High serum bicarbonate level within the normal range prevents the progression of chronic kidney disease in elderly chronic kidney disease patients

Abstract

BackgroundMetabolic acidosis leads to chronic kidney disease (CKD) progression. The guidelines recommend a lower limit of serum bicarbonate level, but no upper limit. For serum bicarbonate level to be clinically useful as a therapeutic target marker, it is necessary to investigate the target serum bicarbonate level within the normal range to prevent CKD progression.MethodsOne hundred and thirteen elderly CKD patients, whose serum bicarbonate level was controlled within the normal range, were enrolled in this retrospective cohort study in Ibaraki, Japan. Outcome was defined as a decrease of 25% or more in estimated glomerular filtration rate (eGFR) or starting dialysis. We used Cox proportional hazard models adjusted for patients’ characteristics to examine the association between serum bicarbonate level and the outcome.ResultsFemale patients were 36.3%: average age (SD), 70.4 (6.6) years; eGFR, 25.7 (13.6) ml/min/1.73 m2; serum bicarbonate level, 27.4 (3.2) mEq/l. Patients with the lowest quartile of serum bicarbonate levels [23.4 (1.8) mEq/l] showed a high risk of CKD progression compared with patients with high serum bicarbonate levels [28.8 (2.3) mEq/l]: adjusted hazard ratio (HR), 3.511 (95% CI, 1.342-9.186). A 1 mEq/l increase in serum bicarbonate level was associated with a low risk of CKD progression: adjusted HR, 0.791 [95% confidence interval (CI), 0.684-0.914].ConclusionsIn elderly CKD patients, our findings suggest that serum bicarbonate level is independently associated with CKD progression, and that a high serum bicarbonate level is associated with a low risk of CKD progression. A high target serum bicarbonate level within the normal range may be effective for preventing CKD progression.

Study of association of serum bicarbonate levels with mortality in chronic kidney disease

“…The optimal management of metabolic acidosis in chronic kidney disease patients including the monitoring or administration of bicarbonate has not been established yet. [1][2][3] However various guidelines have recommended serum bicarbonate levels to be maintained at or above twenty two mleq/ltr bicarbonate replacement therapy in On Dialysis 62%…”

“…The approximate prevalence of CKD in India is 800 per million population. 1 Prevalence of CKD patients will continue to rise, reflecting the growing elderly population and increasing number of patients with diabetes and hypertension. 1,2 Metabolic acidosis is a feature of CKD due to the reduced capacity of the kidney to synthesize ammonia and excrete hydrogen ions.…”

“…1 Prevalence of CKD patients will continue to rise, reflecting the growing elderly population and increasing number of patients with diabetes and hypertension. 1,2 Metabolic acidosis is a feature of CKD due to the reduced capacity of the kidney to synthesize ammonia and excrete hydrogen ions. This may be corrected by oral bicarbonate supplementation or by increasing the bicarbonate concentration in the dialysate fluid during dialysis.…”

Osteoporosis management in patient with renal function impairment

“…(41) have shown that the maintenance of serum bicarbonate at high-normal levels reduced CKD progression and increased patient survival. Reduction of protein catabolism and the hospitalization rate were also reported (24,42,43). KDIGO consensus (1) establishes that patients with CKD and serum bicarbonate < 22 mmol/L require oral bicarbonate replacement.…”

The Role of Bicarbonate in CKD

“…A systematic review concluded that the studies were suggestive but not definitive for a beneficial effect, with little indication of significant adverse effects (16). In addition, some observational studies are consistent with a beneficial effect of a higher bicarbonate (or lower acid intake) on CKD progression (17)(18)(19)(20).…”