Larissa Rodrigues Neto Angeloco1, Gabriela Cristina Arces de Souza2, Elen Almeida Romão3, Lynda Frassetto4, Paula Garcia Chiarello2. 1. Department of Health Science, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil. lari.angeloco@gmail.com. 2. Department of Health Science, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil. 3. Department of Internal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil. 4. Department of Medicine, University of California San Francisco, San Francisco, CA, USA.
Abstract
BACKGROUND/ OBJECTIVES: Diet can affect the acid-base status depending on the balance between the intake of acid-inducing foods and base-inducing foods. The purpose of this study was to estimate the dietary acid load and evaluate its association with serum bicarbonate in patients with stages 3 and 4 chronic kidney disease. SUBJECTS/ METHODS: One hundred adults (aged ≥ 20 years) with chronic kidney disease (CKD) stages 3 and 4 were enrolled in a cross-sectional study. A food diary was used to estimate the animal and plant protein intakes, which were used in the potential renal acid load (PRAL) formula described by Remer and Manz. PRAL was divided into quartiles. Regression models unadjusted and adjusted for age, gender, body mass index, diabetes, systolic and diastolic blood pressure, creatinine clearance were performed using the stepwise regression method. RESULTS: The median level (25th, 75th percentiles) of PRAL was 8.3 mEq/day (1.6, 15.6). The highest quartile of PRAL had a higher consumption of animal protein (77.8 ± 10.9%) and a reduced consumption of plant protein (22.2 ± 10.9%), compared to the lowest quartile (59.5 ± 18.6% animal protein, 40.5 ± 18.6% plant protein), p for trend <0.0001. In the adjusted analysis, a significant association was observed between the highest quartile of PRAL and serum bicarbonate in CKD patients compared to the lowest quartile (β: 2.07, 95% CI: 0.21-3.92). According to the multiple linear regression, for each increase of 1 unit of PRAL there was a reduction of 0.25 mmol/L in serum bicarbonate (HCO3). Using the stepwise method, animal protein intake and PRAL were determinants of HCO3 (r = 0.49). CONCLUSIONS: In CKD patients of stages 3 and 4, the dietary acid load was associated with HCO3. Limiting dietary acid load could be a complementary approach in the dietary treatment of CKD. In addition, studies are needed to analyze the effect of replacing animal protein with plant protein.
BACKGROUND/ OBJECTIVES: Diet can affect the acid-base status depending on the balance between the intake of acid-inducing foods and base-inducing foods. The purpose of this study was to estimate the dietary acid load and evaluate its association with serum bicarbonate in patients with stages 3 and 4 chronic kidney disease. SUBJECTS/ METHODS: One hundred adults (aged ≥ 20 years) with chronic kidney disease (CKD) stages 3 and 4 were enrolled in a cross-sectional study. A food diary was used to estimate the animal and plant protein intakes, which were used in the potential renal acid load (PRAL) formula described by Remer and Manz. PRAL was divided into quartiles. Regression models unadjusted and adjusted for age, gender, body mass index, diabetes, systolic and diastolic blood pressure, creatinine clearance were performed using the stepwise regression method. RESULTS: The median level (25th, 75th percentiles) of PRAL was 8.3 mEq/day (1.6, 15.6). The highest quartile of PRAL had a higher consumption of animal protein (77.8 ± 10.9%) and a reduced consumption of plant protein (22.2 ± 10.9%), compared to the lowest quartile (59.5 ± 18.6% animal protein, 40.5 ± 18.6% plant protein), p for trend <0.0001. In the adjusted analysis, a significant association was observed between the highest quartile of PRAL and serum bicarbonate in CKDpatients compared to the lowest quartile (β: 2.07, 95% CI: 0.21-3.92). According to the multiple linear regression, for each increase of 1 unit of PRAL there was a reduction of 0.25 mmol/L in serum bicarbonate (HCO3). Using the stepwise method, animal protein intake and PRAL were determinants of HCO3 (r = 0.49). CONCLUSIONS: In CKDpatients of stages 3 and 4, the dietary acid load was associated with HCO3. Limiting dietary acid load could be a complementary approach in the dietary treatment of CKD. In addition, studies are needed to analyze the effect of replacing animal protein with plant protein.