Oral glutamine and amino acid supplementation inhibit whole-body protein degradation in children with Duchenne muscular dystrophy.
BACKGROUND
Glutamine has been shown to acutely decrease whole-body protein degradation in Duchenne muscular dystrophy (DMD).


OBJECTIVE
To improve nutritional support in DMD, we tested whether oral supplementation with glutamine for 10 d decreased whole-body protein degradation significantly more than did an isonitrogenous amino acid control mixture.


METHODS
Twenty-six boys with DMD were included in this randomized, double-blind parallel study; they received an oral supplement of either glutamine (0.5 g . kg(-1) . d(-1)) or an isonitrogenous, nonspecific amino acid mixture (0.8 g . kg(-1) . d(-1)) for 10 d. The subjects in each group were not clinically different at entry. Leucine and glutamine metabolisms were estimated in the postabsorptive state by using a primed continuous intravenous infusion of [1-(13)C]leucine and [2-(15)N]glutamine before and 10 d after supplementation.


RESULTS
A significant effect of time was observed on estimates of whole-body protein degradation. A significant (P < 0.05) decrease in the rate of leucine appearance (an index of whole-body protein degradation) was observed after both glutamine and isonitrogenous amino acid supplementation [x +/-SEM: 136 +/- 9 to 124 +/- 6 micromol . kg fat-free mass (FFM)(-1) . h(-1) for glutamine and 136 +/- 6 to 131 +/- 8 micromol . kg FFM(-1) . h(-1) for amino acids]. A significant (P < 0.05) decrease in endogenous glutamine due to protein breakdown was also observed (91 +/- 6 to 83 +/- 4 micromol . kg FFM(-1) . h(-1) for glutamine and 91 +/- 4 to 88 +/- 5 micromol . kg FFM(-1) . h(-1) for amino acids). The decrease in the estimates of whole-body protein degradation did not differ significantly between the 2 supplemental groups.


CONCLUSIONS
Oral glutamine or amino acid supplementation over 10 d equally inhibits whole-body protein degradation in DMD.
Mok
Elise
E
Centre d'Investigation Clinique 9202 INSERM, Assistance Publique-Hôpitaux de Paris, Hôpital Robert Debré, Paris, France.
Eléouet-Da Violante
Catherine
C
Daubrosse
Christel
C
Gottrand
Frédéric
F
Rigal
Odile
O
Fontan
Jean-Eudes
JE
Cuisset
Jean-Marie
JM
Guilhot
Joëlle
J
Hankard
Régis
R
D000284:Administration, Oral; D000293:Adolescent; D000596:Amino Acids / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D002247:Carbon Isotopes; D002648:Child; D019587:Dietary Supplements; D004311:Double-Blind Method; D005973:Glutamine / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D006801:Humans; D007262:Infusions, Intravenous; D007930:Leucine / Q000032:analysis / Q000378:metabolism; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000188:drug therapy / Q000378:metabolism*; D009587:Nitrogen Isotopes; D014176:Protein Biosynthesis / Q000187:drug effects; D011506:Proteins / Q000378:metabolism*
D000596:Amino Acids; D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D011506:Proteins; D005973:Glutamine; D007930:Leucine