Kidney Week

Abstract: TH-PO986

Bicarbonate Administration and Vascular Function in CKD: A Randomized Placebo-Controlled Trial

Session Information

• Late-Breaking Clinical Trials (Posters)
  November 03, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: Fluid‚ Electrolyte‚ and Acid-Base Disorders

• 1002 Fluid‚ Electrolyte‚ and Acid-Base Disorders: Clinical

Authors

• Kendrick, Jessica B., University of Colorado, Denver, Colorado, United States

Jessica B. Kendrick,

• Farmer-Bailey, Heather, University of Colorado, Denver, Colorado, United States

Heather Farmer-Bailey,

• Nowak, Kristen L., University of Colorado, Denver, Colorado, United States

Kristen L. Nowak,

• Steele, Cortney, University of Colorado, Denver, Colorado, United States

Cortney Steele,

• You, Zhiying, University of Colorado, Denver, Colorado, United States

Zhiying You,

• Chonchol, Michel, University of Colorado, Denver, Colorado, United States

Michel Chonchol,

• Moreau, Kerrie, University of Colorado, Denver, Colorado, United States

Kerrie Moreau,

• Wang, Wei, University of Colorado, Denver, Colorado, United States

Wei Wang,

Background

Lower serum bicarbonate levels, even within the normal laboratory range, are strongly linked to risks of cardiovascular disease in chronic kidney disease (CKD), possibly by modifying vascular function. However, the effects of sodium bicarbonate (NaHCO₃) on patient outcomes in moderate to advanced CKD are lacking. We examined the effect of NaHCO₃ on vascular endothelial function and arterial stiffness in patients with CKD stage 3B-4.

Methods

We performed a prospective, double-blind, placebo-controlled randomized trial of 109 patients with CKD stage 3B-4 (eGFR 15-44 ml/min/1.73m²) with serum bicarbonate levels 22-27 mEq/L. Participants were randomly assigned to receive either NaHCO₃ or placebo at a dose of 0.5 mEq/LBW-kg/day for 12 months. The co-primary endpoints were change in brachial artery flow mediated dilation (FMD) and in aortic pulse wave velocity (aPWV) over 12 months.

Results

90 patients completed the study. The mean (SD) age and eGFR were 61.7 ± 11.6 years and 35.9 ± 9.8 ml/min/1.73m², respectively. The mean (SD) serum bicarbonate level at baseline was 23.4 ± 2.2 mEq/L. After 12 months, serum bicarbonate levels increased significantly in the NaHCO₃ group compared to placebo (difference between groups 1.35 95% CI (0.34-2.36), p=0.003). NaHCO₃ did not result in a significant improvement in aPWV from baseline (Figure). NaHCO₃ did result in a significant increase in FMD after 1 month, however this effect disappeared at follow-up. NaHCO₃ resulted in a significant increase in 24-hour urine citrate and decrease in 24-hour urine ammonia. There was no significant change in eGFR over 12 months with NaHCO₃, however, there was a trend of a decrease in urine protein excretion. NaHCO₃ was safe and well-tolerated with no significant changes in blood pressure, antihypertensive medication, weight, calcium or potassium levels.

Conclusion

Twelve months of NaHCO₃ in patients with moderate to advanced CKD and normal serum bicarbonate levels did not improve vascular endothelial function or reduce arterial stiffness.

*p<0.01

Funding

• Other NIH Support