- Last Update On : 2013-01-07
Measurement of serum creatinine is the most widely used measure of renal function. The diagnostic usefulness of serum creatinine as an indicator of glomerular filtration rate (GFR) is based upon its constant production from muscle creatine and its relatively constant renal excretion rate. About 1 to 2% of the creatine in muscle is converted to creatinine daily (15 to 30 mg creatinine per kg body weight). The amount of creatinine formed is proportional to muscle mass. Creatinine is removed from plasma by glomerular filtration and then excreted in the urine without significant tubular reabsorption.
Serum creatinine is a crude indicator of renal disease. Moderate changes in GFR may not be detected by serum creatinine levels. A change in serum creatinine from 0.6 to1.2 mg/dL reflects a 50% decline in GFR, even though creatinine is still within the normal range. If a previous baseline creatinine is not available for comparison, a serum creatinine level of 1.2 mg/dL might be consi