The glomerular filtration rate (GFR) is considered the best measure of renal function. Which of the following is commonly used to estimate GFR in clinical practice?

• A. Serum creatinine
• B. Serum albumin
• C. Urine glucose
• D. Blood urea nitrogen (BUN)

Answer: (A)

Verified step by step guidance

1. Understand the concept of glomerular filtration rate (GFR): GFR is a measure of how well the kidneys filter blood, removing waste and excess substances. It is a critical indicator of renal function.
2. Recognize the role of serum creatinine: Serum creatinine is a waste product of muscle metabolism that is filtered by the kidneys. Its levels in the blood are commonly used to estimate GFR because they reflect kidney filtration efficiency.
3. Eliminate incorrect options: Serum albumin, urine glucose, and blood urea nitrogen (BUN) are not direct measures of GFR. While BUN can provide some information about kidney function, it is influenced by factors like hydration and protein intake, making it less reliable for estimating GFR.
4. Learn about the formula used in clinical practice: GFR is often estimated using equations like the Modification of Diet in Renal Disease (MDRD) or Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula, which incorporate serum creatinine levels along with factors like age, sex, and race.
5. Understand why serum creatinine is preferred: Serum creatinine is widely used because it is easy to measure, cost-effective, and provides a reliable estimate of GFR when used in conjunction with appropriate formulas.