title: 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.affiliation: Setor de Função Pulmonar e Fisiologia Clínica do Exercício, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
authors.forename: A C
authors.initials: AC
authors.lastname: Gimenes
authors.affiliation: Setor de Função Pulmonar e Fisiologia Clínica do Exercício, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
authors.forename: D M
authors.initials: DM
authors.lastname: Bravo
authors.affiliation: Setor de Função Pulmonar e Fisiologia Clínica do Exercício, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
authors.forename: L M
authors.initials: LM
authors.lastname: Nápolis
authors.affiliation: Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
authors.forename: M T
authors.initials: MT
authors.lastname: Mello
authors.affiliation: Setor de Doenças Neuromusculares, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
authors.forename: A S B
authors.initials: AS
authors.lastname: Oliveira
authors.affiliation: Setor de Função Pulmonar e Fisiologia Clínica do Exercício, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
authors.forename: J A
authors.initials: JA
authors.lastname: Neder
authors.affiliation: Setor de Função Pulmonar e Fisiologia Clínica do Exercício, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
authors.forename: L E
authors.initials: LE
authors.lastname: Nery
mesh_terms: D000328:Adult; D002331:Carnitine / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005080:Exercise Test / Q000187:drug effects; D017079:Exercise Tolerance / Q000187:drug effects*; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008875:Middle Aged; D017240:Mitochondrial Myopathies / Q000188:drug therapy; D053580:Muscle Strength / Q000187:drug effects; D017246:Ophthalmoplegia, Chronic Progressive External / Q000188:drug therapy*; D010085:Oxidative Phosphorylation / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D013147:Spirometry; D014803:Vitamin B Complex / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D014803:Vitamin B Complex; D019344:Lactic Acid; D002331:Carnitine