Association between the FRAX algorithm and bone mineral density in postmenopausal women with sarcopenia

Abstract

   Background. The current version of the Fracture Risk Assessment Tool (FRAX) does not account for the presence of sarcopenia. In addition, the assessment of nutritional status within the algorithm is limited to body weight and body mass index (BMI), which may be overestimated in this patient population due to age-related height loss.    Aim. To evaluate the relationship between FRAX scores and bone mineral density (BMD) in postmenopausal women according to the severity of sarcopenia.    Materials and methods. The study included postmenopausal women with impaired bone mineral density (osteoporosis with or without fragility fractures, or osteopenia) who were referred for treatment to the National Medical Research Center for Rehabilitation and Balneology of the Ministry of Health of the Russian Federation in 2022–2023. All participants were examined by an endocrinologist-nutritionist and underwent fracture risk assessment using FRAX. Clinical history, including previous fractures, dual-energy X-ray absorptiometry (DXA), and bioelectrical impedance analysis (BIA) data were evaluated. Participants were classified into normal and sarcopenia groups according to the skeletal muscle mass index obtained by BIA.    Results. The strongest correlations between FRAX scores and BMD were observed for the femoral neck and total hip BMD (ρ= –0.849 and ρ= –0.756, respectively; p < 0.001), whereas no significant associations were found for lumbar spine BMD. The strength of these correlations decreased with increasing severity of sarcopenia.    Conclusions. Sarcopenia may affect the informative value of conventional methods used to assess osteoporotic fracture risk. The progressive weakening of the association between FRAX scores and bone mineral density with increasing sarcopenia severity may indicate a growing contribution of additional fracture risk factors that are not incorporated into the FRAX algorithm.