Neuromuscular Electrical Stimulation Reduces Skeletal Muscle Protein Degradation and Stimulates Insulin-Like Growth Factors in an Age- and Current-Dependent Manner

A Randomized, Controlled Clinical Trial in Major Abdominal Surgical Patients

Abstract

Objective: 

To investigate the effect of neuromuscular electrical stimulation (NMES) on skeletal muscle metabolism after major abdominal surgery.

Summary Background Data: 

Protein catabolism associated with surgical interventions leads to reduced muscle strength, increased clinical complications and prolonged convalescence. Immobilization is suggested as a major stimulus for muscle wasting. This study investigates the potency of NMES on skeletal muscle growth factors and degradation processes in surgical patients.

Methods: 

This observer blind study included 26 patients after major abdominal surgery mainly due to cancer aged 60 ± 10 years. Starting on the first postoperative day, 1 randomly assigned thigh of each patient was treated on 4 consecutive days with NMES, whereas the other leg was used as sham-stimulated control. Thereafter, muscle biopsies from both legs were performed. Differences in mRNA level, protein expression, and enzyme activity between legs were analyzed by cross-over analysis of variance (Clinical Trial Registration Number: NCT00635440).

Results: 

NMES significantly increased total RNA content and total sarcoplasmatic protein content. NMES significantly reduced ubiquitin-conjugated sarcoplasmatic proteins and proteasome activity. The mechano growth factor mRNA level correlated positively with the applied current and negatively with the body mass index of the patients. The increase in insulin like growth factor-1Ea mRNA after NMES correlated negatively with the age of the patients.

Conclusions: 

This study shows that NMES significantly increases total RNA content and reduces protein degradation in postoperative patients. Moreover, the induction of growth factors by NMES reveals dependency on body mass index, age, and applied current. We conclude that NMES is a useful clinical tool to reduce protein catabolism in postoperative patients.

In Brief

This randomized, controlled, investigator blind study investigates the potency of postoperative short-term neuromuscular electrical stimulation on skeletal muscle growth factors and ubiquitin-proteasome system in major abdominal surgical patients. Neuromuscular electrical stimulation significantly increases total RNA content and reduces protein degradation. The induction of growth factors reveals dependency on body mass index, age, and applied current.