Kidney Week

Abstract: TH-PO517

Dietary Acid Reduction with Fruits and Vegetables Better Prevents Transition of Stage 3 CKD to Stage 4 Than Oral NaHCO3

Session Information

• CKD: Clinical Trials and Tubulointerstitial Disorders
  November 02, 2017 | Location: Hall H, Morial Convention Center
  Abstract Time: 10:00 AM - 10:00 AM

Category: Chronic Kidney Disease (Non-Dialysis)

• 305 CKD: Clinical Trials and Tubulointerstitial Disorders

Authors

• Goraya, Nimrit, Baylor Scott and White Health, Temple, Texas, United States

Nimrit Goraya,

• Simoni, Jan, Texas Tech University Health Sciences Center, Lubbock, Texas, United States

Jan Simoni,

• Munoz Maldonado, Yolanda, Baylor Scott & White Health, Temple, Texas, United States

Yolanda Munoz Maldonado,

• Wesson, Donald E., Diabetes Health and Wellness Institute, Dallas, Texas, United States

Donald E. Wesson,

Background

The USRDS most recently reported a net increased prevalence of individuals with chronic kidney disease (CKD) stage 3 (eGFR=30-59 ml/min/m²). The CKD 3 to CKD 4 transition yields the greatest net increase in morbidity and care cost in the CKD 1 to CKD 4 progression, supporting need for kidney-protective interventions. Because dietary acid reduction added to pharmacologic anti-angiotensin II therapy appears to provide adjunctive kidney protection, we tested the hypothesis that oral NaHCO₃ (HCO₃) or base-producing fruits and vegetables (F+V) reduce the proportion of CKD 3 subjects who transition to CKD 4.

Methods

One hundred eight macroalbuminuric, non-diabetic CKD 3 subjects with metabolic acidosis but with serum [HCO₃] between 22 -24 meq/L were randomized to receive F+V (n=36) in amounts to reduce dietary potential renal acid load by half, oral NaHCO₃ (HCO₃, n=36) 0.3 meq/Kg bw/day to approximate the base-producing potential of F+V, or to Usual Care (UC, n=36). All had a systolic blood pressure (SBP) goal < 130 mm Hg using drug regimens including ACE inhibition. Cystatin C-based eGFR and SBP were followed at baseline and annually for five years.

Results

Baseline eGFR among UC, HCO₃, and F+V (39.5 ± 6.9, 39.6 ± 6.6, and 39.4 ± 6.4 ml/min/m², respectively, p=0.99) was not different but baseline SBP for UC (159 ± 11 mm Hg) was lower (p=0.04) than HCO₃ and F+V (165 ± 10, and 163 ± 12 mm Hg, respectively). At five years, the % of patients (%, 95% confidence interval or CI) that maintained eGFR> 30 ml/min/m² was higher in F+V (40%, CI=24-58) than UC (6%, CI=0.7 - 20) but that for HCO₃ (34%, CI=19 – 52) was not higher than UC. Although the five-year increase in plasma [HCO₃] was not different between F+V (0.89 mM, CI=0.68-1.09) and HCO₃ (0.87 mM, CI=0.67-1.08) supporting similar dietary acid reduction, a greater % of F+V (89%, CI= 73-97) than HCO₃ (17%, CI=7-34) achieved SBP goal of < 130 mm Hg, possibly contributing to better eGFR preservation in F+V.

Conclusion

Adjunctive dietary acid reduction with F+V but not NaHCO₃ yielded a significantly greater proportion of CKD 3 patients who did not progress to CKD 4, possibly due to a greater proportion of F+V achieving blood pressure goal. The data support that dietary acid reduction with F+V better prevents the CKD 3 to CKD 4 transition than NaHCO3.