Kidney Week

Abstract: SA-PO141

Dietary Acid Reduction with Either Fruits and Vegetables or Oral NaHCO3 Reduces Oxidative Stress and Slows Progression of Kidney Injury in Stage 1 CKD

Session Information

• Nutrition, Inflammation, Metabolism: Clinical Trials, Biomarkers, Epidemiology
  November 04, 2017 | Location: Hall H, Morial Convention Center
  Abstract Time: 10:00 AM - 10:00 AM

Category: Nutrition, Inflammation, and Metabolism

• 1401 Nutrition, Inflammation, Metabolism

Authors

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

Nimrit Goraya,

• Sager, Lauren N, Baylor Scott & White, Temple, Texas, United States

Lauren N Sager,

• Simoni, Jan, Baylor Scott & White Health, Temple, Texas, United States

Jan Simoni,

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

Donald E. Wesson,

Background

Chronic kidney disease stage 1 (eGFR > 90 ml/min/m², CKD 1) patients with macroalbuminuria (urine albumin-to-creatinine ratio > 200 mg/g creatinine) are at increased risk for CKD progression with higher morbidity, mortality, and costs. Dietary acid (H⁺) induces nephropathy progression in animal models of CKD, mediated in part though angiotensin II (AII)-induced oxidative stress. We tested the hypothesis that dietary H⁺ reduction with base-producing fruits and vegetables (F+V) or oral NaHCO₃ (HCO₃) prevents further kidney injury in CKD 1.

Methods

Seventy-one macroalbuminuric, non-diabetic CKD 1 subjects had systolic blood pressure (SBP) reduced to < 150 mm Hg with regimens including ACE inhibition and were then randomized to receive F+V (n=23) in amounts to reduce dietary potential renal acid load by half, oral NaHCO₃ (HCO₃, n=23) 0.4 meq/Kg bw/day, or no additional intervention (Usual Care, n=25). Creatinine-based eGFR and spot urine levels of the following, factored per g creatinine, were measured at baseline and yearly for five years: albumin (Ualb), an index of kidney injury, angiotensinogen (UAGT), an index of kidney angiotensin II, and isoprostane 8-isoprostaglandin F_2a (8-iso), an index of oxidative stress.

Results

Baseline eGFR, Ualb, UAGT, and U8-iso were not different among the groups. The five-year course (mean, 95% confidence limit or CI) of Ualb was lower than Usual Care (406 mg/g, CI=376-435) in both F+V (332 mg/g, CI=312-352) and HCO₃ (324 mg/g, CI=299-349), consistent with less kidney injury in each dietary acid reduction group. Combining F+V and HCO₃ into one dietary acid reduction group, UAGT course was lower than Usual Care (p<0.02), consistent with lower kidney AII. The five-year course of U8-iso was lower than Usual Care (1.24 ug/g, CI=1.19-1.29) in both F+V (1.10 ug/g, CI=1.06-1.15) and HCO₃ (1.11 ug/g, CI=1.07-1.14), consistent with less oxidative stress in both dietary reduction groups. There was no significant change in eGFR over the five years in any of the three groups.

Conclusion

Dietary acid reduction in CKD 1 with either F+V or NaHCO₃ yielded less kidney injury and less oxidative stress than Usual Care, possibly mediated though reduced kidney AII, supporting that dietary acid reduction reduces the risk for progression to advanced CKD stages .