Management of CKD-MBD in non-dialysis patients under regular nephrology care: a prospective multicenter study

Background: Knowledge about mineral bone disorder (MBD) management in non-dialysis chronic kidney disease (ND-CKD) patients is scarce, although essential to identifying areas for therapeutic improvement. Methods: We prospectively evaluated current management of CKD-MBD in two visits, performed 6 months apart, in 727 prevalent ND-CKD stage 3b–5 patients from 19 nephrology clinics. Therapeutic inertia was defined as lack of treatment despite hyperphosphatemia and/or hypocalcemia, and/or hyperparathyroidism. The primary endpoint was the prevalence of achieved target for CKD-MBD parameters and related treatments (phosphate binders, vitamin D and calcium supplements). The secondary endpoint was the assessment of prevalence and clinical correlates of therapeutic inertia. Results: Over 65 % of patients did not reach parathormone (PTH) targets, while 15 and 19 % did not reach phosphate and calcium targets, respectively. The proportion of untreated patients decreased from stage 3b to 5 (at baseline, from 60 to 16 %, respectively). From baseline to the 6-month visit, the achievement of targets remained stable. Low protein diet was prescribed in 26 % of patients, phosphate binders in 17.3 % (calcium-based binders 15.5 %, aluminium binders 1.8 %), and vitamin D in 50.5 %. The overall prevalence of therapeutic inertia at the 6-month visit was 34.0 % (for hyperphosphatemia, 54.3 %). Compared to CKD stage 3, the likelihood of therapeutic inertia was 40 and 68 % lower at stage 4 and 5, respectively. Conclusions: PTH, calcium and phosphate targets were not reached in a significant proportion of patients. One-third of patients with at least one MBD parameter not-at-target remained untreated. Therapeutic inertia regarding CKD-MBD treatment may be a major barrier to optimizing the prevention and cure of CKD-MBD.