The production of urine and the removal of waste products from the body is based on filtering blood through the glomerular membrane in the kidneys. The best assessment to measure how much blood the kidneys filter each minute is to use what is referred to as the Glomerular Filtration Rate (GFR).

The ability to measure GFR aids physicians in understanding and diagnosing kidney pathophysiology. Measuring GFR can be done through agents filtered via the kidney, but not produced by the body, such as inulin and iohexol; the process is complicated, time-consuming, and thus often impractical to use.

GFR can be estimated based on a formula using creatinine, a waste product derived from dietary protein digestion and the normal breakdown of muscle tissue. The level of creatinine in the blood indicates kidney function; however, other factors such as diet, muscle mass, nutrition, gender, and intra-individual variation can impact creatinine levels in the blood.

Aculabs will implement the new recommended eGFR using CKD-EPI 2021 as of May 1, 2024. 

Over the years, several formulas have been developed to estimate eGFR based on creatinine levels. Some commonly used formulas include the Modification of Diet in Renal Disease Study (MDRD) equation, and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI).

The factor of race has historically been incorporated in the MDRD and the CKD-EPI; however, healthcare professionals have called for removing race from clinical algorithms since race is a social and not a biological construct. In response, the National Kidney Foundation (NKF) and the American Society of Nephrology (ASN) created the Task Force on Reassessing the Inclusion of Race in Diagnosing Kidney Diseases to examine the issue and provide recommendations for the United States.

The new CKD-EPI 2021 equation for eGFR was published in the September 23, 2021 issue of the New England Journal of Medicine, which includes the implementation of the new CKD-EPI 2021 creatinine equation without race. The journal also emphasized increasing the effort to use cystatin C to confirm eGFR in adults at risk of CKD and increasing the research and funding on GFR with new endogenous filtration markers and interventions to eliminate race and ethnic disparities.

Geriatric populations may be given nephrotoxic medications that interact with kidney function while facing an increased risk of chronic kidney disease due to factors that damage the kidneys over time such as hypertension, diabetes, and vascular disease.

By ensuring a more accurate estimate of GFR via the CKD-EPI 2021 formula, healthcare providers are enabled to identify chronic kidney disease earlier in older patients and ensure timely interventions to slow disease progression. Aculabs believes implementing the CKD-EPI 2021 formula will greatly benefit the geriatric populations we proudly serve.

– Dr. Rita Khoury

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