Reduced dietary salt for the prevention of cardiovascular disease: a meta-analysis of randomized controlled trials (Cochrane review)

Association of sodium intake and major cardiovascular outcomes: a dose-response meta-analysis of prospective cohort studies

Background

The association of sodium intake with the risk of cardiovascular morbidity and mortality is inconsistent. Thus, the present meta-analysis was conducted to summarize the strength of association between sodium intake and cardiovascular morbidity and mortality.

Methods

PubMed, Embase, and the Cochrane Library were searched systematically to identify the relevant studies up to October 2017. The effect estimates for 100 mmol/day increase in sodium intake were calculated using 95% confidence intervals (CIs) of cardiac death, total mortality, stroke, or stroke mortality for low (< 3 g/d), moderate (3–5 g/d), or heavy (> 5 g/d) sodium intake, and minimal sodium intake comparison.

Results

A total of 16 prospective cohort studies reported data on 205,575 individuals. The results suggested that an increase in sodium intake by 100 mmol/d demonstrated little or no effect on the risk of cardiac death (P = 0.718) and total mortality (P = 0.720). However, the risk of stroke incidence (P = 0.029) and stroke mortality (P = 0.007) was increased significantly by 100 mmol/day increment of sodium intake. Furthermore, low sodium intake was associated with an increased risk of cardiac death (P = 0.003), while moderate (P < 0.001) or heavy (P = 0.001) sodium intake was associated with an increased risk of stroke mortality.

Conclusions

These findings suggested that sodium intake by 100 mmol/d increment was associated with an increased risk of stroke incidence and stroke mortality. Furthermore, low sodium intake was related to an increased cardiac death risk, while moderate or heavy sodium intake was related to an increased risk of stroke mortality.

Periarterial fat from two human vascular beds is not a source of aldosterone to promote vasoconstriction

Mouse adipocytes have been reported to release aldosterone and reduce endothelium-dependent relaxation. It is unknown whether perivascular adipose tissue (PVAT) releases aldosterone in humans. The present experiments were designed to test the hypothesis that human PVAT releases aldosterone and induces endothelial dysfunction. Vascular reactivity was assessed in human internal mammary and renal segmental arteries obtained at surgery. The arteries were prepared with/without PVAT, and changes in isometric tension were measured in response to the vasoconstrictor thromboxane prostanoid receptor agonist U46619 and the endothelium-dependent vasodilator acetylcholine. The effects of exogenous aldosterone and of mineralocorticoid receptor (MR) antagonist eplerenone were determined. Aldosterone concentrations were measured by ELISA in conditioned media incubated with human adipose tissue with/without angiotensin II stimulation. Presence of aldosterone synthase and MR mRNA was examined in perirenal, abdominal, and mammary PVAT by PCR. U46619 -induced tension and acetylcholine-induced relaxation were unaffected by exogenous and endogenous aldosterone (addition of aldosterone and MR blocker) in mammary and renal segmental arteries, both in the presence and absence of PVAT. Aldosterone release from incubated perivascular fat was not detectable. Aldosterone synthase expression was not consistently observed in human adipose tissues in contrast to that of MR. Thus, exogenous aldosterone does not affect vascular reactivity and endothelial function in ex vivo human arterial segments, and the tested human adipose tissues have no capacity to synthesize/release aldosterone. In perspective, physiologically relevant effects of aldosterone on vascular function in humans are caused by systemic aldosterone originating from the adrenal gland.

2018 ESC/ESH Guidelines for the management of arterial hypertension: The Task Force for the management of arterial hypertension of the European Society of Cardiology and the European Society of Hypertension: The Task Force for the management of arterial hypertension of the European Society of Cardiology and the European Society of Hypertension

: Document reviewers: Guy De Backer (ESC Review Co-ordinator) (Belgium), Anthony M. Heagerty (ESH Review Co-ordinator) (UK), Stefan Agewall (Norway), Murielle Bochud (Switzerland), Claudio Borghi (Italy), Pierre Boutouyrie (France), Jana Brguljan (Slovenia), Héctor Bueno (Spain), Enrico G. Caiani (Italy), Bo Carlberg (Sweden), Neil Chapman (UK), Renata Cifkova (Czech Republic), John G. F. Cleland (UK), Jean-Philippe Collet (France), Ioan Mircea Coman (Romania), Peter W. de Leeuw (The Netherlands), Victoria Delgado (The Netherlands), Paul Dendale (Belgium), Hans-Christoph Diener (Germany), Maria Dorobantu (Romania), Robert Fagard (Belgium), Csaba Farsang (Hungary), Marc Ferrini (France), Ian M. Graham (Ireland), Guido Grassi (Italy), Hermann Haller (Germany), F. D. Richard Hobbs (UK), Bojan Jelakovic (Croatia), Catriona Jennings (UK), Hugo A. Katus (Germany), Abraham A. Kroon (The Netherlands), Christophe Leclercq (France), Dragan Lovic (Serbia), Empar Lurbe (Spain), Athanasios J. Manolis (Greece), Theresa A. McDonagh (UK), Franz Messerli (Switzerland), Maria Lorenza Muiesan (Italy), Uwe Nixdorff (Germany), Michael Hecht Olsen (Denmark), Gianfranco Parati (Italy), Joep Perk (Sweden), Massimo Francesco Piepoli (Italy), Jorge Polonia (Portugal), Piotr Ponikowski (Poland), Dimitrios J. Richter (Greece), Stefano F. Rimoldi (Switzerland), Marco Roffi (Switzerland), Naveed Sattar (UK), Petar M. Seferovic (Serbia), Iain A. Simpson (UK), Miguel Sousa-Uva (Portugal), Alice V. Stanton (Ireland), Philippe van de Borne (Belgium), Panos Vardas (Greece), Massimo Volpe (Italy), Sven Wassmann (Germany), Stephan Windecker (Switzerland), Jose Luis Zamorano (Spain).The disclosure forms of all experts involved in the development of these Guidelines are available on the ESC website www.escardio.org/guidelines.

Association of soil potassium and sodium concentrations with spatial disparities of prevalence and mortality rates of hypertensive diseases in the USA

Crop available soil potassium is generally low and on the decline in the southeastern states of the USA because of the increasing crop and runoff removal and decreasing application of potassium fertilizer. Hypertension-related mortality rates are also high in the southeastern states and are on the rise. Among 41 elements analyzed from 4856 sites across all 48 states, potassium is identified as the only independent element whose soil concentration has significant association with spatial disparities of essential hypertension and hypertension-related mortality rates in the 48 states between 1999 and 2014. Essential hypertension and hypertension-related mortality rates of the 6 states with the lowest soil potassium concentration are about 50-26% higher than that of the 6 states with the highest soil potassium concentration in the 48 states (RR: 1.50, 1.26, low CI 95% 1.47, 1.25 and upper CI 95% 1.53, 1.27, respectively). Though sodium was not identified as an independent factor, an apparent significant inverse correlation exists between hypertension prevalence rates and soil sodium concentration in the 48 states (r = - 0.66, p = 0.00). There likely has been a decline of potassium in USA produces per unit weight over time and a likely association between this decline and increasing hypertension rate, particularly in the southeastern states. Hence, results of this study suggest the need of increasing potassium intakes for reducing hypertension-related mortality rates in the southeastern states. Results of this study also support further examination of potential benefits of sodium from mixture of non-chloride salts in natural produces.

Diet-Induced Hyperinsulinemia as a Key Factor in the Etiology of Both Benign Prostatic Hyperplasia and Essential Hypertension?

Benign prostatic hyperplasia and hypertension are common age-related comorbidities. Although the etiology of benign prostatic hyperplasia (BPH) is still largely unresolved and poorly understood, a significant age-independent association was found between BPH and hypertension, indicating a common pathophysiological factor for both diseases. It has previously been suggested that the development of essential hypertension may be related to diet-induced hyperinsulinemia. This study follows the question, whether BPH may develop due to the same mechanism, thereby explaining the well-known comorbidity of these 2 disorders. The scientific evidence presented shows that BPH and hypertension share the same pathophysiological changes, with hyperinsulinemia as the driving force. It further shows that significant dietary changes during human history cause disruption of a finely tuned metabolic balance that has evolved over millions of years of evolution: high-insulinemic food, typical of current “Western” diets, has the potential to cause hyperinsulinemia and insulin resistance, as well as an abnormally increased activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system, alterations that play a pivotal role in the pathogenesis of BPH and hypertension.

The effect of dietary sodium modification on blood pressure in adults with systolic blood pressure less than 140 mmHg: a systematic review

BACKGROUND

Modifying dietary sodium intake is a cornerstone of diet advice for lowering blood pressure (BP) under the assumption that it is protective against cardiovascular disease. Previous meta-analyses of normotensive participants have not excluded all studies that recruited participants with systolic blood pressure (SBP) > 140 mmHg, which greatly hinders generalization to the wider normotensive population.

OBJECTIVES

The objective of this review was to identify the effectiveness of reducing or increasing sodium intake on BP in normotensive participants with SBP ≤ 140 mmHg.

INCLUSION CRITERIA TYPES OF PARTICIPANTS

This review considered studies on adult participants (≥18 years) with SBP ≤ 140 mmHg. Studies on pregnant women or patients prescribed antihypertensive or vasoactive medications were excluded.

TYPES OF INTERVENTIONS

Interventions that quantitatively evaluated dietary sodium intake for equal to or greater than four weeks duration were considered. Only studies that included two study arms comprising different levels of sodium intake were included.

TYPES OF OUTCOMES

Studies that reported SBP, diastolic blood pressure (DBP), pulse wave velocity (PWV), pulse wave analysis or flow mediated dilatation were considered.

TYPES OF STUDIES

Experimental study designs including randomized controlled trials and non-randomized controlled trials were considered.

SEARCH STRATEGY

An initial search strategy was conducted on databases MEDLINE and CINAHL before an extensive search of all relevant published and gray literature databases, and clinical trial registries were searched.

METHODOLOGICAL QUALITY

Potential papers were assessed for methodological validity using the standardized critical appraisal instrument from the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI).

DATA EXTRACTION

Quantitative data were extracted from papers using the standardized data extraction tool from JBI-MAStARI.

DATA SYNTHESIS

Quantitative data were pooled in statistical meta-analysis. Effect sizes were expressed as weighted mean differences and 95% confidence intervals. Meta-analysis was conducted using a random-effect model, and heterogeneity assessed statistically using the standard Chi-square test and the I index. A priori sub-group analysis was undertaken on studies achieving ≥40 mmol versus <40 mmol in urinary sodium excretion and post hoc on studies with a mean body mass index (BMI) ≥ 30 versus less than 30.

RESULTS

Five trials were included with a total of 1214 participants. The overall reduction in SBP was -0.71 mmHg (95% CI: -2.62, 1.20, P = 0.47) and DBP -0.57 mmHg (95% CI: -1.26, 0.12, P = 0.10). There was no significant change in PWV following reduction of dietary sodium over a four to six-week period. Sub-group analysis did not find a significant effect of urinary sodium excretion or BMI on outcomes; however, a trend toward a greater reduction in BP was observed in those with a higher BMI (MD -2.41, 95% CI -5.72, +0.91, P = 0.16).

CONCLUSION

Blood pressure in normotensive participants was not significantly affected by sodium modification and was controlled to within 1% of baseline values. Reducing dietary sodium in normotensive participants may still be of importance for cardiovascular risk management; however, good quality interventional research is limited.

Age- and gender-dependent associations of blood pressure and serum sodium and potassium-renal and extrarenal regulations

Association analyses between blood pressure (BP) and serum sodium and potassium for 14,657 men and 16,977 women between ages 12 and 85 years show that responses of BP to serum sodium and potassium are age and gender dependent. The data were from the National Health and Nutrition Examination Survey between 2003 and 2014. Associations between serum sodium and BP are positive only for advanced age groups and for serum sodium level greater than 139-140 mmol/L in less advanced groups. These positive associations can be explained by traditional renal-centered mechanism. Inverse associations between systolic BP and serum sodium exist when sodium is less than ∼140 mmol/L in less advanced age groups (<60 for men and <70 for women). These inverse associations can partially be explained by the extrarenal regulatory mechanism in which sodium storage in negatively charged glycosaminoglycans in the interstitium may be involved. Associations of high serum potassium and low BP are consistent and exist in most age groups. Effect of potassium on systolic BP and diastolic BP are more prominent in less advanced age groups. Age-dependent associations between sodium and BP support the theory that sodium homeostasis in the body may not be regulated by renal-centered responses alone. There might be regulation of an extrarenal system in which sodium attraction by negatively charged glycosaminoglycans plays a role.

Exercise and other nonpharmacological strategies to reduce blood pressure in older adults: a systematic review and meta-analysis

The incidence of hypertension increases with advancing age and represents a significant burden of disease. Lifestyle modification represents the first-line intervention in treatment algorithms; however, the majority of evidence for this comes from studies involving young participants using interventions that may not always be feasible in the elderly. This manuscript presents a systematic review of all randomized controlled trials involving participants with a mean age of 65 or over investigating nonpharmacological strategies to reduce blood pressure (BP). Fifty-three randomized controlled trials were included. The majority of interventions described aerobic exercise training, dynamic resistance exercise training, or combined aerobic and dynamic resistance exercise training (COM), with limited studies reporting isometric exercise training or alternative lifestyle strategies. Aerobic exercise training, dynamic resistance exercise training, COM, and isometric exercise training all elicited significant reductions in both systolic and diastolic BP, with no additional benefit of COM compared with single modality exercise training. Three months of traditional exercise-based lifestyle intervention may produce a reduction in BP of approximately 5 mmHg systolic and 3 mmHg diastolic in older individuals, similar to that expected in younger individuals.

Non-uniform relationship between salt status and aldosterone activity in patients with chronic kidney disease

BACKGROUND

Hypertension is prevalent in chronic kidney disease (CKD). Studies suggest that reduction in dietary salt intake reduces blood pressure (BP). We studied relationships between salt intake, BP and renin-angiotensin system regulation in order to establish if it is disordered in CKD.

METHODS

Mechanistic crossover study of CKD patients versus non-CKD controls. Participants underwent modified saline suppression test prior to randomization to either low or high salt diet for 5 days and then crossed over to the alternate diet. Angiotensin-II stimulation testing was performed in both salt states. BP, urea and electrolytes, and plasma aldosterone concentration (PAC) were measured.

RESULTS

Twenty-seven subjects were recruited (12 CKD, 15 control). There was no difference in age and baseline BP between the groups. Following administration of intravenous saline, systolic BP increased in CKD but not controls (131 ± 16 to 139 ± 14 mmHg, P=0.016 vs 125 ± 20 to 128 ± 22 mmHg, P=0.38). Median PAC reduced from 184 (124,340) to 95 (80,167) pmol in controls (P=0.003), but failed to suppress in CKD (230 (137,334) to 222 (147,326) pmol (P=0.17)). Following dietary salt modification, there was no change in BP in either group. Median PAC was lower following high salt compared with low salt diet in CKD and controls. There was a comparable increase in systolic BP in response to angiotensin-II in both groups.

DISCUSSION

We demonstrate dysregulation of aldosterone in CKD in response to salt loading with intravenous saline, but not to dietary salt modification.

Understanding the Two Faces of Low-Salt Intake

Fierce debate has developed whether low-sodium intake, like high-sodium intake, could be associated with adverse outcome. The debate originates in earlier epidemiological studies associating high-sodium intake with high blood pressure and more recent studies demonstrating a higher cardiovascular event rate with both low- and high-sodium intake. This brings into question whether we entirely understand the consequences of high- and (very) low-sodium intake for the systemic hemodynamics, the kidney function, the vascular wall, the immune system, and the brain. Evolutionarily, sodium retention mechanisms in the context of low dietary sodium provided a survival advantage and are highly conserved, exemplified by the renin-angiotensin system. What is the potential for this sodium-retaining mechanism to cause harm? In this paper, we will consider current views on how a sodium load is handled, visiting aspects including the effect of sodium on the vessel wall, the sympathetic nervous system, the brain renin-angiotensin system, the skin as "third compartment" coupling to vascular endothelial growth factor C, and the kidneys. From these perspectives, several mechanisms can be envisioned whereby a low-sodium diet could potentially cause harm, including the renin-angiotensin system and the sympathetic nervous system. Altogether, the uncertainties preclude a unifying model or practical clinical guidance regarding the effects of a low-sodium diet for an individual. There is a very strong need for fundamental and translational studies to enhance the understanding of the potential adverse consequences of low-salt intake as an initial step to facilitate better clinical guidance.

The Myth of Water and Salt: From Aquaretics to Tenapanor

The impact of water intake has been studied in several renal diseases. For example, increasing water intake is useful to prevent primary and secondary nephrolithiasis. In autosomal dominant polycystic kidney disease, arginine vasopressin (AVP) is involved in the progression of the disease, and water intake could play a therapeutic role by inhibiting the synthesis of AVP, but its efficacy is still controversial. Conversely, the use of aquaretics, which are antagonists of AVP V2 receptors, results in the reduction of the increase rate of total kidney volume with a slower decline of glomerular filtration rate. In chronic kidney disease, AVP contributes to glomerular hyperfiltration, arterial hypertension, and synthesis of renin, resulting in renal sclerosis. Increased water intake could reduce AVP activation determining a potential protective effect on the kidney, but its efficacy has not yet been clearly demonstrated. On the other side, sodium and potassium play an important role in the control of arterial blood pressure and are involved in the development and progression of chronic kidney disease. Reduction of sodium intake and increase of potassium intake determine a decrease of arterial blood pressure with a beneficial effect on the kidney; however, adherence to sodium restriction is very poor. Regarding this, sodium-hydrogen exchanger isoform 3 inhibitors may reduce sodium absorption in the gut. The most recent sodium-hydrogen exchanger isoform 3 inhibitor, known as tenapanor, reduces extracellular fluid volume, left ventricular hypertrophy, albuminuria, and blood pressure in experimental studies and increases fecal loss of sodium in humans.

Addictive salt may not be solely responsible for causing hypertension: A sweet and fatty hypothesis

In literature, since many decades, it is often believed and condoned that excessive common salt (Nacl) ingestion can lead to hypertension. Hence, every health organisation, agencies and physicians have been advising salt restriction to hypertensive patients. However, there is no concrete evidence suggesting that salt restriction can reduce the risk of hypertension (HTN). The present article is based on the current literature search which was performed using MEDLINE, EMBASE, Google Scholar and PubMed. The meta-analysis, randomised control trials, clinical trials and review articles were chosen. The present review article suggests that consumption of high salt diet does not lead to hypertension and there are other factors which can lead to hypertension, sugar and fats being the main reasons. Salt can however lead to addiction and generally, these salty food items have a larger proportion of sugar and fats, which if over-consumed has a potential to cause obesity, hyperlipidaemia and subsequently, hypertension and other cardiovascular disorders. Hence, through the present review, I would like to suggest all the physicians to ask the hypertensive patients to cut down the intake of sugar and fat containing food items and keep a check on addiction of salty food items.

Cost-effectiveness of salt reduction to prevent hypertension and CVD: a systematic review

Objective

To analyse and compare the cost-effectiveness of different interventions to reduce salt consumption.

Design

A systematic review of published cost-effectiveness analyses (CEA) and cost-utility analyses (CUA) was undertaken in the databases EMBASE, MEDLINE (PubMed), Cochrane and others until July 2016. Study selection was limited to CEA and CUA conducted in member countries of the Organisation for Economic Co-operation and Development (OECD) in English, German or French, without time limit. Outcomes measures were life years gained (LYG), disability-adjusted life years (DALY) and quality-adjusted life years (QALY). Relevant aspects in modelling were analysed and compared. Quality assessments were conducted using the Drummond and Jefferson/British Medical Journalchecklist.

Setting

OECD member countries.

Subjects

Mainly adults.

Results

Fourteen CEA and CUA were included in the review which analysed different strategies: salt reduction or substitution in processed foods, taxes, labelling, awareness campaigns and targeted dietary advice. Fifty-nine out of sixty-two scenarios were cost-saving. The incremental cost-effectiveness ratio in international dollars (Intl.$; 2015) was particularly low for taxes, a salt reduction by food manufacturers and labelling (<−3072 Intl.$/QALY, −6187 Intl.$/LYG and <584 Intl.$/DALY over the time horizon compared with the status quo or no intervention). Targeted dietary advice was rather not cost-effective (24 600 Intl.$/QALY and >303 900 Intl.$/DALY). However, only six studies analysed cost-effectiveness from a societal perspective and quality assessments showed flaws in conducting and a lack of transparency in reporting.

Conclusions

A population-wide salt reduction could be cost-effective in prevention of hypertension and CVD in OECD member countries. However, comparability between study results is limited due to differences in modelling, applied perspectives and considered data.

Distinctive Risk Factors and Phenotype of Younger Patients With Resistant Hypertension: Age Is Relevant

Resistant hypertension, defined as blood pressure >140/90 mm Hg despite using ≥3 antihypertensive medications, is a well-recognized clinical entity. Patients with resistant hypertension are at an increased risk of cardiovascular disease compared with those with more easily controlled hypertension. Coronary heart disease mortality rates of younger adults are stagnating or on the rise. The purpose of our study was to characterize the phenotype and risk factors of younger patients with resistant hypertension, given the dearth of data on cardiovascular risk profile in this cohort. We conducted a cross-sectional analysis with predefined age groups of a large, ethnically diverse cohort of 2170 patients referred to the Hypertension Clinic at the University of Alabama at Birmingham. Patients (n=2068) met the inclusion criteria and were classified by age groups, that is, ≤40 years (12.7% of total cohort), 41 to 55 years (32.1%), 56 to 70 years (36.1%), and ≥71 years (19.1%). Patients aged ≤40 years compared with those aged ≥71 years had significantly earlier onset of hypertension (24.7±7.4 versus 55.0±14.1 years; P<0.0001), higher rates of obesity (53.4% versus 26.9%; P<0.0001), and significantly higher levels of plasma aldosterone (11.3±9.8 versus 8.9±7.4 ng/dL; P=0.005), plasma renin activity (4.9±10.2 versus 2.5±5.0 ng/mL per hour; P=0.001), 24-hour urinary aldosterone (13.4±10.0 versus 8.2±6.2 µg/24 h; P<0.0001), and sodium excretion (195.9±92.0 versus 146.8±67.1 mEq/24 h; P<0.0001). Among patients with resistant hypertension, younger individuals have a distinct phenotype characterized by overlapping risk factors and comorbidities, including obesity, high aldosterone, and high dietary sodium intake compared with elderly.

High salt intake is associated with a higher risk of cardiovascular events: a 7.2-year evaluation of a cohort of hypertensive patients

BACKGROUND

It is controversial whether high salt intake is directly associated with cardiovascular (CV) events and how far this relation is independent of blood pressure (BP). As Portugal has higher salt consumption and higher mortality by stroke than other European countries, we examined whether salt intake could predict the development of stroke and CV events in a hypertensive population.

METHODS

In a longitudinal retrospective study of a cohort of 608 adult treated hypertensive patients 54.1±14.3 years of age, BMI 29.3±8.3 kg/m, 56.3% women and 17.1% diabetics, we evaluate the long-term prognostic significance of urinary sodium (UNa) excretion measured in 24 h valid samples within the first 3 months after admission along with 24 h ambulatory blood pressure monitoring and pulse wave velocity [(PWV), complior)] measurements.

RESULTS

The mean follow-up duration was 7.2 years (0.5-11.1 years), during which 122 CV events occurred including 80 strokes and 36 coronary events. In 608 patients (group A=507 without events and group B=101 with events: 69 strokes, 26 coronary events, six others), the mean 24 h UNa was 208±79 mmol/day, corresponding to a salt intake of 12.1±4.6 g/day. Twenty-four hours UNa correlated positively with BMI, PWV and systolic blood pressure (SBP) particularly with night-time SBP. Group B versus A showed higher UNa (260+98 vs. 198+71 mmol/day, P<0.001) and higher PWV, BP office, 24 h, daytime and night-time SBP. Logistic regression analysis identified age, night-time SBP and 24 h UNa+ [HR=1.09 (95% CI, 1.06-1.12, P<0.001)] for each 10 mmol increase of UNa+ as the only independent predictors of CV events. UNa+ above the median (189 mmol sodium/day) predicted CV events with HR=2.99 (95% CI, 1.75-5.13, P<0.001) with worse CV event-free survival rates (log rank statistics of 17.44, P<0.001).

CONCLUSION

In a cohort of hypertensive patients, high salt intake independently predicts the occurrence of CV events, particularly of stroke.

Impact of food choice on sodium intake patterns from multiple NHANES surveys

To examine how the food consumption from various food groups would impact American adults' sodium intake and whether this impact structurally changes over time, data were obtained from six-cycle National Health and Nutrition Examination Survey (NHANES) 1999-2010. Foods were categorized by the first two digits of the USDA food code. Regression models were employed to investigate the associations between the consumption of each food group and sodium intake, and whether there were changes in the associations in consecutive six cycles. Results show that the calorie consumption of oils, beverages and water, fruit juices, fruits, lamb, fruit products, and sugars and sweets had no significant impact on individuals' sodium intake, while calorie consumption of tomatoes, fish, dark-green vegetables, and crackers contributes the most to sodium intake. The contribution to sodium intake of most food groups does not change significantly over time, with the exception of salad dressing whose contribution to sodium intake increased in four consecutive years when compared to that of 1999-2000. The sodium amount contributed by one calorie consumption (sodium density) of most food was above the daily recommendation level, 1.2 mg per calorie per day. Lowering individuals' sodium intake involves either guiding individuals to consume more fruit related products or decreasing the amount of sodium in most food groups at the production or food preparation stages.

Salt, Aldosterone, and Parathyroid Hormone: What Is the Relevance for Organ Damage?

Structured interventions on lifestyle have been suggested as a cost-effective strategy for prevention of cardiovascular disease. Epidemiologic studies demonstrate that dietary salt restriction effectively decreases blood pressure, but its influence on cardiovascular morbidity and mortality is still under debate. Evidence gathered from studies conducted in patients with primary aldosteronism, essential hypertension, or heart failure demonstrates that long-term exposure to elevated aldosterone results in cardiac structural and functional changes that are independent of blood pressure. Animal experiments and initial clinical studies indicate that aldosterone damages the heart only in the context of an inappropriately elevated salt status. Recent evidence suggests that aldosterone might functionally interact with the parathyroid hormone and thereby affect calcium homeostasis with important sequelae for bone mineral density and strength. The interaction between aldosterone and parathyroid hormone might have implications also for the heart. Elevated dietary salt is associated on the one hand with increased urinary calcium excretion and, on the other hand, could facilitate the interaction between aldosterone and parathyroid hormone at the cellular level. This review summarizes the evidence supporting the contribution of salt and aldosterone to cardiovascular disease and the possible cardiac and skeletal consequences of the mutual interplay between aldosterone, parathyroid hormone, and salt.

Sodium and Its Role in Cardiovascular Disease - The Debate Continues

Guidelines have recommended significant reductions in dietary sodium intake to improve cardiovascular health. However, these dietary sodium intake recommendations have been questioned as emerging evidence has shown that there is a higher risk of cardiovascular disease with a low sodium diet, including in individuals with type 2 diabetes. This may be related to the other pleotropic effects of dietary sodium intake. Therefore, despite recent review of dietary sodium intake guidelines by multiple organizations, including the dietary guidelines for Americans, American Diabetes Association, and American Heart Association, concerns about the impact of the degree of sodium restriction on cardiovascular health continue to be raised. This literature review examines the effects of dietary sodium intake on factors contributing to cardiovascular health, including left ventricular hypertrophy, heart rate, albuminuria, rennin-angiotensin-aldosterone system activation, serum lipids, insulin sensitivity, sympathetic nervous system activation, endothelial function, and immune function. In the last part of this review, the association between dietary sodium intake and cardiovascular outcomes, especially in individuals with diabetes, is explored. Given the increased risk of cardiovascular disease in individuals with diabetes and the increasing incidence of diabetes worldwide, this review is important in summarizing the recent evidence regarding the effects of dietary sodium intake on cardiovascular health, especially in this population.

Relationships between Lifestyle, Living Environments, and Incidence of Hypertension in Japan (in Men): Based on Participant's Data from the Nationwide Medical Check-Up

This study aims to investigate factors that contribute to the differences in incidence of hypertension between different regions in Japan, by accounting for not only individual lifestyles, but also their living environments. The target participants of this survey were individuals who received medical treatment for hypertension, as well as hypertension patients who have not received any treatment. The objective variable for analysis was the incidence of hypertension as data aggregated per prefecture. We used data (in men) including obesity, salt intake, vegetable intake, habitual alcohol consumption, habitual smoking, and number of steps walked per day. The variables within living environment included number of rail stations, standard/light vehicle usage, and slope of habitable land. In addition, we analyzed data for the variables related to medical environment including, participation rate in medical check-ups and number of hospitals. We performed multiple stepwise regression analyses to elucidate the correlation of these variables by using hypertension incidence as the objective variable. Hypertension incidence showed a significant negative correlation with walking and medical check-ups, and a significant positive correlation with light-vehicle usage and slope. Between the number of steps and variables related to the living environment, number of rail stations showed a significant positive correlation, while, standard- and light-vehicle usage showed significant negative correlation. Moreover, with stepwise multiple regression analysis, walking showed the strongest effect. The differences in daily walking based on living environment were associated with the disparities in the hypertension incidence in Japan.

Effects of high-intensity interval training on cardiometabolic health: a systematic review and meta-analysis of intervention studies

The current review clarifies the cardiometabolic health effects of high-intensity interval training (HIIT) in adults. A systematic search (PubMed) examining HIIT and cardiometabolic health markers was completed on 15 October 2015. Sixty-five intervention studies were included for review and the methodological quality of included studies was assessed using the Downs and Black score. Studies were classified by intervention duration and body mass index classification. Outcomes with at least 5 effect sizes were synthesised using a random-effects meta-analysis of the standardised mean difference (SMD) in cardiometabolic health markers (baseline to postintervention) using Review Manager 5.3. Short-term (ST) HIIT (<12 weeks) significantly improved maximal oxygen uptake (VO₂ max; SMD 0.74, 95% CI 0.36 to 1.12; p<0.001), diastolic blood pressure (DBP; SMD -0.52, 95% CI -0.89 to -0.16; p<0.01) and fasting glucose (SMD -0.35, 95% CI -0.62 to -0.09; p<0.01) in overweight/obese populations. Long-term (LT) HIIT (≥12 weeks) significantly improved waist circumference (SMD -0.20, 95% CI -0.38 to -0.01; p<0.05), % body fat (SMD -0.40, 95% CI -0.74 to -0.06; p<0.05), VO₂ max (SMD 1.20, 95% CI 0.57 to 1.83; p<0.001), resting heart rate (SMD -0.33, 95% CI -0.56 to -0.09; p<0.01), systolic blood pressure (SMD -0.35, 95% CI -0.60 to -0.09; p<0.01) and DBP (SMD -0.38, 95% CI -0.65 to -0.10; p<0.01) in overweight/obese populations. HIIT demonstrated no effect on insulin, lipid profile, C reactive protein or interleukin 6 in overweight/obese populations. In normal weight populations, ST-HIIT and LT-HIIT significantly improved VO₂ max, but no other significant effects were observed. Current evidence suggests that ST-HIIT and LT-HIIT can increase VO₂ max and improve some cardiometabolic risk factors in overweight/obese populations.

The Science of Salt: A Systematic Review of Quality Clinical Salt Outcome Studies June 2014 to May 2015

Studies identified from an updated systematic review (from June 2014 to May 2015) on the impact of dietary salt intake on clinical and population health are reviewed. Randomized controlled trials, cohort studies, and meta-analyses of these study types on the effect of sodium intake on blood pressure, or any substantive adverse health outcomes were identified from MEDLINE searches and quality indicators were used to select studies that were relevant to clinical and public health. From 6920 studies identified in the literature search, 144 studies were selected for review, of which only three (n=233,680) met inclusion criteria. Between them, the three studies demonstrated a harmful association between excess dietary salt and all-cause mortality, noncardiovascular and cardiovascular disease mortality, and headache. None of the included studies found harm from lowering dietary salt. The findings of this systematic review are consistent with the large body of research supportive of efforts to reduce population salt intake and congruent with our last annual review from June 2013 to May 2014.

Does a medical history of hypertension influence disclosing genetic testing results of the risk for salt-sensitive hypertension, in primary care?

Objective

Disclosing genetic testing results may contribute to the prevention and management of many common diseases. However, whether the presence of a disease influences these effects is unclear. This study aimed to clarify the difference in the effects of disclosing genetic testing results of the risk for developing salt-sensitive hypertension on the behavioral modifications with respect to salt intake in hypertensive and nonhypertensive patients.

Methods

A cross-sectional study using a self-administered questionnaire was conducted for outpatients aged >20 years (N=2,237) at six primary care clinics and hospitals in Japan. The main factors assessed were medical histories of hypertension, salt preferences, reduced salt intakes, and behavior modifications for reducing salt intake. Behavioral modifications of participants were assessed using their behavior stages before and after disclosure of the hypothetical genetic testing results.

Results

Of the 2,237 participants, 1,644 (73.5%) responded to the survey. Of these respondents, 558 (33.9%) patients were hypertensive and 1,086 (66.1%) were nonhypertensive. After being notified of the result “If with genetic risk”, the nonhypertensive participants were more likely to make positive behavioral modifications compared to the hypertensive patients among all participants and in those aged <65 years (adjusted relative ratio [ad-RR], 1.76; 95% confidence interval, 1.12−2.76 and ad-RR, 1.99; 1.11−3.57, respectively). In contrast, no difference in negative behavioral modifications between hypertensive and nonhypertensive patients was detected after being notified of the result “If without genetic risk” (ad-RR, 1.05; 95% confidence interval, 0.70−1.57).

Conclusion

The behavior of modifying salt intake after disclosure of the genetic testing results differed between hypertensive and nonhypertensive patients. Disclosing a genetic risk for salt-sensitive hypertension was likely to cause nonhypertensive patients, especially those aged <65 years, to improve their behavior regarding salt intake. We conclude that disclosing genetic testing results could help prevent hypertension, and that the doctor should communicate the genetic testing results to those patients with a medical history of hypertension, or those who are at risk of developing hypertension.

Pro: Reducing salt intake at population level: is it really a public health priority?

A reduction in salt intake reduces blood pressure, stroke and other cardiovascular events, including chronic kidney disease, by as much as 23% (i.e. 1.25 million deaths worldwide). It is effective in both genders, any age, ethnic group, and in high-, medium- and low-income countries. Population salt reduction programmes are both feasible and effective (preventive imperative). Salt reduction programmes are cost-saving in all settings (high-, middle- and low-income countries) (economic imperative). Public health policies are powerful, rapid, equitable and cost-saving (political imperative). The important shift in public health has not occurred without obstinate opposition from organizations concerned primarily with the profits deriving from population high salt intake and less with public health benefits. A key component of the denial strategy is misinformation (with 'pseudo' controversies). In general, poor science has been used to create uncertainty and to support inaction. This paper summarizes the evidence in favour of a global salt reduction strategy and analyses the peddling of well-worn myths behind the false controversies.

GlycA, a novel proinflammatory glycoprotein biomarker, and high-sensitivity C-reactive protein are inversely associated with sodium intake after controlling for adiposity: the Prevention of Renal and Vascular End-Stage Disease study

BACKGROUND

The extent to which dietary sodium intake may confer alterations in the inflammatory status is unclear. GlycA is a novel proton nuclear magnetic resonance spectroscopy-measured biomarker of systemic inflammation, which is associated with the development of cardiovascular disease and diabetes.

OBJECTIVE

We determined associations of the inflammatory markers GlycA and high-sensitivity C-reactive protein (hsCRP) with 24-h sodium excretion.

DESIGN

A cross-sectional, population-based study was performed in 3935 subjects who were not using an antihypertensive medication, lipid-lowering drugs, or a glucose-lowering treatment. Urinary sodium excretion was calculated as the mean of two 24-h urine excretions. Linear regression models were used, with 24-h sodium excretion as an independent variable and GlycA or ln hsCRP as a dependent variable.

RESULTS

The mean ± SD sodium excretion was 143.0 ± 53.4 mmol/24 h. The GlycA concentration was 343.6 ± 58.7 μmol/L, and the geometric mean of the hsCRP concentration was 1.20 mg/L (95% CI: 1.16, 1.25 mg/L). In age- and sex-adjusted analyses, GlycA and ln hsCRP were not significantly associated with 24-h sodium excretion [B: 1.23 (95% CI: -0.67, 3.13; P = 0.21) and 0.03 (95% CI: -0.004, 0.07; P = 0.08), respectively, per 1-SD increase]. After additional adjustment for body mass index (BMI), both GlycA (B: -2.76; 95% CI: -4.65, -0.86; P = 0.004) and ln hsCRP (B: -0.07; 95% CI: -0.11, -0.04; P < 0.001) were inversely associated with 24-h sodium excretion. These associations were similar if adjustment was performed for waist circumference instead of BMI or if additional adjustment was performed for relevant clinical and laboratory variables and were particularly present in men.

CONCLUSIONS

The proinflammatory biomarkers GlycA and hsCRP are inversely related to higher 24-h sodium excretion when taking into account the variation in adiposity. These inverse relations remain present after taking into account other covariates.

Evaluating the healthiness of chain-restaurant menu items using crowdsourcing: a new method

Objective

To develop a technology-based method for evaluating the nutritional quality of chain-restaurant menus to increase the efficiency and lower the cost of large-scale data analysis of food items.

Design

Using a Modified Nutrient Profiling Index (MNPI), we assessed chain-restaurant items from the MenuStat database with a process involving three steps: (i) testing ‘extreme’ scores; (ii) crowdsourcing to analyse fruit, nut and vegetable (FNV) amounts; and (iii) analysis of the ambiguous items by a registered dietitian.

Results

In applying the approach to assess 22 422 foods, only 3566 could not be scored automatically based on MenuStat data and required further evaluation to determine healthiness. Items for which there was low agreement between trusted crowd workers, or where the FNV amount was estimated to be >40 %, were sent to a registered dietitian. Crowdsourcing was able to evaluate 3199, leaving only 367 to be reviewed by the registered dietitian. Overall, 7 % of items were categorized as healthy. The healthiest category was soups (26 % healthy), while desserts were the least healthy (2 % healthy).

Conclusions

An algorithm incorporating crowdsourcing and a dietitian can quickly and efficiently analyse restaurant menus, allowing public health researchers to analyse the healthiness of menu items.

Mineral essential elements for nutrition in different chocolate products

In this work, the essential mineral nutritional elements in cocoa beans, in chocolates at different cocoa percentage (60,70,80 and 90%) and in milk chocolate are evaluated. Dark chocolates are confirmed as an excellent source of magnesium (252.2 mg/100 g) and iron (10.9 mg/100 g): in chocolate containing 90% cocoa, their content corresponds to, respectively, 67.0% and 80.3 of Nutrient Reference Values (NRV) in the European Union. The chocolate containing 90% cocoa is also a good source of zinc (3.5 mg/100 g), which is important for the immune system, and selenium (0.1 mg/100 g). Three main components suitable to explain the mineral concentrations are analyzed by factor analysis. The component 1 can be interpreted as the contribution from the cocoa beans, owing to the mineral characteristics of the soil in which they have grown; the component 2 is mainly due to the manipulation and transformation of the cocoa in chocolate, while the component 3 represents the milk powder.

Nutrition and Cardiovascular Disease: Finding the Perfect Recipe for Cardiovascular Health

The increasing burden of cardiovascular disease (CVD) despite the progress in management entails the need of more effective preventive and curative strategies. As dietary-associated risk is the most important behavioral factor influencing global health, it appears the best target in the challenge against CVD. Although for many years, since the formulation of the cholesterol hypothesis, a nutrient-based approach was attempted for CVD prevention and treatment, in recent years a dietary-based approach resulted more effective in reducing cardiovascular risk worldwide. After the publication of randomized trials on the remarkable effects of the Mediterranean diet and the Dietary Approach to Stop Hypertension (DASH) diet on CVD, new efforts were put on research about the effects of complex dietary interventions on CVD. The purpose of this paper is to review the evidence on dietary interventions in the prevention and disease modification of CVD, focusing on coronary artery disease and heart failure, the main disease responsible for the enormous toll taken by CVD worldwide.

Dietary sodium and health: more than just blood pressure

Sodium is essential for cellular homeostasis and physiological function. Excess dietary sodium has been linked to elevations in blood pressure (BP). Salt sensitivity of BP varies widely, but certain subgroups tend to be more salt sensitive. The mechanisms underlying sodium-induced increases in BP are not completely understood but may involve alterations in renal function, fluid volume, fluid-regulatory hormones, the vasculature, cardiac function, and the autonomic nervous system. Recent pre-clinical and clinical data support that even in the absence of an increase in BP, excess dietary sodium can adversely affect target organs, including the blood vessels, heart, kidneys, and brain. In this review, the investigators review these issues and the epidemiological research relating dietary sodium to BP and cardiovascular health outcomes, addressing recent controversies. They also provide information and strategies for reducing dietary sodium.

The activation of p38 MAPK limits the abnormal proliferation of vascular smooth muscle cells induced by high sodium concentrations

The aim of the present study was to ascertain whether high sodium levels can directly promote the proliferation of vascular smooth muscle cells (VSMCs) and to elucidate the underlying mechanisms. Additional sodium chloride (NaCl) was added to the routine culture medium. Cell proliferation was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay. The mRNA expression level of proliferating cell nuclear antigen (PCNA) was measured by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The protein expression levels of PCNA and phosphorylated c-Jun amino N-terminal kinase (p-JNK), phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) and phosphorylated p38 mitogen-activated protein kinase (p-p38 MAPK) were measured by western blot analysis. Cell proliferation assay revealed that Na⁺ rather than Cl⁻ or osmotic pressure promoted the proliferation of the VSMCs. The high sodium level upregulated the expression of PCNA and the phosphorylation levels of JNK, ERK1/2 and p38 MAPK. The inhibition of JNK and ERK1/2 decreased PCNA expression. Of note, the inhibition of p38 MAPK using the inhibitor, SB203580, increased PCNA expression. However, when p38 MAPK was activated by anisomycin, PCNA expression was decreased. On the whole, our findings demonstrate that a relatively high sodium level per se directly promotes the proliferation of VSMCs through the JNK/ERK1/2/PCNA pathway. At the same time, this induction of the proliferation of VSMCs due to high sodium levels can be maintained at a low level via the activation of p38 MAPK.

Renal Effects and Underlying Molecular Mechanisms of Long-Term Salt Content Diets in Spontaneously Hypertensive Rats

Several evidences have shown that salt excess is an important determinant of cardiovascular and renal derangement in hypertension. The present study aimed to investigate the renal effects of chronic high or low salt intake in the context of hypertension and to elucidate the molecular mechanisms underlying such effects. To this end, newly weaned male SHR were fed with diets only differing in NaCl content: normal salt (NS: 0.3%), low salt (LS: 0.03%), and high salt diet (HS: 3%) until 7 months of age. Analysis of renal function, morphology, and evaluation of the expression of the main molecular components involved in the renal handling of albumin, including podocyte slit-diaphragm proteins and proximal tubule endocytic receptors were performed. The relationship between diets and the balance of the renal angiotensin-converting enzyme (ACE) and ACE2 enzymes was also examined. HS produced glomerular hypertrophy and decreased ACE2 and nephrin expressions, loss of morphological integrity of the podocyte processes, and increased proteinuria, characterized by loss of albumin and high molecular weight proteins. Conversely, severe hypertension was attenuated and renal dysfunction was prevented by LS since proteinuria was much lower than in the NS SHRs. This was associated with a decrease in kidney ACE/ACE2 protein and activity ratio and increased cubilin renal expression. Taken together, these results suggest that LS attenuates hypertension progression in SHRs and preserves renal function. The mechanisms partially explaining these findings include modulation of the intrarenal ACE/ACE2 balance and the increased cubilin expression. Importantly, HS worsens hypertensive kidney injury and decreases the expression nephrin, a key component of the slit diaphragm.

Volume Overload in Heart Failure: An Evidence-Based Review of Strategies for Treatment and Prevention

Acute decompensated heart failure is the leading cause of hospital admission in the United States, with a high risk of readmission within 30 days. Most acute decompensated heart failure admissions are driven by congestive signs and symptoms resulting from fluid and sodium overload. We reviewed the evidence base addressing the management and prevention of fluid overload in heart failure, focusing on recent clinical trials. All the references in this review were obtained through PubMed and had at least 1 of the following key words: heart failure and volume overload, congestion, loop diuretics, thiazide diuretics, aldosterone antagonists, dopamine, cardiorenal syndrome, nesiritide, vasopressin antagonists, ultrafiltration, sodium restriction, fluid restriction, telemonitoring, and invasive hemodynamic monitoring. We also reviewed relevant references cited in the obtained articles, especially articles addressing methods of treating or preventing volume overload in patients with heart failure.

Adequacy of nutritional intake among older men living in Sydney, Australia: findings from the Concord Health and Ageing in Men Project (CHAMP)

Previous research shows that older men tend to have lower nutritional intakes and higher risk of under-nutrition compared with younger men. The objectives of this study were to describe energy and nutrient intakes, assess nutritional risk and investigate factors associated with poor intake of energy and key nutrients in community-dwelling men aged ≥75 years participating in the Concord Health and Ageing in Men Project - a longitudinal cohort study on older men in Sydney, Australia. A total of 794 men (mean age 81·4 years) had a detailed diet history interview, which was carried out by a dietitian. Dietary adequacy was assessed by comparing median intakes with nutrient reference values (NRV): estimated average requirement, adequate intake or upper level of intake. Attainment of NRV of total energy and key nutrients in older age (protein, Fe, Zn, riboflavin, Ca and vitamin D) was incorporated into a 'key nutrients' variable dichotomised as 'good' (≥5) or 'poor' (≤4). Using logistic regression modelling, we examined associations between key nutrients with factors known to affect food intake. Median energy intake was 8728 kJ (P5=5762 kJ, P95=12 303 kJ), and mean BMI was 27·7 (sd 4·0) kg/m2. Men met their NRV for most nutrients. However, only 1 % of men met their NRV for vitamin D, only 19 % for Ca, only 30 % for K and only 33 % for dietary fibre. Multivariate logistic regression analysis showed that only country of birth was significantly associated with poor nutritional intake. Dietary intakes were adequate for most nutrients; however, only half of the participants met the NRV of ≥5 key nutrients.

High sodium intake: review of recent issues on its association with cardiovascular events and measurement methods

There has been a long-known association between high dietary sodium intake and hypertension, as well as the increased risk of cardiovascular disease. Reduction of sodium intake is a major challenge for public health. Recently, there have been several controversial large population-based studies regarding the current recommendation for dietary sodium intake. Although these studies were performed in a large population, they aroused controversies because they had a flaw in the study design and methods. In addition, knowledge of the advantages and disadvantages of the methods is essential in order to obtain an accurate estimation of sodium intake. I have reviewed the current literatures on the association between sodium intake and cardiovascular events, as well as the methods for the estimation of sodium intake.

What is the feasibility of implementing effective sodium reduction strategies to treat hypertension in primary care settings? A systematic review

OBJECTIVE

To evaluate whether efficacious counseling methods on sodium restriction can be successfully incorporated into primary care models for the management of hypertension.

METHODS

We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews of Effects and Health Technology Assessment to identify randomized controlled trials of dietary counseling for salt intake reduction that reported significant reduction in 24-h urinary sodium and blood pressure levels among adults with untreated hypertension. Data extraction and assessment of reproducibility and feasibility were done in duplicate and any disagreements were resolved by consensus.

RESULTS

Six trials were included for assessment of methods as they were efficacious in reducing sodium intake (24-h urinary sodium excretion) by 73 to 93 mmol/day (intervention) vs. 3.2 to 12.5 mmol/day (control). This was paralleled with a reduction in blood pressure (-4 to -27  mmHg) between groups. In four of the six trials, the methods were described in sufficient detail to be reproducible, but in none of these trials were the 'counseling methods' feasible for application in primary care settings. Apart from multiple sessions of counseling, the reported interventions were supplemented with provision of prepared food, community cooking classes, and intensive inpatient training sessions.

CONCLUSION

Despite the availability of efficacious counseling methods for the reduction of sodium intake among newly diagnosed hypertensive patients (feasible within a clinical trial setting), none of these methods, in their present form, are suitable for incorporation into existing primary care settings in countries such as Canada, United States, and UK.

The science of salt: a systematic review of clinical salt studies 2013 to 2014

The authors provided a systematic review of the clinical and population health impact of increased dietary salt intake during 1 year. Randomized controlled trials or cohort studies or meta-analyses on the effect of sodium intake were examined from Medline searches between June 2013 to May 2014. Quality indicators were used to select studies that were relevant to clinical and public health. A total of 213 studies were reviewed, of which 11 (n=186,357) were eligible. These studies confirmed a causal relationship between increasing dietary salt and increased blood pressure and an association between several adverse health outcomes and increased dietary salt. A new association between salt intake and renal cell cancer was published. No study that met inclusion criteria found harm from lowering dietary salt. The findings of this systematic review are consistent with previous data relating increased dietary salt to increased blood pressure and adverse health outcomes.

Living in a 'fat swamp': exposure to multiple sources of accessible, cheap, energy-dense fast foods in a deprived community

This study assesses the levels of fats, including trans-fatty acids, and salt in common takeaway fast foods in a deprived urban municipality in the West Midlands, England, and implications in the context of the spatial distribution of fast food takeaways. The results of the compositional analysis of over 250 take-out foods were compared with established and derived standards. About 70% of products exceeded the recommendation that a meal should contain less than 30% of a Guideline Daily Amount (GDA). More than half of them exceeded 50% GDA for at least one metric, including 81% of all analyses for SFA. And 17% of samples exceeded the GDA for SFA, including each of two meals that contained about twice the GDA. Over 30% samples exceeded the children's GDA for total fat or SFA. 27% of salt analyses exceeded the GDA. People in Sandwell are exposed to large portion sizes and high levels of fats and salt in takeaway foods, with levels in some foods having increased since 2010. Given this population's limited options to break out of a highly compromising environment of living simultaneously in a 'swamp' of unhealthy, readily accessible and cheap takeaways, and a 'desert' of healthy options, an immediate and innovative package of interventions is required.

2013 Korean Society of Hypertension guidelines for the management of hypertension. Part II-treatments of hypertension

Treatment strategies are provided in accordance with the level of global cardiovascular risk, from lifestyle modification in the lower risk group to more comprehensive treatment in the higher risk group. Considering the common trend of combination drug regimen, the choice of the first drug is suggested more liberally according to the physician's discretion.

Uptake of Dietary Sodium Restriction by Overweight and Obese Patients After Cardiac Revascularization

PURPOSE

High sodium intake increases the risk of cardiovascular diseases. Cardiac patients are recommended a daily sodium restriction of ≤1,500 mg. The purpose of this article is to describe daily sodium intake and sodium restriction adherence and its correlates in cardiac rehabilitation (CR) program participants following cardiac revascularizations.

DESIGN

This is a descriptive correlational study.

METHODS

A subanalysis was performed using the data collected from a randomized controlled trial to determine the effect of a 12-week weight management intervention.

FINDINGS

The average daily sodium intake was 3,020 mg ± 1,134 at baseline, 4,047 mg ±1,517 at 4 months, and 4,399 mg ± 1,722 at 6 months. The adherence rates were 4.8% at baseline and zero at 4 and 6 months. The factors influencing daily sodium intake were identified.

CONCLUSION

The CR program participants failed to adhere to the sodium restriction guidelines.

CLINICAL RELEVANCE

Rehabilitation nurses need to identify effective strategies to educate CR participants and their family members regarding dietary sodium adherence in CR participants.

Reducing salt intake for prevention of cardiovascular disease--times are changing

The evidence relating blood pressure to salt intake in humans originates from population studies and randomized clinical trials of interventions on dietary salt intake. Estimates from meta-analyses of trials in normotensive subjects generally are similar to estimates derived from prospective population studies (+1.7 mm Hg increase in systolic blood pressure per 100-mmol increment in 24-hour urinary sodium). This estimate, however, does not translate into an increased risk of incident hypertension in subjects consuming a high salt diet. Prospective studies relating health outcomes to 24-hour urinary sodium excretion produced inconsistent results. Taken together, available evidence does not support the current recommendations of a generalized and indiscriminate reduction of salt intake at the population level, although the blood pressure-lowering effect of dietary sodium restriction might be of value in hypertensive patients.

Knowledge, attitude and behaviour regarding dietary salt intake among medical students in Angola

BACKGROUND

Levels of salt consumption and its awareness among medical students in Angola remain insufficiently studied. This study determined salt intake and assessed medical students' knowledge, attitude and behaviour regarding salt consumption.

METHODS

Were collected 24-hour urine samples from a random sample of 123 undergraduate medical students aged 17-43 years who were studying at the University of Agostinho Neto in Luanda. Their knowledge, attitude and behaviour regarding dietary salt were surveyed. Socio-demographic, clinical and anthropometric data were collected.

RESULTS

Average salt intake was 14.2 ± 5.1 g/day, without significant difference between genders (p = 0.221). In total, 96.7% consumed over 5 g/day, but only 6.5% of participants were aware of their excessive salt intake. The majority knew about salt-related health consequences and 45.5% reported they controlled their salt intake.

CONCLUSIONS

This study indicated a high salt intake and inadequate behaviour regarding dietary salt consumption among medical students studying at the University of Agostinho Neto. This highlights the need for nutritional education to improve their dietary habits and future role in counselling.

Assessing the associations of sodium intake with long-term all-cause and cardiovascular mortality in a hypertensive cohort

BACKGROUND

Although higher sodium intake is known to increase blood pressure, its association with cardiovascular mortality is less established. We examined the association of baseline sodium intake in a hypertensive cohort with all-cause and cardiovascular mortality over a mean follow-up of 18.6 years.

METHODS

Three thousand five hundred five subjects were participants in a worksite hypertension program. Sodium intake was estimated by 24-hour urine excretion. Mortality data were obtained from the U.S. National Death Index. Unadjusted and multivariable-adjusted associations between sodium quartiles (quartile I (QI) to quartile IV (QIV)) and mortality were assessed using Cox models.

RESULTS

Estimated mean ± SD sodium intake was 130±69 mmol overall (55±20 mmol in QI; 220±56 mmol in QIV). Baseline systolic blood pressure did not vary significantly between groups. Last available mean systolic blood pressure was highest in QI and lowest in QIV (137±16 vs. 134±14 mm Hg; P = 0.009). Overall there were 1,013 deaths (399 cardiovascular). Unadjusted models exhibited significant inverse relationships between sodium and mortality outcomes. In adjusted models, sodium intake was not significantly associated with cardiovascular mortality (QI vs. QIV: hazard ratio (HR) = 1.00; 95% confidence interval (CI) = 0.71-1.42; P = 0.99). A borderline significant direct association with all-cause mortality was observed (QI vs. QIV: HR = 0.81; 95% CI = 0.66-1.00; P = 0.05) driven partly by noncardiovascular deaths.

CONCLUSIONS

Our study found no significant association between sodium intake and cardiovascular outcomes, although a significant association with all-cause mortality was observed. Although these findings suggest that sodium may not have a strong relationship with cardiovascular mortality, the inconsistent results cast doubt on whether a single measurement can reliably predict mortality over a prolonged follow-up period.