Beyond muscles: Investigating immunoregulatory myokines in acute resistance exercise – A systematic review and meta‐analysis

Ringleb M; Javelle F; Haunhorst S; Bloch W; Fennen L; Baumgart S; Drube S; Reuken PA; Pletz MW; Wagner H; Gabriel HHW; Puta C

Abstract

Myokines, released from the muscle, enable communication between the working muscles and other tissues. Their release during physical exercise is assumed to depend on immune–hormonal–metabolic interactions concerning mode (endurance or resistance exercise), duration, and intensity. This meta‐analysis aims to examine the acute changes of circulating myokines inducing immunoregulatory effects caused by a bout of resistance exercise and to consider potential moderators of the results. Based on this selection strategy, a systematic literature search was conducted for resistance exercise intervention studies measuring interleukin (IL‐) 6, IL‐10, IL‐1ra, tumor necrosis factor (TNF‐) α, IL‐15, IL‐7, transforming growth factor (TGF‐) β1, and fractalkines (FKN) before and immediately after resistance exercise in healthy individuals. Random‐effects meta‐analysis was performed for each myokine. We identified a moderate positive effect of resistance exercise for IL‐6 and IL‐1ra. Regarding IL‐15 and TNF‐α, small to moderate effects were found. For IL‐10, no significant effect was observed. Due to no data, meta‐analyses for IL‐7, TGF‐β1, and FKN could not be performed. No moderators (training status, type of exercise, risk of bias, age, sex, time of day, exercise volume, exercise intensity, exercise dose) of the results were detected for all tested myokines. Taken together, this systematic review and meta‐analysis showed immediate positive effects of an acute resistance exercise session on IL‐6, IL‐1ra, TNF‐α, and IL‐15 levels. This systematic review and meta‐analysis found a significant moderate positive effect of acute resistance exercise for IL‐6 and IL‐1ra and a small to moderate effect for IL‐15 and TNF‐α. For IL‐10, no significant effect was observed. Due to no data, meta‐analyses for IL‐7, TGF‐β1, and FKN could not be performed. No moderators of the effects were detected for all tested myokines. Figure created with Biorender.com