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

2011 ◽  
Vol 110 (2) ◽  
pp. 468-471 ◽  
Author(s):  
Mirian J. Starmans-Kool ◽  
Alice V. Stanton ◽  
Yun Y. Xu ◽  
Simon A. McG Thom ◽  
Kim H. Parker ◽  
...  

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 (Pf) and backward (Pb) 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 (Pb/Pf) 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.

2005 ◽  
Vol 85 (2) ◽  
pp. 679-715 ◽  
Author(s):  
Pierre Meneton ◽  
Xavier Jeunemaitre ◽  
Hugh E. de Wardener ◽  
Graham A. Macgregor

Epidemiological, migration, intervention, and genetic studies in humans and animals provide very strong evidence of a causal link between high salt intake and high blood pressure. The mechanisms by which dietary salt increases arterial pressure are not fully understood, but they seem related to the inability of the kidneys to excrete large amounts of salt. From an evolutionary viewpoint, the human species is adapted to ingest and excrete <1 g of salt per day, at least 10 times less than the average values currently observed in industrialized and urbanized countries. Independent of the rise in blood pressure, dietary salt also increases cardiac left ventricular mass, arterial thickness and stiffness, the incidence of strokes, and the severity of cardiac failure. Thus chronic exposure to a high-salt diet appears to be a major factor involved in the frequent occurrence of hypertension and cardiovascular diseases in human populations.


Author(s):  
Minjung Kang ◽  
Eunjeong Kang ◽  
Hyunjin Ryu ◽  
Yeji Hong ◽  
Seung Seok Han ◽  
...  

Abstract Background Diet is a modifiable factor of chronic kidney disease (CKD) progression. However, the effect of dietary salt intake on CKD progression remains unclear. Therefore, we analyzed the effect of dietary salt intake on renal outcome in Korean patients with CKD. Methods We measured 24-h urinary sodium (Na) excretion as a marker of dietary salt intake in the prospective, multi-center, longitudinal KoreaN cohort study for Outcome in patients With CKD (KNOW-CKD). Data were analyzed from CKD patients at Stages G3a to G5 (n = 1254). We investigated the association between dietary salt intake and CKD progression. Patients were divided into four quartiles of dietary salt intake, which was assessed using measured 24-h urinary Na excretion. The study endpoint was composite renal outcome, which was defined as either halving the estimated glomerular filtration rate or developing end-stage renal disease. Results During a median (interquartile range) follow-up of 4.3 (2.8–5.8) years, 480 (38.7%) patients developed the composite renal event. Compared with the reference group (Q2, urinary Na excretion: 104.2 ≤ Na excretion &lt; 145.1 mEq/day), the highest quartile of measured 24-h urinary Na excretion was associated with risk of composite renal outcome [Q4, urinary Na excretion ≥192.9 mEq/day, hazard ratio 1.8 (95% confidence interval 1.12–2.88); P = 0.015] in a multivariable hazards model. Subgroup analyses showed that high-salt intake was particularly associated with a higher risk of composite renal outcome in women, in patients &lt;60 years of age, in those with uncontrolled hypertension and in those with obesity. Conclusions High salt intake was associated with increased risk of progression in CKD.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Irina Tasevska ◽  
Sofia Enhörning ◽  
Philippe Burri ◽  
Olle Melander

This study investigated if copeptin is affected by high salt intake and whether any salt-induced changes in copeptin are related to the degree of salt sensitivity. The study was performed on 20 men and 19 women. In addition to meals containing 50 mmol NaCl daily, capsules containing 100 mmol NaCl and corresponding placebo capsules were administered during 4 weeks each, in random order. Measurements of 24 h blood pressure, body weight, 24 h urinary volume, and fasting plasma copeptin were performed at high and low salt consumption. Copeptin increased after a high compared to low dietary salt consumption in all subjects 3,59 ± 2,28 versus 3,12 ± 1,95 (P= 0,02). Copeptin correlated inversely with urinary volume, at both low (r= −0,42;P= 0,001) and high (r= −0,60;P< 0,001) salt consumption, as well as with the change in body weight (r= −0,53;P< 0,001). Systolic salt sensitivity was inversely correlated with salt-induced changes of copeptin, only in females (r= −0,58;P= 0,017). As suppression of copeptin on high versus low salt intake was associated with systolic salt sensitivity in women, our data suggest that high fluid intake and fluid retention may contribute to salt sensitivity.


Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Sean D Stocker ◽  
Megan M Wenner ◽  
William B Farquhar

Observational cohort studies suggest that severe salt restriction increases cardiovascular morbidity/mortality, and the relationship between cardiovascular morbidity and dietary salt intake resembles a J-shaped curve. A high salt diet exaggerates sympathetic nerve activity (SNA) and arterial blood pressure (ABP) responses to several cardiovascular reflexes in salt-resistant animals. This study assessed whether salt restriction also exaggerates cardiovascular reflex responses and sensitizes central autonomic networks. To test this hypothesis, male Sprague-Dawley rats were fed low (0.01% NaCl), normal (0.1% NaCl), and high (4.0% NaCl) salt diet for 14-21 days. Baseline mean ABP was not different across groups (low: 104±4, normal: 107±4, high: 107±4mmHg). Activation of sciatic afferents (1ms pulse, 500uA, 5s duration, 2-20Hz) produced significantly greater increases in renal SNA (5Hz; low: 196±12, normal: 136±9, high: 177±8%, n=8, P<0.05) and ABP (5Hz; low: 29±3, normal: 16±1, high: 24±2 mmHg, n=8, P<0.05) of rats fed low and high versus normal NaCl diets. Activation of the aortic depressor nerve (2ms pulse, 500uA, 15s duration, 2-20Hz) produced significantly greater decreases in renal SNA (5Hz; low: -55±9, normal: -34±8, high: -63±13%, n=7-8, P<0.05) and ABP (5Hz; low: -31±3, normal: -15±5, high: -32±5 mmHg, n=7-8, P<0.05) of rats fed low and high versus normal NaCl diets. To test whether dietary salt intake sensitized central sympathetic circuits, microinjection of L-glutamate (0.1-1nmol, 30nL) in the rostral ventrolateral medulla produced significantly greater increases in renal SNA (0.1nmol; low: 212±15, normal: 149±8, high: 183±17%, n=7-8, P<0.05) and ABP (0.1Hz; low: 20±2, normal: 12±2, high: 22±2 mmHg, n=7-8, P<0.05) of rats fed low and high versus normal NaCl diets. Finally, rats fed low or high NaCl versus normal NaCl diets displayed exaggerated cardiovascular responses to cage switch or mild restraint and increased 24-h blood pressure variability. The present findings show that severe salt restriction and excess dietary salt intake exaggerate sympathetic and cardiovascular responses, and may be explained by a parallel change in the sensitivity of central autonomic networks to resemble a J-shaped curve.


Circulation ◽  
2012 ◽  
Vol 125 (suppl_10) ◽  
Author(s):  
Gregory A Harshfield ◽  
Evan Mulloy ◽  
Melinda Beavers

Background: The prevalence of hypertension and blood pressure-related target organ damage in African-Americans is among the highest in the world. We hypothesize that this is in part due to aldosterone dysregulation among African-Americans beginning in youth and leading to the early development of cardiovascular disease in this population. To begin to test this hypothesis, we examined ethnic differences in aldosterone regulation in normal, healthy adolescents. Methods: The subjects in this study were 145 (60 Caucasian, 85 African-American) healthy, normotensive youth aged 15–19 years. Testing was performed following 72 hours on a controlled sodium diet. Testing consisted of the collection of aldosterone, systolic blood pressure (SBP), and urinary sodium excretion (U Na V) during continuous water intake (400 ml total) over a 2 hour period. An echocardiogram was also performed to measure target organ changes. Log transformations were performed on aldosterone levels prior to analyses. Results: African-American compared to Caucasian subjects had higher casual SBP (109±10 v 104±10; p=.006) and relative wall thickness (0.32±.03 v 0.34±.04; p=.003). During the testing procedure African-Americans also had lower levels of aldosterone (4.78±.6 v 4.35±.6 pg/ml; p =.001). In the Caucasian subjects only, aldosterone was inversely correlated with U Na V (r=−0.427; p=.001) and U Na V was positively correlated with SBP (r=0.356; p=.001). The subjects were divided into those in the upper and lower quartiles of salt intake for further analysis. The interaction between race and salt intake was significant for aldosterone (F=7.173; p=.008). Caucasian subjects with high salt intake had lower aldosterone (4.56±.59 v 5.02±0.59 pg/ml). However, aldosterone levels did not differ by salt intake in African-Americans. Summary and Conclusion: African-American subjects did not show the expected associations between aldosterone and the pressure natriuresis relation. Furthermore, African-Americans on the high salt intake failed to suppress aldosterone. These findings are consistent with our hypothesis that aldosterone dysregulation in youth may lead to the early development of cardiovascular disease in Africans-Americans.


2020 ◽  
Author(s):  
Genevieve Alexandria Bell ◽  
Hillary Ellis ◽  
Michael Tordoff

High salt intake has been linked to obesity in humans and rodents, although the direction of causation and underlying mechanisms are unclear. One hypothesis suggests that consuming salt stimulates thirst, which is assuaged by drinking sugar-sweetened beverages, leading to excess energy intake and thus obesity. We attempted to test this hypothesis using a mouse model. Adult male C57BL/6J mice ate semi-synthetic diets with either low (0.56 g Na+/kg diet) or high (5.62 g Na+/kg diet) salt content for 8 weeks. Half the mice fed each diet could drink water; the other half could drink both water and a 16% sucrose solution. Mice fed the high-salt diet with water to drink ingested ~25% more water than did those fed the low-salt diet with water to drink, demonstrating that salt stimulated thirst. However, there was no influence of dietary salt on water or sucrose intake in the groups with access to both water and sucrose. This was probably because sucrose intakes were near-maximal in both groups; mice apparently do not require salt to encourage them to drink sucrose. Dietary salt level had no effect on body weight. Relative to mice that drank only water, those that drank sucrose had a net increase in energy intake but, surprisingly, gained less body weight, perhaps because they consumed too little protein to thrive. In sum, our results do not support the hypothesis that salt increases sugar-sweetened beverage consumption, leading to obesity; however, the simple mouse model used here may not provide a competent test of this hypothesis.


Author(s):  
Amisha Maheshwari ◽  
Divya Juyal ◽  
Deepak Kohli

Hypertension is an important public health challenge worldwide. Hypertension is defined as systolic blood pressure of 120 mmHg or higher or diastolic blood pressure of 80 mmHg or higher. It can be classified into two groups. First is Primary hypertension and another is Secondary hypertension. Hypertension is directly responsible for 57% of all stroke deaths and 24% of all coronary heart disease deaths in India. Food intake plays an important role in hypertension disease as high salt intake increases the risk of hypertension and cardiovascular disease. Hypertension was significantly higher in those who take alcohol and in subjects with raised total cholesterol level but in multivariate analysis only age, education and cholesterol level were in dependently associated in hypertension. Hypertension has been associated with increased risk of coronary artery disease and is an independent risk factor for cardiovascular and cerebrovascular disease. A meta-analysis also reported that lower values of blood pressure are associated with higher risk of cardiovascular disease and also with chronic kidney disease. The Present study deals with the survey on the awareness and the effective medication that could take place to reduce the risk of hypertension. The study include around 50 patients of hypertension on the basis of their prescription given to them. The aim and objective is to reduce the side effect and lesser toxicity, diet to be followed during the treatment and observe the patients of hypertension with effective medication in different hospitals.


1993 ◽  
Vol 264 (6) ◽  
pp. H1810-H1816 ◽  
Author(s):  
M. A. Boegehold

This study evaluated the influence of high dietary salt intake on nitric oxide (NO) activity in the arteriolar network of rats resistant to salt-induced hypertension. The spinotrapezius muscle microvasculature was studied in inbred Dahl salt-resistant (SR/Jr) rats fed low (0.45%)- or high (7%)-salt diets for 4–5 wk. Arterial pressures were not different between groups at any time during the study. NO synthesis inhibition with NG-nitro-L-arginine-methyl ester (L-NAME) constricted arcade arterioles in low-salt SR/Jr and dilated arcade arterioles in high-salt SR/Jr. Arcade arteriole dilation to acetylcholine (ACh), but not sodium nitroprusside (SNP), was impaired in high-salt SR/Jr. In contrast, transverse and distal arteriole responses to L-NAME, ACh, and SNP were identical in high- and low-salt SR/Jr. These findings indicate that high salt intake, in the absence of increased arterial pressure, suppresses the influence of basal and evoked NO on vascular tone in arcading arterioles, but not in smaller transverse and distal arterioles. Unaltered SNP responses in high-salt SR/Jr suggest that this effect does not involve a change in arteriolar smooth muscle responsiveness to NO.


2011 ◽  
Vol 301 (2) ◽  
pp. F263-F270 ◽  
Author(s):  
M. C. Fiore ◽  
P. M. Jimenez ◽  
D. Cremonezzi ◽  
L. I. Juncos ◽  
N. H. García

High salt intake (HS) is a risk factor for cardiovascular and kidney disease. Indeed, HS may promote blood-pressure-independent tissue injury via inflammatory factors. The lipid-lowering 3-hydroxy 3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors exert beneficial lipid-independent effects, reducing the expression and synthesis of inflammatory factors. We hypothesized that HS impairs kidney structure and function in the absence of hypertension, and these changes are reversed by atorvastatin. Four groups of rats were treated for 6 wk in metabolic cages with their diets: normal salt (NS); HS, NS plus atorvastatin and HS plus atorvastatin. We measured basal and final body weight, urinary sodium and protein excretion (UProtV), and systolic blood pressure (SBP). At the end of the experimental period, cholesterolemia, creatinine clearance, renal vascular reactivity, glomerular volume, cortical and glomerular endothelial nitric oxide synthase (eNOS), and transforming growth factor (TGF)-β1 expression were measured. We found no differences in SBP, body weight, and cholesterolemia. HS rats had increased creatinine clearence, UProtV, and glomerular volume at the end of the study. Acetylcholine-induced vasodilatation decreased by 40.4% in HS rats ( P < 0.05). HS decreased cortical and glomerular eNOS and caused mild glomerular sclerosis, interstitial mononuclear cell infiltration, and increased cortical expression of TGF-β1. All of these salt-induced changes were reversed by atorvastatin. We conclude that long-term HS induces inflammatory and hemodynamic changes in the kidney that are independent of SBP. Atorvastatin corrected all, suggesting that the nitric oxide-oxidative stress balance plays a significant role in the earlier stages of salt induced kidney damage.


1995 ◽  
Vol 269 (5) ◽  
pp. R1225-R1229 ◽  
Author(s):  
T. Ishida ◽  
M. Ishida ◽  
H. Matsuura ◽  
R. Ozono ◽  
G. Kajiyama ◽  
...  

To determine whether abnormal cellular Ca2+ handling is involved in salt-induced hypertension of Dahl salt-sensitive rats (DS), we investigated Ca2+ handling in fura 2-loaded platelets of DS and Dahl salt-resistant rats (DR) fed a high-NaCl (8%) or a low-NacL (0.3%) diet for 4 wk from 5 wk of age. At 5 wk of age, blood pressure, resting cytosolic Ca2+ concentration ([Ca2+]i), the thrombin-evoked increase in [Ca2+]i and the size of internal Ca2+ stores of DS were comparable with those of DR. After 4 wk on the diets, resting [Ca2+]i of DS on high-NaCl diet was lower than that of DS on low-NaCl diet, and there was no effect of high salt intake on resting [Ca2+]i in DR. In DS, high salt intake attenuated the [Ca2+]i response to thrombin in the presence of external Ca2+. In contrast, the [Ca2+]i response to thrombin in the absence of external Ca2+ was enhanced by high salt intake in DS. The size of internal Ca2+ stores was increased by high salt intake in DS but not in DR. These data suggest that it is not obligatory for hypertension to be accompanied by an increase in platelet [Ca2+]i.


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