What’s the Fracture Risk after Kidney Transplantation?

Analysis of population-based data questions whether kidney transplant recipients are truly a “high-risk” group for fractures, reports a study in Transplantation.

Using Ontario healthcare databases, the researchers estimated cumulative rates of proximal humerus, forearm, and hip fractures at three, five, and ten years after kidney transplantation. These and other fracture outcomes were assessed in 4821 adult transplant recipients, median age 50 years, stratified by sex and age.

Female kidney recipients aged 50 years or older had the highest three-year cumulative incidence of nonvertebral fractures: 3.1 percent. In the overall sample of transplant recipients, three-year fracture incidence was 1.6 percent. That was significantly higher than the 0.5 percent rate in the general population with no previous nonvertebral fractures or the 1.1 percent rate among patients with chronic kidney disease not receiving dialysis.

However, the fracture incidence for kidney transplant recipients was lower than the 2.3 percent rate among the general population with previous nonvertebral fracture. For all kidney recipients, the 10-year cumulative incidence of hip fracture was 1.7 percent, compared to the 3.0 percent cutoff point defined as “high risk” in current clinical guidelines. The three-year cumulative incidence of falls among all transplant patients was 7.9 percent, increasing to 11.1 percent for women aged 50 or older.

Kidney transplant patients have sometimes been considered a group at high risk for fractures, although reported rates vary widely. The new analysis suggests that, while relative fracture risk is higher than in other populations, the absolute risk appears low. The researchers write, “[D]espite the changes in mineral metabolism and the use of steroids after kidney transplantation, recipients may not be a high-risk group for fracture” [Naylor KL, et al. Fracture incidence in adult kidney transplant recipients. Transplantation 2016; 100:167–175].