Living kidney donors predisposed to vertebral fractures

Individuals who have donated a kidney appear to be at increased risk of vertebral fractures, according to a study.

For the study, 5,065 living kidney donors from three large transplant centres in Minnesota, US, and 16,156 population-based nondonor controls without a history of comorbidities that would have precluded kidney donation were invited to complete a survey about their bone health and history of fractures.

A total of 2,132 living kidney donors (mean age 67.1 years, 58.4 percent women) and 2,014 controls (mean age 68.6 years, 56.6 percent women) completed the survey. 

The mean time between donation or index date and survey date was 24.2 years for donors and 27.6 years for controls. The overall rate of fractures was significantly lower among living kidney donors than among controls, with a standardized incidence ratio (SIR) of 0.89 (95 percent confidence interval [CI], 0.81–0.97).

However, vertebral fractures occurred with significantly greater frequency among living kidney donors than among controls, with an SIR of 1.42 (95 percent CI, 1.05–1.83).

The findings suggest the possibility of deficits in trabecular bone among kidney donors, and additional investigation needed to explore this possibility. Moreover, dietary supplements such as vitamin D₃ may help reduce the number of vertebral fractures and morbidity among living kidney donors.