Creatine, its metabolite creatinine, and an associated enzyme, creatine kinase, are measured in the blood to evaluate health conditions. Creatine is typically not measured, although creatinine concentration is frequently tested. Creatine is absorbed from foods, especially red meats, and synthesized from the liver and kidneys. It functions to replenish energy for the cells, especially nerve and muscle. The breakdown product of creatine, creatinine, is then secreted by the kidneys.
Causes
High creatine is generally caused by supplemental intake for the enhancement of athletic performance. The creatinine produced by excess intake is readily excreted by normal kidneys. High creatinine is caused by kidney problems, which may be congenital or acquired. Autoimmune problems, infections, tumors, diabetes, high blood pressure, blood vessel diseases, toxins, certain drugs, trauma or metabolic issues can damage the kidneys and raise creatine metabolites.
Symptoms and Signs
Elevated creatine or creatinine does not cause any problems for the body. However, the underlying cause of the elevation can cause noticeable problems. Kidney damage can lead to fluid retention with resulting shortness of breath and leg swelling, itching, muscle cramps, confusion, nausea, fatigue, and increased or decreased urine production.
Diagnosis
Creatine is not routinely measured in the blood. However, creatinine is measured as part of a blood test called a metabolic panel. The diagnosis of problems leading to increased creatinine starts with a comprehensive medical history, including the symptoms of the present illness, any past illnesses and medications used. This is followed by a physical exam and, if warranted, laboratory tests and imaging.
Treatment
High creatine or creatinine itself is not actually treated, but as an indicator of underlying problems, it is used to initiate or continue therapy. For example, in complete kidney failure, dialysis is instituted. Dialysis utilizes a machine outside the body to filter the blood, as such it is an external, artificial kidney. It filters out toxins from the blood, and restores normal levels of chemicals to the blood, including creatinine.
References
- "Physiology"; Linda S.Costanzo; 4th Ed 2008
- "Harrison's Principles of Internal Medicine"; Anthony S Fauci, et al.; 17th Ed 2008
- "Henry's Clinical Diagnosis and Management by Laboratory Methods"; Richard A. McPherson, et al.; 21st Ed 2006
