AUTHOR=Valle-Hita Cristina , Becerra-Tomás Nerea , Díaz-López Andrés , Vázquez-Ruiz Zenaida , Megías Isabel , Corella Dolores , Goday Albert , Martínez J. Alfredo , Alonso-Gómez Ángel M. , Wärnberg Julia , Vioque Jesús , Romaguera Dora , López-Miranda José , Estruch Ramon , Tinahones Francisco J. , Lapetra José , Serra-Majem Lluís , Bueno-Cavanillas Aurora , Tur Josep A. , Martín-Sánchez Vicente , Pintó Xavier , Gaforio José J. , Matía-Martín Pilar , Vidal Josep , Amengual-Galbarte Angela , Daimiel Lidia , Ros Emilio , García-Arellano Ana , Barragán Rocío , Fitó Montse , Peña-Orihuela Patricia J. , Asencio-Aznar Alberto , Gómez-Gracia Enrique , Martinez-Urbistondo Diego , Morey Marga , Casas Rosa , Garrido-Garrido Eva María , Tojal-Sierra Lucas , Damas-Fuentes Miguel , Goñi Estibaliz , Ortega-Azorín Carolina , Castañer Olga , Garcia-Rios Antonio , Gisbert-Sellés Cristina , Sayón-Orea Carmen , Schröder Helmut , Salas-Salvadó Jordi , Babio Nancy 

TITLE=Longitudinal association of dietary acid load with kidney function decline in an older adult population with metabolic syndrome

JOURNAL=Frontiers in Nutrition

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.986190

DOI=10.3389/fnut.2022.986190

ISSN=2296-861X

ABSTRACT=Background: Diets high in acid load may contribute to kidney function impairment. This study aimed to investigate the association between dietary acid load and one-year changes in glomerular filtration rate (eGFR) and urine albumin/creatinine ratio (UACR).
Methods: Older adults with overweight/obesity and metabolic syndrome (mean age 65±5 years, 48% women) from the PREDIMED-Plus study who had available data on eGFR (n=5874) or UACR (n=3639) at baseline and after one year of follow-up were included in this prospective analysis. Dietary acid load was estimated as potential renal acid load (PRAL) and net endogenous acid production (NEAP) at baseline from a food frequency questionnaire. Linear and logistic regression models were fitted to evaluate the associations between baseline tertiles of dietary acid load and kidney function outcomes. One year-changes in eGFR and UACR were set as the primary outcomes. We secondarily assessed ≥10% eGFR decline or ≥10% UACR increase.
Results: After multiple adjustments, individuals in the highest tertile of PRAL or NEAP showed higher one-year changes in eGFR (PRAL, β: -0.64 ml/min/1.73m2; 95% CI: -1.21 to -0.08 and NEAP, β: -0.56 ml/min/1.73m2; 95% CI: -1.13 to 0.01) compared to those in the lowest category. No associations with changes in UACR were found. Participants with higher levels of PRAL and NEAP had significantly higher odds of developing ≥10% eGFR decline (PRAL, OR: 1.28; 95% CI: 1.07 to 1.54 and NEAP, OR: 1.24; 95% CI: 1.03 to 1.50) and ≥10 % UACR increase (PRAL, OR: 1.23; 95% CI: 1.04 to 1.46) compared to individuals with lower dietary acid load.
Conclusions: Higher PRAL and NEAP were associated with worse kidney function after one year of follow-up as measured by eGFR and UACR markers in an older Spanish population with overweight/obesity and metabolic syndrome.