Plasma mitochondrial DNA levels were independently associated with lung injury in elderly hip fracture patients.

Abstract

Hip fracture in the elderly can induce systemic inflammatory response (SIRS) and lung injury which increases the risk of lung infection and death. Mitochondrial DNA (mtDNA) plays a role in SIRS and lung injury in patients with multi-trauma, and also in patients with hip fractures. This study evaluated the potential value of plasma mtDNA in the early prognosis of lung injury in elderly fracture patients. This study enrolled 156 elderly patients with intertrochanteric fracture. Plasma mtDNA, IL-6, IL-10, prostaglandin E2 (PGE2) levels were measured at admission. Sixty-one and 31 patients were diagnosed with systemic inflammatory response syndrome (SIRS) and lung injury, respectively. Plasma mtDNA levels were higher in hip fracture patients compared to healthy controls (P<0.001) and significantly higher in the lung injury subgroup compared to the lung injury absent subgroup (P<0.001). MtDNA levels were correlated with the SIRS score (r=0.446, P<0.001), IL-6 (r=0.506, P<0.001), IL-10 (r=0.523, P<0.001), and PGE2 (r=0.360, P<0.001). Logistic regression analysis revealed that plasma mtDNA, IL-6, PGE2 and SIRS score were independent predictors of the risk of lung injury. Plasma mtDNA release induced by hip fracture in elderly patients, might be an early predictor of lung injury in these patients.