Amino acid supplementation decreases plasma and liver triacylglycerols in elderly.
OBJECTIVE
Hypertriglyceridemia is a risk factor for coronary heart disease. The aim of this study was to determine the effect of amino acid (AA) supplementation on plasma, liver, and muscle lipid concentrations and insulin sensitivity in the elderly.


METHODS
Twelve impaired glucose tolerant elderly (mean +/- SD 67.0 +/- 5.6 y of age, seven women and five men) ingested 11 g of essential AAs plus arginine twice a day for 16 wk, after a 7-wk control run-in. Diet and activity were not otherwise modified. Plasma lipid concentrations and oral glucose tolerance were measured every fourth week and tissue lipid concentrations (magnetic resonance spectroscopy) every eighth week.


RESULTS
No changes in plasma lipids were observed during the control run-in. AA supplementation lowered plasma triacylglycerol (TG; P < 0.001), total cholesterol (P = 0.048), and very low-density lipoprotein cholesterol (P < 0.001) concentrations. Plasma TG decreased approximately 20% from the initial value of 1.45 +/- 0.18 mmol/L (mean +/- SE, 128 +/- 16 mg/dL), with the greatest decrease in the subjects starting out with the highest concentrations (r = -0.83). Similarly, liver fat content (liver TG/Intralipid standard) decreased approximately 50% from the initial value of 0.34 +/- 0.06 (P = 0.021, n = 8), with the greatest decrease in the subjects who initially had the highest values (r = -0.86). Intramuscular fat content and insulin sensitivity did not change.


CONCLUSIONS
Diet supplementation with AAs lowers plasma TG, total cholesterol, and very low-density lipoprotein cholesterol concentrations and liver lipid content in impaired glucose tolerant elderly. AA supplementation may have a potential role in the treatment of hypertriglyceridemia or hepatic steatosis.
Børsheim
Elisabet
E
Department of Surgery/Shriners Hospitals for Children, University of Texas Medical Branch, Galveston, Texas, USA. elborshe@utmb.edu
Bui
Quynh-Uyen T
QU
Tissier
Sandrine
S
Cree
Melanie G
MG
Rønsen
Ola
O
Morio
Beatrice
B
Ferrando
Arny A
AA
Kobayashi
Hisamine
H
Newcomer
Bradley R
BR
Wolfe
Robert R
RR
D000368:Aged; D000601:Amino Acids, Essential / Q000008:administration & dosage / Q000494:pharmacology*; D001120:Arginine / Q000008:administration & dosage / Q000494:pharmacology; D002784:Cholesterol / Q000097:blood; D015243:Cholesterol, VLDL / Q000097:blood; D019587:Dietary Supplements; D005260:Female; D018149:Glucose Intolerance / Q000097:blood; D006801:Humans; D015228:Hypertriglyceridemia / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D007328:Insulin / Q000378:metabolism*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D016896:Treatment Outcome; D014280:Triglycerides / Q000097:blood* / Q000378:metabolism
D000601:Amino Acids, Essential; D015243:Cholesterol, VLDL; D007328:Insulin; D014280:Triglycerides; D001120:Arginine; D002784:Cholesterol