High dietary salt intake increases carotid blood pressure and wave reflection in normotensive healthy young men

Abstract

Dietary salt intake is associated with high brachial blood pressure (BP) and increased risk of cardiovascular disease. We investigated whether changes in dietary salt intake are associated with changes in central BP and wave reflection in healthy volunteers. Ten healthy normotensive male volunteers (22-40 yr) participated in a 6-wk double-blind randomized crossover study to compare a low-dietary salt intake (60-80 mmol sodium/day) with a high-salt intake (low salt intake supplemented with 128 mmol sodium/day) on central BP and wave reflection. Brachial and carotid BP, carotid blood flow velocity, forward (P(f)) and backward (P(b)) pressure, wave intensity, body weight, and urinary electrolyte excretion were measured at the end of each crossover period. High salt intake significantly increased carotid systolic BP [98 (SD 11) vs. 91 mmHg (SD 13), P < 0.01] and increased wave reflection [ratio of backward to forward pressure (P(b)/P(f)) 0.13 (SD 0.02) vs. 0.11 (SD 0.03), P = 0.04] despite only small effects on brachial BP [114 (SD 9) vs. 112 mmHg (SD 6), P = 0.1]. Urinary sodium excretion and body weight were also increased following high salt intake. High salt intake disproportionately increases central BP compared with brachial BP as a result of enhanced wave reflection. These effects may contribute to the adverse effect of high dietary salt intake on the risk of cardiovascular disease.

Central systolic blood pressure and aortic stiffness response to dietary sodium in young and middle-aged adults

“…The increase in cSBP observed in our YG group is in agreement with Starmans-Kool et al [16], who also reported an increase in cSBP in normotensive, healthy young men after a high sodium diet. The present study also reports data on a MA group, providing information on a larger age range.…”

“…It appears the increases in forward and reflected wave amplitudes are contributing to the larger augmentation of cSBP observed in the MA group. It should be noted that Starmans-Kool et al [16] reported increased reflected wave amplitudes following a high sodium diet in young, healthy males. We have also demonstrated that the CSBP response to dietary sodium appears to be greater in women.…”

“…In a study of normotensive, healthy, young men, high sodium intake was associated increased cSBP, arterial stiffness, and reflected wave amplitude [16]. Additional studies have found arterial stiffness to be reduced with lower sodium intake in hypertensive individuals [17] and when compared to age and blood pressure matched individuals on a normal sodium diet [13].…”

The blood pressure and hypertension experience among North American Indigenous populations

“…Many North American Indigenous populations continue to experience food insecurity and limited access to quality foods [37][38][39]. These limitations in diet, and increase in processed foods may lead to increased salt intake, altering blood pressure [37,39,40]. Further, less physically active lifestyles and experiences of racism may also influence blood pressure among Indigenous populations [41,42].…”

Lower potassium intake is associated with increased wave reflection in young healthy adults

“…Increased arterial stiffness and wave reflection are independent predictors of cardiovascular events [7-11]. Acutely, a high sodium meal has been shown to increase augmentation index in normotensive adults [12] while two weeks of a high salt intake in young, healthy, normotensive males increased wave reflection and carotid BP [13]. Further, two weeks of dietary sodium restriction improved carotid arterial compliance and augmentation index in older individuals with systolic hypertension [14].…”