Associations between dietary electrolytes and pulse wave velocity
Background: Pulse wave velocity (PWV) is a non-invasive measure of arterial stiffness, and a recognised predictor of cardiovascular morbidity and mortality. Given this, it is likely that investigating the determinants of PWV will improve our understanding of cardiovascular health. At present, there is disagreement regarding the relationship between dietary sodium and potassium intakes, and PWV. Hence, further research is needed in order to confirm whether dietary sodium and potassium are determinants of PWV. Objective: The aim of this cross-sectional study was to investigate the associations between dietary sodium and potassium intake, and PWV in the general population. Methods: This cross-sectional study used baseline data from Health And Bread Intervention Trial (HABIT). Spot urine samples were used to estimate dietary sodium and potassium intake. Weighed three-day diet records were analysed for self-reported dietary sodium and potassium intake. Brachial blood pressure, and carotid-femoral PWV were measured with the SphygmoCor 2000. Results: Sixty-five HABIT participants were included in this study. Overall, 52.3% were males, with a mean±SD age of 34.5±18.3years, body mass index (BMI) of 24.9±4.5kg/m2; BP of 126.5/74.8±17.7/11.2mmHg, and PWV of 7.2±1.6m/s. Mean sodium intakes as assessed by spot urine samples and diet records were above New Zealand’s Upper Limit of 2300mg/day (urinary sodium: 3021±756mg/day; dietary sodium: 2784±1067mg/day). Mean potassium intakes, also assessed by spot urine samples and diet records, were below the Adequate Intake for New Zealand of 3800mg/day for males and 2800mg/day for females (male, urinary potassium: 2002±386.9mg/day; male, dietary potassium: 3500±1242.2mg/day; female, urinary potassium: 1902.6±428.5mg/day; female, dietary potassium: 2783.3±991.3mg/day). Dietary intakes of sodium, potassium, and sodium-to-potassium ratio as assessed by spot urine samples and diet records were not independently associated with PWV. In multi-variate analysis age was positively associated with PWV (a 1-year increase in age was associated with a 0.05 m/s increase in PWV). Conclusions: This small cross-sectional study found dietary intakes of sodium, potassium, and sodium-to-potassium were not independent predictors of PWV, suggesting the prediction of PWV is multi-factorial. Future adequately-powered studies should examine these relationships.
Advisor: Black, Katherine; Brown, Rachel
Degree Name: Master of Dietetics
Degree Discipline: Human Nutrition
Publisher: University of Otago
Keywords: pulse wave velocity; arterial stiffness; cardiovascular health; sodium; potassium; sodium-to-potassium
Research Type: Thesis