The Burden of CKD–Mineral and Bone Disorder in Maintenance Hemodialysis: Insights from a Longitudinal Registry

Abstract

Background

Chronic kidney disease–mineral and bone disorder (CKD–MBD) is a frequent complication in patients receiving maintenance hemodialysis and is associated with adverse skeletal and cardiovascular outcomes. Real-world longitudinal data describing biochemical burden and guideline target attainment remain limited.

Methods

We conducted a retrospective, registry-based descriptive study of adult maintenance hemodialysis patients between January 2021 and September 2025. Laboratory measurements of calcium, phosphate, calcium–phosphate product, and intact parathyroid hormone (iPTH) were extracted from monthly registry tables. Test-level analyses included all available measurements. For patient-level categorization, the most recent available value per patient per analyte was used. Parameters were classified according to KDIGO guideline-based targets, with iPTH interpreted using an upper limit of normal (ULN) of 65 pg/mL.

Results

A total of 1,042 calcium, 1,037 phosphate, 966 calcium–phosphate product, and 141 iPTH measurements were analysed. Mean serum calcium was 8.38 ± 1.02 mg/dL, mean phosphate 5.65 ± 2.17 mg/dL, mean calcium–phosphate product 47.2 ± 18.2 mg²/dL², and mean iPTH 593 ± 518 pg/mL, indicating substantial biochemical variability.

At the patient level, calcium was within target in 59.3% of patients, while phosphate was above target in 46.3%. An elevated calcium–phosphate product (>55 mg²/dL²) was observed in 27.0%. Among patients with iPTH measurements, 43.2% were within the KDIGO-recommended range (2–9×ULN), 36.5% were above target, and 20.3% were below target.

Conclusion

Maintenance hemodialysis patients in this registry demonstrated a persistent burden of CKD–MBD abnormalities with suboptimal attainment of KDIGO targets, particularly for phosphate and iPTH, highlighting the need for improved monitoring and guideline-aligned management.