Incidence of Fractures Before and After Dialysis Initiation

Abstract

Fractures are common in dialysis patients, but little is known about the trajectory of incidence rates of different types of fractures before and after dialysis initiation. To address this, we investigated the incidence of major fractures before and after dialysis initiation. We performed a retrospective statistical analysis using the Swedish Renal Registry of 9041 incident dialysis patients (median age 67 years, 67% men) starting dialysis 2005 through 2015 to identify major fractures (hip, spine, humerus, and forearm) occurring during the dialysis transition period from 1 year before until 1 year after dialysis initiation. Using flexible parametric hazard models and the Fine-Gray model, we estimated adjusted fracture incidence rates and predictors of major fractures. We identified 361 cases with primary diagnosis of major fracture, of which 196 (54%) were hip fractures. The crude incidence rate of major fractures before dialysis initiation was 17 per 1000 patient-years (n = 157) and after dialysis initiation it was 24 per 1000 patient-years (n = 204). The adjusted incidence rate of major fractures began to increase 6 months before dialysis initiation, and then stabilized at a higher rate after 1 year. The adjusted incidence rate of hip fractures started to increase sharply 3 months before dialysis initiation, peaked at initiation, and declined thereafter. In contrast, the adjusted incidence rate of non-hip fractures was stable during the transition period and gradually increased over time. Higher age, female sex, and history of previous major fractures were associated with increased fracture incidence both before and after dialysis initiation. We conclude that the incidence of major fractures, especially hip fractures, start to rise 6 months before initiation of dialysis therapy, indicating that heightened surveillance with implementation of preventive measures to avoid fractures is warranted during the transition period to dialysis. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Keywords: DIALYSIS; END-STAGE KIDNEY DISEASE; FRACTURE; RENAL OSTEODYSTROPHY.

Fig 1

Location of the first Fx occurring from 1 year before dialysis initiation to 1 year after dialysis initiation. Fx = fracture.

Fig 2

Crude (A) and adjusted (B) incidence rate of first major fracture occurring from 12 months before until 12 months after dialysis initiation. The adjusted incidence rate of fracture was calculated using flexible parametric survival models in hypothetical 67‐year‐old patient (median age) after adjusting for gender, age, history of major fractures, diabetes mellitus, cancer, dementia, ischemic heart disease, congestive heart failure, peripheral vascular disease, cerebrovascular disease, hyperparathyroidism, psychoactive substance abuse, RAAS inhibitor, vitamin D and its analogues, phosphate binders, estrogen, statins, anti‐anxiolytics, steroids, anti‐depressives, and calendar year of dialysis initiation. py = patient‐years.

Fig 3

Impact of gender (A), age (B), and history of previous major fractures (C) on adjusted incidence rate of major fractures expressed as fractures per 1000 py occurring from 12 months before until 12 months after dialysis initiation. The adjusted incidence rate of fractures was calculated using flexible parametric survival models in a hypothetical 67‐year‐old patient (median age) after adjusting for diabetes mellitus, cancer, dementia, ischemic heart disease, congestive heart failure, peripheral vascular disease, cerebrovascular disease, hyperparathyroidism, psychoactive substance abuse, RAAS inhibitors, vitamin D and its analogues, phosphate binders, estrogen, statins, anti‐anxiolytics, steroids, anti‐depressives, and calendar year of dialysis initiation. py = patient‐years.

Fig 4

Crude and adjusted incidence rate of hip fractures (A,B) and non‐hip fractures (C,D) occurring from 12 months before until 12 months after dialysis initiation. Adjusted incidence rate of fracture was made using flexible parametric survival models in hypothetical 67‐year‐old patient (median age) after adjusting for gender, age, history of major fractures, diabetes mellitus, cancer, dementia, ischemic heart disease, congestive heart failure, peripheral vascular disease, cerebrovascular disease, hyperparathyroidism, psychoactive substance abuse, RAAS inhibitor, vitamin D and its analogues, phosphate binders, estrogen, statins, anti ‐anxiolytics, steroids, anti‐depressives, and calendar year of dialysis initiation. py = patient‐years.