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This Article Full Text Full Text (PDF) All Versions of this Article: 38/2/169    most recent 00056.2009v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Dennis, R. A. Articles by Peterson, C. A. PubMed PubMed Citation Articles by Dennis, R. A. Articles by Peterson, C. A.

Muscle expression of genes associated with inflammation, growth, and remodeling is strongly correlated in older adults with resistance training outcomes

¹ Geriatric Reasearch, Education, and Clinical Center, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
² Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
³ College of Public Health, University of Kentucky, Lexington, Kentucky
⁴ College of Health Sciences, University of Kentucky, Lexington, Kentucky

A group (n = 8) of healthy older (68 ± 6 yr) adults participated in a 36-session progressive resistance exercise training program targeting the thigh muscles to determine the relationship between muscle gene expression and gains in muscle size and strength. Biopsies were obtained from the vastus lateralis at baseline 72 h after an acute bout of exercise and 72 h after completion of the training program. Training increased thigh muscle size (7%) and strength for the three exercises performed: knee extension (30%) and curl (28%) and leg press (20%). We quantified 18 transcripts encoding factors that function in inflammation, growth, and muscle remodeling that were demonstrated previously to be regulated by aging and acute exercise. The gain in extension strength and muscle size showed a high number of significant correlations with gene expression. These gains were most strongly correlated (P 0.003, R 0.89) with the baseline mRNA levels for insulin-like growth factor-1, matrix metalloproteinase-2 and its inhibitor TIMP1, and ciliary neurotrophic factor. Moreover, strength gains were inversely correlated with the change in these mRNA levels after training (P 0.002 and R –0.90). Changes in gene expression after acute exercise were not associated with training outcomes. These results suggest that higher baseline expression for key genes in muscle conveys an adaptive advantage for certain older adults. Individuals with lower baseline expression of these genes show less adaptation to exercise despite increased gene expression in response to training. These genes hold promise as useful predictors of training outcomes that could be used to design more effective exercise regimens for maintaining muscle function in older adults.

growth factors; metallopeptidase; ciliary neurotrophic factor; aging; resistance exercise; skeletal muscle