CS: "Let's Stop Playing the Race Card in eGFR Reporting.” That's the provocative title of your article in the Clinical Journal of the American Society of Nephrology, and it certainly got our attention. Are you surprised?
VG: Pleasantly, no, not surprised. I was hoping for that.
CS: First, Dr. Grubbs, what is eGFR, and how does it relate to patients, especially Black patients, who could be diagnosed with declining kidney function?
VG: eGFR stands for Estimated Glomerular Filtration Rate, and that's all fancy medical language that simply means how well are your kidneys filtering your blood. We have an equation that uses a simple blood test, the creatinine, to factor into this equation and, and help us figure out how well the kidneys are filtering.
CS: Why are you concerned, especially in the area of achieving an accurate unbiased patient diagnosis, that the current criteria for GFR testing is deeply flawed without a scientific basis and may even be racist? What are the consequences?
VG: I definitely think so because, when the equation was developed, the researchers were considering all the things that they thought might affect how the kidneys filter this creatinine, which is produced at a pretty steady rate in our bodies every day, and it comes primarily from muscle cells, like waste from our muscle cells. In determining what things might affect creatinine, they thought about, okay, a person's gender because men tend to have higher muscle mass than women and age because younger people tend to have higher muscle mass than older people. And race, this is where they made the big leap that Black people have higher muscle mass than white people.