This study examined whether 24 months of weight training exercises enhanced the effectiveness of risedronate, calcium, and vitamin D in maintaining or improving bone mineral density (BMD) in 223 postmenopausal breast cancer survivors. Subjects who were ≥50% adherent to exercise had no improvement in BMD but were less likely to lose BMD. Introduction This study examined whether (1) postmenopausal breast cancer survivors (BCS) with bone loss taking 24 months of risedronate, calcium, and vitamin D had increased bone mineral density (BMD) at the total hip, femoral neck, L1-L4 spine, total radius and 33% radius, and decreased bone turnover; (2) subjects who also participated in strength/weight training (ST) exercises had greater increases in BMD and greater decreases in bone turnover; and (3) subjects who also exercised were more likely to preserve (at least maintain) BMD. Methods Postmenopausal BCS (223) were randomly assigned to exercise plus medication or medication only groups. Both groups received 24 months of 1,200 mg of calcium and 400 IU of vitamin D daily and 35 mg of risedronate weekly, and the exercise group additionally had ST exercises twice weekly. Results After 24 months, women who took medications without exercising had significant improvements in BMD at the total hip (+1.81%) and spine (+2.85%) and significant decreases in Alkphase B (−8.7%) and serum NTx (−16.7%). Women who also exercised had additional increases in BMD at the femoral neck (+0.29%), total hip (+0.34%), spine (+0.23%), total radius (+0.30%), and additional decreases in Alkphase B (−2.4%) and Serum NTx (−6.5%). Additional changes in BMD and bone turnover with exercise were not significant. Subjects who were ≥50% adherent to exercise were less likely to lose BMD at the total hip (chi-square [1]=4.66, p=0.03) and femoral neck (chi-square [1]=4.63, p=0.03).

More studies are needed for examining relationships between muscle strength and balance in postmenopausal BCS with bone loss and their incidence of falls and fractures.

Adherence to calcium, vitamin D, and alendronate therapy was above 95%, and adherence to strength training exercises was above 85%. Over the 12 months, the 21 participants had significant improvements in dynamic balance, muscle strength for hip flexion, hip extension, and knee flexion, and BMD of the spine and hip. Participants had a significant decrease in BMD of the forearm. Three of the 21 women who had measurable bone loss at baseline had normal BMD after 12 months of the intervention.

Breast cancer survivors on aromatase inhibitor therapy often experience musculoskeletal symptoms (joint pain and stiffness, bone and muscle pain, and muscle weakness), and these musculoskeletal symptoms may be related to low serum levels of vitamin D. The primary purpose of this pilot exploratory study was to determine whether serum levels of 25-hydroxyvitamin D concentration (25 [OH] D) were below normal (<30 ng/ml) in 29 breast cancer survivors (BCS) on aromatase inhibitor therapy (AIs) and if musculoskeletal symptoms were related to these low vitamin D levels. The mean serum 25(OH) D level was 25.62 ± 4.93 ng/mL; 86% (n = 25) had levels below 30 ng/mL. Patients reported muscle pain in the neck and back, and there was a significant inverse correlation between pain intensity and serum 25(OH) D levels (r = − 0.422; p <.05 [2-tailed]). This sample of BCS taking AIs had below normal levels of serum 25(OH) D despite vitamin D supplements. This is one of the few studies to document a significant relationship between vitamin D levels and muscle pain in BCS on AI therapy. Findings from this pilot study can be used to inform future studies examining musculoskeletal symptoms in BCS on AI therapy and relationships with low serum levels of vitamin D.