Oral phosphate binders and incident osteoporotic fracture in patients on dialysis

End-stage kidney disease (ESKD) has an elevated risk of osteoporotic fractures in relation to mineral and bone disorder (MBD) as well as conventional risks of osteoporosis. We investigated the association between oral phosphate binders, the mainstay of MBD treatment, and osteoporotic fracture in dialysis patients.

We obtained data from the National Health Insurance database for incident dialysis patients without a history of osteoporotic fractures. Participants were categorized into four groups based on their initial 1-year prescription profiles: calcium-based phosphate binder (CBPB), non-calcium-based phosphate binder (NCBPB), both CBPB and NCBPB (mixed), and non-phosphate binder (non-user) groups. The primary outcome was the occurrence of new-onset osteoporotic fractures after 1 year of dialysis. Secondary outcomes included cardiovascular events and mortality.

Out of 69 368 incident dialysis patients, 22 326, 5020, 2853 and 39 169 were included in the CBPB, NCBPB, mixed and non-user groups, respectively. The overall risk of osteoporotic fractures was lower in patients taking any phosphate binders compared with non-users. Specifically, only the CBPB group showed a reduced risk of vertebral [adjusted hazard ratio (aHR) 0.83 (0.76-0.92)], hip [aHR 0.81 (0.74-0.89)] and distal radius [aHR 0.88 (0.78-0.99)] fractures compared with non-users. This relationship presented in a time-dependent manner with fracture risk reduction in patients taking CBPB for 3-6 months [aHR 0.9 (0.83-0.99)] and ≥6 months [aHR 0.83 (0.78-0.89)], compared with those using CBPB for <3 months. Additionally, only the CBPB group had a lower risk of MACE, cardiac arrest and ventricular arrhythmia than non-users. All phosphorus binder groups showed a reduced mortality risk compared with non-users.

Our findings indicate that the using phosphate binders in ESKD patients is lowers the risk of osteoporotic fractures. Notably, those taking CBPB had a reduced risk without increasing cardiovascular events or mortality compared with non-users.