Objective: Resistance training (RT) reduces fatigue and improves physical function and quality of life (QOL) in breast cancer survivors (BCS). This may be related to reductions in systemic and tissue-specific inflammation. This pilot study examines the hypothesis that RT induces changes in systemic and tissue-specific inflammation that contribute to improvements in physical and behavioral function in postmenopausal BCS.
Methods: Eleven BCS (60 ± 2 years old, body mass index 30 ± 1 kg/m, mean ± SEM) underwent assessments of fatigue (Piper Fatigue Scale), physical function, QOL (SF-36), glucose and lipid metabolism, and systemic, skeletal muscle, and adipose tissue inflammation (n = 9) before and after 16 weeks of moderate-intensity whole-body RT.
Results: Muscle strength improved by 25% to 30% (P < 0.01), QOL by 10% (P = 0.04), chair stand time by 15% (P = 0.01), 6-minute walk distance by 4% (P = 0.03), and fatigue decreased by 58% (P < 0.01), fasting insulin by 18% (P = 0.04), and diastolic and systolic blood pressure by approximately 5% (P = 0.04) after RT. BCS with the worst fatigue and QOL demonstrated the greatest improvements (absolute change vs baseline: fatigue: r = -0.95, P < 0.01; QOL: r = -0.82, P < 0.01). RT was associated with an approximately 25% to 35% relative reduction in plasma and adipose tissue protein levels of proinflammatory interleukin (IL)-6sR, serum amyloid A, and tumor necrosis factor-α, and 75% relative increase in muscle pro-proliferative, angiogenic IL-8 protein content by 75% (all P < 0.05). BCS with the highest baseline proinflammatory cytokine levels had the greatest absolute reductions, and the change in muscle IL-8 correlated directly with improvements in leg press strength (r = 0.53, P = 0.04).
Conclusions: These preliminary results suggest that a progressive RT program effectively lowers plasma and tissue-specific inflammation, and that these changes are associated with reductions in fatigue and improved physical and behavioral function in postmenopausal BCS.