The MDRD equation for estimating GFR uses which variables?

• A. Serum creatinine, Age, Race, and Sex
• B. Serum creatinine, BUN, Age, Sex
• C. Serum creatinine, Albumin, Sodium, Age
• D. Glucose, Creatinine, Age, Race

Answer: (A)

The MDRD equation estimates GFR by using a marker of kidney filtration (serum creatinine) plus demographic adjustments that influence creatinine production and baseline filtration. Serum creatinine reflects how well the kidneys are filtering—the higher it is, the lower the GFR tends to be. Age is included because GFR generally declines with aging. Sex accounts for differences in muscle mass and creatinine generation between men and women, and race adjusts for average differences in creatinine production between races. A typical form multiplies serum creatinine by negative powers and then applies sex- and race-specific multipliers (for example, a value for females and a value for Black individuals) to tailor the estimate. In short, the variables used are serum creatinine, age, race, and sex.