Cross-sectional associations between macronutrient intake and chronic kidney disease in a population at high cardiovascular risk

BACKGROUND & AIMS: The aim was to examine the associations between macronutrient intake and the prevalence of chronic kidney disease (CKD) or microalbuminuria (MiA) in individuals at high cardiovascular risk.

METHODS: Cross-sectional analyses conducted in 2123 nondiabetic individuals from the PREDIMED study. Dietary data were collected using a food-frequency questionnaire. Analysis of covariance was used to assess associations between quartiles of nutrient intake and estimated glomerular filtration rate (eGFR) or urinary albumin-to-creatinine ratio (ACR). The odds ratio (OR) for the presence of CKD or MiA according to quartiles of nutrient intake was assessed by logistic regression models.

RESULTS: Individuals in the highest quartile of n-6 polyunsaturated fatty acid (PUFA) intake showed lower average eGFR. Individuals in the top quartile of fiber intake had a decreased risk of CKD [OR: 0.68; 95% CI: 0.48-0.95]. Conversely, subjects in the highest quartile of n-6 PUFA intake showed an increased risk of CKD [OR: 1.44; 95% CI: 1.03-2.01]. No significant associations were found between the intake of other macronutrients and eGFR, urinary ACR or risk of CKD or MiA.

CONCLUSIONS: A high fiber intake was associated with a decreased risk of CKD, while a high n-6 PUFA intake was inversely associated with eGFR and directly associated with an increased risk of CKD.