Previsores da micro e macroestruturas ósseas em mulheres na pós-menopausa

Abstract

Bone micro- and macrostructures evolve bone mass and geometry properties. Thus, bone strength is not only a function of bone mineral density (BMD), but also of the spatial distribution of intrinsic bone mass in structural geometric properties such as diameter, area, length and angle. Consequently, both low BMD (osteoporosis) and variability in bone geometry have been associated with bone fractures in postmenopausal women (PMW). Thus, early identification of low BMD and a weakened bone geometry is of paramount importance to treat and possibly intervene even before a negative diagnosis (i.e., fracture). Therefore, this study had two objectives. First, verify the association of dynapenia (low muscle strength) and myopenia (low muscle mass) with osteoporosis in PMW. Second, assessing whether the sit-to stand test (TSLC) performed with five repetitions is a predictor of bone geometry indicators in PMW. The volunteers were measured for muscle mass (where they were classified according to cutoff points established by the literature), bone mineral density, bone geometry both by dual energy X-ray absorptiometry (DXA). The handgrip strength assessment was performed using a hydraulic dynamometer and the lower limb strength assessment was performed using the sit and-stand test five repetitions. As a result, isolated myopenia, with a cut-off point established by appendicular muscle mass <15 kg, was the main predictor of osteoporosis in PMW. The TSLC five repetitions predicted bone geometry in PMW. Therefore, myopenia, but not dynapenia, impacts bone health. Just as TSLC seems to be a simple, easy to apply and low-cost predictor of bone geometry and strength.