Home › MCQs › MBBS › Question #10258
Back to Questions
MBBS QUESTION #10258
Question 1
Creatinine clearance is widely used clinically to estimate GFR, even though creatinine is not an ideal filtration marker like inulin, because creatinine:
  • Is freely filtered and not reabsorbed, but is slightly secreted by the renal tubules, causing creatinine clearance to slightly overestimate true GFR✔️
  • Is completely reabsorbed by the proximal tubule
  • Is neither filtered nor secreted by the kidney
  • Provides an underestimate of true GFR in all clinical situations
Correct Answer Explanation
Creatinine is freely filtered and undergoes negligible reabsorption, but a small amount is additionally secreted by the proximal tubule, so creatinine clearance tends to overestimate true GFR slightly — a clinically acceptable approximation given its practicality compared to inulin infusion studies.