Kidney Week

Abstract: FR-OR039

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

Session Information

• Bone and Mineral Metabolism: Clinical Research
  November 08, 2019 | Location: 145, Walter E. Washington Convention Center
  Abstract Time: 06:06 PM - 06:18 PM

Category: Bone and Mineral Metabolism

• 402 Bone and Mineral Metabolism: Clinical

Authors

• Nicholas, Susanne B., UCLA Medical Center, Los Angeles, California, United States

Susanne B. Nicholas, MD, PhD, MPH



Dr. Nicholas is a tenured Associate Professor of Medicine and a Clinical Hypertension Specialist at the David Geffen School of Medicine at University of California, Los Angeles (UCLA) in the Division of Nephrology. She received her medical degree from the University of California, San Diego; Masters in Public Health from San Diego State University; and PhD from UCLA. Her translational research spans studies at the bench, the bedside and the community to understand and identify key factors that promote kidney disease; uncover and validate novel therapeutic targets and predictive biomarkers of DKD to facilitate clinical trials; and perform population studies for the health of ethnic minority populations. She was recently elected to serve on the Executive Council of Women in Nephrology and founded the UCLA Nephrology Women Leaders. Dr. Nicholas has received numerous awards including the Minority Access, Inc. National Role Model Faculty Researcher Award, and the National Kidney Foundation's Medical Advisory Board Distinguished Service Award for 15+ years of dedication to the National Kidney Foundation (NKF), both at the local and national levels. She is currently the President of the local NKF Medical Advisory Executive Advisory Committee and has led the charge around community education and outreach through scientific symposia and CKD screening. Through her research, she has established numerous collaborations locally, nationally and internationally and has published over 90 publications and presented more than 120 abstracts at scientific meetings.

• Sinha, Satyesh K., Charles R Drew University of Medicine and Science, Los Angeles, California, United States

Satyesh K. Sinha,

• Sun, Ling, Xuzhou Central Hospital, Xuzhou, China

Ling Sun,

• Didero, Michelle, University of California, Los Angeles, Los Angeles, California, United States

Michelle Didero,

• Lee, Jae eun, Jackson State Univerity, Madison, Mississippi, United States

Jae eun Lee,

• Meng, Yuan-Xiang, Morehouse School of Medicine, East Point, Georgia, United States

Yuan-Xiang Meng,

• Sung, Jung hye, Jackson State University, Jackson, Mississippi, United States

Jung hye Sung,

• Norris, Keith C., UCLA, Marina Del Rey, California, United States

Keith C. Norris,

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