Effect of L-carnitine on exercise performance in patients with mitochondrial myopathy.

Abstract

Exercise intolerance due to impaired oxidative metabolism is a prominent symptom in patients with mitochondrial myopathy (MM), but it is still uncertain whether L-carnitine supplementation is beneficial for patients with MM. The aim of our study was to investigate the effects of L-carnitine on exercise performance in MM. Twelve MM subjects (mean age±SD=35.4±10.8 years) with chronic progressive external ophthalmoplegia (CPEO) were first compared to 10 healthy controls (mean age±SD=29±7.8 years) before they were randomly assigned to receive L-carnitine supplementation (3 g/daily) or placebo in a double-blind crossover design. Clinical status, body composition, respiratory function tests, peripheral muscle strength (isokinetic and isometric torque) and cardiopulmonary exercise tests (incremental to peak exercise and at 70% of maximal), constant work rate (CWR) exercise test, to the limit of tolerance [Tlim]) were assessed after 2 months of L-carnitine/placebo administration. Patients with MM presented with lower mean height, total body weight, fat-free mass, and peripheral muscle strength compared to controls in the pre-test evaluation. After L-carnitine supplementation, the patients with MM significantly improved their Tlim (14±1.9 vs 11±1.4 min) and oxygen consumption ( V ˙ O 2 ) at CWR exercise, both at isotime (1151±115 vs 1049±104 mL/min) and at Tlim (1223±114 vs 1060±108 mL/min). These results indicate that L-carnitine supplementation may improve aerobic capacity and exercise tolerance during high-intensity CWRs in MM patients with CPEO.

• Authors: A C Gimenes, D M Bravo, L M Nápolis, M T Mello, A S B Oliveira, J A Neder, L E Nery
• Journal: Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas (Braz J Med Biol Res) Vol. 48 Issue 4 Pg. 354-62 (Apr 2015) ISSN: 1414-431X [Electronic] Brazil
• PMID: 25714882 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Vitamin B Complex
• Lactic Acid
• Carnitine

Topics

• Adult
• Carnitine (therapeutic use)
• Cross-Over Studies
• Double-Blind Method
• Exercise Test (drug effects)
• Exercise Tolerance (drug effects)
• Female
• Humans
• Lactic Acid (blood)
• Male
• Middle Aged
• Mitochondrial Myopathies (drug therapy)
• Muscle Strength (drug effects)
• Ophthalmoplegia, Chronic Progressive External (drug therapy)
• Oxidative Phosphorylation (drug effects)
• Oxygen Consumption (drug effects, physiology)
• Spirometry
• Vitamin B Complex (therapeutic use)
• Young Adult