Trends in 24-h urinary sodium excretion in the United States, 1957-2003: a systematic review

Association between Urinary Sodium Excretion and Body Fat in School-Aged Children: Insights from the ARIA Study

Childhood obesity has been associated with increased sodium intake. Nonetheless, evidence linking sodium intake to Body Mass Index (BMI) and Body Fat Mass Percentage (%BF) remains limited, especially in the pediatric age group. Therefore, this study aims to investigate whether there is an association between 24 h urinary sodium excretion with BMI and %BF in a sample group of children from the ARIA study. This cross-sectional analysis included 303 children aged 7 to 12 from across 20 public schools in Porto, Portugal. Weight and %BF were assessed using the Tanita™ BC-418 Segmental Body Analyzer. Children's Total Energy Intake (TEI) was estimated through a single 24 h Recall Questionnaire, and urinary sodium and potassium excretion was estimated by a 24 h urine collection. The association of %BF and BMI with 24 h sodium excretion was estimated by a binary logistic regression adjusted for sex, age, physical activity, total energy intake, parental education, and 24 h urinary excreted potassium. There was a significant positive association between higher levels of urinary sodium excretion and higher %BF values, even after adjusting for confounders. However, the same was not observed for BMI. Our findings suggest that higher sodium intake is associated with higher values of %BF among children, regardless of TEI and potassium intake.

Dietary sodium and fluid intake in heart failure. A clinical consensus statement of the Heart Failure Association of the ESC

Sodium and fluid restriction has traditionally been advocated in patients with heart failure (HF) due to their sodium and water avid state. However, most evidence regarding the altered sodium handling, fluid homeostasis and congestion-related signs and symptoms in patients with HF originates from untreated patient cohorts and physiological investigations. Recent data challenge the beneficial role of dietary sodium and fluid restriction in HF. Consequently, the European Society of Cardiology HF guidelines have gradually downgraded these recommendations over time, now advising for the limitation of salt intake to no more than 5 g/day in patients with HF, while contemplating fluid restriction of 1.5-2 L/day only in selected patients. Therefore, the objective of this clinical consensus statement is to provide advice on fluid and sodium intake in patients with acute and chronic HF, based on contemporary evidence and expert opinion.

Potassium and Hypertension: A State-of-the-Art Review

Hypertension is the single most important and modifiable risk factor for cardiovascular morbidity and mortality worldwide. Non pharmacologic interventions, in particular dietary modifications have been established to decrease blood pressure (BP) and hypertension related adverse cardiovascular events. Among those dietary modifications, sodium intake restriction dominates guidelines from professional organizations and has garnered the greatest attention from the mainstream media. Despite guidelines and media exhortations, dietary sodium intake globally has not noticeably changed over recent decades. Meanwhile, increasing dietary potassium intake has remained on the sidelines, despite similar BP-lowering effects. New research reveals a potential mechanism of action, with the elucidation of its effect on natriuresis via the potassium switch effect. Additionally, potassium-substituted salt has been shown to not only reduce BP, but also reduce the risk for stroke and cardiovascular mortality. With these data, we argue that the focus on dietary modification should shift from a sodium-focused to a sodium- and potassium-focused approach with an emphasis on intervention strategies which can easily be implemented into clinical practice.

Does the Mediterranean Dietary Pattern Promote Lower Sodium Urinary Excretion in Children?

An adequate sodium intake is related to various health benefits. Parallelly, the Mediterranean diet (MD) is a dietary pattern known for its many positive impacts on health. Nonetheless, the association between adherence to the MD and sodium urinary excretion is scarce, even more in children. This study aimed to assess the association between MD adherence and the excretion of sodium, as a proxy of intake. This cross-sectional analysis comprised 295 children (46.8% females, aged 7-11 years, mean age: 8.53 ± 0.73 years) from 20 schools within Porto, Portugal. MD adherence was evaluated utilizing the alternate Mediterranean score (aMED). Higher scores denote a healthier dietary pattern (0-8). Sodium excretion was estimated by 24-h urine collection. The association between adherence to MD and Na excretion was estimated by logistic regression, adjusting for confounders. Children in the higher sodium excretion group had a higher intake of legumes, a higher body mass index and parents with lower education levels compared to children in the lower sodium excretion group. In logistic regression analysis, sodium urinary excretion was not associated with higher MD adherence, even after adjustment for confounders. High MD adherence could not be associated with lower sodium excretion in children.

Role of Sodium and Sodium Restriction in Heart Failure

PURPOSE OF REVIEW

Sodium plays an essential role in the regulation of extracellular volume. The current review discusses the physiologic handling of sodium in the body, underscores pathophysiologic alterations in sodium handling in heart failure and assesses the evidence and rational for sodium restriction in heart failure.

RECENT FINDINGS

Recent trials such as the SODIUM-HF trial have failed to demonstrate a benefit of sodium restriction in heart failure. The current review re-evaluates physiologic elements in sodium handling and discusses how the intrinsic renal sodium avidity, which drives the renal propensity towards retaining sodium, differs amongst patients. The sodium intake in heart failure patients is often above the threshold set by guidelines. This review gives an overview of the pathophysiology of sodium retention in heart failure and the rational for sodium restriction and potential of individualizing sodium restriction recommendations based on renal sodium avidity profiles.

The role of dietary salt in metabolism and energy balance: Insights beyond cardiovascular disease

Dietary salt (NaCl) is essential to an organism's survival. However, today's diets are dominated by excessive salt intake, which significantly impacts individual and population health. High salt intake is closely linked to cardiovascular disease (CVD), especially hypertension, through a number of well-studied mechanisms. Emerging evidence indicates that salt overconsumption may also be associated with metabolic disorders. In this review, we first summarize recent updates on the mechanisms of salt-induced CVD, the effects of salt reduction and the use of salt substitution as a therapy. Next, we focus on how high salt intake can impact metabolism and energy balance, describing the mechanisms through which this occurs, including leptin resistance, the overproduction of fructose and ghrelin, insulin resistance and altered hormonal factors. A further influence on metabolism worth noting is the reported role of salt in inducing thermogenesis and increasing body temperature, leading to an increase in energy expenditure. While this result could be viewed as a positive metabolic effect because it promotes a negative energy balance to combat obesity, caution must be taken with this frame of thinking given the deleterious consequences of chronic high salt intake on cardiovascular health. Nevertheless, this review highlights the importance of salt as a noncaloric nutrient in regulating whole-body energy homeostasis. Through this review, we hope to provide a scientific framework for future studies to systematically address the metabolic impacts of dietary salt and salt replacement treatments. In addition, we hope to form a foundation for future clinical trials to explore how these salt-induced metabolic changes impact obesity development and progression, and to elucidate the regulatory mechanisms that drive these changes, with the aim of developing novel therapeutics for obesity and CVD.

The quantification of sodium intake from discretionary salt intake in New Zealand using the lithium-tagged salt method

Introduction

Discretionary salt (added in cooking at home or at the table) is a source of sodium and iodine in New Zealand. The amount of discretionary salt consumed in a population has implications on policies regarding sodium and iodine. Sodium intake from discretionary salt intake has not been quantified in New Zealand. The aim of this study was to estimate the proportion of total sodium that comes from discretionary salt in adults using the lithium-tagged salt method.

Methods

A total of 116 healthy adults, who were not pregnant or breastfeeding, regularly consume home-cooked meals and use salt during cooking or at the table, aged 18-40 years from Dunedin, New Zealand were recruited into the study. The study took place over a 9-day period. On Day 1, participants were asked to collect a baseline 24-h urine to establish their normal lithium output. From Day 2 to Day 8, normal discretionary salt was replaced with lithium-tagged salt. Between Day 6 and Day 8, participants collected another two 24-h urine samples. A 24-h dietary recall was conducted to coincide with each of the final two 24-h urine collections. Urinary sodium was analysed by Ion-Selective Electrode and urinary lithium and urinary iodine were analysed using Inductively Coupled Plasma Mass Spectrometry. The 24-h dietary recall data was entered into Xyris FoodWorks 10. All statistical analysis were conducted using Stata 17.0.

Results

A total of 109 participants with complete 24-h urine samples were included in the analysis. From the 24-h urine collections, the median urinary excretion of sodium and iodine was 3,222 mg/24 h (25th, 75th percentile: 2516, 3969) and 112 μg/24 h (82, 134). The median estimated sodium intake from discretionary salt was 13% (25th, 75th percentile: 7, 22) of the total sodium intake or 366 mg/24 h (25th, 75th percentile: 186, 705).

Conclusion

The total sodium intake was higher than the suggested dietary target of 2,000 mg/day. In this sample of healthy adults 18 to 40 years old, 13% of total sodium intake derived from discretionary salt. Discretionary salt is an additional source of iodine if iodised salt is used. Policies to reduce sodium intake is recommended to include a range of strategies to target discretionary and non-discretionary sources of salt and will need to take into account the contribution of iodine from discretionary salt intake.

The opposing trends of body mass index and blood pressure during 1977-2020; nationwide registry of 2.8 million male and female adolescents

Background

Elevated blood pressure among adolescents has been shown to be associated with future adverse cardiovascular outcomes and early onset diabetes. Most data regarding systolic and diastolic blood pressure trends are based on surveys of selected populations within 10–20-year periods. The goal of this study was to characterize the secular trend of blood pressure given the rising prevalence of adolescent obesity.

Methods

This nationwide population-based study included 2,785,515 Israeli adolescents (41.6% females, mean age 17.4 years) who were medically evaluated and whose weight, height and blood pressure were measured, prior to mandatory military service between 1977 and 2020. The study period was divided into 5-year intervals. Linear regression models were used to describe the P for trend along the time intervals. Analysis of covariance was used to calculate means of blood pressure adjusted for body mass index.

Results

During the study period, the mean body mass index increased by 2.1 and 1.6 kg/m² in males and females, respectively (P for trend  < 0.001 in both sexes). The mean diastolic blood pressure decreased by 3.6 mmHg in males and by 2.9 mmHg in females (P  < 0.001 in both sexes). The mean systolic blood pressure increased by 1.6 mmHg in males and decreased by 1.9 mmHg in females. These trends were also consistent when blood pressure values were adjusted to body mass index.

Conclusion

Despite the increase in body mass index over the last four decades, diastolic blood pressure decreased in both sexes while systolic blood pressure increased slightly in males and decreased in females.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01433-0.

Association between ultrapocessed food and chronic kidney disease

The modern diet is closely linked to the consumption of processed foods, causing an increase in the intake of salt, simple sugars, phosphorus and added potassium. This excess intake is associated with an increased risk of obesity, diabetes, hypertension and chronic kidney disease (CKD). CKD, which according to data from the ENRICA study affects 15% of the population, magnifies its impact due to the higher prevalence of diabetes and hypertension and due to limitations in the management of sodium and phosphorus. The intake of these products far exceeds the established recommendations, assuming 72% of total sodium, 25%-35% of phosphorus, 12%-18% of potassium and exceeding 10% of the caloric intake in simple sugars. Measures are necessary to reduce their contribution through nutritional advice, labeling review, education campaigns on healthy habits, fees and institutional actions that involve food safety agencies, industry, distribution and scientific societies.

Dietary Policies and Programs: Moving Beyond Efficacy and Into "Real-World" Settings

Purpose: Dietary behaviors are key modifiable risk factors in averting cardiovascular disease (CVD), the leading cause of morbidity, mortality, and disability in the United States. Before investing in adoption and implementation, community-based organizations, public health practitioners, and policymakers—often working with limited resources—need to compare the population health impacts of different food policies and programs to determine priorities, build capacity, and maximize resources. Numerous reports, reviews, and policy briefs have synthesized across evidence-based policies and programs to make recommendations, but few have made a deep acknowledgment that dietary policies and programs are not implemented in a vacuum, and that “real-world” settings are complex, multifaceted and dynamic.

Methods: A narrative review was conducted of currently recommended evidence-based approaches to improving dietary behaviors, to describe and characterize applied and practical factors for consideration when adopting and implementing these dietary policies and programs across diverse settings.

Results: From the narrative review, six key considerations emerged to guide community-based organizations, public health practitioners, and policymakers on moving from the evidence base, toward implementation in local and community settings.

Conclusions: Considerations of “real-world” contextual factors are necessary and important when adopting and selecting evidence-based policies and programs to improve dietary behaviors and ultimately improve CVD outcomes. Promising approaches include those that apply community-partnered research and systems science to examine the equitable implementation of evidence-based dietary policies and programs.

Development of an Intervention to Promote Physical Activity and Reduce Dietary Sodium Intake for Preventing Hypertension and Chronic Disease in Filipino Americans

Hypertension is a common chronic health condition affecting Filipino Americans. This pilot study examined the feasibility of addressing high rates of hypertension among Filipino Americans through the implementation of a culturally tailored education intervention. Filipino Americans living in the Greater Philadelphia Area were recruited through community-based organizations for participation and were engaged using a community-based participatory research (CBPR) framework. The study included pre- and post-intervention blood pressure measurements, self-reported body mass index, and questionnaires about physical activity and salt intake. The intervention to promote physical activity and reduce salt intake was conducted through two educational sessions and was accompanied by follow-up at 3 months and by the collection of urine samples for 24-h urinary sodium intake biomarker analysis. Following intervention, a non-statistically significant decrease in urine sodium was observed in both the intervention and the control groups. For systolic blood pressure, a reduction of 12.6 mmHg and an increase in 5.3 mmHg was observed in the intervention and control groups, respectively. Diastolic pressure decreased 3.8 mmHg for the intervention group and increased 5.6 mmHg among controls. The culturally tailored education intervention reported here represents a promising tool for blood pressure reduction in high-risk ethnic populations. The methods used were effective for the recruitment and retention of ethnic minorities in a community-based setting.

Strategies for Reducing Sodium Intake in Bakery Products, a Review

Nowadays, the dietary sodium chloride intake is higher than the daily recommended levels, especially due to its prominent presence in food products. This may cause an increase of high blood pressure leading to cardiovascular diseases. Cereal products, and in particular bread, are the main source of salt in human diet. However, salt is a critical ingredient in bread making, and its reduction can have a negative impact on bread quality. This review focuses on physiological role of sodium chloride, its effect on the human body and legislative recommendations on its consumption. Moreover, it presents sodium chloride effects on the bread making from the technological and sensory point of view and presents different options for salt reduction in foods focusing on bakery products. It may be concluded that salt reduction in bread making while maintaining dough rheological properties, yeast fermentation rate, bread quality through its loaf volume, color, textural properties, sensory characteristics is difficult to be achieved due to sodium chloride’s multifunctional role in the bread-making process. Several strategies have been discussed, focusing on sodium chloride replacement with other type of salts, dry sourdough and flavor enhancers.

Association between ultrapocessed food and chronic kidney disease

The modern diet is closely linked to the consumption of processed foods, causing an increase in the intake of salt, simple sugars, phosphorus and added potassium. This excess intake is associated with an increased risk of obesity, diabetes, hypertension and chronic kidney disease (CKD). CKD, which according to data from the ENRICA study affects 15% of the population, magnifies its impact due to the higher prevalence of diabetes and hypertension and due to limitations in the management of sodium and phosphorus. The intake of these products far exceeds the established recommendations, assuming 72% of total sodium, 25-35% of phosphorus, 12-18% of potassium and exceeding 10% of the caloric intake in simple sugars. Measures are necessary to reduce their contribution through nutritional advice, labeling review, education campaigns on healthy habits, fees and institutional actions that involve food safety agencies, industry, distribution and scientific societies.

Mechanisms of Dietary Sodium-Induced Impairments in Endothelial Function and Potential Countermeasures

Despite decades of efforts to reduce sodium intake, excess dietary sodium remains commonplace, and contributes to increased cardiovascular morbidity and mortality independent of its effects on blood pressure. An increasing amount of research suggests that high-sodium diets lead to reduced nitric oxide-mediated endothelial function, even in the absence of a change in blood pressure. As endothelial dysfunction is an early step in the progression of cardiovascular diseases, the endothelium presents a target for interventions aimed at reducing the impact of excess dietary sodium. In this review, we briefly define endothelial function and present the literature demonstrating that excess dietary sodium results in impaired endothelial function. We then discuss the mechanisms through which sodium impairs the endothelium, including increased reactive oxygen species, decreased intrinsic antioxidant defenses, endothelial cell stiffening, and damage to the endothelial glycocalyx. Finally, we present selected research findings suggesting that aerobic exercise or increased intake of dietary potassium may counteract the deleterious vascular effects of a high-sodium diet.

Global epidemiology, health burden and effective interventions for elevated blood pressure and hypertension

High blood pressure is one of the most important risk factors for ischaemic heart disease, stroke, other cardiovascular diseases, chronic kidney disease and dementia. Mean blood pressure and the prevalence of raised blood pressure have declined substantially in high-income regions since at least the 1970s. By contrast, blood pressure has risen in East, South and Southeast Asia, Oceania and sub-Saharan Africa. Given these trends, the prevalence of hypertension is now higher in low-income and middle-income countries than in high-income countries. In 2015, an estimated 8.5 million deaths were attributable to systolic blood pressure >115 mmHg, 88% of which were in low-income and middle-income countries. Measures such as increasing the availability and affordability of fresh fruits and vegetables, lowering the sodium content of packaged and prepared food and staples such as bread, and improving the availability of dietary salt substitutes can help lower blood pressure in the entire population. The use and effectiveness of hypertension treatment vary substantially across countries. Factors influencing this variation include a country's financial resources, the extent of health insurance and health facilities, how frequently people interact with physicians and non-physician health personnel, whether a clear and widely adopted clinical guideline exists and the availability of medicines. Scaling up treatment coverage and improving its community effectiveness can substantially reduce the health burden of hypertension.

Salt need needs investigation

Expensive and extensive studies on the epidemiology of excessive Na intake and its pathology have been conducted over four decades. The resultant consensus that dietary Na is toxic, as well as the contention that it is less so, ignores the root cause of the attractiveness of salted food. The extant hypotheses are that most Na is infiltrated into our bodies via heavily salted industrialised food without our knowledge and that mere exposure early in life determines lifelong intake. However, these hypotheses are poorly evidenced and are meagre explanations for the comparable salt intake of people worldwide despite their markedly different diets. The love of salt begins at birth for some, vacillates in infancy, climaxes during adolescent growth, settles into separate patterns for men and women in adulthood and, with age, fades for some and persists for others. Salt adds flavour to food. It sustains and protects humans in exertion, may modulate their mood and contributes to their ailments. It may have as yet unknown benefits that may promote its delectability, and it generates controversy. An understanding of the predilection for salt should allow a more evidence-based and effective reduction of the health risks associated with Na surfeit and deficiency. The purpose of this brief review is to show the need for research into the determinants of salt intake by summarising the little we know.

Salt, No Salt, or Less Salt for Patients With Heart Failure?

Restricting dietary sodium is a common recommendation given by clinicians to patients with heart failure and is one supported by current guidelines. However, the quality of evidence for this recommendation is suboptimal, and there is no consensus on the optimal level of sodium intake. Though excessive sodium intake is associated with left ventricular hypertrophy and hypertension, recent data have suggested that very low sodium intake is paradoxically associated with worse outcomes for patients with heart failure. This is possibly explained by the association between low sodium intake and activation of the sympathetic and renin-angiotensin-aldosterone systems. Nevertheless, sodium restriction is routinely recommended and remains a cornerstone of heart failure and blood pressure therapy. In this review we discuss the pros and cons of sodium restriction for patients with heart failure from the current literature.

Effect of urinary sodium-to-potassium ratio change on blood pressure in participants of the longitudinal health of adults study - ELSA-Brasil

To assess the effect of changing the sodium to potassium (Na/K) ratio on blood pressure at 4 years of follow-up.The measurements were carried out under identical conditions in two study periods (2008-2010 and 2012-2014). Urinary excretion of sodium and potassium (mmol/L) over 12 nocturnal hours was used to calculate the Na/K ratio and categorized by quintile. The 24-hour sodium and potassium intake was estimated using a validated equation. The mean BP was calculated from 3 measurements after 5 minutes of rest. Of the 15,105 participants at baseline, 14,014 completed the first follow-up. Participants without validated urine collection (n = 5,041), using antihypertensive medication (n = 3,860) at either time points or reporting bariatric surgery during follow-up (n = 45) were excluded. The differences between follow-up and baseline values were calculated for BP and the Na/K ratio. Analyses were stratified by sex and adjusted for confounding variables.Sodium intake did not change from baseline, but potassium intake increased by approximately 150 mg in both sexes (P < .001), with a consequent reduction of the Na/K ratio. The highest quintile of change in the Na/K ratio was associated with greater variation in BP. When adjusted for covariates, it is possible to observe an increase in SBP in women from the third quintile of the Na/K ratio, in men this increase was observed from the fourth quintile. However, for DBP this increase is observed from the third quintile in both men and women.Increase in SBP was observed in women from the third quintile of the Na/K ratio, in men this increase is observed from the fourth quintile. However, for DBP this increase is observed from the third quintile in both men and women. The Na/K ratio demonstrated a greater association in BP.

Reducing Dietary Sodium to 1000 mg per Day Reduces Neurovascular Transduction Without Stimulating Sympathetic Outflow

The American Heart Association recommends no more than 1500 mg of sodium/day as ideal. Some cohort studies suggest low-sodium intake is associated with increased cardiovascular mortality. Extremely low-sodium diets (≤500 mg/d) elicit activation of the renin-angiotensin-aldosterone system and stimulate sympathetic outflow. The effects of an American Heart Association-recommended diet on sympathetic regulation of the vasculature are unclear. Therefore, we assessed whether a 1000 mg/d diet alters sympathetic outflow and sympathetic vascular transduction compared with the more commonly recommended 2300 mg/d. We hypothesized that sodium reduction from 2300 to 1000 mg/d would not affect resting sympathetic outflow but would reduce sympathetic transduction in healthy young adults. Seventeen participants (age: 26±2 years, 9F/8M) completed 10-day 2300 and 1000 mg/d sodium diets in this randomized controlled feeding study (crossover). We measured resting renin activity, angiotensin II, aldosterone, blood pressure, muscle sympathetic nerve activity, and norepinephrine. We quantified beat-by-beat changes in mean arterial pressure and leg vascular conductance (femoral artery ultrasound) following spontaneous sympathetic bursts to assess sympathetic vascular transduction. Reducing sodium to 1000 mg/d increased renin activity, angiotensin II, and aldosterone ( P<0.01 for all) but did not alter mean arterial pressure (78±2 versus 77±2 mm Hg, P=0.56), muscle sympathetic nerve activity (13.9±1.3 versus 13.9±0.8 bursts/min, P=0.98), or plasma/urine norepinephrine. Sympathetic vascular transduction decreased ( P<0.01). These data suggest that reducing sodium from 2300 to 1000 mg/d stimulates the renin-angiotensin-aldosterone system, does not increase resting basal sympathetic outflow, and reduces sympathetic vascular transduction in normotensive adults.

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.

Urinary sodium excretion, blood pressure, cardiovascular disease, and mortality: a community-level prospective epidemiological cohort study

BACKGROUND

WHO recommends that populations consume less than 2 g/day sodium as a preventive measure against cardiovascular disease, but this target has not been achieved in any country. This recommendation is primarily based on individual-level data from short-term trials of blood pressure (BP) without data relating low sodium intake to reduced cardiovascular events from randomised trials or observational studies. We investigated the associations between community-level mean sodium and potassium intake, cardiovascular disease, and mortality.

METHODS

The Prospective Urban Rural Epidemiology study is ongoing in 21 countries. Here we report an analysis done in 18 countries with data on clinical outcomes. Eligible participants were adults aged 35-70 years without cardiovascular disease, sampled from the general population. We used morning fasting urine to estimate 24 h sodium and potassium excretion as a surrogate for intake. We assessed community-level associations between sodium and potassium intake and BP in 369 communities (all >50 participants) and cardiovascular disease and mortality in 255 communities (all >100 participants), and used individual-level data to adjust for known confounders.

FINDINGS

95 767 participants in 369 communities were assessed for BP and 82 544 in 255 communities for cardiovascular outcomes with follow-up for a median of 8·1 years. 82 (80%) of 103 communities in China had a mean sodium intake greater than 5 g/day, whereas in other countries 224 (84%) of 266 communities had a mean intake of 3-5 g/day. Overall, mean systolic BP increased by 2·86 mm Hg per 1 g increase in mean sodium intake, but positive associations were only seen among the communities in the highest tertile of sodium intake (p<0·0001 for heterogeneity). The association between mean sodium intake and major cardiovascular events showed significant deviations from linearity (p=0·043) due to a significant inverse association in the lowest tertile of sodium intake (lowest tertile <4·43 g/day, mean intake 4·04 g/day, range 3·42-4·43; change -1·00 events per 1000 years, 95% CI -2·00 to -0·01, p=0·0497), no association in the middle tertile (middle tertile 4·43-5·08 g/day, mean intake 4·70 g/day, 4·44-5.05; change 0·24 events per 1000 years, -2·12 to 2·61, p=0·8391), and a positive but non-significant association in the highest tertile (highest tertile >5·08 g/day, mean intake 5·75 g/day, >5·08-7·49; change 0·37 events per 1000 years, -0·03 to 0·78, p=0·0712). A strong association was seen with stroke in China (mean sodium intake 5·58 g/day, 0·42 events per 1000 years, 95% CI 0·16 to 0·67, p=0·0020) compared with in other countries (4·49 g/day, -0·26 events, -0·46 to -0·06, p=0·0124; p<0·0001 for heterogeneity). All major cardiovascular outcomes decreased with increasing potassium intake in all countries.

INTERPRETATION

Sodium intake was associated with cardiovascular disease and strokes only in communities where mean intake was greater than 5 g/day. A strategy of sodium reduction in these communities and countries but not in others might be appropriate.

FUNDING

Population Health Research Institute, Canadian Institutes of Health Research, Canadian Institutes of Health Canada Strategy for Patient-Oriented Research, Ontario Ministry of Health and Long-Term Care, Heart and Stroke Foundation of Ontario, and European Research Council.

Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: a pooled analysis of 1018 population-based measurement studies with 88.6 million participants

BACKGROUND

Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure.

METHODS

We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probit-transformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure.

RESULTS

In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the high-income Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association.

CONCLUSIONS

Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups.

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.

Longitudinal Change of Perceived Salt Intake and Stroke Risk in a Chinese Population

BACKGROUND AND PURPOSE

Data for a relationship between salt intake and stroke have been inconsistent. This inconstancy could be because of the majority of studies evaluated salt intake at a single time point, which may be insufficient to accurately characterize salt intake throughout the observation period.

METHODS

Included were 77 605 participants from the Kailuan study. We assessed perceived salt intake via questionnaire in 2006, 2008, and 2010. Salt intake trajectories from 2006 to 2010 were identified using latent mixture models. Incident stroke cases were identified from 2010 to 2015 and confirmed by review of medical records. Cox proportional hazards model was used to examine the association between salt intake trajectories and stroke risk after adjusting for possible confounders, including age, sex, lifestyle, social economic status, body mass index, use of medicines, blood pressure, and lipoprotein profiles.

RESULTS

Identified were 5 distinct salt intake trajectories: moderate-stable (n=59 241), moderate-decreasing (n=9268), moderate-increasing (n=2975), low-increasing (n=2879), and high-decreasing (n=3242). During the 5-year follow-up period, there were 1564 incident strokes cases. Compared with individuals with the moderate-stable salt intake trajectory, individuals with moderate-decreasing salt intake trajectory had significantly lower cerebral infarction stroke risk (adjusted hazard ratio, 0.76; 95% confidence interval, 0.63-0.92) but not intracerebral hemorrhage risk (adjusted hazard ratio, 0.84; 95% confidence interval, 0.55-1.29). Further adjustment for 2006 or 2010 perceived salt intakes generated similar results. When baseline perceived salt intake only was used as the exposure, a significant dose-response relationship between higher perceived salt intake and higher stroke risk was observed (P trend=0.006).

CONCLUSIONS

Change in salt intake was associated with the stroke risk. These data support the dietary recommendation to the reduction of salt intake.

Estimated 24-Hour Urinary Sodium and Potassium Excretion in US Adults

Importance

In 2010, the Institute of Medicine (now the National Academy of Medicine) recommended collecting 24-hour urine to estimate US sodium intake because previous studies indicated 90% of sodium consumed was excreted in urine.

Objective

To estimate mean population sodium intake and describe urinary potassium excretion among US adults.

Design, Setting, and Participants

In a nationally representative cross-sectional survey of the US noninstitutionalized population, 827 of 1103 (75%) randomly selected, nonpregnant participants aged 20 to 69 years in the examination component of the National Health and Nutrition Examination Survey (NHANES) collected at least one 24-hour urine specimen in 2014. The overall survey response rate for the 24-hour urine collection was approximately 50% (75% [24-hour urine component response rate] × 66% [examination component response rate]).

Exposures

24-hour collection of urine.

Main Outcomes and Measures

Mean 24-hour urinary sodium and potassium excretion. Weighted national estimates of demographic and health characteristics and mean electrolyte excretion accounting for the complex survey design, selection probabilities, and nonresponse.

Results

The study sample (n = 827) represented a population of whom 48.8% were men; 63.7% were non-Hispanic white, 15.8% Hispanic, 11.9% non-Hispanic black, and 5.6% non-Hispanic Asian; 43.5% had hypertension (according to 2017 hypertension guidelines); and 10.0% reported a diagnosis of diabetes. Overall mean 24-hour urinary sodium excretion was 3608 mg (95% CI, 3414-3803). The overall median was 3320 mg (interquartile range, 2308-4524). In secondary analyses by sex, mean sodium excretion was 4205 mg (95% CI, 3959-4452) in men (n = 421) and 3039 mg (95% CI, 2844-3234) in women (n = 406). By age group, mean sodium excretion was 3699 mg (95% CI, 3449-3949) in adults aged 20 to 44 years (n = 432) and 3507 mg (95% CI, 3266-3748) in adults aged 45 to 69 years (n = 395). Overall mean 24-hour urinary potassium excretion was 2155 mg (95% CI, 2030-2280); by sex, 2399 mg (95% CI, 2253-2545) in men and 1922 mg (95% CI, 1757-2086) in women; and by age, 1986 mg (95% CI, 1878-2094) in adults aged 20 to 44 years and 2343 mg (95% CI, 2151-2534) in adults aged 45 to 69 years.

Conclusions and Relevance

In cross-sectional data from a 2014 sample of US adults, estimated mean sodium intake was 3608 mg per day. The findings provide a benchmark for future studies.

Urinary Sodium-to-Potassium Ratio Tracks the Changes in Salt Intake during an Experimental Feeding Study Using Standardized Low-Salt and High-Salt Meals among Healthy Japanese Volunteers

The Na/K ratio is considered to be a useful index, the monitoring of which allows an effective Na reduction and K increase, because practical methods (self-monitoring devices and reliable individual estimates from spot urine) are available for assessing these levels in individuals. An intervention trial for lowering the Na/K ratio has demonstrated that a reduction of the Na/K ratio mainly involved Na reduction, with only a small change in K. The present study aimed to clarify the relationship between dietary Na intake and the urinary Na/K molar ratio, using standardized low- and high-salt diets, with an equal dietary K intake, to determine the corresponding Na/K ratio. Fourteen healthy young adult volunteers ingested low-salt (3 g salt per day) and high-salt (20 g salt per day) meals for seven days each. Using a portable urinary Na/K meter, participants measured their spot urine at each voiding, and 24-h urine was collected on the last day of each diet period. On the last day of the unrestricted, low-salt, and high-salt diet periods, the group averages of the 24-h urine Na/K ratio were 4.2, 1.0, and 6.9, while the group averages of the daily mean spot urine Na/K ratio were 4.2, 1.1, and 6.6, respectively. The urinary Na/K ratio tracked changes in dietary salt intake, and reached a plateau approximately three days after each change in diet. Frequent monitoring of the spot urine Na/K ratio may help individuals adhere to an appropriate dietary Na intake.

Asian American Dietary Sources of Sodium and Salt Behaviors Compared with Other Racial/ethnic Groups, NHANES, 2011-2012

OBJECTIVE

Asian Americans consume more sodium than other racial/ethnic groups. The purpose of this analysis was to describe major sources of sodium intake to inform sodium reduction initiatives.

METHODS

Cross-sectional data on adults (aged >18 years) from the National Health and Nutrition Examination Survey (NHANES) 2011-2012 with one 24-hour dietary recall were analyzed (n=5,076). Population proportions were calculated from "What We Eat in America" (WWEIA) food categories.

RESULTS

Asian Americans had a higher sodium density vs adults of other racial/ethnic groups (means in mg/1000kcal: Asian American, 2031.1; Hispanic,1691.6; White: 1666.5; Black: 1655.5; P<.05, all). Half of sodium consumed by Asian Americans came from the top 10 food categories, in contrast to Hispanics (43.6%), Whites (39.0%), and Blacks (36.0%). Four food categories were a top source of sodium for Hispanics, Whites, Blacks, and others, but not among Asian Americans: cold cuts and cured meats; meat mixed dishes; eggs and omelets; and cheese. The top three food category sources of sodium among Asians were soups, rice, and yeast breads accounting for 28.9% of dietary sodium. Asian Americans were less likely to add salt at the table, but used salt in food preparation 'very often' (P for both <.01).

CONCLUSIONS

Mean sodium consumption and sources vary across racial/ethnic groups with highest consumption in Asian Americans. Given the smaller number of food categories contributing to sodium intake in Asian Americans, results imply that targeted activities on a few food items would have a large impact on reducing sodium intake in this group.

Applying recovery biomarkers to calibrate self-report measures of sodium and potassium in the Hispanic Community Health Study/Study of Latinos

Measurement error in assessment of sodium and potassium intake obscures associations with health outcomes. The level of this error in a diverse US Hispanic/Latino population is unknown. We investigated the measurement error in self-reported dietary intake of sodium and potassium and examined differences by background (Central American, Cuban, Dominican, Mexican, Puerto Rican and South American). In 2010-2012, we studied 447 participants aged 18-74 years from four communities (Miami, Bronx, Chicago and San Diego), obtaining objective 24-h urinary sodium and potassium excretion measures. Self-report was captured from two interviewer-administered 24-h dietary recalls. Twenty percent of the sample repeated the study. We examined bias in self-reported sodium and potassium from diet and the association of mismeasurement with participant characteristics. Linear regression relating self-report with objective measures was used to develop calibration equations. Self-report underestimated sodium intake by 19.8% and 20.8% and potassium intake by 1.3% and 4.6% in men and women, respectively. Sodium intake underestimation varied by Hispanic/Latino background (P<0.05) and was associated with higher body mass index (BMI). Potassium intake underestimation was associated with higher BMI, lower restaurant score (indicating lower consumption of foods prepared away from home and/or eaten outside the home) and supplement use. The R2 was 19.7% and 25.0% for the sodium and potassium calibration models, respectively, increasing to 59.5 and 61.7% after adjusting for within-person variability in each biomarker. These calibration equations, corrected for subject-specific reporting error, have the potential to reduce bias in diet-disease associations within this largest cohort of Hispanics in the United States.

Renin Phenotypes Characterize Vascular Disease, Autonomous Aldosteronism, and Mineralocorticoid Receptor Activity

CONTEXT

Mild cases of autonomous aldosterone secretion may go unrecognized using current diagnostic criteria for primary aldosteronism (PA).

OBJECTIVE

To investigate whether the inability to stimulate renin serves as a biomarker for unrecognized autonomous aldosterone secretion and mineralocorticoid receptor (MR) activation.

PARTICIPANTS

Six hundred sixty-three normotensive and mildly hypertensive participants, who were confirmed to not have PA using current guideline criteria and were on no antihypertensive medications.

DESIGN

Participants had their maximally stimulated plasma renin activity (PRA) measured while standing upright after sodium restriction. Tertiles of maximally stimulated PRA were hypothesized to reflect the degree of MR activation: lowest PRA tertile = "Inappropriate/Excess MR Activity;" middle PRA tertile = "Intermediate MR Activity;"; and highest PRA tertile = "Physiologic MR Activity." All participants underwent detailed biochemical and vascular characterizations under conditions of liberalized sodium intake, and associations with stimulated PRA phenotypes were performed.

RESULTS

Participants with lower stimulated PRA had greater autonomous aldosterone secretion [higher aldosterone-to-renin ratio (P = 0.002), higher urine aldosterone excretion rate (P = 0.003), higher systolic blood pressure (P = 0.004), and lower renal plasma flow (P = 0.04)] and a nonsignificant trend toward lower serum potassium and higher urine potassium excretion, which became significant after stratification by hypertension status.

CONCLUSIONS

In participants without clinical PA, the inability to stimulate renin was associated with greater autonomous aldosterone secretion, impaired vascular function, and suggestive trends in potassium handling that indicate an extensive spectrum of unrecognized MR activation.

Knowledge, attitudes and behaviours related to dietary salt among adults in the state of Victoria, Australia 2015

Background

Information on consumer’s knowledge, attitudes and behaviours (KABs) related to salt can be used to inform awareness and education campaigns and serve as a baseline measure to monitor changes in KABs over time. The aim of this study was to determine KABs related to salt intake among Victorian adults.

Methods

Cross-sectional survey conducted in Victorian adults aged 18–65 years. Participants were recruited from shopping centres located in Melbourne and Geelong and via online methods (Facebook and Consumer Research Panel) to complete an online survey assessing KABs related to dietary salt. Descriptive statistics (mean (SD) or n (%)) were used to report survey findings.

Results

A total of 2398 participants provided a valid survey (mean age 43 years (SD 13), 57% female). The majority (80%) were born in Australia and 63% were the main household grocery shopper. The majority (89%) were aware of the health risks associated with a high salt intake. Eighty three percent believed that Australians eat too much salt. Three quarters (75%) correctly identified salt from processed foods as being the main source of salt in the diet. Less than a third (29%) of participants believed their own individual salt intake exceeded dietary recommendations and only 28% could correctly identify the maximum recommended daily intake for salt. Just under half (46%) of participants were concerned about the amount of salt in food. Almost two thirds (61%) of participants believed that there should be laws which limit the amount of salt added to manufactured foods and 58% agreed that it was difficult to find lower salt options when eating out.

Conclusions

The findings of this study serve as a baseline assessment of KABs related to salt intake in Victorian adults and can be used to assess changes in salt related KABs over time. Public concern about salt is low as many people remain unaware of their own salt intake. An increased awareness of the excessive amount of salt consumed and increased availability of lower salt foods are likely to reduce population salt intake.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4451-0) contains supplementary material, which is available to authorized users.

Worldwide trends in blood pressure from 1975 to 2015: a pooled analysis of 1479 population-based measurement studies with 19·1 million participants

BACKGROUND

Raised blood pressure is an important risk factor for cardiovascular diseases and chronic kidney disease. We estimated worldwide trends in mean systolic and mean diastolic blood pressure, and the prevalence of, and number of people with, raised blood pressure, defined as systolic blood pressure of 140 mm Hg or higher or diastolic blood pressure of 90 mm Hg or higher.

METHODS

For this analysis, we pooled national, subnational, or community population-based studies that had measured blood pressure in adults aged 18 years and older. We used a Bayesian hierarchical model to estimate trends from 1975 to 2015 in mean systolic and mean diastolic blood pressure, and the prevalence of raised blood pressure for 200 countries. We calculated the contributions of changes in prevalence versus population growth and ageing to the increase in the number of adults with raised blood pressure.

FINDINGS

We pooled 1479 studies that had measured the blood pressures of 19·1 million adults. Global age-standardised mean systolic blood pressure in 2015 was 127·0 mm Hg (95% credible interval 125·7-128·3) in men and 122·3 mm Hg (121·0-123·6) in women; age-standardised mean diastolic blood pressure was 78·7 mm Hg (77·9-79·5) for men and 76·7 mm Hg (75·9-77·6) for women. Global age-standardised prevalence of raised blood pressure was 24·1% (21·4-27·1) in men and 20·1% (17·8-22·5) in women in 2015. Mean systolic and mean diastolic blood pressure decreased substantially from 1975 to 2015 in high-income western and Asia Pacific countries, moving these countries from having some of the highest worldwide blood pressure in 1975 to the lowest in 2015. Mean blood pressure also decreased in women in central and eastern Europe, Latin America and the Caribbean, and, more recently, central Asia, Middle East, and north Africa, but the estimated trends in these super-regions had larger uncertainty than in high-income super-regions. By contrast, mean blood pressure might have increased in east and southeast Asia, south Asia, Oceania, and sub-Saharan Africa. In 2015, central and eastern Europe, sub-Saharan Africa, and south Asia had the highest blood pressure levels. Prevalence of raised blood pressure decreased in high-income and some middle-income countries; it remained unchanged elsewhere. The number of adults with raised blood pressure increased from 594 million in 1975 to 1·13 billion in 2015, with the increase largely in low-income and middle-income countries. The global increase in the number of adults with raised blood pressure is a net effect of increase due to population growth and ageing, and decrease due to declining age-specific prevalence.

INTERPRETATION

During the past four decades, the highest worldwide blood pressure levels have shifted from high-income countries to low-income countries in south Asia and sub-Saharan Africa due to opposite trends, while blood pressure has been persistently high in central and eastern Europe.

FUNDING

Wellcome Trust.

Urinary Sodium and Potassium Excretion and Carotid Atherosclerosis in Chinese Men and Women

Limited studies have examined the association between sodium (Na) and potassium (K) levels and the risk of atherosclerosis. This study examined whether higher Na and Na/K levels and low K levels were independent risk factors for atherosclerosis. This community-based cross-sectional study included 3290 subjects (1067 men and 2223 women) 40 to 75 years of age in Guangzhou, China, between 2011 and 2013. Urinary excretion of Na and K were measured from the first morning void, and creatinine-adjusted values were used. The intima-media thickness (IMT) of the carotid common artery and the carotid bifurcation was measured with high-resolution B-mode ultrasonography. Dietary K and Na intake and other covariates were obtained by face-to-face interviews. A significant positive association was seen between urinary Na excretion and carotid atherosclerosis after adjustment for age, sex, and other lifestyle covariates. The odds ratios (OR) and 95% confidence interval (CI) of the highest (vs. lowest) quartile of urinary Na were 1.32 (1.04-1.66) for carotid plaques, 1.48 (1.18-1.87) for increased common carotid artery IMT, and 1.55 (1.23-1.96) for increased carotid bifurcation IMT (all p-trend < 0.01). A similar positive association was observed between urinary Na/K levels and carotid plaque and increased IMT, and between dietary Na intake and increased bifurcation IMT. Regarding potassium data, we only found a significantly lower presence of carotid plaque (OR 0.72, 95% CI 0.57-0.91) for quartile 2 (vs. 1) of urinary K. Our findings suggest that higher levels of urinary excretion Na and Na/K are significantly associated with greater presence of carotid atherosclerosis in Chinese adults.

Feasibility of collecting 24-h urine to monitor sodium intake in the National Health and Nutrition Examination Survey

BACKGROUND

Twenty-four-hour urine sodium excretion is recommended for monitoring population sodium intake. Because of concerns about participation and completion, sodium excretion has not been collected previously in US nationally representative surveys.

OBJECTIVE

We assessed the feasibility of implementing 24-h urine collections as part of a nationally representative survey.

DESIGN

We selected a random half sample of nonpregnant US adults aged 20-69 y in 3 geographic locations of the 2013 NHANES. Participants received explicit instructions, started and ended the urine collection in a urine study mobile examination center, and answered questions about their collection. Among those with a complete 24-h urine collection, a random one-half were asked to collect a second 24-h urine sample. Sodium, potassium, chloride, and creatinine excretion were analyzed.

RESULTS

The final NHANES examination response rate for adults aged 20-69 y in these 3 study locations was 71%. Of those examined (n = 476), 282 (59%) were randomly selected to participate in the 24-h urine collection. Of these, 212 persons [75% of those selected for 24-h urine collection; 53% (equal to 71% × 75% of those selected for the NHANES)] collected a complete initial 24-h specimen and 92 persons (85% of 108 selected) collected a second complete 24-h urine sample. More men than women completed an initial collection (P = 0.04); otherwise, completion did not vary by sociodemographic characteristics, body mass index, education, or employment status for either collection. Mean 24-h urine volume and sodium excretion were 1964 ± 1228 mL and 3657 ± 2003 mg, respectively, for the first 24-h urine sample, and 2048 ± 1288 mL and 3773 ± 1891 mg, respectively, for the second collection.

CONCLUSION

Given the 53% final component response rate and 75% completion rate, 24-h urine collections were deemed feasible and implemented in the NHANES 2014 on a subsample of adults aged 20-69 y to assess population sodium intake. This study was registered at clinicaltrials.gov as NCT02723682.

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.

No Difference in Average Interdialytic Weight Gain Observed in a Randomized Trial With a Technology-Supported Behavioral Intervention to Reduce Dietary Sodium Intake in Adults Undergoing Maintenance Hemodialysis in the United States: Primary Outcomes of the BalanceWise Study

OBJECTIVE

To evaluate the efficacy of behavioral counseling combined with technology-based self-monitoring for sodium restriction in hemodialysis (HD) patients.

DESIGN

Randomized clinical trial.

SUBJECTS

English literate adults undergoing outpatient, in-center intermittent HD for at least 3 months.

INTERVENTIONS

Over a 16-week period, both the intervention and the attention control groups were shown 6 educational modules on the HD diet. The intervention group also received social cognitive theory-based behavioral counseling and monitored their diets daily using handheld computers.

MAIN OUTCOME MEASURES

Average daily interdialytic weight gain (IDWGA) was calculated for every week of HD treatment over the observation period by subtracting the post-dialysis weight at the previous treatment time (t-1) from the pre-dialysis weight at the current treatment time (t), dividing by the number of days between treatments. Three 24-hour dietary recalls were obtained at baseline, 8 weeks, and 16 weeks and evaluated using the Nutrient Data System for Research.

RESULTS

A total of 179 participants were randomized, and 160 (89.4%) completed final measurements. IDWGA did not differ significantly by treatment group at any time point considered (P > .79 for each). A significant differential change in dietary sodium intake observed at 8 weeks (-372 mg/day; P = .05) was not sustained at 16 weeks (-191 mg/day; P = .32).

CONCLUSION

The BalanceWise Study intervention appeared to be feasible and acceptable to HD patients although IDWGA was unchanged and the desired behavioral changes observed at 8 weeks were not sustained. Unmeasured factors may have contributed to the mixed findings, and further research is needed to identify the appropriate patients for such interventions.

How effective is an in-hospital heart failure self-care program in a Japanese setting? Lessons from a randomized controlled pilot study

BACKGROUND

Although the effectiveness of heart failure (HF) disease management programs has been established in Western countries, to date there have been no such programs in Japan. These programs may have different effectiveness due to differences in health care organization and possible cultural differences with regard to self-care. Therefore, the purpose of this study was to evaluate the effectiveness of a pilot HF program in a Japanese setting.

METHODS

We developed an HF program focused on enhancing patient self-care before hospital discharge. Patients were randomized 1:1 to receive the new HF program or usual care. The primary outcome was self-care behavior as assessed by the European Heart Failure Self-Care Behavior Scale (EHFScBS). Secondary outcomes included HF knowledge and the 2-year rate of HF hospitalization and/or cardiac death.

RESULTS

A total of 32 patients were enrolled (mean age, 63 years; 31% female). There was no difference in the total score of the EHFScBS between the two groups. One specific behavior score regarding a low-salt diet significantly improved compared with baseline in the intervention group. HF knowledge in the intervention group tended to improve more over 6 months than in the control group (a group-by-time effect, F=2.47, P=0.098). During a 2-year follow-up, the HF program was related to better outcomes regarding HF hospitalization and/or cardiac death (14% vs 48%, log-rank test P=0.04). In Cox regression analysis after adjustment for age, sex, and logarithmic of B-type natriuretic peptide, the program was associated with a reduction in HF hospitalization and/or cardiac death (hazard ratio, 0.17; 95% confidence interval, 0.03-0.90; P=0.04).

CONCLUSION

The HF program was likely to increase patients' HF knowledge, change their behavior regarding a low-salt diet, and reduce HF hospitalization and/or cardiac events. Further improvement focused on the transition of knowledge to self-care behavior is necessary.

Dietary Salt Restriction in Heart Failure: Where Is the Evidence?

Several dietary guidelines, health organizations and government policies recommend population-wide sodium restriction to prevent hypertension and related comorbidities like heart failure (HF). The current European Society of Cardiology and American College of Cardiology/American Heart Association Heart Failure guidelines recommend restricting sodium in HF patients. However, these recommendations are based on expert opinion (level C), leading to wide variability in application and lack of consensus among providers pertaining to dietary salt restriction. To evaluate the strength of current evidences to recommend dietary salt restriction among HF patients, we performed a comprehensive literature review and explored the safety and efficacy of such recommendations.

Excess maternal salt or fructose intake programmes sex-specific, stress- and fructose-sensitive hypertension in the offspring

The Western diet is typically high in salt and fructose, which have pressor activity. Maternal diet can affect offspring blood pressure, but the extent to which maternal intake of excess salt and fructose may influence cardiovascular function of the offspring is unknown. We sought to determine the effect of moderate maternal dietary intake of salt and/or fructose on resting and stimulated cardiovascular function of the adult male and female offspring. Pregnant rats were fed purified diets (±4 % salt) and water (±10 % fructose) before and during gestation and through lactation. Male and female offspring were weaned onto standard laboratory chow. From 9 to 14 weeks of age, cardiovascular parameters (basal, circadian and stimulated) were assessed continuously by radiotelemetry. Maternal salt intake rendered opposite-sex siblings with a 25-mmHg difference in blood pressure as adults; male offspring were hypertensive (15 mmHg mean arterial pressure (MAP)) and female offspring were hypotensive (10 mmHg MAP) above and below controls, respectively. Sex differences were unrelated to endothelial nitric oxide activity in vivo, but isolation-induced anxiety revealed a significantly steeper coupling between blood pressure and heart rate in salt-exposed male offspring but not in female offspring. MAP of all offspring was refractory to salt loading but sensitive to subsequent dietary fructose, an effect exacerbated in female offspring from fructose-fed dams. Circadian analyses of pressure in all offspring revealed higher mean set-point for heart rate and relative non-dipping of nocturnal pressure. In conclusion, increased salt and fructose in the maternal diet has lasting effects on offspring cardiovascular function that is sex-dependent and related to the offspring’s stress–response axis.