Abstract:Objective To evaluate a predictive model for osteoporosis in elderly patients with lower limb dysfunction after cerebral infarction.Methods A total of 138 elderly patients with lower limb dysfunction after cerebral infarction admitted to Nanjing Brain Hospital from January 2021 to January 2024 were enrolled. They were divided into an osteoporosis group (n = 31) and a non-osteoporosis group (n = 107) based on the presence of osteoporosis. General data were compared between the two groups. A predictive model for osteoporosis in elderly post-stroke patients with lower limb dysfunction was constructed based on the multivariable logistic regression analysis, and a nomogram was developed.Results The osteoporosis group had higher age, longer duration of cerebral infarction, and higher rates of dysphagia and poor sleep (P < 0.05), while exhibiting lower Fugl-Meyer Assessment of Lower Extremity scores, Functional Ambulation Classification scores, bone mineral density (BMD), osteocalcin levels, and vitamin D levels compared to the non-osteoporosis group (P < 0.05). Multivariable logistic regression analysis revealed that advanced age [O^R=1.272 (95% CI: 1.149, 1.407) ], prolonged duration of cerebral infarction [O^R=1.755 (95% CI: 1.100, 2.801) ], low Fugl-Meyer Assessment of Lower Extremity scores [O^R=0.739 (95% CI: 0.574, 0.952) ], dysphagia [O^R=5.199 (95% CI: 1.343, 20.126) ], poor sleep [O^R=5.174 (95% CI: 1.315, 20.353) ], low Functional Ambulation Classification scores [O^R=0.234 (95% CI: 0.098, 0.560) ], low BMD [O^R=0.196 (95% CI: 0.057, 0.670) ], low osteocalcin levels [O^R=0.885 (95% CI: 0.802, 0.977) ], and low vitamin D levels [O^R=0.771 (95% CI: 0.624, 0.952) ] were all risk factors for osteoporosis in elderly post-stroke patients with lower limb dysfunction (P < 0.05). The predictive model based on the multivariable logistic regression analysis achieved an area under the curve of 0.985 (95% CI: 0.970, 1.000), a sensitivity of 96.8% (95% CI: 0.833, 0.999), and a specificity of 98.1% (95% CI: 0.934, 0.998).Conclusion Elderly patients with lower limb dysfunction after cerebral infarction are more prone to developing osteoporosis if they are older, have a longer disease course, poor lower limb motor function, swallowing disorders, poor sleep quality, impaired walking ability, low BMD, low osteocalcin levels, and reduced vitamin D levels. These findings provide a scientific basis for the early identification and intervention of osteoporosis and offer new insights for the comprehensive management of elderly patients following cerebral infarction.