Creatine therapy in myophosphorylase deficiency (McArdle disease): a placebo-controlled crossover trial.
OBJECTIVE
To determine whether treatment with creatine can improve exercise intolerance in myophosphorylase deficiency (McArdle disease).


METHODS
Double-blind, placebo-controlled crossover study with oral creatine monohydrate supplementation.


METHODS
Nine patients with biochemically and genetically proven McArdle disease were treated.


METHODS
Five days of daily high-dose creatine intake (150 mg/kg body weight) were followed by daily low-dose creatine intake (60 mg/kg). Each treatment phase with creatine or placebo lasted 5 weeks.


METHODS
The effect of treatment was estimated at the end of each treatment phase by recording clinical scores, ergometer exercise test results, phosphorus 31 nuclear magnetic resonance spectroscopy, and surface electromyography.


RESULTS
Of 9 patients, 5 reported improvement of muscle complaints with creatine. Force-time integrals (P =.03) and depletion of phosphocreatine (P =.04) increased significantly during ischemic exercise with creatine. Phosphocreatine depletion also increased significantly during aerobic exercise (P =.006). The decrease of median frequency in surface electromyograms during contraction was significantly larger (P =.03) with creatine.


CONCLUSIONS
This is the first controlled study indicating that creatine supplementation improves skeletal muscle function in McArdle disease.
Vorgerd
M
M
Department of Neurology, Ruhr-University Bochum, Kliniken Bergmannsheil, Burkle-de-la-Camp-Platz 1, 44789 Bochum, Germany. matthias.vorgerd@ruhr-uni-bochum.de.
Grehl
T
T
Jager
M
M
Muller
K
K
Freitag
G
G
Patzold
T
T
Bruns
N
N
Fabian
K
K
Tegenthoff
M
M
Mortier
W
W
Luttmann
A
A
Zange
J
J
Malin
J P
JP
D000284:Administration, Oral; D000328:Adult; D002648:Child; D003401:Creatine / Q000008:administration & dosage* / Q000009:adverse effects; D003402:Creatine Kinase / Q000378:metabolism; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004576:Electromyography; D004734:Energy Metabolism / Q000187:drug effects; D005080:Exercise Test; D017079:Exercise Tolerance / Q000187:drug effects; D005260:Female; D006012:Glycogen Storage Disease Type V / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D010725:Phosphocreatine / Q000378:metabolism; D016896:Treatment Outcome
D010725:Phosphocreatine; D003402:Creatine Kinase; D003401:Creatine