Assessment of bone mineral density in patients on hemodialysis: diagnostic capabilities of dual-energy X-ray absorptiometry and limitations of FRAX
TL;DR
In stage 5 chronic kidney disease patients receiving hemodialysis, proximal femur densitometric parameters—particularly femoral neck—demonstrated superior diagnostic informativeness compared to lumbar spine measurements.
Abstract
Background. Mineral and bone disorders are highly prevalent in hemodialysis patients with chronic kidney disease, yet the role of bone mineral density testing and optimal skeletal sites for measurement remain debated. Interpreting dual-energy X-ray absorptiometry in this population is challenging due to CKD-MBD characteristics and limitations of standard fracture risk models.Objective. To assess the diagnostic utility of dual-energy X-ray absorptiometry in stage 5 chronic kidney disease patients on maintenance hemodialysis and identify the most informative measurement sites considering method-specific limitations.Methods. This single-center comparative observational study enrolled 32 stage 5 chronic kidney disease patients on hemodialysis (main group) and 20 individuals without kidney disease (controls). All participants underwent clinical evaluation, laboratory assessment of bone-mineral metabolism, dual-energy X-ray absorptiometry of the proximal femur and lumbar spine, and 10-year fracture risk calculation using FRAX. The primary analysis compared densitometric parameters across anatomical sites and their clinical interpretation in hemodialysis patients.Results. Hemodialysis patients showed most pronounced bone density reduction at the femoral neck and total hip regions, while lumbar spine parameters demonstrated greater variability. Femoral neck T-scores were significantly lower in the main group versus controls, with higher osteopenia prevalence. Lumbar spine findings were less consistent, potentially reflecting degenerative changes and extraskeletal calcification. An inverse trend emerged between parathyroid hormone levels and femoral neck T-scores. FRAX calculations served as supplementary data requiring interpretation within the clinical context of underlying disease and mineral metabolism disturbances.Conclusion. In stage 5 chronic kidney disease patients receiving hemodialysis, proximal femur densitometric parameters—particularly femoral neck—demonstrated superior diagnostic informativeness compared to lumbar spine measurements. FRAX scores should complement rather than replace comprehensive evaluation of clinical, laboratory, and densitometric data in this population.