Why does my creatinine level fluctuate?

Q: I underwent renal transplantation 4 months back. Since then my creatinine level fluctuates ranging from 1.1 to 1.6. Can you tell me whether my kidney function is fine? What will be my diet?

A:Unfortunately the serum creatinine is a difficult test to do in the lab and requires good standardisation so you should do both urea and creatinine together. Urea is a sturdier test across labs. We use both of these to give us an indirect assessment of kidney function. A patient with normal kidney function should have normal food, avoid too much sugar and fatty food.