Influence of renal function and diet on acid-base status in chronic kidney disease patients.
OBJECTIVE
We investigated the influence of potential renal acid load (PRAL) and renal function on the degree of metabolic acidosis in patients with chronic kidney disease (CKD).


DESIGN
This was a cross-sectional study.


SETTING
This study was conducted at the Nephrology Outpatient Division of the Hospital Universitário Clementino Fraga Filho (Rio de Janeiro, Brazil).


PATIENTS
Thirty CKD patients undergoing conservative treatment were divided according to plasma HCO(3)(-) values into acidotic (HCO(3)(-) <or=22 mM, n = 15) and nonacidotic (HCO(3)(-) >22 mM, n = 15).


MAIN OUTCOME MEASURE
Biochemical, nutritional, and anthropometric parameters and PRAL were measured.


RESULTS
The mean of plasma HCO(3)(-) values was 17.7 +/- 2.8 mM in the acidotic group, and 25.1 +/- 2.2 mM in the nonacidotic group. There was no significant difference in mean PRAL values between the acidotic (9.8 +/- 6.4 mEq/day) and nonacidotic (12.7 +/- 10.0 mEq/day) groups, but there was a significant correlation between plasma HCO(3)(-) and creatinine clearance (r = 0.78, P < .0001). Based on the receiver operating characteristic curve, the level of creatinine clearance to begin detection of acidosis was 31.8 mL/min, with a sensitivity and specificity of 86.7%.


CONCLUSION
The acid-base status of this group of CKD patients undergoing conservative treatment was mainly determined by degree of renal insufficiency rather than diet.