Abstract / Summary
Treatment of metabolic acidosis with alkaline is established in clinical care of chronic kidney disease (CKD), although clinical studies revealed conflicting results whether it slows CKD. The aim of the study was to determine whether treatment strategies targeting serum bicarbonate concentrations of approximately 20 ± 1 or 24 ± 1 mmol/L differed with respect to eGFR decline over 104 weeks follow-up. The SoBic study was an open-label randomized trial in CKD stage 3 to 4 patients and serum bicarbonate ≤ 21 mmol/L. Sodium bicarbonate was applied according to serum bicarbonate targets. We randomized 58 subjects and 49 completed follow-up, 2 died, and 4 started dialysis. The median sodium bicarbonate dose in the intervention group was 6.7 (IQR: 4.2 to 8.4) g/day. About 70% in each group reached the target, resulting in a mean difference in serum bicarbonate of 3.57 (95%CI: 2.29 to 4.85) at week 47 and 3.64 (95%CI: 2.21 to 5.07 mmol/L at week 104 across groups. There was an estimated mean decrease in eGFR of 5.8 (95%CI: − 8.77 to − 2.84) and a non-significant difference of eGFR change of − 0.98 (− 3.08 to 1.12, p = 0.648) ml/min per 1.73 m². In conclusion, targeting higher serum bicarbonate concentrations was not associate with a clinically meaningful benefit in subjects with advanced CKD and overt metabolic acidosis.