Increased risk of hip fracture among patients with end-stage renal disease

Abstract

BACKGROUND Although patients with end-stage renal disease (ESRD) are at increased risk for bone loss, the risk of hip fracture in this population is not known. We compared the risk of hip fracture among dialysis patients with the general population. METHODS We used data from the United States Renal Data System (USRDS) to identify all new Caucasian dialysis patients who began dialysis between January 1, 1989, and December 31, 1996. All hip fractures occurring during this time period were ascertained. The observed number of hip fractures was compared with the expected number based on the experience of residents of Olmstead County (MN, USA). Standardized incidence ratios were calculated as the ratio between observed and expected. The risk attributable to ESRD was calculated as the difference between the observed and expected rate of hip fracture per 1000 person-years. RESULTS The number of dialysis patients was 326,464 (55.9% male and 44.1% female). There were 6542 hip fractures observed during the follow-up period of 643, 831 patient years. The overall incidence of hip fracture was 7.45 per 1000 person years for males and 13.63 per 1000 person years for females. The overall relative risk for hip fracture was 4.44 (95% CI, 4.16 to 4.75) for male dialysis patients and 4.40 (95% CI, 4.17 to 4.64) for female dialysis patients compared with people of the same sex in the general population. While the age-specific relative risk of hip fracture was highest in the youngest age groups, the added risks of fracture associated with dialysis rose steadily with increasing age. The relative risk of hip fracture increased as time since first dialysis increased. CONCLUSIONS The overall risk of hip fracture among Caucasian patients with ESRD is considerably higher than in the general population, independent of age and gender.