Health care professionals make medical diagnoses based on history, physical exam, laboratory findings and other special studies. Creatine is a chemical found in the blood that helps restore the main energy carrier of your cells -- ATP. After it is used, creatine is broken down into creatinine and excreted. Elevated creatinine can signal disease in the body. See a physician for the diagnosis and treatment of health conditions.
Metabolism
Creatine is ingested as supplement for athletic performance or found in the diet -- in highest concentrations in red meat. It is absorbed in the intestinal tract and then travels to the tissues, especially muscle and nerve tissue. Creatine enters the cells, and phosphate group is added to make creatine phosphate. When the cells perform work, such as the contraction of muscle, they use ATP, which loses a phosphate to become ADP. Creatine phospate regenerates ATP by donating its phosphate. Creatine is eventually metabolized to creatinine. Creatinine enters the bloodstream, is filtered by the kidneys and is excreted in the urine.
Causes
The primary cause of high creatinine is kidney disease. Normal creatinine is about 0.5 to 1.2 mg/dL, though this varies some by sex and race. Low creatinine is usually insignificant. The degree of kidney disease dictates the level of creatinine; as the kidney function gets worse, the creatinine levels rise. There are many causes and types of kidney disease. Creatinine can also be slightly higher in those with increased muscle mass.
Diagnosis
High creatinine levels are diagnosed by a blood test. Urine creatinine is sometimes measured as well, usually in a 24-hour collection. High urine creatinine is not actually a disease; it is only an indicator of an underlying condition. The next step is to find the underlying cause. This can be accomplished with blood tests, urine studies, imaging of the kidneys such as with ultrasound or a kidney biopsy in which a small amount of kidney tissue is removed for special studies.
Treatment
High creatinine itself is not treated because increased levels do not cause problems for the body. However, when it gets too high, it is indicative that the kidneys are not filtering other substances as well. Some of these substances are toxins or waste products. A dialysis machine may need to be used. This is a machine that acts as an artificial kidney by filtering the blood outside of the body.
References
- "Harrison's Principles of Internal Medicine"; Anthony S Fauci, et al.; 2008
- "Robbins and Cotran Pathologic Basis of Disease"; Vinay Kumar, et al.; 2009
- "Henry's Clinical Diagnosis and Management by Laboratory Methods"; Richard A. McPherson, et al.; 2006
