Effect of supervised and home exercise training on bone mineral density among breast cancer patients. A 12-month randomised controlled trial

Abstract

The ability of combined step aerobic- and circuit-training to prevent bone loss after breast cancer treatments was related to skeletal site and patients' menopausal status. Among premenopausal breast cancer survivors, a 12-month exercise intervention completely prevented bone loss at the femoral neck, whereas no exercise effect was seen at lumbar spine or at neither site in postmenopausal women. The primary objective of this randomised clinical trial was to determine the preventive effect of supervised weight-bearing jumping exercises and circuit training on bone loss among breast cancer patients. Of 573 breast cancer survivors aged 35-68years randomly allocated into exercise or control group after adjuvant treatments, 498 (87%) were included in the final analysis. The 12-month exercise intervention comprised weekly supervised step aerobic- and circuit-exercises and similar home training. Bone mineral density (BMD) at lumbar spine and femoral neck were measured by dual-energy X-ray absorptiometry. Physical performance was assessed by 2-km walking and figure-8 running tests, and the amount of physical activity was estimated in metabolic equivalent-hours/week. In premenopausal women, bone loss at the femoral neck was prevented by exercise, the mean BMD changes being -0.2% among the trainees vs. -1.4% among the controls (p = 0.01). Lumbar bone loss could not be prevented (-1.9% vs. -2.2%). In postmenopausal women, no significant exercise-effect on BMD was found either at the lumbar spine (-1.6% vs. -2.1%) or femoral neck (-1.1% vs. -1.1%). This 12-month aerobic jumping and circuit training intervention completely prevented femoral neck bone loss in premenopausal breast cancer patients, whereas no effect on BMD was seen in postmenopausal women.