30) than CKD-EPI.
• In US non-Black cohorts, EKFC and r-LMR also demonstrated improved bias compared to CKD-EPI.
• Performance differences were less pronounced in US Black individuals and absent in US cohorts overall for P30. CKD-EPI may be more accurate in hyperfiltration.

Conclusions:

• EKFC and r-LMR creatinine-based equations exhibit superior performance compared to CKD-EPI in young populations.
• These findings suggest EKFC and r-LMR are more reliable for eGFR estimation in this age group.
• An exception may exist for individuals experiencing hyperfiltration, where CKD-EPI might be preferable.