Role of Body Composition in the Prediction of Skeletal Fragility Induced by Hormone Deprivation Therapies in Cancer Patients

PURPOSE OF REVIEW

This review paper is intended to show that changes in body composition are key in the pathogenesis of bone fragility amongst patients with breast and prostate cancer receiving hormone deprivation therapies (HDTs) and that the mechanism is based on the development of alterations in bone quality rather than in bone quantity.

RECENT FINDINGS

Preclinical and clinical data suggest a tight connection amongst bone, adipose and muscular tissues by means of several soluble mediators, potentially leading to (1) bone resorption and bone quality deterioration in sarcopenic obese subjects, (2) bone mineral deposition in healthy trained subjects. Cancer patients treated with HDTs frequently fall into the first condition, named osteosarcopenic obesity. Current clinical guidelines for the prevention of treatment-induced osteoporosis focus on bone mineral density (BMD) as a main predictive factor for fracture risk; however, the pathophysiology underlying HDT-induced bone fragility differs from that of primary and postmenopausal osteoporosis, suggesting a prevalent role for bone quality alterations. Focusing on available data from clinical trials, in our review we suggest osteosarcopenic obesity as a common target for the prevention and treatment of HDTs-related metabolic and skeletal complications, beyond a BMD-centred approach.

Short-term effects of whole-body vibration on the soleus of ooforectomized rats: Histomorphometric analysis and oxidative stress in an animal model

PURPOSE

The aim of this study was to analyze the effects of mechanical vibration on the histomorphometry and oxidative stress of oophorectomized rats.

METHOD

Seventy-two Wistar rats were randomized to Pseudoophorectomy (P) and Oophorectomy (O) and subdivided into untreated animals and euthanized after four (P4 and O4) and eight (P8 and O8) weeks and animals treated during four (PT4 and OT4) and eight (PT8 and OT8) weeks. The treatment consisted of use of whole-body vibration for 10 min, three times a week. After euthanasia, the soleus muscle was collected. The general morphological analysis was performed in the right soleus muscle and then the cross-sectional area, the largest and the smallest diameter of the muscle fiber in 100 fibers per muscle, also the nuclei and capillary/fiber ratios, and percentage of connective tissue were measured. The left soleous was used for oxidative stress analysis.

RESULTS

PT4 presented higher values in cross-sectional area than P4 and PT8, while O8 was lower than O4, P8 and OT8; for the fiber diameters, the oophorectomized animals had lower values than the pseudo-oophorectomized animals and the treatments values higher than the ones that had no treatment. In oxidative stress, O8 and OT8 presented higher lipoperoxidation, without any alterations to the activities of superoxide dismutase, catalase and cholinesterase.

CONCLUSION

Whole-body vibration induced muscle hypertrophy in the pseudo-oophorectomized rats after four weeks, as well as being able to reverse the changes caused by the surgery in eight weeks in that variable.