Decreased creatinine clearance indicates which of the following?

• A. Impaired Renal Function or Pre-renal
• B. Normal Renal Function
• C. Liver Disease
• D. Post-renal Obstruction

Answer: (A)

Creatinine clearance is an estimate of glomerular filtration rate, the kidneys’ filtering power. When clearance is decreased, the kidneys aren’t filtering as well, so GFR has dropped. This happens with impaired renal function and with pre-renal states where kidney blood flow is reduced (like dehydration or reduced circulatory flow). Normal renal function would give normal clearance, and liver disease doesn’t directly lower creatinine clearance. Post-renal obstruction can also reduce clearance, but the key idea is that a lower clearance reflects reduced filtration due to kidney dysfunction or decreased perfusion.