Polypharmacy and Dynapenia in Older Adults Undergoing Rehabilitation After Fracture or Elective Orthopedic Surgery

Background and Objectives: Polypharmacy is common among older adults and its impact on the onset of dynapenia, reduced muscle strength and function, is largely unknown. Older adults hospitalized for either post-fracture or elective orthopedic surgery (knee, femur, or hip) and undergoing rehabilitation were included to investigate the association between polypharmacy and dynapenia. A further aim is to investigate associations between polypharmacy and dynapenia with outcomes including mortality, falls, and hospitalizations. Materials and Methods: On the fifth day following surgery, medical doctors administered a structured questionnaire along with physical and instrumental assessments. Polypharmacy was defined as the concurrent and regular use of 5 or more medications, dynapenia was assessed by measuring handgrip strength. The association between dynapenia and polypharmacy was detected with logistic regression, and their impact on adverse outcomes was assessed using Cox models, Kaplan-Meier curves and log-rank tests. Results: A total of 205 older adults (mean age 77.5 years; 79.5% women) were enrolled. After adjusting for sex, age, and the presence of multidimensional frailty, dynapenia was significantly associated with increased adverse outcomes such as mortality, falls, and hospitalizations (HR 2.96, 95% CI 1.22-7.20, p = 0.016). Similarly, polypharmacy was independently linked to a higher risk of mortality, falls and hospitalizations (HR 2.23, 95% CI 1.24-4.10, p = 0.007). At 6 months follow-up, polypharmacy showed a strong and significant association with dynapenia (adjusted OR 2.63, 95% CI 1.21-4.63, p = 0.019). Conclusions: These findings suggest that polypharmacy is strongly associated with dynapenia, both conditions are associated with adverse clinical outcomes in older hospitalized patients. Close monitoring and tailored interventions are recommended to mitigate these risks and improve rehabilitation outcomes in this vulnerable population.