Inadequate assessment, diagnosis, and stratification of patients with bone mass loss can lead to an increased risk of osteoporotic fractures. Therefore, alternative and advanced methods to support screening and diagnosis of osteoporosis (OP) are becoming increasingly essential, particularly considering specific gender differences. In this context, evaluating new methods and innovative techniques is a global challenge. To address this challenge, in 2018, the IRCCS Istituto Ortopedico Rizzoli (IOR) filed a European patent (European Patent No. 3008470, March 21, 2018; Inventors: Fini M, Giardino R, Salamanna F) related to an in vitro method for correlating the vitality of peripheral blood mononuclear cells (PBMCs) with bone metabolism alterations and OP through simple optical microscope observation. Additionally, specific gender-related differences have been observed in the number, size, differentiation time, and gene and protein expression profiles of PBMCs from osteoporotic patients of different sexes. In this context, the purpose of this study is to fully expand and develop the patent filed by IRCCS IOR in 2018 in order to: a) improve the understanding of the mechanisms of action and observed behavior in PBMCs on which the IOR patent is based; b) correlate the in vitro behavior of PBMCs with different levels of bone metabolism alteration (from osteopenia to fragility fractures); c) evaluate the correlation between the Dual-X-ray Absorptiometry (DXA) T-score and other blood factors related to OP (parameters related to platelets, pro- and anti-inflammatory cytokines, lymphocyte subpopulations) with the in vitro behavior of PBMCs in the presence of different levels of bone metabolism alteration, considering specific gender differences.