Background:
Both sodium bicarbonate (NaHCO
3
) and base-producing fruits and vegetables (F+V) improve metabolic acidosis in chronic kidney disease (CKD) and appear to provide similar levels of kidney protection. Because F+V themselves reduce blood pressure, we examined if treatment of metabolic acidosis in CKD with F+V was associated with improved blood pressure control, using fewer anti-hypertensive drugs, and thereby with lower cost of hypertension management.
Methods:
We randomized 108 subjects with CKD stage 3 eGFR (30-59 ml/min) and metabolic acidosis as follows: F+V (n=36) added to reduce dietary potential renal acid load (PRAL) 50%, oral NaHCO
3
(HCO
3
, n=36) to reduce PRAL 50%, or no alkali (Usual Care, n=36). All were treated toward systolic blood pressure (SBP) <130 mmHg with regimens including ACE inhibition and followed 5 years.
Results:
Entry SBP and initial doses of 5 formulary anti-hypertensive drugs most commonly used for blood pressure control in CKD were not different among the 3 groups. At 5 years, SBP was lower in F+V (125±5 mm Hg) than both HCO
3
and Usual Care (135±5 and 134±5 mm Hg, respectively, p<0.01 vs. F+V for each). Daily doses for the following drugs at year 5 were lower in F+V than HCO
3
and Usual Care: Enalapril (8.3±2.4 vs. 11.1±3.6 and 11.7±4.8, mg/day, respectively, p<0.01), Diltiazem (1.7±7.0 vs. 145.8±36.0 and 153.3±35.7, mg/day, p<0.01), Clonidine (0.14±0.20 vs. 0.65±0.15 and 0.63±0.16, mg/day, p<0.01), Atenolol (0 vs. 6.25±15.1 and 6.25±15.1 mg/day, p<0.02) but there was no difference among groups in the year 5 dose of hydrochlorthiazide (16.1±9.9 vs. 21.9±16.2 and 21.5±16.3 mg/day, p=0.27). Five-year drug cost of hypertension management was less in F+V ($79,760) than both HCO
3
($155,372) and Usual Care ($152,305).
Conclusions:
Treating metabolic acidosis in CKD patients with F+V but not NaHCO
3
was associated with lower SBP, use of fewer and lower doses of anti-hypertensive drugs, and lower group cost of hypertension management. The data support that clinicians consider these adjunctive benefits of F+V on hypertension management when recommending treatment strategies for metabolic acidosis in CKD.
SP046EFFECT OF SODIUM BICARBONATE LOAD ON 24-HOUR AMBULATORY BLOOD PRESSURE MEASUREMENTS IN PATIENTS WITH CHRONIC METABOLIC ACIDOSIS AND CHRONIC KIDNEY DISEASE: PRELIMINARY RESULTS OF THE SOBIC STUDY
