What Is Creatinine Clearance?

Creatinine is a metabolite of creatine. Creatine is directly proportional to muscle mass. The body produces and releases creatinine into the blood at a constant rate, which is carried to the kidneys by the blood circulation and excreted from the urine. Blood creatinine includes endogenous creatinine and exogenous creatinine. Endogenous creatinine is produced by the hydrolysis and metabolism of creatine phosphate contained in muscle and is not affected by food. Exogenous creatinine comes from ingested fish and meat foods. Creatinine is mainly the effect of endogenous creatinine. Because creatinine has a small molecular weight and does not bind to plasma proteins, it can pass freely through the glomeruli and is not reabsorbed by the renal tubules. It is also not excreted by the renal tubules when there is no abnormal increase in serum creatinine. Instead of inulin clearance (Cin) represents the glomerular filtration rate (GFR). Endogenous creatinine clearance is a sensitive indicator for judging glomerular filtration dysfunction and is often checked before renal function tests.

Basic Information

Chinese name

Endogenous creatinine clearance

Foreign name

Creatinine Clearance

Short name

Creatinine clearance

Meaning

One of the 21st century clinical renal function tests

Main exhaust route

Glomerulus

Clinical significance of endogenous creatinine clearance

1. Determine whether the glomerular function is damaged and its degree. When the endogenous creatinine clearance rate of adults is below 80 ml per minute, it indicates that the glomerular filtration function is impaired; if it is reduced to 70 to 51 ml per minute, it is mild damage; to 50 to 31 ml per minute, it is moderate damage; Severe damage to less than 30ml per minute; reduction to 20 to 10ml per minute is early renal insufficiency, which indicates poor prognosis for patients with chronic nephritis; reduction to 10 to 5ml per minute is advanced renal insufficiency; less than 5ml per minute is End-stage renal insufficiency.

2. Guide clinical medication and treatment.

3. The gradual rise of endogenous creatinine clearance in patients with kidney transplantation indicates that the transplantation was successful, otherwise it indicates that there is rejection.

4. With the increase of age in healthy people, the renal parenchymal volume shrinks, and the endogenous creatinine clearance rate may decrease. The reduction for the elderly can reach 60 ml / (min · 1.73 square meters).

5. Others: Hypothyroidism, renal hypertension, strenuous exercise, and the use of certain drugs such as vitamin C, steroids, levodopa, etc. have increased endogenous creatinine clearance.

Reference value for endogenous creatinine clearance

Normal value: 80 120ml / min / 1.73m ^ 2 per minute