SummaryBackground and objectives Metabolic acidosis may contribute to morbidity and disease progression in patients with chronic kidney disease (CKD). The ratio of dietary protein, the major source of nonvolatile acid, to dietary potassium, which is naturally bound to alkali precursors, can be used to estimate net endogenous acid production (NEAP). We tested the association between estimated NEAP and serum bicarbonate in patients with CKD. Design, setting, participants, & measurements NEAP was estimated among 462 African American adults with hypertensive CKD using published equations: NEAP (mEq/d) = -10.2 + 54.5 (protein [g/d]/potassium [mEq/d]). Dietary protein and potassium intake were estimated from 24-hour urinary excretion of urea nitrogen and potassium, respectively. All of the eligible measurements during follow-up were modeled using generalized linear regression clustered by participant and adjusted for demographics, 24-hour urinary sodium, kidney function, and selected medications. Results Higher NEAP was associated with lower serum bicarbonate in a graded fashion (P trend < 0.001). Serum bicarbonate was 1.27 mEq/L lower among those in the highest compared with the lowest quartile of NEAP (P < 0.001). There was a greater difference in serum bicarbonate between the highest and lowest quartiles of NEAP among patients with stage 4/5 CKD (-2.43 mEq/L, P < 0.001) compared with those with stage 2/3 disease (-0.77 mEq/L, P = 0.01; P-interaction = 0.02). Conclusions Reducing NEAP, through reduction of dietary protein and increased intake of fruits and vegetables, may prevent metabolic acidosis in patients with CKD.
AD - Division of Nephrology, Johns Hopkins University School of Medicine, 301 Mason F. Lord Drive, Suite 2500, Baltimore, MD 21224. jsciall1@jhmi.edu. AN - 21700817 BT - Clinical Journal of the American Society of Nephrology DA - -48222939307 ET - 2011/06/28 LA - eng M1 - 7 N1 - Scialla, Julia JAppel, Lawrence JAstor, Brad CMiller, Edgar R 3rdBeddhu, SrinivasanWoodward, MarkParekh, Rulan SAnderson, Cheryl A MUnited StatesClinical journal of the American Society of Nephrology : CJASNClin J Am Soc Nephrol. 2011 Jul;6(7):1526-32. Epub 2011 Jun 23. N2 -SummaryBackground and objectives Metabolic acidosis may contribute to morbidity and disease progression in patients with chronic kidney disease (CKD). The ratio of dietary protein, the major source of nonvolatile acid, to dietary potassium, which is naturally bound to alkali precursors, can be used to estimate net endogenous acid production (NEAP). We tested the association between estimated NEAP and serum bicarbonate in patients with CKD. Design, setting, participants, & measurements NEAP was estimated among 462 African American adults with hypertensive CKD using published equations: NEAP (mEq/d) = -10.2 + 54.5 (protein [g/d]/potassium [mEq/d]). Dietary protein and potassium intake were estimated from 24-hour urinary excretion of urea nitrogen and potassium, respectively. All of the eligible measurements during follow-up were modeled using generalized linear regression clustered by participant and adjusted for demographics, 24-hour urinary sodium, kidney function, and selected medications. Results Higher NEAP was associated with lower serum bicarbonate in a graded fashion (P trend < 0.001). Serum bicarbonate was 1.27 mEq/L lower among those in the highest compared with the lowest quartile of NEAP (P < 0.001). There was a greater difference in serum bicarbonate between the highest and lowest quartiles of NEAP among patients with stage 4/5 CKD (-2.43 mEq/L, P < 0.001) compared with those with stage 2/3 disease (-0.77 mEq/L, P = 0.01; P-interaction = 0.02). Conclusions Reducing NEAP, through reduction of dietary protein and increased intake of fruits and vegetables, may prevent metabolic acidosis in patients with CKD.
PY - 2011 SN - 1555-905X (Electronic)1555-9041 (Linking) SP - 1526 EP - 32 T2 - Clinical Journal of the American Society of Nephrology TI - Estimated net endogenous Acid production and serum bicarbonate in african americans with chronic kidney disease VL - 6 ER -