Abstract: FR-PO204
Association of Serum Bicarbonate Levels with Kidney Function Decline in Patients with Polycystic Kidney Disease
Session Information
- CKD: Epidemiology, Risk Factors, Prevention - II
October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 1901 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention
Authors
- Yapa, Roshini, University of Colorado, Denver, Colorado, United States
- You, Zhiying, UC Denver, Aurora, Colorado, United States
- Gitomer, Berenice Y., Div. Renal Diseases and Hypertension,, Aurora, Colorado, United States
- Chonchol, Michel, University of Colorado, Denver, Colorado, United States
- Kendrick, Jessica B., University of Colorado School of Medicine, Aurora, Colorado, United States
Background
Lower serum bicarbonate levels are associated with kidney disease progression in patients with chronic kidney disease. Whether serum bicarbonate levels are associated with kidney disease progression in patients with polycystic kidney disease (PKD) is unknown. We tested the hypothesis that lower bicarbonate levels are associated with kidney function decline in patients with PKD.
Methods
We included 774 patients from the HALT-PKD Study A (N=395) and B (N=379) with baseline serum bicarbonate levels and at least three measurements of estimated glomerular filtration rate (eGFR). Bicarbonate was examined as a continuous variable and in categories (≤ 24, 25-28 and >28 mEq/L, with 25-28 mEq/L as the reference group). The outcome was yearly change in slope of eGFR. Linear regression models were used to examine the association between serum bicarbonate and change in eGFR.
Results
The mean (SD) age was 43 ± 10 years. The mean (SD) serum bicarbonate and eGFR at baseline was 26.7 ± 2.4 mEq/L and 70 ± 26 ml/min/1.73m2, respectively. Participants with serum bicarbonate ≤ 24 mEq/L had lower eGFR, higher body mass index (BMI) and systolic blood pressure (SBP) than those with bicarbonate levels >24 mEq/L. In the fully adjusted model, each 1 mEq/L increase in serum bicarbonate level was associated with a 0.1 ml/min/1.73m2 increase in annual slope of eGFR (β 0.1 ml/min/1.73m2, 95% CI 0.002 to 0.15, p=0.04). A serum bicarbonate level ≤ 24 mEq/L was associated with a yearly decline in eGFR slope in unadjusted analysis and in partially adjusted analysis, but only trended towards significance in the fully adjusted model (p=0.09).
Conclusion
Lower serum bicarbonate levels are associated with an increased risk of decline in eGFR in patients with PKD.
β Estimate (95% CI)
| Serum Bicarbonate mEq/L | Unadjusted | Model 1 | Model 2 |
| Per 1 mEq/L increase | 0.1 (0.05 to 0.2) | 0.1 (0.02 to 0.18) | 0.1 (0.002 to 0.15) |
| ≦ 24 25-28 > 28 | -0.7 (-1.22 to -0.16) REF 0.3 (-0.15 to 0.78) | -0.5 (-1.06 to -0.04) REF 0.2 (-0.20 to 0.69) | -0.4 (-0.93 to 0.07) REF 0.2 (-0.26 to 0.64) |
Model 1: adjusted for age, gender, race, treatment randomization Model 2: adjusted for model 1 plus smoking, cardiac history, BMI, SBP, baseline eGFR and urine albumin to creatinine ratio
Funding
- Other NIH Support