Kidney Week

Abstract: SA-PO184

Active Vitamin D Use and Fractures in Hemodialysis Patients: Results From the International DOPPS

Session Information

• Vascular Calcification, Nephrolithiasis, Bone
  November 05, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: Bone and Mineral Metabolism

• 402 Bone and Mineral Metabolism: Clinical

Authors

• Komaba, Hirotaka, Tokai University School of Medicine, Isehara, Japan

Hirotaka Komaba,

• Zhao, Junhui, Arbor Research Collaborative for Health, Ann Arbor, Michigan, United States

Junhui Zhao,

• Karaboyas, Angelo, Arbor Research Collaborative for Health, Ann Arbor, Michigan, United States

Angelo Karaboyas,

• Yamamoto, Suguru, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan

Suguru Yamamoto,

• Dasgupta, Indranil, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom

Indranil Dasgupta,

• Hassan, Mohamed H., Seha Kidney Care, Abu Dhabi, United Arab Emirates

Mohamed H. Hassan,

• Zuo, Li, Peking University People's Hospital, Beijing, China

Li Zuo,

• Christensson, Anders, Skåne University Hospital, Malmö, Sweden

Anders Christensson,

• Combe, Christian, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, Aquitaine, France

Christian Combe,

• Robinson, Bruce M., Arbor Research Collaborative for Health, Ann Arbor, Michigan, United States

Bruce M. Robinson,

• Fukagawa, Masafumi, Tokai University School of Medicine, Isehara, Japan

Masafumi Fukagawa,

Background

Active vitamin D is used commonly to control secondary hyperparathyroidism and associated high-turnover bone disease in dialysis patients. It is unknown whether active vitamin D improves bone strength and prevents fracture through direct action on bone metabolism, independent of its action to suppress parathyroid hormone (PTH).

Methods

We included 41,677 in-center hemodialysis patients from 21 countries in phases 3-6 (2005-2018) of the Dialysis Outcomes and Practice Patterns Study (DOPPS). We analyzed the association between prescription (yes/no) of active vitamin D at study enrollment and incidence of (1) any fracture and (2) hip fracture. We used Cox regression, adjusted for PTH and other potential confounders, and used a per-protocol approach to censor patients at treatment switch during follow-up. As a sensitivity analysis, we also performed a facility preference approach to reduce confounding by indication, assigning exposures at the facility-level based on the proportion of patients prescribed active vitamin D in the facility.

Results

The proportion of patients prescribed active vitamin D at study enrollment was 55% overall and ranged from 72% in Sweden to 25% in France. Event rates (per patient-year) were 0.024 for any fracture and 0.010 for hip fracture. The adjusted HR (95% CI) comparing patients prescribed vs. not prescribed active vitamin D was 1.01 (0.89, 1.16) for any fracture and 0.99 (0.80, 1.22) for hip fracture. In the facility preference approach, compared to the reference group of <40% of patients prescribed active vitamin D, the adjusted HR (95% CI) for fracture was 1.07 (0.88, 1.31) for 40-54%, 1.11 (0.90, 1.37) for 55-69%, and 1.21 (0.99, 1.49) for >=70%. Results were similar when treating hip fracture as the outcome.

Conclusion

Active vitamin D use was not associated with the risk of any fracture or hip fracture in hemodialysis patients. Our results do not support the role of active vitamin D in fracture prevention beyond the suppression of PTH. Randomized clinical trials are needed to confirm these findings.

Funding

• Commercial Support – Kyowa Kirin