Advanced Age, High β-CTX Levels, and Impaired Renal Function are Independent Risk Factors for All-Cause One-Year Mortality in Hip Fracture Patients

Abstract

Risk factors for increased mortality in hip fracture patients include older age, male sex, fracture type, bone mineral density, and pre-existing co-morbidities. The role of biochemical and other anthropometric parameters on hip fracture mortality remains unclear. The aim of this study was to identify the risk factors for one-year mortality in patients with hip fractures. A total of 236 consecutive patients (59 males) with hip fractures were followed over a one-year period. Patient age, gender, type of fracture, type of treatment, time from admission to surgery, type of anesthesia, body mass index, and electrocardiograms were recorded. Complete blood counts, serum electrolytes, urea, creatinine, d-dimers, calcium, phosphate, osteocalcin, and beta-isomerised C-terminal telopeptide of collagen type I (β-CTX) were measured at admission and estimated glomerular filtration rate (eGFR) was calculated. Multivariate Cox regression models were used to analyze the association of these parameters with survival. One-year mortality rate was 28.4%. Age was independently associated with mortality (HR 1.117, 95% CI 1.062-1.174, P < 0.001). In a multivariable model, mortality was increased in patients with higher β-CTX (HR 4.63 95% CI 1.87-11.45, P = 0.001) and lower eGFR (HR 0.972, 95% CI 0.956-0.987, P < 0.001). Patients younger than 84 years, with eGFR < 55.4 ml/min had ten times higher mortality rates (3.2 vs. 24.5%, HR 9.73, 95% CI 2.06-45.93) as well as those with β-CTX > 0.276 g/L (3.5 vs. 25.7%, HR 9.5, 95% CI 2.11-42.76). Advanced age, high β-CTX levels, and impaired renal function are independent risk factors of mortality in patients with hip fractures.

Keywords: Age; Hip fractures; One-year mortality; Renal function; Risk factors; eGFR; β-CTX.