title: Essential amino acids and exercise tolerance in elderly muscle-depleted subjects with chronic diseases: a rehabilitation without rehabilitation?
abstract: Exercise intolerance remains problematic in subjects with chronic heart failure (CHF) and/or chronic obstructive pulmonary disease (COPD). Recent studies show that supplemented essential amino acids (EAAs) may exert beneficial effects on CHF/COPD physical capacity. The results from 3 investigations (2 conducted on CHF and 1 on COPD subjects) served as the basis for this paper. The 3 studies consistently showed that elderly CHF and COPD improved exercise intolerance after 1-3 months of EAA supplementation (8 g/d). In CHF exercise capacity increased 18.7% to 23% (watts; bicycle test), and 12% to 22% (meters) in 6 min walking test. Moreover, patients reduced their resting plasma lactate levels (by 25%) and improved tissue insulin sensitivity by 16% (HOMA index). COPD subjects enjoyed similar benefits as CHF ones. They increased physical autonomy by 78.6% steps/day and decreased resting plasma lactate concentrations by 23%. EAA mechanisms explaining improved exercise intolerance could be increases in muscle aerobic metabolism, mass and function, and improvement of tissue insulin sensitivity (the latter only for the CHF population). These mechanisms could be accounted for by EAA's intrinsic physiological activity which increases myofibrils and mitochondria genesis in skeletal muscle and myocardium and glucose control. Supplemented EAAs can improve the physical autonomy of subjects with CHF/COPD.
authors.affiliation: Servizio di Fisiopatologia Metabolico-Nutrizionale e Nutrizione Clinica, Fondazione S. Maugeri, IRCCS, Istituto Scientifico di Montescano, Via per Montescano 31, Montescano, 27040 Pavia, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Aquilani
authors.affiliation: Laboratorio Universitario per lo Studio delle Attività Motorie nelle Malattie Rare (LUSAMMR), Via Ugo Foscolo 13, Voghera, 27058 Pavia, Italy ; Dipartimento di Medicina Molecolare, Università degli Studi di Pavia, Viale Taramelli 3/B, 27100 Pavia, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: D'Antona
authors.affiliation: Direzione Scientifica Centrale, Fondazione Salvatore Maugeri, IRCCS, Via Salvatore Maugeri 8-10, 27100 Pavia, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Baiardi
authors.affiliation: Consorzio Valutazioni Biologiche e Farmacologiche, Via Luigi Porta 14, 27100 Pavia, Italy.
authors.forename: Arianna
authors.identifier: 0000-0002-0804-1160
authors.initials: A
authors.lastname: Gambino
authors.affiliation: Dipartimento di Biologia e Biotecnologie, Università degli Studi di Pavia, Via Ferrata 1, 27100 Pavia, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Iadarola
authors.affiliation: Dipartimento di Medicina Molecolare, Università degli Studi di Pavia, Viale Taramelli 3/B, 27100 Pavia, Italy.
authors.forename: Simona
authors.identifier: 0000-0001-5020-478X
authors.initials: S
authors.lastname: Viglio
authors.affiliation: Fondazione S. Maugeri, IRCCS, Istituto Scientifico di Lumezzane, Via Mazzini 9, Lumezzane, 25065 Brescia, Italy.
authors.forename: Evasio
authors.initials: E
authors.lastname: Pasini
authors.affiliation: Dipartimento di Medicina Legale, Scienze Forensi e Farmaco-Tossicologiche "A. Fornari", Sezione di Scienze Farmacologiche e Tossicologiche, Università degli Studi di Pavia, 27100 Pavia, Italy.
authors.forename: Manuela
authors.identifier: 0000-0003-3734-9540
authors.initials: M
authors.lastname: Verri
authors.affiliation: Dipartimento di Scienze del Farmaco, Università degli Studi di Pavia, Viale Taramelli 14, 27100 Pavia, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Barbieri
authors.affiliation: Dipartimento di Scienze del Farmaco, Università degli Studi di Pavia, Viale Taramelli 14, 27100 Pavia, Italy.
authors.forename: Federica
authors.identifier: 0000-0002-3192-6397
authors.initials: F
authors.lastname: Boschi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005081:Exercise Therapy; D017079:Exercise Tolerance; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000503:physiopathology / Q000534:rehabilitation; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000503:physiopathology; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000503:physiopathology / Q000534:rehabilitation; D016138:Walking
chemical_list: D019344:Lactic Acid