Peripheral Blood T Cell Gene Expression Responses to Exercise and HMB in Sarcopenia

Abstract

Background: Sarcopenia is a major health problem in older adults. Exercise and nutrient supplementation have been shown to be effective interventions but there are limited studies to investigate their effects on the management of sarcopenia and its possible underlying mechanisms. Here, we studied T cell gene expression responses to interventions in sarcopenia. Methods: The results of this study were part of a completed trial examining the effectiveness of a 12-week intervention with exercise and nutrition supplementation in community-dwelling Chinese older adults with sarcopenia, based on the available blood samples at baseline and 12 weeks from 46 randomized participants from three study groups, namely: exercise program alone (n = 11), combined-exercise program and nutrition supplement (n = 23), and waitlist control group (n = 12). T cell gene expression was evaluated, with emphasis on inflammation-related genes. Real-time PCR (RT-PCR) was performed on CD3 T cells in 38 selected genes. Correlation analysis was performed to relate the results of gene expression analysis with lower limb muscle strength performance, measured using leg extension tests. Results: Our results showed a significant improvement in leg extension for both the exercise program alone and the combined groups (p < 0.001). Nine genes showed significant pre- and post-difference in gene expression over 12 weeks of intervention in the combined group. Seven genes (RASGRP1, BIN1, LEF1, ANXA6, IL-7R, LRRN3, and PRKCQ) showed an interaction effect between intervention and gene expression levels on leg extension in the confirmatory analysis, with confounder variables controlled and FDR correction. Conclusions: Our findings showed that T cell-specific inflammatory gene expression was changed significantly after 12 weeks of intervention with combined exercise and HMB supplementation in sarcopenia, and that this was associated with lower limb muscle strength performance.