Background: The study aim was to determine the kinetics of serum pro- and anti-inflammatory cytokines and C-reactive protein (CRP) in hip-fracture patients over a month postfracture, and their relationship to postoperative (postop) complications and cognitive level.
Methods: Forty-one elderly hip-fracture patients were prospectively followed. Serum was obtained during the first 10 hours postfracture and presurgery, 48-60 hours postop, 7 and 30 days postop, measuring CRP, interleukin-1beta (IL-1beta), IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), IL-10, and IL-1 receptor antagonist (IL-1RA).
Results: A significant increase was found postop for CRP, IL-6, TNF-alpha, IL-1RA (p <.001), IL-10 (p <.002), and IL-8 (p =.05). CRP kinetics curves were higher in patients with complications as a group, and in those suffering from infections, delirium, and cardiovascular complications (p <.05). IL-6 increase in patients with complications approached significance. Additional complications appeared in patients with impaired mental status (IMS) versus cognitively normal patients (p =.037). Higher kinetics curves in the IMS patients were found for CRP and IL-6 (p <.05). Analyzing the interaction effect of complications and IMS on CRP and cytokines production demonstrated that the increase in CRP was independently related to complications and IMS. IL-6, IL-8, and IL-10 were higher in IMS patients but not in patients with complications without IMS (p <.05).
Conclusions: Serum CRP and cytokines increased drastically in postop hip-fracture elderly patients. Only CRP significantly and independently increased in IMS patients and in patients with complications, whereas cytokines significantly increased only in IMS patients. This study raises questions about possible effects that cytokine generation, after hip-fracture repair, might have on cognition and complications.