Creatinine is a product of muscle metabolism. It is produced at a nearly constant rate and is excreted in the urine.
If kidney function is significantly reduced, the urine creatinine will fall. With more severe degrees of kidney failure, the serum creatinine will eventually rise.
Vigorous exercise or muscular trauma occurring during the collection will cause an increased amount of creatinine in the blood.
Creatinine may be elevated in:
Impaired renal function
Muscle disease
Diabetic ketoacidosis
Starvation
Hyperthyoridism
Diet unusually high in meat products
Excessive Vitamin C intake
Normal Values*
Men
0.6-1.2 mg/dl
53-106 µmol/L
Women
<1.5 mg/dl
<133 µmol/L
Pregnancy
<1.0 mg/dl
<88 µmol/L
Children
0.3-0.7 mg/dl
26-62 µmol/L
*These are general values taken from a variety of sources. The actual normal values may vary from lab to lab and from one type of testing protocol to another.
Source: Operational Medicine 2001, Health Care in Military Settings, NAVMED P-5139, May 1, 2001, Bureau of Medicine and Surgery, Department of the Navy, 2300 E Street NW, Washington, D.C., 20372-5300
