Carnitine Deficiency

Carnitine Deficiency General Information

Carnitine is an ammonium compound that is biosynthesized from methionine and the amino acid, lysine. It is also called levocarnitine or L-carnitine. It was first found as a factor for the growth of mealworms. The natural form is the L-stereoisomer. It is responsible for the transport of fatty acids from the cytosol to the mitochondria. It is known to help in the disposal and consumption of fats in the human organism. It can be often bought as a nutritional supplement. This betaine commonly occurs in the skeletal muscles and in the liver. Carnitine Deficiency or CD is the result of an inadequate intake or an inability to metabolize the amino acid carnitine. Therefore, we can affirm that Carnitine Deficiency is the metabolic state characterized by lower levels of carnitine concentrations in tissues and plasma than is usually and normally needed for a normal function of the human organism. Significant clinical biological effects of the low levels of this compound are only important when they are under 15% than the normal quantity. Carnitine Deficiency has a primary and a secondary stage. The first type of deficiency is the result of a lack in the plasma of the carnitine transporter. This fact impairs the long chain fatty acids to enter into the mitochondrial matrix. Once these long chain fatty acids are not sufficient for the production of energy and beta-oxidation, ketone bodies are not produced anymore. When dealing with the secondary stage of this disease, organic acidemias, fatty acids oxidation disorders or other metabolic disorders are causing it. This type of deficiency affects people from all around the world and it appears in 1 per 50,000 births.

Carnitine Deficiency Symptoms

The main signs and symptoms of Carnitine Deficiency include muscle weakness, severe confusion and angina. This kind of deficiency is generally staged as primary or secondary. The primary stage of the deficiency is caused by many underlying problems, such as the low level of natural synthesis of carnitine in the patient’s organism and the altered transport of carnitine along the muscle cellular membrane. The secondary stage of the deficiency occurs because of the lack of carnitine in the patient’s diet or any state that causes abnormal loss or over utilization of carnitine. Signs and symptoms and the age at which symptoms develop depend on the cause. Carnitine Deficiency can lead to severe muscle necrosis, myoglobinuria, lipid-storage myopathy, hypoglycemia, fatty liver, and hyperammonemia with muscle aches, fatigue, confusion, and cardiomyopathy. The cardiomyopathy is progressive and affects the much elder persons. If this condition is not diagnosed correctly and if the necessary carnitine is not given, this progressive failure of the heart ends up with the patient’s death. Patients with respiratory disorders or mitochondrial disorders at the secondary stage of the deficiency can present an abnormal fatigability and lactic acidosis associated with exertion. These patients can also present an encephalopathy or lipid storage myopathy and carnitine depletion. Carnitine Deficiency has been observed in young patients with urea cycle defects, and it can exacerbate episodes of hyperammonemia. Signs or symptoms of cardiac hypertrophy can be obvious, with gallop or heart murmur on the cardiac examination. Death may occur suddenly as a first clinical manifestation of the primary deficiency in people who were, unfortunately, asymptomatic. In patients with secondary deficiency of this kind, death may also occur but it is due to fibrillations and ventricular tachycardia.

Carnitine Deficiency Treatment

If you present any of the symptoms and signs listed above, you should call your health care provider and go immediately to a medical consultation. He or she will guide you then to a nutritionist or to genetic metabolic clinics. Because this medical condition may sometimes be asymptomatic, regular medical checks are recommended in order to proceed in time with medical care, if needed. The evaluations for Carnitine Deficiency are usually done on an outpatient basis. When dealing with severe insufficiencies, in the acute stage of the disease inpatients studies may be required. The stabilization of the patient usually follows this step. Excess loss, inadequate dietary intake, some enzyme deficiencies, increased requirements or decreased synthesis are usually the causes of Carnitine Deficiency and demand therapies with L-carnitine and a dosage of 20mg/kg every six hours. Stabilization with 15% dextrose in water at rates of 15 mg/kg given intravenously is necessary in the case of patients who also suffer from hypoketotic hypoglycemic encephalopathy. In the first stage, L-carnitine enables the production of ketone bodies and is important in correcting the severe depletion of carnitine and other abnormalities at the metabolic level. In the next stage, it enhances the generation of free CoA and the elimination of metabolites that may be toxic. The necessary concentrations of carnitine for the transport of fatty acids to the mitochondria are assured by administrating intravenous carnitine.

Carnitine is administrated this way only when the diagnosis of primary Carnitine Deficiency is confirmed or entertained. Also, in this case, a medication with carnitine administrated orally can help in improving cardiac functions, cognitive performance, growth or ketogenesis. This method is really controversial because of its potential to be arrhythmogenic and may also be used in methylmalonic acidemia, isovaleric acidemia, propionic acidemia and other types of acidemias, when the oral intake is not feasible. In the case of cardiomyopathy, pharmacological support must be considered. In secondary Carnitine Deficiency the treatment may include supplements such as biotin, glycine or riboflavin. Diet is a very important factor when dealing with Carnitine Deficiency. In the primary stage of this disease, the patients do not require a special diet if they are not starving or live under stress and they are taking their supplements of carnitine. Early morning hypoglycemia must be prevented by eating uncooked cornstarch before bedtime. Those patients who have a fatty acid oxidation problem should follow a diet rich in carbohydrates and very low in fats (only 20% calories from fats) and their meals should also be frequent.

Essential fatty acids and medium chain triglycerides are given as supplements to some patients with long chain fatty acid problems. Usually, the deficiency of fatty acids is also associated with dermatitis and growth restrictions that are corrected by prescribing supplements of some of the essential fatty acids, such as linolenic and linoleic acids. Some patients may present (in association with the secondary form of Carnitine Deficiency) organic acidemias or aminoacidopathies. In such cases, they may need to follow a specific protein-restricted diet. Strenuous exercises and fasting must be avoided by all the patients. Growth, cardiac functioning and strength are obviously improved in the primary stage once the patient has started his treatment with supplements of carnitine. It is recommended that in the secondary stage some activities be tempered and may be restricted. If physical activity is done, the necessary hydration must be assured, as well as frequent snacks.