title: Exercise augments the acute anabolic effects of intradialytic parenteral nutrition in chronic hemodialysis patients.
abstract: Decreased dietary protein intake and hemodialysis (HD)-associated protein catabolism are among several factors that predispose chronic hemodialysis (CHD) patients to uremic malnutrition and associated muscle wasting. Intradialytic parenteral nutrition (IDPN) acutely reverses the net negative whole body and forearm muscle protein balances observed during the HD procedure. Exercise has been shown to improve muscle protein homeostasis, especially if performed with adequately available intramuscular amino acids. We hypothesized that exercise performance would provide additive anabolic effects to the beneficial effects of IDPN. We studied six CHD patients at two separate HD sessions: 1) IDPN administration only and 2) IDPN + exercise. Patients were studied 2 h before, during, and 2 h after an HD session by use of a primed constant infusion of l-[1-(13)C]leucine and l-[ring-(2)H(5)] phenylalanine. Exercise combined with IDPN promoted additive twofold increases in forearm muscle essential amino acid uptake (455 +/- 105 vs. 229 +/- 38 nmol.100 ml(-1).min(-1), P < 0.05) and net muscle protein accretion (125 +/- 37 vs. 56 +/- 30 microg.100 ml(-1).min(-1), P < 0.05) during HD compared with IDPN alone. Measurements of whole body protein homeostasis and energy expenditure were not altered by exercise treatment. In conclusion, exercise in the presence of adequate nutritional supplementation has potential as a therapeutic intervention to blunt the loss of muscle mass in CHD patients.
authors.affiliation: Division of Nephrology, S-3223 MCN, Vanderbilt University Medical Center, 1161 21st Avenue South & Garland, Nashville, TN 37232-2372, USA.
authors.forename: Lara B
authors.initials: LB
authors.lastname: Pupim
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Flakoll
authors.forename: Deanna K
authors.initials: DK
authors.lastname: Levenhagen
authors.forename: T Alp
authors.initials: TA
authors.lastname: Ikizler
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000596:Amino Acids / Q000097:blood / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism; D018592:Cross-Over Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006728:Hormones / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D007676:Kidney Failure, Chronic / Q000150:complications / Q000628:therapy; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000254:growth & development* / Q000502:physiology; D010084:Oxidation-Reduction; D010288:Parenteral Nutrition; D011506:Proteins / Q000378:metabolism; D006435:Renal Dialysis / Q000009:adverse effects*
chemical_list: D000596:Amino Acids; D001786:Blood Glucose; D006728:Hormones; D007328:Insulin; D011506:Proteins