Abstract: SA-PO186
Free 25(OH)D Concentrations and Clinical Outcomes in Elderly Community-Living Adults: The Health, Aging, and Body Composition Study
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
- Cheng, Jonathan, University of California San Diego, La Jolla, California, United States
- Hoofnagle, Andrew N., University of Washington, Seattle, Washington, United States
- Katz, Ronit, University of Washington, Seattle, Washington, United States
- Kritchevsky, Stephen B., Wake Forest University, Winston-Salem, North Carolina, United States
- Shlipak, Michael, University of California San Francisco, San Francisco, California, United States
- Sarnak, Mark J., Tufts University School of Medicine, Boston, Massachusetts, United States
- Ix, Joachim H., University of California San Diego, La Jolla, California, United States
- Ginsberg, Charles, University of California San Diego, La Jolla, California, United States
Background
25(OH)D deficiency is believed to contribute to mineral-bone and cardiovascular diseases. 25(OH)D exists as free (~1%) or bound (~99% to vitamin D binding protein) and studies have suggested that serum 25(OH)D may not accurately reflect active, free 25(OH)D concentrations. The associations between measured free 25(OH)D concentrations with clinical outcomes have not been well studied.
Methods
We used a case-cohort study design and compared the strength of associations between measured free 25(OH)D with either kidney function decline (≥30% decline in estimated glomerular filtration rate (eGFR) from baseline), fracture, incident cardiovascular disease (CVD), or incident heart failure (HF) in well-functioning community-living adults aged 70 to 79 years in the Health, Aging, and Body Composition Study. Baseline free 25(OH)D concentrations were measured in a random sub-cohort of 459 participants and in participants with kidney function decline (n=381), fractures (n=174), incident CVD (n=151), and incident HF (n=117) during a median 10 years of follow-up. Weighted Cox regression adjusting for age, sex, race, BMI, season of measurements, clinic site, eGFR, calcium, phosphorus, FGF-23, iPTH, and vitamin D supplementation status was used for statistical analysis.
Results
In fully adjusted models, a two-fold higher concentration of free 25(OH)D was associated with a 25% higher risk of kidney function decline (95% CI 1.03-1.52) and a 25% lower risk of incident HF (95% CI 0.58-0.96). Free 25(OH)D was not associated with incident CVD (HR=0.87; 95% CI 0.66-1.16) or fractures (HR=1.00; 95% CI 0.66-1.50).
Conclusion
Higher concentrations of free 25(OH)D are independently associated with increased risk of kidney function decline and decreased risk of incident HF in community-living older adults. Future studies are needed to determine if these relationships are causal.
Association between Measured Serum 25(OH)D Concentration and Clinical Outcomes
| Hazard Ratio (95% CI)* | |
| Incident CVD | 0.87 (0.66, 1.16) |
| Incident HF | 0.75 (0.58, 0.96)# |
| Kidney Function Decline | 1.25 (1.03, 1.52)# |
| Fracture | 1.00 (0.66, 1.50) |
*Hazard ratios per Two-Fold Higher vitamin D. #p<0.05. Fully adjusted models.
Funding
- NIDDK Support