Oral calcitriol lowers vertebral fracture risk in patients undergoing hemodialysis: Study

Italy: Oral calcitriol had a strong correlation with decreased vertebral fracture (VF) in hemodialysis (HD) patients without increasing the load of vascular calcifications (VCs), says an article published in the Journal of Bone and Mineral Research.

Fractures and vascular calcifications are prevalent in chronic renal disease patients (CKD). They are linked to CKD-related changes in phosphorus, vitamin D metabolism, parathyroid hormone, calcium, and fibroblast growth factor 23 (FGF23)/Klotho. In CKD, bone and vascular abnormalities are caused by impaired vitamin D metabolism and aberrant levels of calcium, phosphate, parathyroid hormone (PTH), and FGF23/Klotho. It is unknown if oral calcitriol reduces fracture risk without increasing the load of calcifications. Maria Fusaro and colleagues, therefore, aimed to evaluate whether calcitriol medication altered the occurrence of fractures and VC development in hemodialysis (HD) patients.

This research is a secondary analysis of the Vitamin K Italian (VIKI) trial, which included 387 HD patients. This study measured vitamin 25(OH)D, alkaline phosphatase, calcium, osteocalcin or bone Gla protein, phosphate, matrix Gla protein, PTH, and vitamin K levels. Spine radiographs were used to identify vertebral fractures (VFs) and VCs. A VF was defined as a decrease of more than 20% of vertebral body height. The length of calcific lesions along the arteries was used to calculate VCs.

The results of this study stated as follow:

1. There were 177 individuals out of 387 who were given oral calcitriol (45.7%).

2. Patients receiving oral calcitriol had a lower prevalence of VF than those who were not (48.6% versus 61.0%), whereas the presence of aortic and iliac calcifications was comparable (aortic: 81.9% versus 79.5%, respectively; iliac: 52.0% and 59.5%, respectively).

3. Oral calcitriol was related to a 40.2% lower risk of fracture in a multivariable logistic regression analysis (OR 0.598).

In conclusion, according to the researchers, vitamin K1 insufficiency is the best predictor of vertebral fracture in HD patients. In the adjusted analysis, a lack of vitamin K1 and iliac calcifications were linked with 2.9- and 1.7-fold higher chances of fracture, respectively. More prospective and interventional research is required to corroborate these findings.

Reference:

Fusaro M, Cianciolo G, Tripepi G, et al. Oral calcitriol use, vertebral fractures, and vitamin K in hemodialysis patients: a cross-sectional study. J Bone Miner Res. 2021 Dec;36(12):2361-2370. doi:10.1002/jbmr.4440