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Abstract: FR-OR039

Vitamin D3 Repletion Improves Vascular Function, as Measured by Full-Length Osteopontin, in a High-Risk African American Cohort

Session Information

Category: Bone and Mineral Metabolism

  • 402 Bone and Mineral Metabolism: Clinical

Authors

  • Nicholas, Susanne B., UCLA Medical Center, Los Angeles, California, United States
  • Sinha, Satyesh K., Charles R Drew University of Medicine and Science, Los Angeles, California, United States
  • Sun, Ling, Xuzhou Central Hospital, Xuzhou, China
  • Didero, Michelle, University of California, Los Angeles, Los Angeles, California, United States
  • Lee, Jae eun, Jackson State Univerity, Madison, Mississippi, United States
  • Meng, Yuan-Xiang, Morehouse School of Medicine, East Point, Georgia, United States
  • Sung, Jung hye, Jackson State University, Jackson, Mississippi, United States
  • Norris, Keith C., UCLA, Marina Del Rey, California, United States
Background

Vitamin D deficiency is common among patients with chronic kidney disease (CKD). African Americans (AAs) suffer disproportionately fromCKD and cardiovascular (CV) disease, and 80% of AAs are vitamin D deficient. The effects of vitamin D on vascular and renal health in patients with CKD have been contradictory, in part due to different study designs.Hence, the impact of vitamin D therapy on CV health in CKD patients, especially AAs is unknown. We examined the effect of vitamin D supplement on the cardio-renal biomarkers: full-length osteopontin (flOPN), c-terminal fibroblast growth factor-23 (cFGF23), and plasminogen activator inhibitor-1 (PAI-1), which have been implicated in the pathology of both vascular and renal function in CKD.

Methods

We performed a randomized, placebo-controlled study of high-risk, overweight AAs with controlled hypertension, normal renal function and vitamin D deficiency, treated with 100,000 IU vitamin D3 (N=65) or placebo (N=65) every 4 weeks for 12 weeks. We measured renal function (CKD-EPI eGFR, urinary albumin-to-creatinine ratio (ACR)), and quantified plasma cFGF23, PAI-1 and flOPN by ELISA, vascular function (pulse wave velocity (PWV), augmentation index, waist circumference (WC), and 24h-ambulatory blood pressure (BP)). We performed multiple regression controlling for the placebo-treated group to understand the relationship between the log values of flOPN, cFGF23, and PAI-1 with cardiovascular and renal risk factors.

Results

Compared to placebo vitamin D3 repletion did not change eGFR and BP values. Vitamin D3 levels increased 2-fold (p<0.0001) and iPTH levels decreased 13% (p=0.007) with repletion, which was associated with a 10% reduction in log-flOPN levels (p=0.03). There were no significant changes in log-cFGF23 or log-PAI-1 with vitamin D3 repletion. Multiple regression analysis indicated that flOPN was associated with reduced PWV (p=0.04) and diastolic BP (p=0.02), while cFGF-23 was associated only with reduced diastolic BP (p=0.05), and a trend for increased eGFR (p=0.06).

Conclusion

Vitamin D3 repletion may improve vascular function in a subset of AAs with controlled hypertension and vitamin D3 deficiency. Compared to cFGF-23 and PAI-1, flOPN may be a more sensitive vascular function biomarker in this population.

Funding

  • Other NIH Support