Journal Article

Leucine Supplementation Does Not Attenuate Skeletal Muscle Loss during Leg Immobilization in Healthy, Young Men

Van Kranenburg, Janneau, Janssen, Anniek A.W., Snijders, Tim, Marzuca-Nassr, Gabriel N., De Groot, Lisette C.P.G.M., Fuchs, Cas J., Van Loon, Luc J.C., Smeets, Joey S., Backx, Evelien M.P., Verdijk, Lex B., Horstman, Astrid M.H.

2018

Overview

Background: Short successive periods of physical inactivity occur throughout life and contribute considerably to the age-related loss of skeletal muscle mass. The maintenance of muscle mass during brief periods of disuse is required to prevent functional decline and maintain metabolic health. Objective: To assess whether daily leucine supplementation during a short period of disuse can attenuate subsequent muscle loss in vivo in humans. Methods: Thirty healthy (22 ± 1 y) young males were exposed to a 7-day unilateral knee immobilization intervention by means of a full leg cast with (LEU, n = 15) or without (CON, n = 15) daily leucine supplementation (2.5 g leucine, three times daily). Prior to and directly after immobilization, quadriceps muscle cross-sectional area (computed tomography (CT) scan) and leg strength (one-repetition maximum (1-RM)) were assessed. Furthermore, muscle biopsies were taken in both groups before and after immobilization to assess changes in type I and type II muscle fiber CSA. Results: Quadriceps muscle cross-sectional area (CSA) declined in the CON and LEU groups (p < 0.01), with no differences between the two groups (from 7712 ± 324 to 7287 ± 305 mm2 and from 7643 ± 317 to 7164 ± 328 mm2; p = 0.61, respectively). Leg muscle strength decreased from 56 ± 4 to 53 ± 4 kg in the CON group and from 63 ± 3 to 55 ± 2 kg in the LEU group (main effect of time p < 0.01), with no differences between the groups (p = 0.052). Type I and II muscle fiber size did not change significantly over time, in both groups (p > 0.05). Conclusions: Free leucine supplementation with each of the three main meals (7.5 g/d) does not attenuate the decline of muscle mass and strength during a 7-day limb immobilization intervention.

• Publisher: MDPI AG,MDPI
• Subject: biopsy / Chair Nutrition and Health over the Lifecourse / computed tomography / Diet / Dietary Supplements / Global Nutrition / HNE Nutrition and Health over the Lifecourse / HNE Voeding en Gezondheid in de Levenscyclus / Humans / Immobilization - adverse effects / Knee / Leg / leucine / Leucine - administration & dosage / Male / males / men / muscle fibers / muscle strength / Muscle Strength - drug effects / Muscle Strength - physiology / Muscle, Skeletal - pathology / Muscle, Skeletal - physiopathology / muscles / Muscular Atrophy - etiology / Muscular Atrophy - pathology / Muscular Atrophy - prevention & control / Musculoskeletal system / Quadriceps Muscle - pathology / Quadriceps Muscle - physiopathology / skeletal muscle / VLAG / Wereldvoeding / Young Adult