Resistance training enhances physical function in older breast cancer survivors
A progressive resistance training (RT) programme is beneficial to postmenopausal breast cancer survivors in terms of reducing plasma and tissue-specific inflammation—changes that parallel the decline in fatigue and improvements in physical and behavioural function, a study has shown.
“[The results] support progressive RT as a strategy to offset the negative behavioural functional effects of breast cancer treatment that adversely affect the lifestyle of older breast cancer survivors,” the authors said.
A 16-week programme of moderate-intensity whole-body RT was found to produce marked improvements in muscle strength (25 to 30 percent; p<0.01), quality of life (QOL; 10 percent; p=0.04), chair stand time (15 percent; p=0.01) and 6-minute walk distance (4 percent; p=0.03), fatigue (–58 percent; p<0.01), fasting insulin (–18 percent; p=0.04), and diastolic and systolic blood pressure (–5 percent; p=0.04). [Menopause 2017;doi:10.1097/GME.0000000000000969]
The greatest improvements were observed in women with the worst fatigue and QOL (p<0.01 for both).
RT was also associated with a roughly 25 to 35 percent relative reduction in plasma and adipose tissue protein levels of proinflammatory interleukin (IL)-6sR, serum amyloid A and tumour necrosis factor-α, as well as a 75 percent relative increase in muscle proproliferative, angiogenic IL-8 protein content (p<0.05 for all).
Women with the highest baseline levels of proinflammatory cytokine showed the greatest absolute reductions, with the change in muscle IL-8 directly correlating with leg press strength improvement (p=0.04).
“The finding that the breast cancer survivors with the highest cytokine levels and worst baseline psychological and physical function derive the greatest health benefits from RT suggests that there is potential for these improvements to occur across a broad range of physiological and psychological dysfunction in survivors,” the authors said.
A total of 11 breast cancer survivors (mean age 60 years) comprised the study population, with the majority being overweight or obese (mean body mass index, 30 kg/m2) and deconditioned (mean VO2max, 24 ml/kg/min). The mean time from breast cancer diagnosis was 10 years.
The authors pointed out that despite the small sample size and lack of follow-up, “the magnitude of the physical and behavioural improvements observed in [the participants] in response to a carefully supervised resistive exercise training programme is substantial and clinically relevant.”
As RT can be carried out at gymnasiums with standard strength training equipment, it would be practical to conduct larger, community-based trials to confirm the current preliminary findings and assess the longer-term health-related benefits of RT in more breast cancer survivors, they added.
“Future studies also should consider the randomization of participants to appropriate control groups and the combined effects of RT with other lifestyle interventions, including aerobic exercise and dietary modification,” the authors said.