Increased risk of hip fracture among Japanese hemodialysis patients

Minako Wakasugi, Junichiro James Kazama, Masatomo Taniguchi, Atsushi Wada, Kunitoshi Iseki, Yoshiharu Tsubakihara, Ichiei Narita

Incidence of hip fracture in dialysis patients is significantly higher than that in the general population. As information is lacking about Asian dialysis patients, we compared the incidence of hip fracture in hemodialysis patients with that in the general population in Japan. We conducted a retrospective cohort study using panel data from the Japanese Society for Dialysis Therapy registry. The study included patients without history of hip fracture who received hemodialysis three times per week as of December 31, 2007. We compared the observed number of hip fractures to the expected number derived from a national survey, and calculated standardized incidence ratios (SIRs) and the incidence rate difference. Subgroup analysis was performed according to vintage and diabetic status. During the one-year study period, 1,437 hip fractures were recorded in the 128,141 hemodialysis patients (61.9 % male). The overall incidence was 7.57 and 17.43 per 1,000 person-years in men and women, respectively. The SIRs for male and female patients were 6.2 [95 % confidence interval (CI) 5.7-6.8] and 4.9 (95 % CI 4.6-5.3) compared to the general population, and remained nearly constant until 16 years vintage, but increased steeply thereafter. The incidence rate difference of hip fracture increased with age. The SIRs for diabetics of both genders were higher than those for non-diabetics. Our study provides additional evidence that hip fracture risk among Asian dialysis patients is also significantly higher than in the general population.