L-Carnitine and exercise tolerance in medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency: A pilot study

  title={L-Carnitine and exercise tolerance in medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency: A pilot study},
  author={P. J. Lee and E. L. Harrison and M. G. Jones and S. Jones and James V. Leonard and Ronald A. Chalmers},
  journal={Journal of Inherited Metabolic Disease},
SummarySkeletal muscle function may be impaired in patients with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, but the value of L-carnitine in their long-term management is not clear. This study was designed as a pilot to examine the effects of L-carnitine on exercise tolerance in patients with MCAD deficiency. Four clinically asymoptomatic MCAD-deficient patients, aged 8 to 20 years, were studied. Incremental ramp exercise tests were carried out before and after 4 weeks’ treatment… 

Patients with medium-chain acyl-coenzyme a dehydrogenase deficiency have impaired oxidation of fat during exercise but no effect of L-carnitine supplementation.

It is indicated that patients with MCADD have an impaired ability to increase FAO during exercise but less so than that observed in patients with a number of other disorders of fat oxidation, which explains the milder skeletal muscle phenotype in MCADD.

Prolonged moderate-intensity exercise without and with L-carnitine supplementation in patients with MCAD deficiency

It is suggested that medium-chain acyl-CoA dehydrogenase deficiency patients are able to increase carnitine biosynthesis during exercise to compensate for Carnitine losses.

L-Carnitine Supplementation: Influence upon Physiological Function

Promising findings for L-carnitine use have been observed for various pathologies, including cardiovascular diseases, which show it might mitigate some negative effects and enhance physical function.

Management Principles for Acute Illness in Patients With Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency

This clinical report is to provide pediatricians with additional information regarding the acute clinical care of patients with medium-chain acyl-coenzyme A dehydrogenase deficiency.

Current issues regarding treatment of mitochondrial fatty acid oxidation disorders

Critical questions that are currently under debate in mitochondrial fatty acid oxidation (FAO) defects are discussed, including the use of bezafibrates in myopathic long-chain defects and whether triheptanoin is more effective than even-chain MCT.

Medium-chain acyl-Coenzyme A dehydrogenase deficiency (MCADD): a cause of severe hypoglycaemia in an apparently well child

This is a case of an otherwise healthy 23-month-old baby girl who presented with severe hypoglycaemia with some initial diagnostic dilemma.

Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency-GeneReviews®-NCBI Bookshelf

The prognosis is excellent once the diagnosis is established and frequent feedings are instituted to avoid any prolonged period of fasting.

Liver Disease in Children: Inborn Errors of Mitochondrial Fatty Acid Oxidation

FAO disorders have become an important group of inherited metabolic disorders causing morbidity and mortality and may cause sudden unexpected death if unrecognized and untreated.



Intravenous L-Carnitine and Acetyl-L-Carnitine in Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency and Isovaleric Acidemia

It is concluded that there was no evidence of enhanced fatty acid β-oxidation or enhanced branched-chain amino acid oxidation in vivo by the administration of high doses of L-carnitine or acetyl-L-c Carnitine in these two patients.

Urinary Excretion of l-Carnitine and Acylcarnitines by Patients with Disorders of Organic Acid Metabolism: Evidence for Secondary Insufficiency of l-Carnitine

Despite naturally occurring attempts to increase endogeneous l-carnitine biosynthesis, there is insufficient carnitine available to restore the mass action ratio as demonstrated by the further increase in acylc Carnitine excretion when patients were given oral l-Carnitines.

Renal Handling of Carnitine in Secondary Carnitine Deficiency Disorders

Reduced plasma and tissue concentrations of carnitine, a cofactor required for fatty acid oxidation, are present in patients with inherited disorders of mitochondrial acyl-CoA oxidation that are associated with accumulations of acylcarnitines, suggesting secondary carnitines deficiency in these patients is due to indirect as well as direct effects of accumulated acylCarnitine.

Improvement in exercise tolerance in isovaleric acidaemia with L-carnitine therapy

It is concluded that, in this single patient with isovaleric acidaemia, L-carnitine supplementation had objective benefits and further studies on more patients are warranted.

Effects of L- and DL-carnitine on patients with impaired exercise tolerance.

It is demonstrated that L-c Carnitine increases and DL-carnitine decreases exercise tolerance in patients with impaired exercise tolerance.

Effect of L-carnitine on submaximal exercise metabolism after depletion of muscle glycogen.

During submaximal exercise after glycogen depletion (i.e., at a high lipid flux) substrate metabolism is not influenced by L-carnitine supplementation, and fat oxidation estimated from respiratory gas exchange doubled after glycogens depletion for the same exercise intensity.

Carnitine metabolism during exercise.

The effect of oral supplementation with l-carnitine on maximum and submaximum exercise capacity

It is concluded, that carnitine supplementation may be of little benefit to exercise performance since the observed effects were small and inconsistent.

Carnitine metabolism during exercise in patients on chronic hemodialysis.

Patients on hemodialysis had a lower muscle total carnitine content than control subjects which was correlated to exercise performance, and the change in muscle short-chain acylcarnitines content with exercise was correlated with the increase in muscle lactate content.

Prolonged submaximal exercise and L-carnitine in humans

In normal human subjects the increased demand for fatty acid oxidation resulting from exercise seems to be adequately supported by endogenous levels of carnitine, as well as the physiological parameters and circulating metabolites.