In renal dysfunction, which statement best describes urine amylase and urine creatinine levels?

In renal dysfunction, which statement best describes urine amylase and urine creatinine levels?

• A. Amylase decreased; Creatinine increased
• B. Amylase increased; Creatinine decreased
• C. Amylase increased; Creatinine increased
• D. Amylase decreased; Creatinine decreased

Answer: (A)

In renal dysfunction the kidney’s ability to filter and excrete substances into urine is impaired. Amylase reaches urine mainly by glomerular filtration, so when GFR falls, less amylase is filtered into the urine and urine amylase levels drop. Creatinine, produced at a steady rate, is normally excreted in urine, but when urine output is reduced (oliguria) and the urine becomes more concentrated, the measured concentration of creatinine in the urine can rise. So the pattern that fits renal dysfunction is lower urine amylase due to reduced filtration, and higher urine creatinine concentration due to concentration of urine.

In renal dysfunction the kidney’s ability to filter and excrete substances into urine is impaired. Amylase reaches urine mainly by glomerular filtration, so when GFR falls, less amylase is filtered into the urine and urine amylase levels drop. Creatinine, produced at a steady rate, is normally excreted in urine, but when urine output is reduced (oliguria) and the urine becomes more concentrated, the measured concentration of creatinine in the urine can rise. So the pattern that fits renal dysfunction is lower urine amylase due to reduced filtration, and higher urine creatinine concentration due to concentration of urine.