Kidney Week

Abstract: TH-PO134

The Vitamin D Metabolite Ratio Is Associated with Volumetric Bone Density in Older Men

Session Information

• Bone and Mineral Metabolism: CKD-MBD Updates
  November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Bone and Mineral Metabolism

• 502 Bone and Mineral Metabolism: Clinical

Authors

• Ginsberg, Charles, University of California San Diego, La Jolla, California, United States

Charles Ginsberg,

• Blackwell, Terri L., California Pacific Medical Center Research Institute, San Francisco, California, United States

Terri L. Blackwell,

• Cheng, Jonathan, University of California San Diego, La Jolla, California, United States

Jonathan Cheng,

• Potok, O. Alison, University of California San Diego, La Jolla, California, United States

O. Alison Potok,

• Cauley, Jane, University of Pittsburgh, Pittsburgh, Pennsylvania, United States

Jane Cauley,

• Ensrud, Kristine E., Minneapolis Veterans Affairs Healthcare System, Minneapolis, Minnesota, United States

Kristine E. Ensrud,

• Hsu, Simon, University of Washington, Seattle, Washington, United States

Simon Hsu,

• Kado, Deborah M., Stanford University School of Medicine, Stanford, California, United States

Deborah M. Kado,

• Orwoll, Eric, Oregon Health & Science University School of Medicine, Portland, Oregon, United States

Eric Orwoll,

• Cawthon, Peggy M., California Pacific Medical Center Research Institute, San Francisco, California, United States

Peggy M. Cawthon,

• Ix, Joachim H., University of California San Diego, La Jolla, California, United States

Joachim H. Ix,

Background

The ratio of the vitamin D catabolic product (24,25-dihydroxyvitamin D) to 25(OH)D (vitamin D metabolite ratio or VMR) has been suggested as a superior marker of vitamin D status than 25(OH)D. High-resolution peripheral quantitative computed tomography (HR-pQCT) provides information on bone health beyond bone mineral density (BMD), providing volumetric BMD (vBMD) and bone strength data. We evaluate the associations of the VMR and 25(OH)D₃ with vBMD and bone strength, in the distal radius and tibia in 545 participants in the Osteoporotic Fractures in Men (MrOS) Study.

Methods

We used multivariable linear regression in models adjusted for demographics, season, study site, physical activity, BMI, smoking status, diabetes, blood pressure and estimated glomerular filtration rate (eGFR) among 545 men aged ≥ 65 years who participated in MrOS and provided HR-pQCT data in visit 4 (Year 14 of the study). Our primary outcome was vBMD and secondary outcome was estimated failure load (EFL) at both the distal radius and tibia.

Results

Mean age was 84± 4 years, 88.3% were White, and 32% had an estimated glomerular filtration rate (eGFR) <60ml/min/1.73m². In fully adjusted models, each two-fold higher VMR was associated with 9% (3%, 16%) and 6% (0.4%, 11%) higher vBMD at the distal radius and tibia, respectively (Table). In contrast, we found no association of 25(OH)D₃, with vBMD at either anatomic site. Similarly, each two-fold higher VMR was associated with 13% (5%, 21%) and 10% (4%, 16%) EFL at the distal radius and tibia, respectively (Table). In contrast, we found no association of 25(OH)D₃, with EFL at either anatomic site.

Conclusion

Among community-living older men, a higher VMR is associated with higher vBMD and EFL while 25(OH)D₃ was not. The VMR may serve as a valuable predictor of skeletal health in older men at risk for osteoporosis and fractures.

Funding

• NIDDK Support