Aiming for improvements in kidney function testing
The lack of symptoms in early-stage kidney disease can make it difficult to diagnose. Clinicians usually rely on a glomerular filtration rate (GFR) test to identify disease at an early stage, particularly in high-risk groups.
Testing for GFR can be a complicated and lengthy procedure. Using a formula to estimate GFR is standard practice, but many factors may affect the performance of these equations.
Dr. Lydia Kamaruzaman is a nephrologist at the Hospital Canselor Tuanku Muhriz in Kuala Lumpur, Malaysia, and the National University of Malaysia. In her talk at WCN’22, she will discuss the biomarkers available to estimate GFR and potential estimating equations and their limitations.
Dr. Kamaruzaman explains: “The most common marker used to estimate GFR is creatinine, a by-product of muscle metabolism. But because muscle mass varies depending on a number of factors, the serum concentration of creatinine may differ between individuals with the same level of kidney function.”
She believes there are alternative markers for GFR, which, although not as widely used, have the potential to be more effective, such as cystatin C: “Cystatin C production varies less than creatinine production between individuals, and studies have shown that blood concentrations of cystatin C are fairly similar between individuals who have the same GFR,” she states.
Dr. Kamaruzaman says she is also looking at race as a variable in the GFR equation. “Estimation of the GFR generally incorporates an adjustment for a patient’s race. Recent research has shown that using cystatin C as a biomarker for GFR in place of creatinine can deliver comparable results without differentiating for race in the equation.”
Dr. Kamaruzaman acknowledges that these alternatives present limitations and challenges but hopes that further research will produce more data about the performance of creatinine versus cystatin C equations where race need not be a factor, particularly in special groups such as acute kidney injury patients, renal transplant, and pediatric populations.
Lydia Kamaruzaman: “Update on GFR Estimating Equations”, Theme Symposium “Chronic Kidney Disease”, Friday 25 February, 13:30-14:30 hrs Kuala Lumpur (Malaysia) time, Plenary Hall: https://cm.theisn.org/cmPortal/searchable/WCN2022/config/normal#!sessiondetails/0000016330_0