Is complying with the recommendations of sodium intake beneficial for health in individuals at high cardiovascular risk? Findings from the PREDIMED study

Jordi Merino; Marta Guasch-Ferré; Miguel A Martínez-González; Dolores Corella; Ramon Estruch; Montserrat Fitó; Emilio Ros; Fernando Arós; Mònica Bulló; Enrique Gómez-Gracia; Manuel Moñino; José Lapetra; Lluís Serra-Majem; Cristina Razquin; Pilar Buil-Cosiales; José V Sorlí; Miguel A Muñoz; Xavier Pintó; Luis Masana; Jordi Salas-Salvadó

doi:10.3945/ajcn.114.096750

Is complying with the recommendations of sodium intake beneficial for health in individuals at high cardiovascular risk? Findings from the PREDIMED study

Am J Clin Nutr. 2015 Mar;101(3):440-8. doi: 10.3945/ajcn.114.096750. Epub 2014 Dec 24.

Authors

Jordi Merino¹, Marta Guasch-Ferré¹, Miguel A Martínez-González¹, Dolores Corella¹, Ramon Estruch¹, Montserrat Fitó¹, Emilio Ros¹, Fernando Arós¹, Mònica Bulló¹, Enrique Gómez-Gracia¹, Manuel Moñino¹, José Lapetra¹, Lluís Serra-Majem¹, Cristina Razquin¹, Pilar Buil-Cosiales¹, José V Sorlí¹, Miguel A Muñoz¹, Xavier Pintó¹, Luis Masana¹, Jordi Salas-Salvadó¹

Affiliation

¹ From the Human Nutrition Unit, University Hospital of Sant Joan de Reus, Department of Biochemistry and Biotechnology, Faculty of Medicine and Health Sciences, IISPV, Rovira i Virgili University, Reus, Spain (JM, MG-F, MB, and JS-S); Vascular Medicine and Metabolism Unit, Lipids and Atherosclerosis Research Unit, Sant Joan University Hospital, IISPV, Faculty of Medicine, Rovira i Virgili University, Spanish Biomedical Research Network in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain (JM and LM); CIBERobn, Institute of Health Carlos III, Madrid, Spain (MG-F, MAM-G, DC, RE, MF, ER, FA, MB, EG-G, MM, JL, LS-M, CR, PB-C, JVS, and JS-S); the Department of Preventive Medicine and Public Health, University of Navarra and Servicio Navarro de Salud, Pamplona, Spain (MAM-G, CR, and PB-C); the Department of Preventive Medicine, University of Valencia, Valencia, Spain (DC and JVS); the Department of Internal Medicine, August Pi i Sunyer Institute of Biomedical Research (IDIBAPS), Hospital Clinic, University of Barcelona, Barcelona, Spain (RE); Cardiovascular Risk and Nutrition (Regicor Study Group), Hospital del Mar Medical Research Institute, Barcelona Biomedical Research Park, Barcelona, Spain (MF); Lipid Clinic, Endocrinology and Nutrition Service, IDIBAPS, Hospital Clinic, University of Barcelona, Barcelona, Spain (ER); the Department of Cardiology, University Hospital Araba, Vitoria, Spain (FA); the Department of Preventive Medicine, University of Malaga, Malaga, Spain (EG-G); Institute of Health Sciences, University of Balearic Islands and Son Espases Hospital, Palma de Mallorca, Spain (MM); the Department of Family Medicine, Primary Care Division of Sevilla, San Pablo Health Center, Sevilla, Spain (JL); the Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas, Spain (LS-M); Primary Care Division, Navarra Regional Service of Health (Osasunbidea), Pamplona, Spain (PB-C); Primary Care Division, Ca

PMID: 25733627
DOI: 10.3945/ajcn.114.096750

Abstract

Background: Excess sodium intake is associated with high blood pressure, a major risk factor for cardiovascular disease (CVD). It is unknown whether decreasing sodium intake to <2300 mg/d has an effect on CVD or all-cause mortality.

Objective: The objective was to assess whether reductions in sodium intake to <2300 mg/d were associated with either an increased or a decreased risk of fatal and nonfatal CVD and all-cause mortality.

Design: This observational prospective study of the PREvención con DIeta MEDiterránea (PREDIMED) trial included 3982 participants at high CVD risk. Sodium intake was evaluated with a validated food-frequency questionnaire and categorized as low (<1500 mg/d), intermediate (≥1500 to ≤2300 mg/d), high (>2300 to ≤3400 mg/d), or very high (>3400 mg/d). Subsequently, 1-y and 3-y changes in sodium intake were calculated. Multivariate relative risks were assessed by using Cox proportional hazards ratios. Marginal structural models with inverse probability weighting were used to test the effect of changes in sodium intake and the Mediterranean diet (MedDiet).

Results: We documented 125 CVD events and 131 deaths after a 4.8-y median follow-up. Sodium intake <2300 mg/d was associated with a lower risk of all-cause mortality: 48% (HR: 0.52; 95% CI: 0.30, 0.91; P = 0.02) and 49% (HR: 0.51; 95% CI: 0.26, 0.98; P = 0.04) after 1 and 3 y, respectively. Increasing sodium intake after 1 y was associated with a 72% (HR: 1.72; 95% CI: 1.01, 2.91; P = 0.04) higher risk of CVD events. The incidence rate of CVD was reduced for those who reduced their sodium intake and were randomly assigned to MedDiet interventions [4.1/10,000 (95% CI: 3.1, 8.0) compared with 4.4/10,000 (95% CI: 2.7, 12.4) person-years; P = 0.002].

Conclusions: Decreasing sodium intake to <2300 mg/d was associated with a reduced risk of all-cause mortality, whereas increasing the intake to >2300 mg/d was associated with a higher risk of CVD. Our observational data suggest that sodium intake <2300 mg/d was associated with an enhanced beneficial effect of the MedDiet on CVD. These results should be interpreted with caution, and other confirmatory studies are necessary.

Keywords: Mediterranean diet; PREDIMED study; cardiovascular disease; mortality; sodium intake.

Publication types

Multicenter Study
Observational Study
Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

Aged
Aged, 80 and over
Cardiovascular Diseases / epidemiology
Cardiovascular Diseases / prevention & control*
Cohort Studies
Diet, Mediterranean* / adverse effects
Diet, Sodium-Restricted* / adverse effects
Female
Follow-Up Studies
Health Promotion*
Humans
Incidence
Male
Middle Aged
Mortality
Nutrition Policy*
Patient Compliance*
Patient Education as Topic
Prevalence
Risk Factors
Spain / epidemiology

Associated data

ISRCTN/ISRCTN35739639