Creatinine level is primarily used to assess what aspect of organ function?

• A. It is used to estimate glomerular filtration rate
• B. It measures hepatic synthetic function
• C. It reflects gastric acid secretion
• D. It measures pancreatic exocrine function

Answer: (B)

Creatinine level is used to gauge kidney function by estimating the glomerular filtration rate (GFR). Creatinine is produced at a relatively constant rate and is cleared largely by the kidneys through filtration; when GFR falls, serum creatinine rises. This makes it a practical marker for assessing renal function, tracking CKD progression, and adjusting drug dosing that depends on kidney clearance. It does not measure hepatic synthetic function (which is evaluated with albumin, INR, bilirubin), gastric acid secretion, or pancreatic exocrine function, so those aspects are not reflected by creatinine.