Kidney Week

Abstract: PO2382

Effect of Oral Sodium Bicarbonate on Biomarkers of Bone Turnover in CKD: A Secondary Analysis of the BASE Pilot Trial

Session Information

• CKD: Insights from Recent Clinical Trials and Large Real-World Effectiveness Studies
  November 04, 2021 | Location: On-Demand, Virtual Only
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2102 CKD (Non-Dialysis): Clinical, Outcomes, and Trials

Authors

• Raphael, Kalani L., Oregon Health & Science University School of Medicine, Portland, Oregon, United States

Kalani L. Raphael, MD, MS, FASN

• Katz, Ronit, University of Washington, Seattle, Washington, United States

Ronit Katz,

• Isakova, Tamara, Northwestern University, Evanston, Illinois, United States

Tamara Isakova,

• Sprague, Stuart M., NorthShore University HealthSystem, Evanston, Illinois, United States

Stuart M. Sprague,

• Wolf, Myles, Duke University, Durham, North Carolina, United States

Myles Wolf,

• Raj, Dominic S., George Washington University Medical Faculty Associates, Washington, District of Columbia, United States

Dominic S. Raj,

• Hoofnagle, Andrew N., University of Washington, Seattle, Washington, United States

Andrew N. Hoofnagle,

• Larive, Brett, Cleveland Clinic, Cleveland, Ohio, United States

Brett Larive,

• Kendrick, Cynthia A., Cleveland Clinic, Cleveland, Ohio, United States

Cynthia A. Kendrick,

• Gassman, Jennifer J., Cleveland Clinic, Cleveland, Ohio, United States

Jennifer J. Gassman,

• Fried, Linda F., VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, United States

Linda F. Fried,

• Cheung, Alfred K., University of Utah Health, Salt Lake City, Utah, United States

Alfred K. Cheung,

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

Joachim H. Ix,

Background

CKD clinical practice guidelines recommend treatment with alkali to mitigate adverse effects of metabolic acidosis on several organ systems, including bone. The effect of alkali supplementation on bone turnover in CKD is unclear. We performed a secondary analysis of the Bicarbonate Administration to Stabilize eGFR (BASE) Pilot Trial to investigate the effect of NaHCO₃ on biomarkers of bone turnover.

Methods

BASE randomized 194 individuals with eGFR 20-59 ml/min/1.73m² to receive placebo (n=52) or one of two doses of NaHCO₃ (0.5 mEq/kg/d, n=52; 0.8 mEq/kg/d, n=90) for 28 weeks. We measured serum parathyroid hormone (PTH), bone-specific alkaline phosphatase (B-SAP), c-telopeptide (CTX, marker of bone resorption), and procollagen type I intact N-terminal propeptide (PINP, marker of bone formation) levels from stored samples collected at baseline, week 12, and week 28, and compared the mean change from baseline between placebo and those treated with NaHCO₃ using linear mixed models.

Results

168 of 194 participants (86%) submitted samples for post-hoc measurements (placebo, n=46; lower-dose, n=47; higher-dose, n=75). Baseline characteristics were age 67±12 years, female 28%, Black, 32%, Hispanic 15%, eGFR 37±10 ml/min/1.73m², serum total CO₂ 24±3 mEq/L, B-SAP 12.8±5.6 μg/L , CTX 0.36±0.38 ng/mL, PINP 57±31 ng/mL. NaHCO₃ treatment raised PTH and lowered B-SAP, however there was no significant difference when compared to placebo. NaHCO₃ treatment had no effect on CTX or PINP (Table).

Conclusion

NaHCO₃ treatment did not have consistent effects on biomarkers of bone turnover as assessed by PTH, B-SAP, CTX, or PINP, and no significant effects relative to placebo in patients with CKD.

Funding

• NIDDK Support