Treatment of metabolic acidosis in chronic kidney disease improves cardiovascular risk profile and reduces overall health care costs

Background: Chronic kidney disease (CKD) patients have increased cardiovascular disease (CVD) risk that is further elevated by metabolic acidosis. Nevertheless, it is unknown if treatment of metabolic acidosis in CKD reduces CVD risk. Because CKD-related metabolic acidosis can be treated with NaHCO3 or base-producing fruits and vegetables (F+V), we tested the hypothesis that either treatment of CKD-related metabolic acidosis improves CVD risk profile and does so at lower overall health care costs. Methods: One hundred eight non-diabetic CKD patients with stage 3 estimated GFR (eGFR, 30-59 ml/min/1.73m2 ) and metabolic acidosis but with plasma [HCO3 ] above which current guidelines recommend therapy (> 22 meq/L) were randomized to receive F+V (n=36) in amounts to reduce dietary acid 50%, oral NaHCO3 (HCO3 , n=36) 0.3 meq/Kg bw/day to approximate base equivalence of F+V, or to Usual Care (UC, n=36) and were assessed annually for five years. A CVD risk score of 1 for improved, 0 for no change, and -1 for worsened was assigned to the following 4 parameters: plasma [HCO3 ] , LDL, HDL, and change in medication dose. A score of 1 for met goal and 0 for not meeting goal was assigned to eGFR (goal > 30 ml/min/m2 ) and systolic blood pressure (SBP) (goal < 130 mm Hg) at five years. Five-year per patient total healthcare costs were adjusted per positive health outcome and included medications and hospitalizations. F+V's were given to all household members. Results: All groups improved CVD risk scores (p<0.05) but the score was better than UC (1.1 ± 1.4) in both HCO3 and F+V (2.9 ± 1.7 and 7.4 ± 1.6, respectively, p<0.01). The better F+V vs. HCO3 score was due mostly to greater reductions in medication dosage, lower LDL, and a greater % achieving SBP goal. Healthcare costs (median, 9 5% confidence interval) were lower than UC ($2367, 713 - 60992) for both HCO3 and F+V ($ 1128, 433 - 23737 and 1277, 790 - 2863, respectively, p<0.01) due mostly to fewer hospitalizations but costs were not different between HCO3 and F+V (p=0.22). Conclusion: Therapy of CKD-related metabolic acidosis with F+V and NaHCO3 yielded better overall CVD risk profiles in CKD 3 patients than Usual Care and at lower overall health care costs. Treatment of metabolic acidosis in CKD might reduce CVD outcomes and do so cost-effectively.