Arm circumference predicts 12-month mortality in older adults with hip fracture

Purpose Hip fractures (HF) in older adults are a major public health issue due to their high incidence and association with mortality and long-term disability. Simple bedside measures reflecting nutritional and muscular status—such as handgrip strength (HGS), arm circumference, and calf circumference—may help identify patients at higher risk of adverse outcomes. This study compared the predictive value of these parameters for 1-year mortality in older adults hospitalized for hip fracture. Methods We conducted a retrospective study on 295 patients aged ≥65 years admitted for fragility HF at the Azienda Ospedale-Università Padova. Demographic, clinical, and anthropometric data were collected at admission, along with a comprehensive geriatric assessment. Twelve-month mortality was the primary outcome. Prognostic value was assessed using ROC curves, Kaplan–Meier analysis, and multivariable Cox regression. Results At 12 months, mortality was higher among patients with low arm (27.1%) and calf circumference (28.8%) ( p = 0.008 and p = 0.010), while no difference was observed for HGS. ROC curve analysis showed that arm (AUC = 0.704, p < 0.001) and calf circumference (AUC = 0.634, p = 0.006) were associated with mortality, unlike HGS ( p = 0.307). Kaplan–Meier survival analysis confirmed lower survival in patients with arm and calf circumference under 20th percentile, defined, respectively, low arm and calf (log-rank p = 0.003 and p = 0.02, respectively). In Cox models, low arm circumference remained independently associated with mortality across all adjustments (HR = 2.86; 95% CI 1.45–5.64; p = 0.002), whereas the association for calf circumference lost significance. Conclusion Arm circumference is a simple, cost-effective, and reliable bedside tool to help identify older adults at increased risk of mortality after HF.