Load-Specific Inflammation Mediating Effects of Resistance Training in Older Persons

Background: Little is known about the effects of resistance training (RT) on circulating cytokines in older adults. Also, dose-response relationships remain unclear. This study investigated the impact of RT at different external loads on circulating inflammatory mediators in older community-dwelling individuals. Methods: Fifty-six community-dwelling older (68 +/- 5 years) volunteers were randomized to 12 weeks of supervised RT (x 3/week) at either high-resistance training [8 males, 10 females, 2 x 10-15 repetitions at 80% 1 repetition maximum (RM)], low-resistance training (9 males, 10 females, 1 x 80-100 repetitions at 20% 1 RM), or mixed low-resistance training (9 males, 10 females, 1 x 60 repetitions at 20% 1 RM followed by 1 x 10-20 repetitions at 40% 1 RM). Serum was available from 51 out of 56 participants at baseline and after 12 weeks for determination of interleukin (IL)-6, IL-8, IL-10, IL-1 beta, soluble tumor necrosis factor receptor (sTNFR) 1, granulocyte macrophage colony-stimulating factor, and IL-1 receptor antagonist (ra). Results: Twelve weeks of RT significantly increased sTNFR1 from 2.48 +/- 0.57 ng/mL to 2.58 +/- 0.59 ng/mL (overall time-effect P =.033) and Log IL-8 from 0.38 +/- 0.18 pg/mL to 0.53 +/- 0.32 pg/mL (overall time-effect P =.007). No time X group interaction (P =.916) was observed. In males of the high-resistance training group, there was an increase in Log IL-8 (from 0.45 +/- 0.16 pg/mL to 0.68 +/- 0.19 pg/mL; P =.005) and IL-1ra (from 68.60 +/- 24.12 pg/mL to 79.56 +/- 29.07 pg/mL; P =.007). No significant changes were found for the other markers. Conclusions: Our results show that 12 weeks of supervised RT induced an overall significant increase of circulating IL-8 and sTNFR1, independently from the external load applied. We suggest that exercising until volitional fatigue is the main trigger for exercise-induced responses. However, training at high external load also increased anti-inflammatory IL-1ra in male participants, which might be beneficial in combating low-grade inflammation. (c) 2016 AMDA - The Society for Post-Acute and Long-Term Care Medicine.