Plasma L-carnitine measurement is used to evaluate patients with clinical suspicion of a wide range of pathological conditions, including organic acidemias, disorders of fatty acid oxidation, and primary carnitine deficiency.
L-carnitine is a physiological component of human serum. L-carnitine concentrations vary in patients with acute muscle necrosis, renal disease, systemic carnitine deficiency, and diabetes mellitus. L-carnitine is essential for the transport of free fatty acids into the mitochondria, the organelle responsible for fatty acid oxidation which produces energy from fat. Carnitine deficiency has been associated with several cases of myopathy and may play an important role in some disorders of lipid metabolism. Other conditions that can cause abnormal carnitine levels are neuromuscular disorders, gastrointestinal disorders, familial cardiomyopathy, renal tubular lesions, chronic renal failure, prolonged treatment with steroids, antibiotics, anticonvulsants (valproic acid) as well as total parenteral nutrition.
L-carnitine can be synthesized from the amino acids lysine and methionine. L-carnitine is mainly synthesized in the liver but also in the kidneys. L-carnitine plays an important role in the production of energy by conjugation of fatty acids and their transfer to mitochondria. Carnitine deficiency can occur either from hereditary or acquired conditions. Hereditary causes include genetic abnormalities in amino acid degradation and lipid metabolism.
The endogenous biosynthesis of L-carnitine is catalyzed by the coordinated action of five different enzymes. This process requires two essential amino acids (lysine and methionine), iron (Fe2+), vitamin B6, vitamin B3 (niacin), and also vitamin C. One of the first symptoms of vitamin C deficiency is fatigue and is believed to be related to reduced synthesis of L-carnitine.
Meat, poultry, fish, and dairy products are the richest sources of L-carnitine, while fruits, vegetables, and cereals contain relatively small amounts of L-carnitine.
Laboratory test results are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70%-80% of diagnostic decisions are based on laboratory tests. The correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased".
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be interpreted in relation to each individual case and family history, clinical findings, and the results of other laboratory tests and information. Your personal physician should explain the importance of your test results.
At Diagnostiki Athinon we answer any questions you may have about the test you perform in our laboratory and we contact your doctor to get the best possible medical care.