Electrical stimulation counteracts muscle decline in seniors.

Helmut Kern,Feliciano Protasi,Simona Sbardella,Stefan Lã¶Fler,Antonio Musaro,Nejc Sarabon,Vanina Romanello,Sandra Zampieri,Laura Barberi,Ugo Carraro,Laura Pietrangelo,Matthias Krenn,Simone Mosole,Jan Cvecka,Michael Vogelauer,Samantha Burggraf,Marco Sandri,Winfried Mayr,Hannah Fruhmann

doi:10.3389/fnagi.2014.00189

Abstract

The loss in muscle mass coupled with a decrease in specific force and shift in fiber composition are hallmarks of aging. Training and regular exercise attenuate the signs of sarcopenia. However, pathologic conditions limit the ability to perform physical exercise. We addressed whether electrical stimulation (ES) is an alternative intervention to improve muscle recovery and defined the molecular mechanism associated with improvement in muscle structure and function. We analyzed, at functional, structural, and molecular level, the effects of ES training on healthy seniors with normal life style, without routine sport activity. ES was able to improve muscle torque and functional performances of seniors and increased the size of fast muscle fibers. At molecular level, ES induced up-regulation of IGF-1 and modulation of MuRF-1, a muscle-specific atrophy-related gene. ES also induced up-regulation of relevant markers of differentiating satellite cells and of extracellular matrix remodeling, which might guarantee shape and mechanical forces of trained skeletal muscle as well as maintenance of satellite cell function, reducing fibrosis. Our data provide evidence that ES is a safe method to counteract muscle decline associated with aging.

Highlights

There is considerable clinical interest in therapeutic strategies to counteract muscle wasting associated with aging.Skeletal muscle is susceptible to the effects of aging, undergoing a steady reduction in function and losing up to a third of its mass and strength
We recently reported that physical exercise in seniors preserves muscle morphology and ultrastructure, guarantees a greater maximal isometric force and function, and modulates the expression of genes related to autophagy and reactive oxygen species detoxification (Mosole et al, 2014; Zampieri et al, 2014)
With electrical stimulation (ES) training, we improved the time up and go test (TUGT) time (−16.4% ± 6.1 confidence interval (CI), p < 0.0005) and increased the short physical performance battery (SPPB) Score (+11.2% ± 6.8 CI, p < 0.005) (Table 1), resulting in a greater mobility in seniors recruited for this study

Summary

Introduction

Skeletal muscle is susceptible to the effects of aging, undergoing a steady reduction in function and losing up to a third of its mass and strength. This decline in functional performance is due to an overall decrease in muscle integrity, as fibrosis and fat accumulation replace functional contractile tissue, and to loss of the fastest most powerful fibers (Scicchitano et al, 2009; Vinciguerra et al, 2010). It is clear that the most efficient method that has been used to counteract age-related muscle weakness is long term physical exercise (Paffenbarger et al, 1994). Certain pathologic conditions and aging limit the effectiveness of exercise and, the benefits from it

Objectives

Methods

Results

Conclusion