Effects of a Low‐Salt and High‐Potassium Diet on Arterial Stiffness and Left Ventricular Function in Indigenous Papuans

Abstract

Background A sodium‐restricted diet represents a potential non‐pharmacological strategy for improving blood pressure, arterial stiffness, and left ventricular (LV) diastolic function. We investigated age‐related differences in LV structure and function and the relationship between LV function and central hemodynamics in an indigenous Papuan population, who maintain a traditional lifestyle, including a low‐salt and high‐potassium diet. Methods and Results We measured LV dimensions, transmitral blood flow, and mitral annular tissue velocities through echocardiography and Doppler imaging. Blood pressure and brachial‐ankle pulse wave velocity were measured using an automatic device (Omron). Central blood pressure and wave reflection parameters were estimated via oscillometry (Mobil‐O‐Graph, using European calibrations). A total of 82 native Papuans (median age, 42 years; 38 women; no blood pressure treatment) were enrolled. Age‐related difference in brachial systolic pressure was modest but significant, and brachial‐ankle pulse wave velocity significantly increased with age; however, LV mass index remained unchanged. LV ejection fraction and global longitudinal strain were preserved; mitral A‐wave velocity and average E/e´ increased; and e´ and E/A decreased with age. Brachial‐ankle pulse wave velocity and spot urine Na/K were positively and independently correlated with E/e´. Age and heart rate were inversely associated with E/A. In conclusion, LV systolic function was preserved; however, LV diastolic function decreased with age in Papuans. Moreover, age‐related arterial stiffening, but not wave reflections, was inversely related to LV diastolic function. Conclusions Our results suggest that arterial and LV stiffness may not be altered by sodium restriction. Longitudinal studies are warranted to elucidate the effects of diet on arterial and LV function.

Salt Restriction and Angiotensin-Converting Enzyme Inhibitor Improve the Responsiveness of the Small Artery in Salt-Sensitive Hypertension

“…Although previous studies [23][24][25] have shown that high salt intake negatively impacts the response of resistant arteries to vasoactive agents, there was a lack of research focusing on the improvement effects of switching from a high-to low-salt diet in vivo. In a human study [26], found that salt reduction improved endothelium-dependent vasodilation [26] but did not improve arterial stiffness [27] and showed no impact on central and peripheral hemodynamics during exercise [28]. Perhaps it is quite impractical in human studies to design sophisticated procedures to observe the effects of salt restriction on vascular function.…”

High salt intake damages myocardial viability and induces cardiac remodeling via chronic inflammation in the elderly

“…Evidence has shown that high salt intake is one important contributor to left ventricular dysfunction and myocardial remodeling ( 1 – 4 ). Our findings are consistent with the existing evidence ( 1 – 4 ).…”

“…Evidence has shown that high salt intake is one important contributor to left ventricular dysfunction and myocardial remodeling ( 1 – 4 ). Our findings are consistent with the existing evidence ( 1 – 4 ). Salt intake was positively and independently correlated with hallmarks of left ventricular structure and function such as LVM, LVMI, LVRI, and Tei index, and negatively and independently correlated with LVFS and LVEF; however, it was impossible to clarify the causal relationship due to the inherent characteristics of a cross-sectional design.…”

“…First, the daily dietary patterns of the participants were not fully considered. High dietary energy intake and low potassium intake have been demonstrated to be associated with cardiac dysfunction and cardiac remodeling ( 4 , 47 ). Second, this study had a cross-sectional design, which did not clarify causality but only detected associations between study variables; therefore, prospective studies are needed.…”

“…Salt is necessary for the maintenance of normal physiological reactions in the body and evidence has shown that the average daily salt consumption is >10 g in most populations, which is double the recommendation by the World Health Organization (WHO) of 5 g/day, with the target for many countries being 6 g/day (1,2). High salt intake is believed to lead to a significant increase in the damage to numerous organs such as the heart, blood vessels, kidneys, and brain (1)(2)(3)(4) and an association between high salt intake and heart failure has been established (5)(6)(7). High salt intake can cause a sustained increase in the left ventricular load, which results in functional and structural changes in the left ventricle (8,9).…”