Patients treated with bicarbonate therapy had a 64% lower risk of doubling their serum creatinine compared to those treated with standard care (hazard ratio [HR] = 0.36; 95% CI, 0.22-0.58; P < .001; NNT = 9.6).3 Bicarbonate therapy also significantly reduced the risk of dialysis (HR = 0.5; 95% CI, 0.31-0.81; P = .005; NNT = 19); all-cause mortality (HR = 0.43; 95% CI, 0.22-0.87; P = .01; NNT = 27); hospitalization rates (34.6% vs 14.2% by end of study in standard care and bicarbonate groups, respectively; P < .001); and hospital length of stay (1160 total d/y vs 400 total d/y; P < .0001).3 Inspection of Kaplan Meier curves shows outcomes beginning to diverge after 1 to 2 years of treatment. This trial was limited by the lack of blinding, placebo control, and standardization of care protocols.
Recommendations from others
The National Kidney Foundation’s 2012 Kidney Disease Outcomes Quality Initiative guidelines for the management of CKD recommend oral bicarbonate therapy for patients with CKD and serum bicarbonate concentrations < 22 mmol/L.4 The guidelines state that serum bicarbonate levels < 22 mmol/L correlate with an increased risk of CKD progression and death, whereas high bicarbonate levels (> 32 mmol/L) correlate with increased risk of death independent of level of kidney function. These guidelines cite small studies of alkali therapy slowing progression of CKD, although it was noted that the evidence base was not strong.
Editor’s takeaway
The evidence shows a small but consistent effect of bicarbonate therapy on CKD progression. For patients with CKD stages 3 to 5 and metabolic acidosis (defined by serum bicarbonate levels < 22 mmol/L), the use of supplemental oral sodium bicarbonate, which is inexpensive and safe, can delay or prevent progression of serious disease.