This is a prospective, observational, single-center clinical study designed to evaluate serum lumican levels in postmenopausal women undergoing routine osteoporosis assessment. The study will investigate the association of lumican with bone mineral density, handgrip strength, FRAX-based fracture risk, history of falls, and fragility fracture history. No treatment or interventional procedure will be applied. Serum lumican will be measured from venous blood samples, and all other clinical and laboratory data will be collected as part of standard osteoporosis evaluation. The study aims to explore whether lumican may contribute to the identification of fragility risk beyond conventional bone mineral density measurements.