Sixteen weeks of resistance training decrease plasma heat shock protein 72 (eHSP72) and increase muscle mass without affecting high sensitivity inflammatory markers' levels in sarcopenic men

Sarcopenia has been associated with increased systemic inflammation and risk of physical disability in older adults. Recently, extracellular heat shock protein 72 (eHSP72) was proposed as a biomarker of sarcopenia but its response to interventions designed to increase muscle mass has never been evaluated. The present study was designed to (1) assess eHSP72 levels following resistance training and, (2) determine whether changes in eHSP72 correlate to changes in muscle mass and inflammatory markers. A total of 26 sarcopenic men participated in a 16-week resistance training program. The following variables were measured pre-post-intervention: plasma HSP72, serum high sensitivity (hs) inflammatory markers: interleukin-6 (hsIL-6), C-reactive protein (hsCRP), and tumor necrosis factor alpha (hsTNF-alpha), lean body mass (LBM) and appendicular muscle mass index (appMMI). eHSP72 was detected in 47 % of our participants and its level significantly decreased (P = 0.04) after the intervention, with a concomitant increase in several LBM variables and appMMI (all P < 0.035). Serum hsIL-6, hsCRP and hsTNF-alpha changes did not reach significance. Baseline hsIL-6 and hsCRP levels were negatively correlated with several LBM variables but solely baseline hsIL-6 was associated with changes in appLBM. No correlations were found between changes in measured variables. Attenuation of eHSP72 following resistance training in parallel with increase in LBM variables showed a concordance between the evolution of this biomarker and a clinical outcome relevant to sarcopenia. Nevertheless, the low bloodstream detection rate of eHSP72 in a sarcopenic otherwise healthy population might limit its use in clinical settings for now.