Abstract: FR-PO289
Reduced Serum Total CO2 Associates with Lower Urine Citrate Excretion in Clinic Outpatients
Session Information
- CKD: Epidemiology and Risk Factors
November 08, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention
Authors
- Goraya, Nimrit, Baylor Scott and White Health, Temple, Texas, United States
- Mamun, Abdullah A., Baylor Scott & White Health, Dallas, Texas, United States
- Madias, Nicolaos E., St.Elizabeth's Medical Center and Tufts University School of Medicine, Boston, Massachusetts, United States
- Wesson, Donald E., Baylor Scott and White Health and Wellness Center, Dallas, Texas, United States
Background
Emerging data supporting the GFR benefit of reducing the acid (H+) milieu of patients with CKD with serum total CO2 (STCO2) above that for which current KDIGO guidelines recommend alkali therapy suggest the need for a biomarker to identify candidate patients for treatment. Recent small-scale studies suggest that low urine excretion of the a pH-sensitive metabolite citrate (UcitrateV) predicts underlying acid (H+) retention in patients with CKD and serum [HCO3] > 24 mE/L and that dietary H+ reduction reduces H+ retention and increases UcitrateV in these patients (Goraya, et al. Kid Int 95:1190, 2019). Showing an association of low UcitrateV with low serum [HCO3] in a large database of unselected patients would further support the utility of UcitrateV for identifying patients with an increased H+ milieu.
Methods
We queried our electronic database for unique adult outpatients who had simultaneous values obtained for STCO2 (mM) and urine citrate (Ucitrate, mg/l) concentration. Because current KDIGO guidelines recommend alkali treatment for CKD patients with serum [HCO3] < 22 mEq/l and most clinical laboratories consider “normal” serum [HCO3] to be > 24 mEq/l, we compared Ucitrate among patients with serum [HCO3] < 22 mM and >24 mM.
Results
Our electronic database identified 264 unique patients, 55.3% male, with mean age ± SD = 50.7±20.3 years. Ucitrate was lower in patients with STCO2 <22 mEq/l compared to >24 mmEq/l (251±38 vs. 432±26 mg/l, respectively, p=0.003). Linear regression showed a significant relationship between Ucitrate and serum [HCO3] as continuous variables (p=0.025).
Conclusion
This database of unselected patients shows that reduced STCO2 associates with low Ucitrate and supports that an acid milieu promotes citrate conservation that is reflected by reduced urine citrate excretion. The data supports further investigation of urine citrate excretion as a biomarker of an increased acid milieu that might identify patients who are candidates for dietary H+ reduction as a kidney-protection strategy.
Funding
- Private Foundation Support