A comprehensive review on salt and health and current experience of worldwide salt reduction programmes

Impacts of a national strategy to reduce population salt intake in England: serial cross sectional study

BACKGROUND

The UK introduced an ambitious national strategy to reduce population levels of salt intake in 2003. The aim of this study was to evaluate the impact of this strategy on salt intake in England, including potential effects on health inequalities.

METHODS

Secondary analysis of data from the Health Survey for England. Our main outcome measure was trends in estimated daily salt intake from 2003-2007, as measured by spot urine. Secondary outcome measures were knowledge of government guidance and voluntary use of salt in food preparation over this time period.

RESULTS

There were significant reductions in salt intake between 2003 and 2007 (-0.175 grams per day per year, p<0.001). Intake decreased uniformly across all other groups but remained significantly higher in younger persons, men, ethnic minorities and lower social class groups and those without hypertension in 2007. Awareness of government guidance on salt use was lowest in those groups with the highest intake (semi-skilled manual v professional; 64.9% v 71.0% AOR 0.76 95% CI 0.58-0.99). Self reported use of salt added at the table reduced significantly during the study period (56.5% to 40.2% p<0.001). Respondents from ethnic minority groups remained significantly more likely to add salt during cooking (white 42.8%, black 74.1%, south Asian 88.3%) and those from lower social class groups (unskilled manual 46.6%, professional 35.2%) were more likely to add salt at the table.

CONCLUSIONS

The introduction a national salt reduction strategy was associated with uniform but modest reductions in salt intake in England, although it is not clear precisely which aspects of the strategy contributed to this. Knowledge of government guidance was lower and voluntary salt use and total salt intake was higher among occupational and ethnic groups at greatest risk of cardiovascular disease.

Sodium Consumption: An Individual's Choice?

Excess intake of dietary salt is estimated to be one of the leading risks to health worldwide. Major national and international health organizations, along with many governments around the world, have called for reductions in the consumption of dietary salt. This paper discusses behavioural and population interventions as mechanisms to reduce dietary salt. In developed countries, salt added during food processing is the dominant source of salt and largely outside of the direct control of individuals. Population-based interventions have the potential to improve health and to be cost saving for these countries. In developing economies, where salt added in cooking and at the table is the dominant source, interventions based on education and behaviour change have been estimated to be highly cost effective. Regardless, countries with either developed or developing economies can benefit from the integration of both population and behavioural change interventions.

The development of salty taste acceptance is related to dietary experience in human infants: a prospective study

BACKGROUND

Sodium intake is related to hypertension and other diseases, but little is known about the early development of salty taste acceptance.

OBJECTIVE

The prospective study asked whether dietary experience with foods containing sodium is associated with development of infant salty taste preference.

DESIGN

Infants (n = 61) were tested at 2 and 6 mo to assess their response to 0.17 and 0.34 mol NaCl/L in water. Intake tests consisted of randomized double-blind 120-s exposure to salt solutions and water. Acceptance, calculated as solution intake relative to water, was examined as a function of exposure to starchy table food-a significant source of sodium. Dietary exposure (yes or no) was defined by maternal report. As a control, similar comparisons were based on exposure to fruit table food. A subset of 26 subjects returned at 36-48 mo for assessment of salty taste hedonics and preference.

RESULTS

Dietary experience was related to salt acceptance, with only those infants previously exposed to starchy table foods (n = 26) preferring the salty solutions at 6 mo (P = 0.007). Fruit exposure was not associated with sodium chloride acceptance. Infants eating starchy table foods at 6 mo were more likely to lick salt from the surface of foods at preschool age (P = 0.007) and tended to be more likely to eat plain salt (P = 0.08).

CONCLUSIONS

The findings suggest an influential role of early dietary experience in shaping salty taste responses of infants and young children.

Sodium recommendations for special populations and the resulting implications

Based on the most recent Dietary Guidelines for Americans, sodium recommendations are set at 2,300 mg for the general population and 1,500 mg for special populations. However, sodium intake among adults has been shown to be much higher than this; on average 3,436 mg. The Centers for Disease Control and Prevention notes that special populations (those with hypertension, African Americans, and those 40 years of age and older) make up 70% of adults in the United States. Excess sodium in the diet has been shown to contribute to problems such as blood pressure abnormalities, kidney function problems, and congestive heart failure, which account for a large sum of health care costs in the United States. The purpose of this review and accompanying three case studies was to explore if adherence to the sodium recommendations for special populations is feasible. Current literature shows that while a food industry-wide sodium reduction would help reduce overall sodium intake, adherence to low-sodium diets is difficult for the majority of individuals. Three case studies were completed which looked at subjects with a sodium recommendation of 1,500 mg. None of the participants met the recommendation, were aware of their daily sodium intake or knew how much they should be consuming. The snapshot provided by these case studies suggests further research is warranted. Because of the current state of sodium in the American diet, a combination of personal interventions coupled with widespread industry sodium reduction would be the most beneficial way to reduce dietary sodium for most individuals.

Prospective care of heart failure in Japan: lessons from CHART studies

There are approximately 23 million patients with heart failure (HF) worldwide. The prognosis of patients with HF is still poor and a prospective approach for preventing and treating HF is necessary. The number of HF patients in Japan has been increasing since 1950 mainly because of a rapidly aging population. Furthermore, westernized dietary pattern, reduced physical activity, and obesity have become prominent, particularly in younger Japanese men. There is an increasing trend of diabetes and dyslipidemia, and the prevalence of smoking and hypertension continues to remain high. One of the largest HF cohorts in Japan, the CHART Studies, showed that coronary artery disease (CAD) was the most frequent etiology of HF currently. Thus, prospective strategies including accurate risk stratification, effective prevention of disease progression through evidence-based treatments, optimally personalized treatment particularly in elderly individuals, and life-long control of CAD risk factors are required to manage HF in Japan.

Status of cardiovascular health in US adults: prevalence estimates from the National Health and Nutrition Examination Surveys (NHANES) 2003-2008

BACKGROUND

The American Heart Association's 2020 Strategic Impact Goals define a new concept, cardiovascular (CV) health; however, current prevalence estimates of the status of CV health in US adults according to age, sex, and race/ethnicity have not been published.

METHODS AND RESULTS

We included 14 515 adults (≥20 years of age) from the 2003 to 2008 National Health and Nutrition Examination Surveys. Participants were stratified by young (20-39 years), middle (40-64 years), and older (≥65 years) ages. CV health behaviors (diet, physical activity, body mass index, smoking) and CV health factors (blood pressure, total cholesterol, fasting blood glucose, smoking) were defined as poor, intermediate, or ideal. Fewer than 1% of adults exhibited ideal CV health for all 7 metrics. For CV health behaviors, nonsmoking was most prevalent (range, 60.2%-90.4%), whereas ideal Healthy Diet Score was least prevalent (range, 0.2%-2.6%) across groups. Prevalences of ideal body mass index (range, 36.5%-45.3%) and ideal physical activity levels (range, 50.2%-58.8%) were higher in young adults compared with middle or older ages. Ideal total cholesterol (range, 23.7%-36.2%), blood pressure (range, 11.9%-16.3%), and fasting blood glucose (range, 31.2%-42.9%) were lower in older adults compared with young and middle-aged adults. Prevalence of poor CV health factors was lowest in young age but higher at middle and older ages. Prevalence estimates by age and sex were consistent across race/ethnic groups.

CONCLUSIONS

These prevalence estimates of CV health represent a starting point from which effectiveness of efforts to promote CV health and prevent CV disease can be monitored and compared in US adult populations.

Health economic consequences of reducing salt intake and replacing saturated fat with polyunsaturated fat in the adult Finnish population: estimates based on the FINRISK and FINDIET studies

BACKGROUND/OBJECTIVES

To predict the health economic consequences of modest reductions in the daily intake of salt (-1.0 g per day) and replacement of saturated fat (SFA, -1.0 energy percent (E%)) with polyunsaturated fat (PUFA, +1.0 E%) in the Finnish population aged 30-74 years.

SUBJECTS/METHODS

A Markov model with dynamic population structure was constructed to present the natural history of cardiovascular diseases (CVDs) based on the most current information about the age- and sex-specific cardiovascular risk factors, dietary habits and nutrient intake. To predict the undiscounted future health economic consequences of the reduction of dietary salt and SFA, the model results were extrapolated for the years 2010-2030 by replacing the baseline population in the year 2007 with the extrapolated populations from the official Finnish statistics. Finnish costs (€2009, societal perspective) and EQ-5D utilities were obtained from published references.

RESULTS

During the next 20 years, a population-wide intervention directed at salt intake and dietary fat quality could potentially lead to 8000-13,000 prevented CVD cases among the Finnish adults compared the situation in year 2007. In addition, the reduced incidence of CVDs could gain 26,000-45,000 quality-adjusted life years and save €150-225 million over the same time period.

CONCLUSION

A modest reduction of salt and replacement of SFA with PUFA in food products can significantly reduce the burden of CVD in the adult Finnish population. This impact may be even larger in the near future due to the ageing of Finnish population.

24 h-Sodium excretion and hydration status in children and adolescents--results of the DONALD Study

BACKGROUND & AIMS

To describe actual data on intake, sources, age and time trends of urinary sodium excretion and to analyze the potential association between urinary sodium excretion and hydration status respective beverage consumption in a sample of healthy German children and adolescents.

METHODS

Data of 1575 24 h-urine samples and weighed dietary records of 499 children (249 boys) aged 4-18 years of the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study collected in 2003-2009 were analyzed using linear mixed effects regression models. Free water reserve (FWR, measured urine volume (ml/24 h) minus the obligatory urine volume (ml/24 h)) was used as a marker for hydration status.

RESULTS

Urinary sodium excretion was between 1.4 g/day and 3.2 g/day, showing a positive age trend but remained stable during the study period. In girls, there was a significant positive association between salt excretion and FWR (p = 0.04). Per g/MJ urinary sodium excretion, beverage intake increased by 0.05 g/MJ (boys) or 0.08 g/MJ (girls).

CONCLUSION

Hydration status was not affected by salt intake in this sample of healthy children and adolescents in a western life style, due to a compensatory increase in beverage consumption.

Canadians continue to consume too much sodium and not enough potassium

OBJECTIVES

Excessive sodium (Na) intakes and insufficient potassium (K) intakes are known contributors to hypertension. In July 2010, the Health Canada-led multi-stakeholder Sodium Working Group issued recommendations to lower Na intakes of Canadians. Baseline data and ongoing monitoring are needed.

METHODS

Na and K content based on recently analyzed food composite samples from the Canadian marketplace were matched with over 35,000 dietary recalls from the Canadian Community Health Survey (CCHS 2.2). The distributions of usual intakes for Na and K were constructed using SIDE software and estimates by age and sex for the 5th, 10th, 25th, mean, median, 75th, 90th and 95th percentiles were determined.

RESULTS

Based on recent analyses of Canadian foods, the majority of Canadians exceeded the Tolerable Upper Intake Level (UL) for Na for their age and sex group, including infants, children, adolescents and adults. In sharp contrast, few had Adequate Intakes (AI) of K.

CONCLUSION

Canadians of all ages need to decrease Na intakes below the UL. At the same time, increased consumption of dairy products, fruits and vegetables must be promoted to increase K intakes to current recommendations. Both dietary interventions are required to help lower hypertension in the Canadian population. We provide the first report based on direct analysts of Canadian foods, confirming the high Na and low K intakes of the Canadian population. With its annual sampling program of foods commonly consumed in Canada, the Total Diet Study provides an important sentinel system for monitoring these dietary risk factors for hypertension.

A multistakeholder platform to promote health and prevent noncommunicable diseases in the region of the Americas: the Pan American Health Organization partners forum for action

Noncommunicable diseases (NCDs) and obesity are the most serious health problem facing the countries of the Americas in terms of avoidable deaths as well as costs to governments, families, and business. The main causes are ageing of the population, and widespread risks such as tobacco use, unhealthy diet, physical inactivity, and harmful use of alcohol, linked to major changes in the way we live and work, to public policies, cultural norms, and private sector forces. Underlying determinants are globalization, urbanization, poverty, education, gender, ethnicity, and access to health services. Yet, approximately 80% of cardiovascular disease and diabetes, and 40% of cancer, are preventable through a range of cost-effective population and individual measures for those at high risk of living with NCDs. However, the multisectoral nature of NCDs requires a cross-sector response to succeed. Several governments have commenced intersectoral efforts, and civil society and private sector also have many initiatives, but the responses are fragmented and skewed. The Partners Forum is being launched by the Pan American Health Organization in collaboration with the World Economic Forum and a set of partners including member states, partners in civil society, and partners in the private sector, as a multisector platform to catalyze, recognize, and scale up collaborative action to promote health and prevent and control NCDs at regional, subregional, and country level. The principles of partnership and lessons learned from other partnership experiences are being used in its design.

Canadian initiatives to prevent hypertension by reducing dietary sodium

Hypertension is the leading risk for premature death in the world. High dietary sodium is an important contributor to increased blood pressure and is strongly associated with other important diseases (e.g., gastric cancer, calcium containing kidney stones, osteoporosis, asthma and obesity). The average dietary sodium intake in Canada is approximately 3400 mg/day. It is estimated that 30% of hypertension, more than 10% of cardiovascular events and 1.4 billion dollars/year in health care expenses are caused by this high level of intake in Canada. Since 2006, Canada has had a focused and evolving effort to reduce dietary sodium based on actions from Non Governmental Organizations (NGO), and Federal and Provincial/Territorial Government actions. NGOs initiated Canadian sodium reduction programs by developing a policy statement outlining the health issue and calling for governmental, NGO and industry action, developing and disseminating an extensive health care professional education program including resources for patient education, developing a public awareness campaign through extensive media releases and publications in the lay press. The Federal Government responded by striking a Intersectoral Sodium Work Group to develop recommendations on how to implement Canada's dietary reference intake values for dietary sodium and by developing timelines and targets for foods to be reduced in sodium, assessing key research gaps with funding for targeted dietary sodium based research, developing plans for public education and for conducting evaluation of the program to reduce dietary sodium. While food regulation is a Federal Government responsibility Provincial and Territorial governments indicated reducing dietary sodium needed to be a priority. Federal and Provincial Ministers of Health have endorsed a target to reduce the average consumption of sodium to 2300 mg/day by 2016 and the Deputy Ministers of Health have tasked a joint committee to review the recommendations of the Sodium Work Group and report back to them.

Reducing salt intake in the Americas: Pan American Health Organization actions

This article outlines the rationale for reducing dietary salt and some of the Pan American Health Organization actions to facilitate reductions in dietary salt in the Americas. Excessive dietary salt (sodium chloride and other sodium salts) is a major cause of increased blood pressure, which increases risk for stroke, heart disease, and kidney disease. Reduction in salt intake is beneficial for people with hypertension and those with normal blood pressure. The World Health Organization recommends a population salt intake of less than 5 grams/person/day with a Pan American Health Organization expert group recommendation that this be achieved by 2020 in the Americas. In general, the consumption of salt is more than 6 grams/day by age 5 years, with consumption of salt averaging between 9 and 12 grams per day in many countries. Recent salt intake estimates from Brazil (11 grams of salt/day), Argentina (12 grams of salt/day), Chile (9 grams of salt/day) and the United States (8.7 grams of salt/day) confirm that high salt intakes are prevalent in Americas. Sources of dietary salt vary, from 75% of it coming from processed food in developed countries, to 70% coming from discretionary salt added in cooking or at the table in parts of Brazil. The Pan American Health Organization has launched a regionwide initiative called the ?Cardiovascular Disease Prevention Through Dietary Salt Reduction,? led by an expert working group. Working closely with countries, the expert group developed resources to aid policy development through five subgroups: (a) addressing industry engagement and product reformulation; (b) advocacy and communication; (c) surveillance of salt intake, sources of salt in the diet, and knowledge and opinions on salt and health; (d) salt fortification with iodine; and (e) national-level health economic studies on salt reduction.

Effectiveness and cost effectiveness of cardiovascular disease prevention in whole populations: modelling study

OBJECTIVE

To estimate the potential cost effectiveness of a population-wide risk factor reduction programme aimed at preventing cardiovascular disease.

DESIGN

Economic modelling analysis.

SETTING

England and Wales. Population Entire population. Model Spreadsheet model to quantify the reduction in cardiovascular disease over a decade, assuming the benefits apply consistently for men and women across age and risk groups.

MAIN OUTCOME MEASURES

Cardiovascular events avoided, quality adjusted life years gained, and savings in healthcare costs for a given effectiveness; estimates of how much it would be worth spending to achieve a specific outcome.

RESULTS

A programme across the entire population of England and Wales (about 50 million people) that reduced cardiovascular events by just 1% would result in savings to the health service worth at least £30m (€34m; $48m) a year compared with no additional intervention. Reducing mean cholesterol concentrations or blood pressure levels in the population by 5% (as already achieved by similar interventions in some other countries) would result in annual savings worth at least £80m to £100m. Legislation or other measures to reduce dietary salt intake by 3 g/day (current mean intake approximately 8.5 g/day) would prevent approximately 30,000 cardiovascular events, with savings worth at least £40m a year. Legislation to reduce intake of industrial trans fatty acid by approximately 0.5% of total energy content might gain around 570,000 life years and generate NHS savings worth at least £230m a year.

CONCLUSIONS

Any intervention that achieved even a modest population-wide reduction in any major cardiovascular risk factor would produce a net cost saving to the NHS, as well as improving health. Given the conservative assumptions used in this model, the true benefits would probably be greater.

The Canadian effort to prevent and control hypertension: can other countries adopt Canadian strategies?

PURPOSE OF REVIEW

To indicate the key elements of current Canadian programs to treat and control hypertension.

RECENT FINDINGS

In the early 1990s Canada had a hypertension treatment and control rate of 13%. A Canadian strategy to prevent and control hypertension was developed and a coalition of national organizations and volunteers formed to develop increasingly extensive programs. The Canadian effort was largely based on annually updated hypertension management recommendations, an integrated and extensive hypertension knowledge translation program and an increasingly comprehensive outcomes assessment program. After the start of the annual process in 1999, there were very large increases in diagnosis and hypertension treatment coupled with dropping rates of cardiovascular disease. More recent initiatives include an extensive education program for the public and people with hypertension, a program to reduce dietary salt and a funded leadership position. The treatment and control rate increased to 66% when last assessed (2007-2009).

SUMMARY

The study describes important aspects of the Canadian hypertension management programs to aid those wishing to develop similar programs. Many of the programs could be fully or partially implemented by other countries.

Reducing sodium in foods: the effect on flavor

Sodium is an essential micronutrient and, via salt taste, appetitive. High consumption of sodium is, however, related to negative health effects such as hypertension, cardiovascular diseases and stroke. In industrialized countries, about 75% of sodium in the diet comes from manufactured foods and foods eaten away from home. Reducing sodium in processed foods will be, however, challenging due to sodium's specific functionality in terms of flavor and associated palatability of foods (i.e., increase of saltiness, reduction of bitterness, enhancement of sweetness and other congruent flavors). The current review discusses the sensory role of sodium in food, determinants of salt taste perception and a variety of strategies, such as sodium replacers (i.e., potassium salts) and gradual reduction of sodium, to decrease sodium in processed foods while maintaining palatability.

The Standard American Diet and its relationship to the health status of Americans

The Standard American Diet (SAD) has long been implicated in contributing to the health challenges experienced in the United States. Significant changes to the SAD have occurred since the 1950s, including a greater abundance and accessibility to calorie-dense and nutrient-poor food and beverage choices. The disparity of present consumption patterns to diet and nutrition recommendations from the Dietary Guidelines for Americans are addressed.

Dietary patterns among British adults: compatibility with dietary guidelines for salt/sodium, fat, saturated fat and sugars

OBJECTIVE

To examine dietary patterns among British adults, associations with Na and macronutrient intakes, and implications for dietary advice.

DESIGN

Principal component analysis of 7 d weighed dietary records.

SUBJECTS

Adults aged 19-64 years (n 1724).

SETTING

National Diet and Nutrition Survey (2000/2001).

RESULTS

High Na intake was associated with more energy-dense diets, higher in fat and SFA (percentage of energy) but lower in non-milk extrinsic sugars (NMES). Eight patterns (PC1 to PC8) explained 40 % of the total variance in food intakes. Three patterns - PC3 (high loadings on bread, fats and cheese), PC2 (meat products, eggs and chips) and PC7 (red meat, sauces and alcohol) - were associated with high Na intake. Of these, PC3 correlated with high Na density and Na:K ratio, while PC2 correlated with fat. By contrast, three patterns - 'health-conscious' (PC1; vegetables, fruit, fruit juice, fish), 'breakfast cereals and milk' (PC6) and 'chicken and rice' (PC8) - were associated with modest Na intake, lower Na density and lower fat and SFA. PC2 was positively correlated, and PC1 was negatively correlated, with adding salt to food. Other patterns were 'tea/coffee and cakes' (PC4; associated with high SFA and NMES) and 'soft drinks and snacks' (PC5; associated with high NMES but not fat or SFA). The dietary patterns of males and females differed slightly.

CONCLUSIONS

Dietary patterns PC1, PC6, PC8 (vegetables, fruit, fish, milk, breakfast cereals, poultry) were broadly compatible with guidelines for salt, fat, SFA and NMES. However, other patterns tended to be high in either salt or NMES.

Alteration of subcapsular adrenocortical zonation in humans with aging: the progenitor zone predominates over the previously well-developed zona glomerulosa after 40 years of age

Few studies have examined functional adrenal zonation throughout human life. Adrenals from 61 surgical/autopsy patients from 1 day old to 92 years old who had no clinical endocrinological/mineralocorticoid abnormalities were assessed for immunohistochemically defined adrenal zonation. The zona glomerulosa (zG) was well developed in all 11 patients ranging in age from newborn to the 30s. After 40 years of age, however, the zG occupied less than one-quarter of the adrenal circumference, suggestive of zG involution. The other subcapsular areas were occupied by the progenitor zone (zP), which expressed neither cytochrome P450(aldo) nor P450(11β) but 3β-hydroxysteroid dehydrogenase and P450scc, although some autopsy cases had adrenals with zG zonation because of secondary aldosteronism, and others who had experienced severe stresses showed subcapsular zona fasciculata (zF). In conclusion, the adrenal cortex consists of homogeneous zG-topped columns from birth to adolescence. Subsequently, in the fifth decade of life, the cortex is reconstituted by integration of three types of cortical columns: scattered zG-topped columns and zonal zP-topped columns, the latter having the ability for bidirectional differentiation into either zG-topped columns or zF-topped columns, according to secondary aldosteronism or the presence of severe stresses. Such adrenocortical remodeling is ascribed to high-sodium/low-potassium diets.

Longitudinal trends in cardiovascular mortality and blood pressure levels, prevalence, awareness, treatment, and control of hypertension in the Czech population from 1985 to 2007/2008

OBJECTIVES

To assess longitudinal trends in cardiovascular mortality and population mean blood pressure, prevalence, awareness, treatment, and control of hypertension in a representative Czech population sample from 1985 to 2007/2008.

METHODS

Source data on mortality rates were provided by the Czech Statistical Office and further processed by the Institute for Health Information and Statistics of the Czech Republic. Six independent cross-sectional population surveys were conducted in 1985, 1988, 1992, 1997/1998, 2000/2001, and 2007/2008 with randomly selected men and women aged 25-64 years and resident in six districts of the Czech Republic (Praha-východ, Benešov, Pardubice, Chrudim, Cheb, and Jindřichův Hradec). The total number of participants was 13 972.

RESULTS

Since 1985, there has been a significant continuous, almost linear decline in standardized total, cardiovascular disease, ischemic heart disease, and stroke mortality (P < 0.001).There was a significant downward trend in the population mean SBP (from 133.6 ± 20.2 to 129.5 ± 18.5 mmHg; P < 0.001) and DBP (from 84.1 ± 11.3 to 82.5 ± 10.0 mmHg; P < 0.001) from 1985 to 2007/2008. This was associated with a significant decrease in the prevalence of hypertension only in women (from 42.5 to 37.2%; P < 0.001). Awareness of hypertension increased in both sexes (men, from 41.4 to 68.4%; women, from 58.9 to 71.4%; both P < 0.001) as did the number of individuals on antihypertensive medication (men, from 21.1 to 58.2%, women: from 38.9 to 58.9%; both P < 0.001). Control of hypertension improved significantly (from 3.9 to 24.6%) over the same period.

CONCLUSION

The reduction in population blood pressure and improved hypertension control may have contributed substantially to the decrease in cardiovascular disease mortality in the Czech Republic.

Challenges and opportunities for cardiovascular disease prevention

Cardiovascular diseases are highly preventable, yet they remain the most common cause of death in the world. The epidemic is receding in industrialized countries; however, many low-income and middle-income countries have experienced an increase in cardiovascular diseases and 80% of all cardiovascular diseases deaths occur there. In the last 20 years, the epidemiology and surveillance of cardiovascular diseases have laid the foundations for public health interventions that may reduce the burden of disease. Relevant population-specific local data are therefore needed to describe the trends and pattern of risk for atherosclerotic diseases. Once the basis for surveillance and epidemiological research has been laid, cardiovascular disease prevention will require approaches adapted for each individual and population. The existence of effective preventive interventions justifies the assertion that coronary heart disease and stroke could be virtually prevented and controlled. Our goal in this review is to summarize the current challenges and opportunities for cardiovascular medicine, focusing on the need for high-quality local surveillance systems that provide the appropriate data needed to develop sound national cardiovascular disease preventive policies.

Contemporary nutritional transition: determinants of diet and its impact on body composition

The world has experienced a marked shift in the global BMI distribution towards reduced undernutrition and increased obesity. The collision between human biology, shaped over the millennia and modern technology, globalization, government policies and food industry practices have worked to create far-reaching energy imbalance across the globe. A prime example is the clash between our drinking habits and our biology. The shift from water and breast milk as the only beverages available, to a vast array of caloric beverages was very rapid, shaped both by our tastes and aggressive marketing of the beverage industry. Our biology, shaped over millennia by daily consumption of water and seasonal availability of food, was not ready to compensate for the liquid energies. Other dietary changes were similarly significant, particularly the shift towards increased frequency of eating and larger portions. The roles of the food and beverage production, distribution and marketing sectors in not only shaping our diet but also accelerating these changes must be understood. Apart from the role of beverages, there is much less consensus about the role of various components of our diet in energy imbalance. Understanding the determinants of change in the key components of our diet through an array of research provides insights into some of the options we face in attempting to attain a great balance between energy intake and expenditures while creating an overall healthier dietary pattern. A few countries are systematically addressing the causes of poor dietary and physical activity patterns and high energy imbalance.

Lifestyle Intervention Strategies for the Prevention and Treatment of Hypertension: A Review

Hypertension (HTN) is an extraordinarily common progressive cardiovascular syndrome in the United States, afflicting approximately one third of the adult population. HTN is a powerful and unequivocal independent risk factor for cardiovascular and renal diseases, including coronary heart disease, stroke, and renal failure. Despite major advances in the understanding and treatment of HTN over the past several decades, the disease remains the most common primary diagnosis in the United States and is a major public health concern. Adoption of healthy lifestyle modifications has proven to be highly effective in both the prevention of new-onset HTN and in the treatment of those diagnosed with HTN. In view of the continuing epidemic of HTN and blood pressure (BP)—related diseases and the invaluable role of applying nonpharmacological therapy in the prevention and management of HTN, a review of current therapeutic lifestyle strategies appears warranted. This review will define 6 well-established nonpharmacological lifestyle modifications for preventing and managing HTN in addition to 3 novel lifestyle interventions that show promise as effective adjunct strategies for lowering BP. A healthy lifestyle prescription ideally comprising a number of these BP-lowering lifestyle intervention strategies should be dispensed by all primary care physicians for both the prevention and treatment of elevated BP, an action that would have major, positive public health ramifications.

The relationship between hypertension and salt intake in Turkish population: SALTURK study

This population-based epidemiological study was aimed to evaluate the daily salt intake and its relation to blood pressure in a representative group of Turkish population. The enrolled normotensive and hypertensive individuals (n = 1970) completed a questionnaire including demographics, dietary habits, hypertension awareness and drug usage. Blood pressure was measured and to estimate salt consumption, 24-h urine samples were collected. The daily urinary sodium excretion was 308.3 ± 143.1 mmol/day, equal to a salt intake of 18.01 g/day. Salt intake was higher in obese participants, rural residents, participants with lower education levels and elderly. A positive linear correlation between salt intake and systolic and diastolic blood pressures was demonstrated (r = 0.450, p = 0.020; r = 0.406, p = 0.041; respectively), and each 100 mmol/day of salt intake resulted in 5.8 and 3.8 mmHg increase in systolic and diastolic blood pressures, respectively. Salt intake and systolic blood pressure was significantly correlated in normal weight individuals (r = 0.257, p < 0.01). The Turkish population consumes a great amount of salt; salt intake and blood pressure was positively correlated. Efforts in sodium restriction are therefore crucial in the management of hypertension as part of national and global health policies.

High urinary sodium is associated with increased carotid intima-media thickness in normotensive overweight and obese adults

BACKGROUND

Increased dietary sodium has been reported to increase cardiovascular disease (CVD) risk, perhaps through blood pressure (BP)-independent vascular remodeling. Carotid intima-media thickness (IMT) is an accepted measure of structural vascular remodeling and a strong predictor of CVD. This study aimed to determine whether urinary sodium is positively associated with carotid IMT in normotensive overweight and obese adults.

METHODS

We evaluated baseline data from 258 participants in the Slow Adverse Vascular Effects (SAVE) clinical trial. Urinary sodium was measured from one 24-h urine collection from each individual. Carotid IMT was measured using high-resolution B-mode ultrasonography. Participants were categorized into quartiles of urinary sodium.

RESULTS

There was a significant positive trend with greater IMT associated with increasing urinary sodium quartile in univariate linear regression (P = 0.047). This trend was significant when adjusting for age, sex, race, and systolic BP (SBP) (P = 0.03) as well as in a fully adjusted model (P = 0.04). In pairwise comparisons, the highest urinary sodium quartile had a significantly greater mean IMT (0.62 mm) than the lowest urinary sodium quartile (0.59 mm) after adjustment for age, sex, race, and SBP (P = 0.04). This comparison lost significance after the addition of BMI.

CONCLUSIONS

In our community-based sample of normotensive overweight and obese adults, we observed a significant positive trend in carotid IMT with increasing quartile of urinary sodium. If the ongoing clinical trial confirms this relationship between sodium and carotid IMT, it would lend support to efforts to decrease sodium intake in overweight and obese individuals.

Altered dietary salt intake for preventing and treating diabetic kidney disease

BACKGROUND

There is strong evidence that our current consumption of salt is a major factor for increased blood pressure (BP) and a modest reduction in salt intake lowers BP whether BP levels are normal or raised. Tight control of BP in diabetics lowers the risk of strokes, heart attacks and heart failure and slows the progression of diabetic kidney disease (DKD). Currently there is no consensus in restricting salt intake in diabetic patients.

OBJECTIVES

To evaluate the effect of altered salt intake on BP and markers of cardiovascular disease and DKD.

SEARCH STRATEGY

In January 2010, we searched the Cochrane Renal Group's Specialised Register, CENTRAL (in The Cochrane Library), MEDLINE (from 1966) and EMBASE (from 1980) to identify appropriate articles.

SELECTION CRITERIA

We included all randomised controlled trials of salt reduction in individuals with type 1 and type 2 diabetes.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies and resolved differences by discussion with a third independent author. We calculated mean effect sizes using both the fixed-effect and random-effects models.

MAIN RESULTS

Thirteen studies (254 individuals) met our inclusion criteria. These included 75 individuals with type 1 diabetes and 158 individuals with type 2 diabetes. The median reduction in urinary sodium was 203 mmol/24 h (11.9 g/day) in type 1 diabetes and 125 mmol/24 h (7.3 g/day) in type 2 diabetes. The median duration of salt restriction was one week in both type 1 and type 2 diabetes. BP was reduced in both type 1 and type 2 diabetes. In type 1 diabetes (56 individuals), salt restriction reduced BP by -7.11/-3.13 mm Hg (systolic/diastolic); 95% CI: systolic BP (SBP) -9.13 to -5.10; diastolic BP (DBP) -4.28 to -1.98). In type 2 diabetes (56 individuals), salt restriction reduced BP by -6.90/-2.87 mm Hg (95% CI: SBP -9.84 to -3.95; DBP -4.39 to -1.35). There was a greater reduction in BP in normotensive patients, possibly due to a larger decrease in salt intake in this group.

AUTHORS' CONCLUSIONS

Although the studies are not extensive, this meta-analysis shows a large fall in BP with salt restriction, similar to that of single drug therapy. All diabetics should consider reducing salt intake at least to less than 5-6 g/day in keeping with current recommendations for the general population and may consider lowering salt intake to lower levels, although further studies are needed.