The Importance of Population-Wide Sodium Reduction as a Means to Prevent Cardiovascular Disease and Stroke

Factors associated with heart failure hospitalization in patients with high sodium excretion: subanalysis of the ESPRIT, evaluation of sodium intake for the prediction of cardiovascular events in Japanese high-risk patients, cohort study

We have reported that high sodium excretion ≥ 4.0 g/day, assessed by repeated measurements of spot urine, is associated with composite cardiovascular (CV) events of heart failure (HF) hospitalization, acute coronary syndrome, cerebrovascular events, and documented CV deaths in Japanese high-risk patients with either stable and compensated congestive HF, high brain natriuretic peptide, coronary artery disease, cerebrovascular disease, chronic kidney disease, or atrial fibrillation. A total of 520 patients were enrolled. During the median follow-up period of 5.2 years, 105 (20%) experienced composite CV events, which were predominantly driven by 60 (12%) HF hospitalizations. The aim of the present study was to elucidate which subgroups of patients with high sodium excretion were associated with HF hospitalization. We divided the enrolled patients into three groups according to the amount of sodium excretion (< 3.0 g/day, 3.0-3.99 g/day (reference), and ≥ 4.0 g/day) based on a median of 14 measurements during follow-up. We assessed the hazard ratio for HF hospitalization according to age, bodyweight, and gender, using the Cox hazard model. In the total population, high sodium excretion ≥ 4.0 g/day was associated with HF hospitalization [hazard ratio (HR) 1.75, confidence interval (CI) 1.05-2.83] after adjustment for gender, age, and bodyweight, but was not associated with other CV events. In older patients (≥ 75 years old), high sodium excretion ≥ 4.0 g/day was associated with HF hospitalization after adjustment for gender and bodyweight (HR 3.25, CI 1.55-6.55), which was not observed in younger (< 75 years old) patients. In patients with lower bodyweight (< 60 kg), high sodium excretion ≥ 4.0 g/day was associated with HF hospitalization after adjustment for age and gender (HR 3.05, CI 1.34-6.61), which was not observed in heavier (≥ 60 kg) patients. High sodium excretion is associated with HF hospitalization in patients with older age and lower bodyweight in Japanese high-risk patients.

Association of urinary sodium and potassium excretion with systolic blood pressure in the Dietary Approaches to Stop Hypertension Sodium Trial

The 2019 National Academy of Science, Engineering and Medicine Dietary Reference Intakes (DRI) for Sodium (Na⁺) and Potassium (K⁺) Report concluded there remains insufficient evidence to establish a K⁺ DRI. This study tested the hypothesis that reduced Na⁺ and increased K⁺ excretion will positively associate with lower blood pressure in salt sensitive (SS) and salt resistant (SR) participants in the Dietary Approaches to Stop Hypertension Sodium Trial (DASH–Sodium). Via the NHLBI BioLINCC we accessed the DASH-Sodium dataset for data on systolic blood pressure (SBP), 24-h urinary Na⁺ and K⁺ excretion at screening (regular patient diet; N = 186, SS N = 222 SR) and post DASH diet (N = 71 SS, N = 119 SR). The relationships between SBP, urinary Na⁺ and K⁺ excretion, and Na⁺/K⁺ ratio were assessed via linear regression. At screening elevated urinary Na⁺ excretion positively associated with SBP in SS (1 g increase in urinary Na⁺ excretion = +1 0 ± 0.4 mmHg) but not SR participants, and urinary K⁺ excretion of <1 g K⁺/day was associated with higher SBP in SS and SR participants. Urinary K⁺ excretion ≥1 g/day, or a decreases in urinary Na⁺/K⁺ ratio, was not associated with lower SBP. Post the DASH–sodium diet intervention, SBP was reduced in SS and SR participants. However, no correlation was observed between reduced SBP and urinary K⁺ excretion or the urinary Na⁺/K⁺ ratio irrespective of the salt sensitivity of blood pressure. Our data support the DRI recommendation not to establish a K⁺ DRI and suggest further evidence is required to support a reduced Na⁺/K⁺ ratio to lower SBP.

Sodium and health-concordance and controversy

Nancy Cook and colleagues describe the sources of agreement and disagreement about the health effects of sodium and how they might be resolved

Dietary sodium and potassium intake in people with diabetes: are guidelines being met?

OBJECTIVE

Despite public health bodies advocating for lowering dietary sodium and increasing potassium intake to improve cardiovascular outcomes, people with diabetes are not meeting these targets. We hypothesize that (i) both at an individual level and within the cohort, there will be a low adherence to the guidelines and (ii) sodium and potassium intake will remain stable over time.

METHODS

We conducted this prospective study in a cohort of 904 participants with diabetes who provided 24-h urine collections from 2009 to 2015. Dietary sodium and potassium intake were estimated from 24-h urinary sodium (uNa) and potassium (uK) measurements. Additional data were collected for: 24-h urinary volume (uVol), creatinine (uCr),; serum creatinine, urea, estimated glomerular filtration rate (eGFR), glycated haemoglobin (HbA1c), fasting glucose, lipids); clinical characteristics (age, blood pressure (BP), body mass index (BMI) and duration of diabetes). Adherence to recommended dietary sodium (uNa < 2300 mg/24 h (100mmol/24 h)) and potassium (uK > 4680 mg/24 h(120 mmol/24)) intake were the main outcome measures.

RESULTS

Participants (n = 904) completed 3689 urine collections (average four collections/participant). The mean ± SD (mmol/24 h) for uNa was 181 ± 73 and uK was 76 ± 25. After correcting uNa for uCr, 7% and 5% of participants met dietary sodium and potassium guidelines respectively. Males were less likely to meet sodium guidelines (OR 0.40, p < 0.001) but were more likely to meet potassium guidelines (OR 6.13, p < 0.001). Longer duration of diabetes was associated with higher adherence to sodium and potassium guidelines (OR 1.04, p < 0.001 and OR 0.96, p = 0.006 respectively). Increasing age was significantly associated with adherence to potassium guidelines (OR 0.97, p = 0.007).

CONCLUSIONS

People with diabetes do not follow current dietary sodium and potassium guidelines and are less likely to change their dietary intake of sodium and potassium over time.

Development of Durum Wheat Breads Low in Sodium Using a Natural Low-Sodium Sea Salt

Durum wheat is widespread in the Mediterranean area, mainly in southern Italy, where traditional durum wheat breadmaking is consolidated. Bread is often prepared by adding a lot of salt to the dough. However, evidence suggests that excessive salt in a diet is a disease risk factor. The aim of this work is to study the effect of a natural low-sodium sea salt (Saltwell^®) on bread-quality parameters and shelf-life. Bread samples were prepared using different levels of traditional sea salt and Saltwell^®. The loaves were packaged in modified atmosphere conditions (MAPs) and monitored over 90 days of storage. No significant differences (p ≤ 0.05) were found in specific volumes and bread yield between the breads and over storage times, regardless of the type and quantity of salt used. Textural data, however, showed some significant differences (p ≤ 0.01) between the breads and storage times. 5-hydroxymethylfurfural (HMF) is considered, nowadays, as an emerging ubiquitous processing contaminant; bread with the lowest level of Saltwell^® had the lowest HMF content, and during storage, a decrease content was highlighted. Sensory data showed that the loaves had a similar rating (p ≤ 0.05) and differed only in salt content before storage. This study has found that durum wheat bread can make a nutritional claim of being "low in sodium" and "very low in sodium".

Excessive dietary salt promotes aortic stiffness in murine renovascular hypertension

Renovascular hypertension is characterized by activation of the renin-angiotensin-aldosterone system, blunted natriuretic responses, and elevated sympathetic nerve activity. Excess dietary salt intake exaggerates arterial blood pressure (ABP) in multiple models of experimental hypertension. The present study tested whether a high-salt diet exaggerated ABP and vascular dysfunction in a 2-kidney, 1-clip (2K1C) murine model. Male C57BL/6J mice (8-12 wk) were randomly assigned, and fed a 0.1% or 4.0% NaCl diet, and instrumented with telemetry units to measure ABP. Then, the 2K1C model was produced by placing a cuff around the right renal artery. Systolic, diastolic, and mean ABP were significantly higher in mice fed 4.0% vs. 0.1% NaCl at 1 wk but not after 3 wk. Interestingly, 2K1C hypertension progressively increased arterial pulse pressure in both groups; however, the magnitude was significantly greater in mice fed 4.0% vs. 0.1% NaCl at 3 wk. Moreover, pulse wave velocity was significantly greater in 2K1C mice fed 4.0% vs. 0.1% NaCl diet or sham-operated mice fed either diet. Histological assessment of aortas indicated no structural differences among groups. Finally, endothelium-dependent vasodilation was significantly and selectively attenuated in the aorta but not mesenteric arteries of 2K1C mice fed 4.0% NaCl vs. 0.1% NaCl or sham-operated control mice. The findings suggest that dietary salt loading transiently exaggerates 2K1C renovascular hypertension but promotes chronic aortic stiffness and selective aortic vascular dysfunction.NEW & NOTEWORTHY High dietary salt exaggerates hypertension in multiple experimental models. Here we demonstrate that a high-salt diet produces a greater increase in arterial blood pressure at 1 wk after induction of 2-kidney, 1-clip (2K1C) hypertension but not at 3 wk. Interestingly, 2K1C mice fed a high-salt diet displayed an exaggerated pulse pressure, elevated pulse wave velocity, and reduced endothelium-dependent vasodilation of the aorta but not mesenteric arteries. These findings suggest that dietary salt may interact with underlying cardiovascular disease to promote selective vascular dysfunction and aortic stiffness.

Negligible Effect of Sodium Chloride on the Development and Function of TGF-β-Induced CD4+ Foxp3+ Regulatory T Cells

High-salt diets inhibit the suppressive function of thymus-derived natural regulatory T cells (tTreg). Transforming growth factor β (TGF-β)-induced ex vivo regulatory T cells (iTreg) comprise another Treg subset that exhibits similarities and differences with tTreg. Here, we demonstrate that iTregs are completely stable and fully functional under high salt conditions. High salt does not influence the development, differentiation, and functional activities of iTreg but affects Foxp3 stability and function of tTreg in vitro and in vivo. In addition, high salt does not significantly change the transcription profiles of the iTreg signature or pro-inflammatory genes. Therefore, we conclude that iTreg, unlike tTreg, are stable and functional in the presence of high salt. Our findings provide additional evidence that iTreg may have different biological features from tTreg and suggest a greater potential for clinical utility in patients with autoimmune diseases, in which the complicated role of environmental factors, including diet, must be considered.

Screening tool for identifying adults with excessive salt intake among community-dwelling adults: a population-based cohort study

BACKGROUND

Excessive salt intake is widely known to be a cause of hypertension, cardiovascular events, and so on. However, simple tools for screening excessive salt intake are lacking.

OBJECTIVE

We aimed to develop a simple screening tool to identify community-dwelling adults with excessive salt intake.

METHODS

The present study involved participants who received health check-ups in Fukushima, Japan, in 2016 and 2017. We defined data from the 2016 check-up as the derivation set, and data from those who received check-ups in 2017 but not 2016 as the validation set. The outcome measure was excessive salt intake, defined as the estimated daily salt intake of 1 SD or more. Candidate predictors associated with the outcome were extracted using the Delphi method by an expert panel and narrowed down with clinical expertise and stepwise backward selection. The screening tool was developed using a coefficient-based multivariable scoring method and externally validated.

RESULTS

A total of 1101 participants were included in the derivation set and 249 in the validation set. At the conclusion of the deviation process, 8 predictors were selected and scored. The areas under the receiver operating characteristic curve for derivation and external validation were 0.70 (95% CI: 0.67, 0.74) and 0.71 (95% CI: 0.62, 0.80), respectively. The calibration slope and intercept for external validation were 1.16 and -0.03, respectively.

CONCLUSION

We developed a screening tool to identify adults with excessive salt intake. By extracting groups with excessive salt intake, target populations needing intervention for salt reduction can be highlighted efficiently.

Effect of Salt Supplementation on Sympathetic Activity and Endothelial Function in Salt-Sensitive Type 2 Diabetes

CONTEXT

Lower sodium intake is paradoxically associated with higher mortality in type 2 diabetes (T2D).

OBJECTIVE

To determine whether sympathetic nervous system (SNS) activation and endothelial dysfunction contribute to these observations, we examined the effect of salt supplementation on these systems in people with T2D with habitual low sodium. We hypothesized that salt supplementation would lower SNS activity and improve endothelial function compared to placebo.

DESIGN

We conducted a randomized, double-blinded, placebo-controlled crossover trial.

SETTING

The study took place in a tertiary referral diabetes outpatient clinic.

PARTICIPANTS

Twenty-two people with T2D with habitual low sodium intake (24-hour urine sodium <150 mmol/24h) were included.

INTERVENTION

Salt supplementation (100 mmol NaCl/24h) or placebo for 3 weeks was administered.

MAIN OUTCOME MEASURES

The primary outcome of SNS activity and endothelial function was assessed as follows: Microneurography assessed muscle sympathetic nerve activity (MSNA), pulse amplitude tonometry assessed endothelial function via reactive hyperemic index (RHI), and arterial stiffness was assessed via augmentation index (AI). Secondary outcomes included cardiac baroreflex, serum aldosterone, ambulatory blood pressure monitoring (ABPM), heart rate variability (HRV), and salt sensitivity.

RESULTS

Compared to placebo, salt supplementation increased MSNA (burst frequency P = .047, burst incidence P = .016); however, RHI (P = .24), AI (P = .201), ABPM (systolic P = .09, diastolic P = .14), and HRV were unaffected. Salt supplementation improved baroreflex (slope P = .026) and lowered aldosterone (P = .004), and in salt-resistant individuals there was a trend toward improved RHI (P = .07).

CONCLUSIONS

In people with T2D and low habitual sodium intake, salt supplementation increased SNS activity without altering endothelial function or blood pressure but improved baroreflex function, a predictor of cardiac mortality. Salt-resistant individuals trended toward improved endothelial function with salt supplementation.

Whey Protein and Its Components Lactalbumin and Lactoferrin Affect Energy Balance and Protect against Stroke Onset and Renal Damage in Salt-Loaded, High-Fat Fed Male Spontaneously Hypertensive Stroke-Prone Rats

BACKGROUND

Whey protein (WH)-enriched diets are reported to aid in weight loss and to improve cardiovascular health. However, the bioactive components in whey responsible for causing such effects remain unidentified.

OBJECTIVE

We determined the effects of whey and its components [α-lactalbumin (LA) and lactoferrin (LF)] on energy balance, glucose tolerance, gut hormones, renal damage, and stroke onset in rats.

METHODS

Male spontaneously hypertensive stroke-prone (SHRSP) rats (age 8 wk) were fed isocaloric high-fat (40% kcal) and high-salt (4% wt/wt) diets (n = 8-10/group) and randomized for 8 wk to diets enriched as follows: control (CO): 15% kcal from egg albumin, 45% kcal from carbohydrate; WH: 20%kcal WH isolate + 15% kcal egg albumin; LA: 20% kcal LA  + 15% kcal egg albumin; or LF: 20% kcal lactoferrin + 15% kcal egg albumin. Measurements included energy balance (food intake, energy expenditure, and body composition), stroke-related behaviors, brain imaging, glucose tolerance, metabolic hormones, and tissue markers of renal damage. Data were analyzed by linear mixed models with repeated measures or 1-way ANOVA.

RESULTS

Diets enriched with WH, LA, or LF increased survival, with 25% of rats fed these diets exhibiting stroke-associated morbidity, whereas 90% of CO rats were morbid by 8 wk (P < 0.05). The nephritis scores of rats fed WH-, LA-, or LF-enriched diets were 80%, 92%, and 122% lower than those of COs (P = 0.001). The mRNA abundances of renin and osteopontin were 100-600% lower in rats fed WH-, LA-, or LF-enriched diets than in COs (P < 0.05). Urine albumin concentrations and albumin-to-creatinine ratios were 200% lower in rats fed LF-enriched diets than in COs (P < 0.05). Compared with COs, rats fed LF-enriched diets for 2-3 wk had food intake decreased by 29%, body weight decreased by 13-19%, lean mass decreased by 12-19%, and fat mass decreased by 20% (P < 0.001). Relative to COs, rats fed WH and LA had food intake decreased by 10% (P < 0.1), but COs had 12-45% lower weight than rats fed LA- and WH-enriched diets by 3 wk (P < 0.01). Compared with COs, rats fed WH-enriched diets increased energy expenditure by 7%, whereas, rats fed LA-enriched diets had energy expenditure acutely decreased by 7% during the first 4 d, and rats fed LF-enriched diets had energy expenditure decreased by 7-17% throughout the first week ( P < 0.001). Rats fed LA- and LF-enriched diets had blood glucose decreased by 14-19% (P < 0.05) and WH by 9% (P = 0.1), relative to COs. Compared with COs, rats fed LF had GIP decreased by 90% and PYY by 87% (P < 0.05).

CONCLUSION

Together, these findings indicate that whey and its components α-lactalbumin and lactoferrin improved energy balance and glycemic control, and protected against the onset of neurological deficits associated with stroke and renal damage in male SHRSP rats.

High Salt Diet Affects the Reproductive Health in Animals: An Overview

Simple summary

Halophytic plants are a promising animal feed source. However, the extreme NaCl₂ salt content constraints their use. Excess diet salt adversely affects growth performance and animal’s reproduction worldwide. This review focuses on the impact of high salt intake on growth performance and reproduction ability in animals.

Abstract

Salinity is a reliable issue of crop productivity loss in the world and in certain tropical and subtropical zones. However, tremendous progress in the genetic improvement of plants for salinity tolerance has been made over several decades. In light of this, halophytic plants can be used as animal feeds and have promising features because they are a good feed resource. However, the main constraint of saline pasture systems is the extreme concentration of NaCl salt in drinking water and forage plants for grazing animals. Ecological reports revealed that excess diet salt causes mortality and morbidity worldwide. Animal fed halophytic forages may have adverse effects on growth performance and reproductive function in males and females due to inducing reductions in hormone regulation, such as testosterone, FSH, LH, and leptin. It was indicated that high salt intake promotes circulating inflammatory factors in the placenta and is associated with adversative effects on pregnancy. This review focuses on the scientific evidence related to the effect of high salt intake on growth performance, spermatogenesis, sperm function, and testicular morphology changes in male animals. In addition, the review will also focus on its effect on some female reproductive features (e.g., ovarian follicle developments, placental indices, and granulosa cell function).

Thyroid Function and Nutrient Status in the Athlete

Thyroid disease is common in the general population, especially in women, and also may be prevalent among athletes. Autoimmune disorders are the most common cause of thyroid disorders in countries with iodine-fortification programs; however, thyroid dysfunction can be brought on by nutritional factors, including insufficient energy intake and iodine, selenium, iron, and vitamin D deficiency. Additionally, strenuous exercise may be associated with transient alterations in thyroid hormones. While the development of thyroid related disorders has the potential to impact health and peak performance, typical clinical manifestations are highly variable, lack specificity, and are frequently confused with other health problems. The assessment process should focus on anthropometric changes, biochemical tests (thyroid panel), personal and family history, examination for appropriate signs and symptoms, and diet and environmental assessment that includes adequacy of energy, iodine, iron, selenium, and vitamin D intake/status along with excess stress and exposure to environmental contaminants and dietary goitrogens.

Kinetic Models for Glucosamine Production by Acid Hydrolysis of Chitin in Five Mushrooms

In this paper, glucosamine was produced by acid hydrolysis of five mushrooms. The glucosamine yields were investigated, and the optimum conditions were obtained as follows: acid type, sulfuric acid; acid concentration, 6 M; ratio of raw material to acid volume, 1 : 10; hydrolysis temperature, 100°C; and time, 6 h. Under these conditions, the glucosamine conversion from chitin content reached up to 92%. The results of hydrolysis kinetics indicated that hydrolysis of five mushrooms to glucosamine followed zero-order kinetics. Moreover, the relatively low activation energy for hydrolysis of straw mushroom (18.31 kJ/mol) and the highest glucosamine yield (56.8132 ± 3.5748 mg/g DM, 0.9824 g/g chitin) indicated that hydrolysis of straw mushroom was energy-saving. Thus, sulfuric acid hydrolysis of straw mushroom for glucosamine production should be considered as an efficient process for the future industrial application. However, further study is needed for glucosamine purification.

Dietary Relationship with 24 h Urinary Iodine Concentrations of Young Adults in the Mountain West Region of the United States

Background: Iodine deficiency is not seen as a public health concern in the US. However certain subpopulations may be vulnerable due to inadequate dietary sources. The purpose of the present study was to determine the dietary habits that influence iodine status in young adult men and women, and to evaluate the relationship between iodine status and thyroid function. Methods: 111 participants (31.6 ± 0.8 years, 173.2 ± 1.0 cm, 74.9 ± 1.7 kg) provided 24 h urine samples and completed an iodine-specific Food Frequency Questionnaire (FFQ) for assessment of urinary iodine content (UIC) as a marker of iodine status and habitual iodine intake, respectively. Serum Thyroid Stimulating Hormone (TSH) concentration was evaluated as a marker of thyroid function. Spearman correlational and regression analysis were performed to analyze the associations between iodine intake and iodine status, and iodine status and thyroid function. Results: 50.4% of participants had a 24 h UIC < 100 µg/L). Dairy (r = 0.391, p < 0.000) and egg intake (r = 0.192, p = 0.044) were the best predictors of UIC, accounting for 19.7% of the variance (p ≤ 0.0001). There was a significant correlation between UIC and serum TSH (r = 0.194, p < 0.05) but TSH did not vary by iodine status category (F = 1.087, p = 0.372). Discussion: Total dairy and egg intake were the primary predictors of estimated iodine intake, as well as UIC. Iodized salt use was not a significant predictor, raising questions about the reliability of iodized salt recall. These data will be useful in directing public health and clinical assessment efforts in the US and other countries.

Moving the Needle on Hypertension: What Knowledge Is Needed?

This review highlights the gaps in knowledge and methodological challenges discussed during the Experimental Biology 2019 expert panel session titled "Moving the Needle on Hypertension: What Knowledge Is Needed?" Hypertension is a critical public health burden. Despite a demonstrated benefit of blood pressure reduction on measures of hypertension-related morbidity and mortality, rates for successful blood pressure control remain low. Dietary sodium reduction has been shown to reduce both systolic blood pressure by approximately 3.2 mm Hg and diastolic blood pressure by 2.3 mm Hg, depending on baseline blood pressure and degree of sodium reduction. The updated Dietary Reference Intakes for adults released by the National Academies of Sciences, Engineering, and Medicine include a Chronic Disease Risk Reduction sodium intake level of 2300 mg/d, highlighting the importance of dietary sodium intake in reducing elevated blood pressure and indicating that reducing intakes to this level is expected to reduce blood pressure and risk of cardiovascular disease. The average US daily sodium intake of 3400 mg/d is well above the Chronic Disease Risk Reduction of 2300 mg/d, suggesting that dietary sodium reduction has the potential to significantly improve public health. Although the National Academies of Sciences, Engineering, and Medicine report presents intake recommendations based on a systematic, comprehensive, and thorough evaluation of the evidence, several challenges to moving the needle on hypertension remain. Success will require a more advanced understanding of sodium and potassium physiology, as well as development of the tools needed to effectively address existing research gaps and reduce barriers to sodium intake reduction.

Sympathetic regulation of NCC in norepinephrine-evoked salt-sensitive hypertension in Sprague-Dawley rats

Salt sensitivity of blood pressure is characterized by inappropriate sympathoexcitation and renal Na⁺ reabsorption during high salt intake. In salt-resistant animal models, exogenous norepinephrine (NE) infusion promotes salt-sensitive hypertension and prevents dietary Na⁺-evoked suppression of the Na⁺-Cl^- cotransporter (NCC). Studies of the adrenergic signaling pathways that modulate NCC activity during NE infusion have yielded conflicting results implicating α₁- and/or β-adrenoceptors and a downstream kinase network that phosphorylates and activates NCC, including with no lysine kinases (WNKs), STE20/SPS1-related proline-alanine-rich kinase (SPAK), and oxidative stress response 1 (OxSR1). In the present study, we used selective adrenoceptor antagonism in NE-infused male Sprague-Dawley rats to investigate the differential roles of α₁- and β-adrenoceptors in sympathetically mediated NCC regulation. NE infusion evoked salt-sensitive hypertension and prevented dietary Na⁺-evoked suppression of NCC mRNA, protein expression, phosphorylation, and in vivo activity. Impaired NCC suppression during high salt intake in NE-infused rats was paralleled by impaired suppression of WNK1 and OxSR1 expression and SPAK/OxSR1 phosphorylation and a failure to increase WNK4 expression. Antagonism of α₁-adrenoceptors before high salt intake or after the establishment of salt-sensitive hypertension restored dietary Na⁺-evoked suppression of NCC, resulted in downregulation of WNK4, SPAK, and OxSR1, and abolished the salt-sensitive component of hypertension. In contrast, β-adrenoceptor antagonism attenuated NE-evoked hypertension independently of dietary Na⁺ intake and did not restore high salt-evoked suppression of NCC. These findings suggest that a selective, reversible, α₁-adenoceptor-gated WNK/SPAK/OxSR1 NE-activated signaling pathway prevents dietary Na⁺-evoked NCC suppression, promoting the development and maintenance of salt-sensitive hypertension.

Sodium Intake from Foods Exceeds Recommended Limits in the Spanish Population: The ANIBES Study

Excessive sodium consumption is associated with adverse health effects. An elevated dietary intake of salt (sodium chloride) has been related to high blood pressure or hypertension, a major but modifiable risk factor for cardiovascular disease, as well as to other ill health conditions. In the present work, our aim was to describe the contribution of foods to sodium consumption within the Spanish population in a representative sample from the "anthropometric data, macronutrients and micronutrients intake, practice of physical activity, socioeconomic data and lifestyles in Spain" (ANIBES) study (9-75 years), to identify high consumer groups, as well as the major food groups that contribute to sodium intake in the Spanish diet. Intakes were assessed by 3-day food records collected on a tablet device. Sodium intakes across the ANIBES study population exceeded recommendations, as total intakes reached 2025 ± 805 mg of sodium per day, that is approximately 5.06 g/day of salt (excluding discretionary salt, added at the table or during cooking). Sodium intakes were higher in males than in females and within the youngest groups. Main dietary sources of sodium were meat and meat products (27%), cereals and grains (26%), milk and dairy products (14%) and ready-to-eat meals (13%). Given the established health benefits of dietary salt reduction, it would be advisable to continue and even improve the current national initiatives of awareness and educational campaigns and particularly food reformulation to decrease overall salt intakes across the Spanish population.

A high-salt meal does not augment blood pressure responses during maximal exercise

Augmented blood pressure (BP) responses during exercise are predictive of future cardiovascular disease. High dietary sodium (Na⁺) increases BP responses during static exercise. It remains unclear if high dietary Na⁺ augments BP responses during dynamic exercise. The purpose of this study was to test the hypothesis that an acute high-Na⁺ meal would augment BP responses during dynamic exercise. Twenty adults (10 male/10 female; age, 26 ± 5 years; BP, 105 ± 10/57 ± 6 mm Hg) were given a high-Na⁺ meal (HSM; 1495 mg Na⁺) and a low-Na⁺ meal (LSM; 138 mg Na⁺) separated by at least 1 week, in random order. Serum Na⁺ and plasma osmolality were measured. Eighty minutes following the meal, participants completed a graded-maximal exercise protocol on a cycle ergometer. Heart rate, beat-by-beat BP, cardiac output, total peripheral resistance, and manual BP were measured at rest and during exercise. Both serum Na⁺ (HSM: Δ1.6 ± 2.0 vs LSM: Δ1.1 ± 1.8 mmol/L, P = 0.0002) and plasma osmolality (HSM: Δ3.0 ± 4.5 vs LSM: Δ2.0 ± 4.2 mOsm/(kg·H₂O), P = 0.01) were higher following the HSM. However, the HSM did not augment BP during peak exercise (systolic BP: HSM: 170 ± 23 vs LSM: 171 ± 21 mm Hg, P = 0.81). These findings suggest that an acute high-salt meal does not augment BP responses during dynamic exercise in adults. Novelty The high-salt meal increased serum sodium and plasma osmolality compared with the low-salt meal. The high-salt meal did not augment blood pressure responses during maximal dynamic exercise. This is important as augmented blood pressure responses during exercise put individuals at greater risk for development of cardiovascular disease.

Targeting the Gut Microbiota to Investigate the Mechanism of Lactulose in Negating the Effects of a High-Salt Diet on Hypertension

SCOPE

High-salt diets (HSDs) are widely considered to cause health problems such as gut microecological imbalances, constipation, and hypertension. This study explores how lactulose as a safe molecule can stimulate bodily responses to alleviate salt-sensitive hypertension by regulating the gut microbiotas of HSD-fed mice.

METHODS AND RESULTS

After 4 weeks, the blood pressures of mice fed a high-salt plus lactulose diet (HSLD) are significantly lower than those of the HSD-fed mice. The HSD increases the abundances of Alistipes and Ruminococcaceae_UCG_009 and reduced the abundance of Lactobacillus in the gut, while lactulose supplementation increases the abundances of Bifidobacterium, Alloprevotella, and Subdoligranulum. Fecal metabolic profiling shows significant increases in metabolites involved in ATP-binding cassette transporter pathways, and tryptophan metabolism is significantly reduced in the HSLD group compared with the HSD group. Lactulose maintains the intestinal microenvironmental health in the HSD-fed mice by improving glycolipid metabolism, decreasing the small intestinal interleukin-17a (IL-17a) and interleukin-22 (IL-22) mRNA levels and serum IL-17a and IL-22 levels, relieving constipation, increasing fecal sodium, and reducing intestinal permeability.

CONCLUSION

Lactulose negates salt-sensitive hypertension. Regulating the gut microbiota is a potential treatment for salt-sensitive hypertension.

Role of the afferent renal nerves in sodium homeostasis and blood pressure regulation in rats

New Findings

What is the central question of this study?

What are the differential roles of the mechanosensitive and chemosensitive afferent renal nerves in the reno‐renal reflex that promotes natriuresis, sympathoinhibition and normotension during acute and chronic challenges to sodium homeostasis?

What is the main finding and its importance?

The mechanosensitive afferent renal nerves contribute to an acute natriuretic sympathoinhibitory reno‐renal reflex that may be integrated within the paraventricular nucleus of the hypothalamus. Critically, the afferent renal nerves are required for the maintenance of salt resistance in Sprague–Dawley and Dahl salt‐resistant rats and attenuate the development of Dahl salt‐sensitive hypertension.

Abstract

These studies tested the hypothesis that in normotensive salt‐resistant rat phenotypes the mechanosensitive afferent renal nerve (ARN) reno‐renal reflex promotes natriuresis, sympathoinhibition and normotension during acute and chronic challenges to fluid and electrolyte homeostasis. Selective ARN ablation was conducted prior to (1) an acute isotonic volume expansion (VE) or 1 m NaCl infusion in Sprague–Dawley (SD) rats and (2) chronic high salt intake in SD, Dahl salt‐resistant (DSR), and Dahl salt‐sensitive (DSS) rats. ARN responsiveness following high salt intake was assessed ex vivo in response to noradrenaline and sodium concentration (SD, DSR and DSS) and via in vivo manipulation of renal pelvic pressure and sodium concentration (SD and DSS). ARN ablation attenuated the natriuretic and sympathoinhibitory responses to an acute VE [peak natriuresis (µeq min⁻¹) sham 52 ± 5 vs. ARN ablation 28 ± 3, P < 0.05], but not a hypertonic saline infusion in SD rats. High salt (HS) intake enhanced ARN reno‐renal reflex‐mediated natriuresis in response to direct increases in renal pelvic pressure (mechanoreceptor stimulus) in vivo and ARN responsiveness to noradrenaline ex vivo in SD, but not DSS, rats. In vivo and ex vivo ARN responsiveness to increased renal pelvic sodium concentration (chemoreceptor stimulus) was unaltered during HS intake. ARN ablation evoked sympathetically mediated salt‐sensitive hypertension in SD rats [MAP (mmHg): sham normal salt 102 ± 2 vs. sham HS 104 ± 2 vs. ARN ablation normal salt 103 ± 2 vs. ARN ablation HS 121 ± 2, P < 0.05] and DSR rats and exacerbated DSS hypertension. The mechanosensitive ARNs mediate an acute sympathoinhibitory natriuretic reflex and counter the development of salt‐sensitive hypertension.

Dietary intake of people with severe mental illness: systematic review and meta-analysis

BACKGROUND

Severe mental illness (SMI) is thought to be associated with lower diet quality and adverse eating behaviours contributing towards physical health disparities. A rigorous review of the studies looking at dietary intake in psychotic disorders and bipolar disorder is lacking.AimsTo conduct a systematic, comprehensive evaluation of the published research on dietary intake in psychotic disorders and bipolar disorder.

METHOD

Six electronic databases were searched for studies reporting on dietary intakes in psychotic disorders and bipolar disorder. Dietary-assessment methods, and dietary intakes, were systematically reviewed. Where possible, data was pooled for meta-analysis and compared with healthy controls.

RESULTS

In total, 58 eligible studies were identified. People with SMI were found to have significantly higher dietary energy (mean difference 1332 kJ, 95% CI 487-2178 kJ/day, P = 0.002, g = 0.463) and sodium (mean difference 322 mg, 95% CI 174-490 mg, P &lt; 0.001, g = 0.414) intake compared with controls. Qualitative synthesis suggested that higher energy and sodium intakes were associated with poorer diet quality and eating patterns.

CONCLUSIONS

These dietary components should be key targets for preventative interventions to improve weight and other physical health outcomes in people with SMI.Declaration of interestS.B.T. and E.T. have clinical dietitian appointments within the South Eastern Sydney Local Health District and do not receive any further funding.

The Influence of Dietary Salt Beyond Blood Pressure

PURPOSE OF REVIEW

Excess sodium from dietary salt (NaCl) is linked to elevations in blood pressure (BP). However, salt sensitivity of BP varies widely between individuals and there are data suggesting that salt adversely affects target organs, irrespective of BP.

RECENT FINDINGS

High dietary salt has been shown to adversely affect the vasculature, heart, kidneys, skin, brain, and bone. Common mediators of the target organ dysfunction include heightened inflammation and oxidative stress. These physiological alterations may contribute to disease development over time. Despite the adverse effects of salt on BP and several organ systems, there is controversy surrounding lower salt intakes and cardiovascular outcomes. Our goal here is to review the physiology contributing to BP-independent effects of salt and address the controversy around lower salt intakes and cardiovascular outcomes. We will also address the importance of background diet in modulating the effects of dietary salt.

Paucity of high-quality studies reporting on salt and health outcomes from the science of salt: A regularly updated systematic review of salt and health outcomes (April 2017 to March 2018)

The purpose of this review is to identify, summarize, and critically appraise studies on dietary salt and health outcomes that were published from April 2017 to March 2018. The search strategy was adapted from a previous systematic review on dietary salt and health. Identified studies were screened based on a priori defined criteria to identify publications eligible for detailed critical appraisals. Overall, 6747 citations were identified by the search strategy, and 42 health outcome studies were identified. Three of the 42 studies met the criteria for methodological quality and health outcomes and underwent detailed critical appraisals and commentary. In addition, a systematic review and meta-analysis was critically appraised, although it did not strictly meet our methodological criteria. All four of the studies critically appraised found that sodium reduction improved blood pressure, especially in individuals with hypertension. In addition, sodium reduction reduced albuminuria in patients with stage 1-3 chronic kidney disease. Examination of the time course of blood pressure responses to sodium reduction revealed lowering sodium in the context of an average American diet may not produce maximal blood pressure reductions within a 4-week intervention period. This review provides further evidence of the benefit of sodium reduction for blood pressure lowering and gives insights into the subgroups of the population that may derive the greatest benefit from sodium reduction and the time course required to see benefit. Only three high-quality studies were identified during this 12-month review period, highlighting the critical need for more well-conducted rigorous studies in this area.

Dietary salt promotes ischemic brain injury and is associated with parenchymal migrasome formation

Sodium chloride promotes vascular fibrosis, arterial hypertension, pro-inflammatory immune cell polarization and endothelial dysfunction, all of which might influence outcomes following stroke. But despite enormous translational relevance, the functional importance of sodium chloride in the pathophysiology of acute ischemic stroke is still unclear. In the current study, we show that high-salt diet leads to significantly worse functional outcomes, increased infarct volumes, and a loss of astrocytes and cortical neurons in acute ischemic stroke. While analyzing the underlying pathologic processes, we identified the migrasome as a novel, sodium chloride-driven pathomechanism in acute ischemic stroke. The migrasome was previously described in vitro as a migrating organelle, which incorporates and dispatches cytosol of surrounding cells and plays a role in intercellular signaling, whereas a pathophysiological meaning has not been elaborated. We here confirm previously reported characteristics of the migrasome in vivo. Immunohistochemistry, electron microscopy and proteomic analyses further demonstrate that the migrasome incorporates and dispatches cytosol of surrounding neurons following stroke. The clinical relevance of these findings is emphasized by neuropathological examinations, which detected migrasome formation in infarcted brain parenchyma of human stroke patients. In summary, we demonstrate that high-salt diet aggravates stroke outcomes, and we characterize the migrasome as a novel mechanism in acute stroke pathophysiology.

Daily urinary sodium and potassium excretion in Chinese first-generation migrants in Italy

BACKGROUND

China has one of the highest salt intake levels in the world, and Chinese people form one of the largest foreign-born communities now living in Europe. The present study was performed to assess 24-hour urinary sodium and potassium excretion in Chinese migrants in Italy and to explore possible associations with hypertension, hypertension awareness, and length of residence in Italy.

METHODS

A cross-sectional evaluation was conducted on 319 first-generation Chinese migrants (154 women and 165 men) aged 18-70 years. Subjects were asked to do a 24-hour urine collection and the relationships of urinary sodium and potassium and arterial blood pressure, hypertension (BP ≥ 140/90 mmHg or anti-hypertensive drug use), hypertension awareness, and years of residence in Italy were investigated with linear or logistic regression analysis.

RESULTS

Sodium excretion was 145.2 mmol/day (95%CI 138.0-152.3) in men, and 134.7 (95%CI 127.6-141.8) in women corresponding to a dietary salt intake of 9.4 g/day (95%CI 9.0-9.9) and 8.8 (95%CI 8.3-9.2) respectively. Potassium excretion was 35.1 mmol/day (95%CI 33.6-36.5), with no significant difference by gender. At multivariable adjusted linear regression analysis body mass index, low education level, and hypertension were positive predictors of sodium urinary excretion; gender (women), and body mass index were positive predictors of potassium excretion. Sodium and potassium excretion were unaffected by hypertension awareness or years of residence in Italy.

CONCLUSIONS

Sodium excretion in Chinese workers is higher than recommended and in line with high salt intake in Italy. Potassium consumption remains low.

Association of blood pressure with estimates of 24-h urinary sodium and potassium excretion from repeated single-spot urine samples

While the association between 24-h urinary sodium and potassium excretion with blood pressure is well established, the relationships of these ions to spot urine measurements are unclear. Our purpose is to assess the association between blood pressure and the estimated 24-h sodium and potassium excretion from repeated single-spot urine samples. Spot urine and blood pressure were collected annually during a 5-year period from 4360 Japanese workers with ages ranging from 19 to 55 years. Estimates of 24-h sodium and potassium excretion were based on Tanaka's formula. Overall, a single standard deviation increase in the estimated sodium excretion (36.5 mmol/day) was associated with a 1.3 mmHg higher systolic blood pressure and a 0.8 mmHg higher diastolic blood pressure (P < 0.001). A single standard deviation increase in estimated potassium excretion (8.9 mmol/day) was associated with a 1.1 mmHg lower systolic blood pressure and a 0.7 mmHg lower diastolic blood pressure (P < 0.001). As a combined measure of the excretion of both electrolytes, the estimated 24-h sodium-to-potassium ratio was positively associated with both blood pressures (P < 0.001). Associations of blood pressure with sodium and the sodium-to-potassium ratio increased with age and were stronger in men compared to women. Associations with potassium and the sodium-to-potassium ratio were stronger in individuals who were overweight. The findings provide evidence for an association between blood pressure and the estimated 24-h sodium and potassium excretion from repeated single-spot urine samples. As convenient measures of dietary intake for each electrolyte, repeated spot urine samples may be useful for assessing hypertension risk, especially in men, older individuals, and overweight individuals.

Long-term low salt diet increases blood pressure by activation of the renin-angiotensin and sympathetic nervous systems

Background The aim of this study was to investigate the effect of long-term low salt diet on blood pressure and its underlying mechanisms.Methods Male Sprague-Dawley (SD) rats were divided into normal salt diet group (0.4%) and low salt diet group (0.04%). Blood pressure was measured with the non-invasive tail-cuff method. The contractile response of isolated mesenteric arteries was measured using a small vessel myograph. The effects on renal function of the intrarenal arterial infusion of candesartan (10 μg/kg/min), an angiotensin II receptor type 1 (AT₁R) antagonist, were also measured. The expressions of renal AT₁R and mesenteric arterial α_1A, α_1B, and α_1D adrenergic receptors were quantified by immunoblotting. Plasma levels of angiotensin II were also measured.Results Systolic blood pressure was significantly increased after 8 weeks of low salt diet. There were no obvious differences in the renal structure between the low and normal salt diet groups. However, the plasma angiotensin II levels and renal AT₁R expression were higher in low than normal salt diet group. The intrarenal arterial infusion of candesartan increased urine flow and sodium excretion to a greater extent in the low than normal salt diet group. The expressions of α_1A and α_1D, but not α_1B, adrenergic receptors, and phenylephrine-induced contraction were increased in mesenteric arteries from the low salt, relative to the normal salt diet group.Conclusion Activation of the renin-angiotensin and sympathetic nervous systems may be involved in the pathogenesis of long-term low salt diet-induced hypertension.

The relationship between habitual dietary sodium intake and RAAS blockade on circulating microparticle levels in type two diabetes

OBJECTIVE

Low sodium intake is paradoxically associated with adverse cardiovascular outcomes in individuals with type 2 diabetes mellitus (T2D), possibly from renin-angiotensin-aldosterone system (RAAS) activation, leading to endothelial dysfunction. In the present study, we investigated the associations between habitual sodium intake and RAAS blockade on endothelial function by measuring circulating microparticles (MPs) in individuals with T2D.

METHODS

We conducted a prospective, cross-sectional study in 74 individuals with T2D. Habitual dietary sodium intake was estimated by using the mean of three corrected 24-h urine sodium excretion measurements (24hUNa). MP subtypes in platelet-free plasma were quantitated using flow cytometry.

RESULTS

No associations between 24hUNa with levels of endothelial MPs were observed. Instead, a trend toward higher diabetes related CD36+/CD235a+ MP levels was associated with lower 24hUNa (rho = -0.23, P=0.05). When stratified according to tertiles of 24hUNa, platelet-derived CD42b+/CD41+ and CD42+/CD41+/Annexin V+ MPs were higher in the lowest tertile (24hUNa < 157 mmol/24 h) (P=0.02 respectively). Despite RAAS blockade being associated with lower levels of most MP subsets, it was not associated with lower MPs, in the setting of low sodium intake.

CONCLUSION

Lower sodium intake is associated with higher circulating procoagulant MPs, but not with evidence of endothelial dysfunction in individuals with T2D.

Acute NaCl Loading Reveals a Higher Blood Pressure for a Given Serum Sodium Level in African American Compared to Caucasian Adults

Purpose: African American individuals are more prone to salt-sensitive hypertension than Caucasian individuals. Small changes in serum sodium (Na⁺) result in increased blood pressure (BP). However, it remains unclear if there are racial differences in BP responsiveness to increases in serum Na⁺. Therefore, the purpose of this investigation was to determine if African American adults have altered BP responsiveness to acute changes in serum Na⁺ compared to Caucasian adults.

Methods: We measured beat-by-beat BP, serum Na⁺, plasma renin activity (PRA), angiotensin II (Ang II), and aldosterone (Aldo) during a 60-min 3% NaCl infusion (hypertonic saline infusion, HSI) in 39 participants (19 African Americans, age: 23 ± 1, 20 Caucasians, age: 25 ± 1). Data reported as African American vs. Caucasian cohort, mean ± SEM.

Results: Baseline BP and serum Na⁺ were similar between groups and increased during HSI in both African American and Caucasian participants (p < 0.01). However, the peak change in serum Na⁺ was greater in African American participants (Δ5.8 ± 0.34 vs. Δ4.85 ± 0.38 mmol/L, p = 0.03). There was a significant group effect (p = 0.02) and an interaction between race and serum Na⁺ on systolic BP (p = 0.02). Larger categorical changes in serum Na⁺ corresponded to changes in systolic BP (p < 0.01) and African American participants demonstrated greater systolic BP responses for a given categorical serum Na⁺ increase (p < 0.01). Baseline Aldo was lower in African American adults (7.2 ± 0.6 vs. 12.0 ± 1.9 ng/dL, p = 0.03), there was a trend for lower baseline PRA (0.59 ± 0.9 vs. 1.28 ± 0.34 ng/mL/h, p = 0.07), and baseline Ang II was not different (14.2 ± 1.8 vs. 18.5 ± 1.4 pg/mL, p = 0.17). PRA and Aldo decreased during the HSI (p ≤ 0.01), with a greater decline in PRA (Δ–0.31 ± 0.07 vs. Δ–0.85 ± 0.25 ng/mL/h, p < 0.01) and Aldo (Δ–2.5 ± 0.5 vs. Δ–5.0 ± 1.1 ng/dL, p < 0.01) in Caucasian participants. However, the racial difference in PRA (p = 0.57) and Aldo (p = 0.59) reduction were no longer significant following baseline covariate analysis. Conclusion: African American individuals demonstrate augmented serum Na⁺ to an acute hypertonic saline load and greater systolic BP responsiveness to a given serum Na⁺. The altered BP response may be attributable to lower basal PRA and Aldo and a subsequently blunted RAAS response during the HSI.

Diuretics in the Management of Cardiorenal Syndrome

The leading cause of death worldwide is cardiovascular disease. The heart and the kidneys are functionally interdependent, such that dysfunction in one organ may cause dysfunction in the other. By one estimate, more than 60% of patients with congestive heart failure develop chronic kidney disease. Volume overload and congestion are hallmarks of heart failure, and these findings are associated with severe symptoms and poor outcomes. Given the importance of congestion, diuretics remain a cornerstone of heart failure management. However, diuretic treatment remains largely empirical, with little evidence currently available to guide decisions. In this review, we discuss the pathophysiology of cardiorenal syndrome, the pharmacology of loop diuretics, mechanisms of diuretic resistance, and evidence-based treatment paradigms.

Sodium and potassium excretion in an adult Caribbean population of African descent with a high burden of cardiovascular disease

Background

High sodium diets with inadequate potassium and high sodium-to-potassium ratios are a known determinant of hypertension and cardiovascular disease (CVD). The Caribbean island of Barbados has a high prevalence of hypertension and mortality from CVD. Our objectives were to estimate sodium and potassium excretion, to compare estimated levels with recommended intakes and to identify the main food sources of sodium in Barbadian adults.

Methods

A sub-sample (n = 364; 25–64 years) was randomly selected from the representative population-based Health of the Nation cross-sectional study (n = 1234), in 2012–13. A single 24-h urine sample was collected from each participant, following a strictly applied protocol designed to reject incomplete samples, for the measurement of sodium and potassium excretion (in mg), which were used as proxy estimates of dietary intake. In addition, sensitivity analyses based on estimated completeness of urine collection from urine creatinine values were undertaken. Multiple linear regression was used to examine differences in sodium and potassium excretion, and the sodium-to-potassium ratio, by age, sex and educational level. Two 24-h recalls were used to identify the main dietary sources of sodium. All analyses were weighted for the survey design.

Results

Mean sodium excretion was 2656 (2488–2824) mg/day, with 67% (62–73%) exceeding the World Health Organization (WHO) recommended limit of 2000 mg/d. Mean potassium excretion was 1469 (1395–1542) mg/d; < 0.5% met recommended minimum intake levels. Mean sodium-to-potassium ratio was 2.0 (1.9–2.1); not one participant had a ratio that met WHO recommendations. Higher potassium intake and lower sodium-to-potassium ratio were independently associated with age and tertiary education. Sensitivity analyses based on urine creatinine values did not notably alter these findings.

Conclusions

In this first nationally representative study with objective assessment of sodium and potassium excretion in a Caribbean population in over 20 years, levels of sodium intake were high, and potassium intake was low. Younger age and lower educational level were associated with the highest sodium-to-potassium ratios. These findings provide baseline values for planning future policy interventions for non-communicable disease prevention.

Home-Delivered Meals Postdischarge From Heart Failure Hospitalization

Background In patients with heart failure (HF), malnutrition and dietary sodium excess are common and may worsen outcomes. No prior studies have provided low-sodium, nutritionally complete meals following HF hospitalization. Methods and Results The GOURMET-HF study (Geriatric Out-of-Hospital Randomized Meal Trial in Heart Failure) randomized patients discharged from HF hospitalization to 4 weeks of home-delivered sodium-restricted Dietary Approaches to Stop Hypertension meals (DASH/SRD; 1500 mg sodium/d) versus usual care. The primary outcome was the between-group change in the Kansas City Cardiomyopathy Questionnaire summary score from discharge to 4 weeks postdischarge. Additional outcomes included changes in the Kansas City Cardiomyopathy Questionnaire clinical summary score and cardiac biomarkers. All patients were followed 12 weeks for death/all-cause readmission and potential diet-related adverse events (symptomatic hypotension, hyperkalemia, acute kidney injury). Sixty-six patients were randomized 1:1 at discharge to DASH/SRD versus usual care (age, 71±8 years; 30% female; ejection fraction, 39±18%). The Kansas City Cardiomyopathy Questionnaire summary score increased similarly between groups (DASH/SRD 46±23-59±20 versus usual care 43±19-53±24; P=0.38), but the Kansas City Cardiomyopathy Questionnaire clinical summary score increase tended to be greater in DASH/SRD participants (47±22-65±19 versus 45±20-55±26; P=0.053). Potentially diet-related adverse events were uncommon; 30-day HF readmissions (11% versus 27%; P=0.06) and days rehospitalized within that timeframe (17 versus 55; P=0.055) trended lower in DASH/SRD participants. Conclusions Home-delivered DASH/SRD after HF hospitalization appeared safe in selected patients and had directionally favorable effects on HF clinical status and 30-day readmissions. Larger studies are warranted to clarify the effects of postdischarge nutritional support in patients with HF. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT02148679.

Correlation between Na/K ratio and electron densities in blood samples of breast cancer patients

The main purpose of this study was to investigate the relationship between the electron densities and Na/K ratio which has important role in breast cancer disease. Determinations of sodium and potassium concentrations in blood samples performed with inductive coupled plasma-atomic emission spectrometry. Electron density values of blood samples were determined via ZXCOM. Statistical analyses were performed for electron densities and Na/K ratio including Kolmogorov-Smirnov normality tests, Spearman's rank correlation test and Mann-Whitney U test. It was found that the electron densities significantly differ between control and breast cancer groups. In addition, statistically significant positive correlation was found between the electron density and Na/K ratios in breast cancer group.

Dietary sodium, sodium-to-potassium ratio, and risk of stroke: A systematic review and nonlinear dose-response meta-analysis

BACKGROUND & AIMS

The association of high sodium intake with risk of stroke has been accepted. But considering the proposed J/U-shaped association between sodium intake and risk of all-cause mortality, the shape of the dose-response relationship has not been determined yet. This study aimed to test the dose-response association of dietary sodium and sodium-to-potassium ratio with risk of stroke in adults aged 18 years or older.

METHODS

We performed a systematic search using PubMed and Scopus, from database inception up to October 2017. Prospective and retrospective observational studies reporting risk estimates of stroke for three or more quantitative categories of dietary sodium or sodium-to-potassium ratio were included. Studies that reported results as continuous were also included. Two independent authors extracted the information and assessed the quality of included studies. Pooled relative risk (RR) was calculated using a random-effects model. Publication bias was tested. Sensitivity and subgroup analyses were done.

RESULTS

Of initial 20,412 studies identified, 14 prospective cohort studies, one case-cohort study, and one case-control study (total n = 261,732) with 10,150 cases of stroke were included. The Pooled RRs of stroke were 1.06 (95%CI: 1.02, 1.10; I² = 60%, n = 14 studies) for a 1 gr/d increment in dietary sodium intake, and 1.22 (95%CI: 1.04, 1.41; I² = 60%, n = 5 studies) for a one-unit increment in dietary sodium-to-potassium ratio (mmol/mmol). The risk of stroke increased linearly with increasing dietary sodium intake, and also along with the increase in dietary sodium-to-potassium ratio. No evidence of a J/U-shaped association was found in the analyses of total stroke, stroke incidence, and stroke mortality. High sodium intake was associated with a somewhat worse prognosis among Asian countries as compared to westerns.

CONCLUSION

Higher sodium intake and higher dietary sodium-to-potassium ratio were associated with a higher risk of stroke. Reducing dietary sodium-to-potassium ratio can be considered as a supplementary approach in parallel with the decrease in sodium intake in order to decrease stroke risk. The interpretation of the results is limited by observational nature of studies examined.

Evaluation of a Healthy Chinese Take-Out Sodium-Reduction Initiative in Philadelphia Low-Income Communities and Neighborhoods

OBJECTIVES

Sodium reduction in restaurant foods is important because 77% of sodium in the United States is consumed by eating prepared and restaurant foods. We evaluated a sodium-reduction intervention, Healthy Chinese Take-Out Initiative, among Chinese take-out restaurants in low-income neighborhoods in Philadelphia, Pennsylvania. Our objectives were to (1) analyze changes in the sodium content of food samples and (2) collect data on changes in chefs' and owners' knowledge about the health risks of sodium overconsumption, perceptions of the need for sodium reduction, self-efficacy for lowering sodium use, and perceptions of training needs for sodium-reduction strategies.

METHODS

The initiative trained chefs from 206 Chinese take-out restaurants on strategies to reduce sodium in prepared dishes. We analyzed changes in the sodium content of the 3 most frequently ordered dishes-shrimp and broccoli, chicken lo mein, and General Tso's chicken-from baseline (July-September 2012) to 36 months after baseline (July-September 2015) among 40 restaurants. We conducted a survey to examine the changes in chefs' and owners' knowledge, perceptions, and self-efficacy of sodium reduction. We used multilevel analysis and repeated-measures analysis of variance to examine effects of the intervention on various outcomes.

RESULTS

We found significant reductions in the sodium content of all 3 dishes 36 months after a low-sodium cooking training intervention (coefficients range, -1.06 to -1.69, P < .001 for all). Mean knowledge (range, 9.2-11.1), perceptions (range, 4.6-6.0), and self-efficacy (range, 4.2-5.9) ( P < .001 for all) of sodium reduction improved significantly from baseline (August 2012) to posttraining (also August 2012), but perceptions of the need for sodium reduction and self-efficacy for lowering sodium use returned to baseline levels 36 months later (August 2015).

CONCLUSIONS

The intervention was a useful population health approach that led to engaging restaurants in sodium-reduction practices. Local public health agencies and professionals could partner with independent restaurants to introduce environmental changes that can affect population health on a broad scale, particularly for vulnerable populations.

High sodium intake and sodium to potassium ratio may be linked to subsequent increase in vascular damage in adults aged 40 years and older: the Korean multi-rural communities cohort (MRCohort)

PURPOSE

Subclinical vascular damage is a chronic intermediate process in cardiovascular disease (CVD) and high sodium (Na) has been regarded as an adverse factor in subclinical vascular health; however, the longitudinal relationship between Na intake and subclinical vascular damage has not been studied. We aimed to evaluate the longitudinal relationship of dietary Na intake and sodium to potassium ratio (Na:K) with brachial-ankle pulse wave velocity (baPWV) and carotid intima media thickness (cIMT) in healthy adults aged 40 years and older in Korea.

METHODS

The present study was based on participants (n = 2145 for baPWV analysis and n = 2494 for cIMT analysis) who visited three times during 2005-2013 (median 5.3 years of follow-up). We used both dietary Na intake and Na:K at baseline and its average (baseline, 2nd, 3rd), which was obtained from food frequency questionnaire (FFQ) as exposure at every visit. baPWV and cIMT levels at the third visit and change from baseline to the third visit were used to represent the level of subclinical vascular damage.

RESULTS

After adjustment for potential confounders, significant positive relationships between dietary Na intake and both baPWV_3rd and cIMT_3rd were observed (baPWV: p for trend ≤ 0.0001 for Na_average; cIMT: p for trend = 0.013 for Na_average). Compared with Na:Ks less than 1.0, the levels of both baPWV and cIMT were higher for participants with Na:Ks over 1.0 (baPWV: p for trend = 0.0002 for Na:K_average; cIMT: p for trend = 0.005 for Na:K_average). Similar significant trends were shown in relationships between dietary Na intake and Na:K and changes in baPWV and cIMT levels.

CONCLUSIONS

In conclusion, dietary Na intake and Na:K may be positively linked to subsequent baPWV and cIMT levels in adults aged 40 years and older in Korea. Our findings may provide informative evidence on subclinical vascular damage, particularly for populations with relatively high dietary Na intake and low dietary K intake.

Impact of a hospital-based educational intervention on dietary salt-related knowledge and behaviour in a cardiac care unit population in Lebanon

Background

Cardiovascular disease is the most common cause of morbidity and mortality worldwide. Numerous strategies have been effective in reducing cardiovascular disease risk, from pharmacological approaches to lifestyle modification interventions. One of these strategies includes the reduction in dietary sodium which in turn reduces cardiovascular risk by reducing high blood pressure, perhaps the most important cardiovascular risk factor.

Methods

We evaluated an educational dietary salt reduction intervention in a cardiac care unit population in Lebanon, assessing salt related knowledge and behaviours before and after administering an evidence-based educational leaflet to patients.

Results

Salt-related knowledge improved significantly immediately post-intervention and subsequently fell on 4-week follow-up, but remained above baseline. Three of the four salt-related behaviours measured improved on 4-week follow-up: trying to buy low-salt foods increased from 54% to 74% (P=0.007), adding salt at the table reduced from 44% to 34% (P=0.03) and trying to buy food with no added salt increased from 24% to 52% (P=0.02) of the cohort. Adding salt during cooking did not differ significantly. A trend towards improved behavioural risk category in the cohort overall was observed on follow-up (P=0.07), 32% of participants were categorised as high behavioural risk pre-intervention, reducing to 17% on follow-up. Multi-ordered regression modelling identified being in the high-risk behavioural category at baseline as a predictor of being in the high-risk or moderate-risk category on follow-up.

Conclusions

This hospital-based educational intervention had a modestly positive impact on salt-related knowledge and behaviour, with participants in the highest behavioural risk category at baseline being most resistant to behavioural improvement.

High salt diet stimulates gut Th17 response and exacerbates TNBS-induced colitis in mice

This study focuses on characterizing the effect of a high salt diet (HSD) on intestinal immunity and the risk of inflammatory bowel diseases (IBD). We found that mice on a HSD had an increased frequency of IL-17A producing cells in the intestinal lamina propria (LP) compared to mice on a normal diet (ND). Furthermore, most intestinal IL-17A producing cells were CD4⁺TCRβ⁺ cells. A HSD increased the LP T helper 17 (Th17) responses in both the small and large intestines but did not increase the Th17 response of other gut-associated lymphoid organ. Although, HSD did not change the percentage of regulatory T (Treg) cells, HSD significantly inhibit secretion of IL-10 and the suppressive function of Treg cells. Moreover, we found that HSD exacerbates trinitrobenzenesulfonic acid (TNBS) induced colitis, and Th17 response was significantly increased in the colonic LP of HSD TNBS-treated mice compared with the ND TNBS-treated mice. This study demonstrates that HSD stimulates the intestinal Th17 response but inhibits the function of Treg cells. Moreover, HSD exacerbates TNBS induced mice colitis, suggesting that HSD disrupts the intestinal immunity and increases the risk of IBD.