Sodium, potassium intake and risk of CVD

High sodium intake has been linked to an increased risk of hypertension, cardiovascular morbidity, and death in an almost linear dose-response relationship.^1-3 The research has estimated that 1.65 million deaths globally as well as over 50,000 myocardial infarctions and 30,000 strokes per year in the United States were due to high sodium intake.^1,2 However, other studies have reported conflicting results, showing a J-shaped dose-response relationship instead of linear.⁴ 

In a recent article published in Nutrients (DOI: https://doi.org/10.3390/nu14051121), researchers investigated the relationship of long-term sodium and potassium consumption to address some gaps in the literature surrounding the risk of developing cardiovascular diseases (CVDs).  

The 180,156 participants included in this study were taken from the Million Veteran Program (MVP), a nationally representative cohort of veterans used to research determinants of chronic diseases. Individuals with a self-reported history of cancer or CVD were excluded from the study. Other exclusion criteria included those who did not provide dietary information or reported implausible dietary intakes at baseline.  

Dietary intake was self-reported through a semi-quantitative food frequency questionnaire and energy as well as nutrient content were taken from the Harvard University Food Consumption Database. Information including age, sex, race, body mass index (BMI) and other baseline data was taken from the self-reported MVP Baseline Survey. Additionally, information from the VA Corporate Data Warehouse (CDW), Centers for Medicaid & Medicare Services database, and the National Death Index database was used to retrieve cases of non-fatal myocardial infarction (MI) and acute ischemic stroke (AIS). 

Study findings 

The energy-adjusted average intakes of sodium (Na) and potassium (K) were 1246 mg/day and 2600 mg/day respectively. The participants with higher sodium intake and Na/K ratio were more likely to be inactive, have a lower education attainment, lower family income, more chronic conditions, and a poor-quality diet. After adjusting for known and suspected intervening variables, increased consumption of sodium was significantly linked with an increased risk of CVD in an approximately linear dose-response relationship. The NA/K ratio was also significantly associated with an increasing risk of total CVD in a linear relationship. In contrast, a higher potassium intake was linked to a 13% lower risk of total CVD with a slight nonlinear relationship; the decreasing trend plateaued after around 3g/day.  

The researchers conclude that these “findings support the recommendation of dietary patterns with lower dietary sodium to potassium ratio to prevent major cardiovascular diseases.” 

References 

1. Mozaffarian D, Fahimi S, Singh GM, Micha R, Khatibzadeh S, Engell RE, Lim S, Danaei G, Ezzati M, Powles J. Global sodium consumption and death from cardiovascular causes. New England Journal of Medicine. 2014 Aug 14;371(7):624-34. 

2. Bibbins-Domingo K, Chertow GM, Coxson PG, Moran A, Lightwood JM, Pletcher MJ, Goldman L. Projected effect of dietary salt reductions on future cardiovascular disease. New England Journal of Medicine. 2010 Feb 18;362(7):590-9. 

3. Ma Y, He FJ, Sun QI, Yuan C, Kieneker LM, Curhan GC, MacGregor GA, Bakker SJ, Campbell NR, Wang M, Rimm EB. 24-hour urinary sodium and potassium excretion and cardiovascular risk. New England Journal of Medicine. 2022 Jan 20;386(3):252-63. 

4. Kieneker LM, Eisenga MF, Gansevoort RT, de Boer RA, Navis G, Dullaart RP, Joosten MM, Bakker SJ. Association of low urinary sodium excretion with increased risk of stroke. InMayo Clinic Proceedings 2018 Dec 1 (Vol. 93, No. 12, pp. 1803-1809). Elsevier.