Lack of functional benefit with glutamine versus placebo in Duchenne muscular dystrophy: a randomized crossover trial.
BACKGROUND
Oral glutamine decreases whole body protein breakdown in Duchenne muscular dystrophy (DMD). We evaluated the functional benefit of 4 months oral glutamine in DMD.


RESULTS
30 ambulant DMD boys were included in this double-blind, randomized crossover trial with 2 intervention periods: glutamine (0.5 g/kg/d) and placebo, 4 months each, separated by a 1-month wash-out, at 3 outpatient clinical investigation centers in France. Functional benefit was tested by comparing glutamine versus placebo on change in walking speed at 4 months. Secondary outcome measures were: 2-minute walk test, work, power, muscle mass (urinary creatinine), markers of myofibrillar protein breakdown (urinary 3-methyl-histidine/creatinine), serum creatine phospho-kinase, body composition (fat free mass, fat mass percentage), safety and oral nutrient intake. There was no improvement in the primary end point (walking speed) or in secondary measures of muscle function (2-minute walk test, work, power) in the glutamine group compared with placebo. However, subjects receiving glutamine or placebo showed no deterioration in functional measures over the course of the 9-month trial. No differences in muscle mass, markers of protein breakdown or serum creatine phosho-kinase were observed, except for a blunted increase in fat free mass in the glutamine group which led to a greater increase in fat mass percentage. Glutamine was safe and well-tolerated.


CONCLUSIONS
This trial did not identify additional benefit of 4 months oral glutamine over placebo on muscle mass or function in ambulatory DMD boys. Although apparently safe, current data cannot support routine supplementation in this population as a whole, until further research proves otherwise.


BACKGROUND
(ClinicalTrials.gov) NCT00296621.
Mok
Elise
E
INSERM Centre D'Investigation Clinique 802, CHU de Poitiers, Poitiers, France.
Letellier
Guy
G
Cuisset
Jean-Marie
JM
Denjean
André
A
Gottrand
Frédéric
F
Alberti
Corinne
C
Hankard
Régis
R
D000284:Administration, Oral; D001823:Body Composition; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000652:urine; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005500:Follow-Up Studies; D005973:Glutamine / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D020714:Maximum Tolerated Dose; D008762:Methylhistidines / Q000378:metabolism; D018482:Muscle, Skeletal / Q000503:physiopathology; D020388:Muscular Dystrophy, Duchenne / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology
D008762:Methylhistidines; D005973:Glutamine; D003404:Creatinine; C028118:3-methylhistidine