Association of Urinary Sodium Excretion With Blood Pressure and Cardiovascular Clinical Events in 17,033 Latin Americans

Pablo M Lamelas; Andrew Mente; Rafael Diaz; Andres Orlandini; Alvaro Avezum; Gustavo Oliveira; Fernando Lanas; Pamela Seron; Patricio Lopez-Jaramillo; Paul Camacho-Lopez; Martin J O Donnell; Sumathy Rangarajan; Koon Teo; Salim Yusuf

doi:10.1093/ajh/hpv195

Association of Urinary Sodium Excretion With Blood Pressure and Cardiovascular Clinical Events in 17,033 Latin Americans

Am J Hypertens. 2016 Jul;29(7):796-805. doi: 10.1093/ajh/hpv195. Epub 2015 Dec 18.

Authors

Affiliations

¹ The Population Health Research Institute, Hamilton Health Sciences, McMaster University, Hamilton, ON, Canada; pablo.lamelas@phri.ca.
² The Population Health Research Institute, Hamilton Health Sciences, McMaster University, Hamilton, ON, Canada; Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada;
³ Department of Laboratory Medicine, McMaster University, Hamilton, ON, Canada; Estudios Clínicos Latinoamérica, Rosario, Argentina;
⁴ Dante Pazzanese Institute of Cardiology, São Paulo, Brazil;
⁵ Universidad de la Frontera, Temuco, Chile;
⁶ Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada; Fundación Oftalmológica de Santander Medical School, Universidad de Santander, Floridablanca, Colombia;
⁷ Fundación Oftalmológica de Santander Medical School, Universidad de Santander, Floridablanca, Colombia;
⁸ The Population Health Research Institute, Hamilton Health Sciences, McMaster University, Hamilton, ON, Canada; Department of Medicine, McMaster University, Hamilton, ON, Canada.
⁹ The Population Health Research Institute, Hamilton Health Sciences, McMaster University, Hamilton, ON, Canada;
¹⁰ The Population Health Research Institute, Hamilton Health Sciences, McMaster University, Hamilton, ON, Canada; Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada; Department of Medicine, McMaster University, Hamilton, ON, Canada.

Abstract

Background: Information on actual sodium intake and its relationships with blood pressure (BP) and clinical events in South America is limited. The aim of this cohort study was to assess the relationship of sodium intake with BP, cardiovascular (CV) events, and mortality in South America.

Methods: We studied 17,033 individuals, aged 35-70 years, from 4 South American countries (Argentina, Brazil, Chile, and Colombia). Measures of sodium excretion, estimated from morning fasting urine, were used as a surrogate for daily sodium intake. We measured BP and monitored the composite outcome of death and major CV events.

Results: Overall mean sodium excretion was 4.70±1.43g/day. A positive, nonuniform association between sodium and BP was detected, with a significant steeper slope for the relationship at higher sodium excretion levels (P < 0.001 for interaction). With a median follow-up of 4.7 years, the primary composite outcome (all-cause death, myocardial infarction, stroke, or heart failure) occurred in 568 participants (3.4%). Compared with sodium excretion of 5-6g/day (reference group), participants who excreted >7g/day had increased risks of the primary outcome (odds ratio (OR) 1.73; 95% confidence interval (CI) 1.24 to 2.40; P < 0.001), as well as death from any cause (OR 1.87; 95% CI 1.23 to 2.83; P = 0.003) and major CV disease (OR 1.77; 95% CI 1.12 to 2.81; P = 0.014). Sodium excretion of <3g/day was associated with a statistically nonsignificant increased risk of the primary outcome (OR 1.20; 95% CI 0.86 to 1.65; P = 0.26) and death from any cause (OR 1.25; 95% CI 0.81 to 1.93; P = 0.29), and a significant increased risk of major CV disease (OR 1.50; 95% CI 1.01 to 2.24; P = 0.048), as compared to the reference group.

Conclusions: Our results support a positive, nonuniform association between estimated urinary sodium excretion and BP, and a possible J-shaped pattern of association between sodium excretion over the entire range and clinical outcomes.

Keywords: blood pressure; cardiovascular disease; hypertension; mortality.; sodium intake.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Blood Pressure*
Cardiovascular Diseases / mortality
Cardiovascular Diseases / urine*
Cohort Studies
Female
Humans
Male
Middle Aged
Sodium / urine*
South America / epidemiology

Substances

Sodium

Grants and funding

CIHR/Canada