title: Hemodialysis stimulates muscle and whole body protein loss and alters substrate oxidation.
abstract: The hemodialysis (HD) procedure has been implicated as a potential catabolic factor predisposing the chronic HD (CHD) patients to protein calorie malnutrition. To assess the potential effects of HD on protein and energy metabolism, we studied 11 CHD patients 2 h before, during, and 2 h after HD by use of primed constant infusion of L-[1-13C]leucine and L-[ring-2H5]phenylalanine. Our results showed that HD led to increased whole body (10%) and muscle protein (133%) proteolysis. Simultaneously, whole body protein synthesis did not change, and forearm synthesis increased (120%). The net result was increased net whole body protein loss (96%) and net forearm protein loss (164%). During the 2-h post-HD period, the muscle protein breakdown trended toward baseline, whereas whole body protein breakdown increased further. Substrate oxidation during the post-HD was significantly altered, with diminished carbohydrate and accelerated lipid and amino acid oxidation. These data demonstrate that hemodialysis is an overall catabolic event, decreasing the circulating amino acids, accelerating rates of whole body and muscle proteolysis, stimulating muscle release of amino acids, and elevating net whole body and muscle protein loss.
authors.affiliation: Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA. alp.ikizler@mcmail.vanderbilt.edu
authors.forename: T Alp
authors.initials: TA
authors.lastname: Ikizler
authors.forename: Lara B
authors.initials: LB
authors.lastname: Pupim
authors.forename: John R
authors.initials: JR
authors.lastname: Brouillette
authors.forename: Deanna K
authors.initials: DK
authors.lastname: Levenhagen
authors.forename: Kali
authors.initials: K
authors.lastname: Farmer
authors.forename: Raymond M
authors.initials: RM
authors.lastname: Hakim
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Flakoll
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D004734:Energy Metabolism; D005260:Female; D005542:Forearm / Q000098:blood supply; D006400:Hematocrit; D006728:Hormones / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism*; D010084:Oxidation-Reduction; D010447:Peptide Hydrolases / Q000378:metabolism; D011446:Prospective Studies; D011506:Proteins / Q000378:metabolism*; D012039:Regional Blood Flow; D006435:Renal Dialysis; D012119:Respiration; D013379:Substrate Specificity
chemical_list: D000596:Amino Acids; D001786:Blood Glucose; D006728:Hormones; D011506:Proteins; D010447:Peptide Hydrolases