One-Year Conservative Care Using Sodium Bicarbonate Supplementation Is Associated with a Decrease in Electronegative LDL in Chronic Kidney Disease Patients: A Pilot Study

Abstract

<b><i>Background:</i></b> Chronic kidney disease (CKD) patients develop metabolic acidosis when approaching stages 3 and 4, a period in which accelerated atherogenesis may ensue. Studies in vitro show that low pH may increase low-density lipoprotein (LDL) oxidation, suggesting a role for chronic metabolic acidosis in atherosclerosis. The present study attempted to evaluate the effects of conservative care using oral sodium bicarbonate (NaHCO₃) supplementation on the electronegative LDL [LDL(-)], a minimally oxidized LDL, plasma levels in CKD patients. <b><i>Methods:</i></b> Thirty-one CKD patients were followed by a multidisciplinary team during 15 months of care in which 1.0 mmol/kg/day oral NaHCO₃ supplementation was first given in the third month. Blood samples were collected 3 months before the initiation of oral NaHCO₃ supplementation (T1), at the time of the beginning of supplementation (T2), and thereafter, each 4 months (T3, T4 and T5) until month 15 of care. Blood parameters and LDL(-) were measured from these collections. <b><i>Results:</i></b> After 12 months of conservative care, creatinine clearance (MDRD) was kept stable, and serum bicarbonate (HCO₃^-) increased from 20.5 ± 2.9 to 22.6 ± 1.1 m<smlcap>M</smlcap> (<i>p</i> < 0.003). LDL(-) plasma levels declined from 4.5 ± 3.3 to 2.1 ± 0.9 U/L (<i>p</i> < 0.007) after reaching mean serum HCO₃^- levels of 22.6 ± 1.1 m<smlcap>M</smlcap>. <b><i>Conclusions:</i></b> Conservative care using oral NaHCO₃ supplementation was able to stabilize renal function and decrease serum levels of LDL(-), a modified proatherogenic lipoprotein, only when mean serum HCO₃^- levels approached 22 m<smlcap>M</smlcap>. This study constitutes evidence that alkali therapy, in addition to its beneficial effect on renal disease progression, might serve as a preventive strategy to attenuate atherogenesis in CKD patients.