Understanding sex differences in osteoporotic vertebral fractures: The impact of nutritional status on radiological risk.
INTRODUCTION Osteoporotic vertebral fractures (OVFs) are a major cause of morbidity in older adults, leading to pain, disability, and decreased quality of life. Although osteoporosis is traditionally associated with women, men also experience substantial morbidity and mortality after fractures. However, the mechanisms underlying sex differences in OVF remain unclear. This study aimed to investigate sex differences in comorbidities, bone mineral density (BMD), nutritional status, and MRI findings in patients with OVF. METHODS We retrospectively analyzed 492 patients (126 men and 366 women) hospitalized for OVF between 2015 and 2021. Clinical data, including comorbidities, BMD, Prognostic Nutritional Index (PNI), and MRI signal patterns, were collected. MRI patterns were classified into low- and high-risk groups for delayed bone union. Multivariate logistic regression analysis was performed to identify independent factors associated with high-risk MRI patterns. RESULTS Men had a significantly higher prevalence of cardiac, renal, and brain disorders, as well as malignancy, compared with women. Men also had significantly higher BMD but lower PNI values. High-risk MRI patterns were more frequent in men in univariate analysis (41.3% vs. 30.0%, p = 0.039). However, multivariate logistic regression analysis revealed that PNI was independently associated with high-risk MRI patterns (OR 0.943 per point increase, 95% CI 0.902-0.986, p = 0.0098), whereas sex was not. CONCLUSIONS Poor nutritional status was independently associated with high-risk MRI patterns in patients with OVF. The observed sex differences in acute radiological risk may be partially explained or mediated by differences in baseline nutritional status rather than biological sex itself.