title: Protein supplementation increases postexercise plasma myostatin concentration after 8 weeks of resistance training in young physically active subjects.
abstract: Myostatin (MSTN) is a negative regulator of muscle growth even if some studies have shown a counterintuitive positive correlation between MSTN and muscle mass (MM). Our aim was to investigate the influence of 2 months of resistance training (RT) and diets with different protein contents on plasma MSTN, interleukin 1 beta (IL-1β), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and insulin-like growth factor 1 (IGF-1). Eighteen healthy volunteers were randomly divided in two groups: high protein (HP) and normal protein (NP) groups. Different protein diet contents were 1.8 and 0.85 g of protein·kg bw(-1)·day(-1) for HP and NP, respectively. Subjects underwent 8 weeks of standardized progressive RT. MSTN, IGF-1, IL-1β, IL-6, and TNF-α were analyzed before and after the first and the last training sessions. Lean body mass, MM, upper-limb muscle area, and strength were measured. Plasma MSTN showed a significant increase (P<.001) after the last training in the HP group compared with NP group and with starting value. IGF-1 plasma concentration showed a positive correlation with MSTN in HP after the last training (r(2)=0.6456; P=.0295). No significant differences were found between NP and HP for IL-1β, IL-6, TNF-α, and strength and MM or area. These findings suggest a "paradoxical" postexercise increase of plasma MSTN after 8 weeks of RT and HP diets. This MSTN elevation correlates positively with IGF-1 plasma level. This double increase of opposite (catabolic/anabolic) mediators could explain the substantial overlapping of MM increases in the two groups.
authors.affiliation: 1 Department of Biomedical Sciences (DBS), University of Padova , Padova, Italy .
authors.forename: Antonio
authors.initials: A
authors.lastname: Paoli
authors.forename: Quirico F
authors.initials: QF
authors.lastname: Pacelli
authors.forename: Marco
authors.initials: M
authors.lastname: Neri
authors.forename: Luana
authors.initials: L
authors.lastname: Toniolo
authors.forename: Pasqua
authors.initials: P
authors.lastname: Cancellara
authors.forename: Marta
authors.initials: M
authors.lastname: Canato
authors.forename: Tatiana
authors.initials: T
authors.lastname: Moro
authors.forename: Marco
authors.initials: M
authors.lastname: Quadrelli
authors.forename: Aldo
authors.initials: A
authors.lastname: Morra
authors.forename: Diego
authors.initials: D
authors.lastname: Faggian
authors.forename: Mario
authors.initials: M
authors.lastname: Plebani
authors.forename: Antonino
authors.initials: A
authors.lastname: Bianco
authors.forename: Carlo
authors.initials: C
authors.lastname: Reggiani
mesh_terms: D000328:Adult; D001823:Body Composition / Q000187:drug effects*; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000494:pharmacology; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D053583:Interleukin-1beta / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D055435:Myostatin / Q000097:blood*; D055070:Resistance Training; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D055815:Young Adult
chemical_list: D004044:Dietary Proteins; D053583:Interleukin-1beta; D015850:Interleukin-6; C525911:MSTN protein, human; D055435:Myostatin; D014409:Tumor Necrosis Factor-alpha; D007334:Insulin-Like Growth Factor I
keywords: cytokines; diet; exercise; myostatin; nutritional supplement