Significant Association of Fracture of the Lumbar Spine with Mortality in Female Hemodialysis Patients: A Prospective Observational Study

Prevalent fracture of the lumbar spine is established as a predictor of increased mortality in the general population. To examine whether this association is retained in hemodialysis patients, we conducted a single-center prospective observational study in 635 hemodialysis patients (60.3 ± 12.0 years old, male/female 369/266). Patients were divided into two groups (with and without lumbar fracture, assessed by simple lateral radiograph), and survival was followed for an average of 53.8 months. Lumbar fracture was present in 62 patients (9.76%; male 9.76%, female 9.77%). During the follow-up period, there were 176 all-cause deaths (27.7%; male 27.6%, female 27.8%), of which 72 were from cardiovascular diseases. In Kaplan–Meier analysis, all-cause and noncardiovascular mortality rates, but not cardiovascular mortality, were significantly higher in patients with fracture than in those without (P < 0.0001). In multivariate Cox proportional hazard analysis, the presence of lumbar fracture was significantly associated with increased noncardiovascular mortality (HR = 2.035, 95% CI 1.135–3.652, P < 0.05) after adjustment for age, duration of hemodialysis, presence of diabetes, body mass index, and serum calcium, phosphate, and albumin. Significantly higher all-cause and noncardiovascular mortality rates were also evident for patients with fracture in separate analyses in males and females, but multivariate analysis showed a significant association of lumbar fracture with increased all-cause (HR = 2.151, 95% CI 1.033–4.478, P < 0.05) and noncardiovascular (HR = 2.637, 95% CI 1.014–6.858, P < 0.05) mortality rates only in females. In conclusion, lumbar fracture is significantly associated with all-cause mortality in female patients.