Sodium Intake and Related Diseases.

Moderation in the use of salt (sodium chloride) in food and food preparations prevents the tendency of blood pressure to increase with age, and this is documented by many studies in current literature [...].

Trend of salt intake measured by 24-h urine collection in the Italian adult population between the 2008 and 2018 CUORE project surveys.

BACKGROUND AND AIMS: The WHO Global Action Plan for the Prevention of non-communicable diseases (NCDs) recommends a 30% relative reduction in mean population salt/sodium intake. The study assessed the trend in the habitual salt intake of the Italian adult population from 2008 to 2012 to 2018-2019 based on 24-h urinary sodium excretion, in the framework of the CUORE Project/MINISAL-GIRCSI/MENO SALE PIU' SALUTE national surveys. METHODS AND RESULTS: Data were from cross-sectional surveys of randomly selected age and sex-stratified samples of resident persons aged 35-74 years in 10 (out of 20) Italian Regions distributed in North, Centre and South of the Country. Urinary sodium and creatinine measurements were carried out in a central laboratory. The analyses included 942 men and 916 women examined in 2008-2012, and 967 men and 1010 women examined in 2018-2019. The age-standardized mean daily population salt (sodium chloride) intake was 10.8 g (95% CI 10.5-11.1) in men and 8.3 g (8.1-8.5) in women in 2008-2012 and respectively 9.5 g (9.3-9.8) and 7.2 g (7.0-7.4) in 2018-2019. A statistically significant (p<0.0001) salt intake reduction was thus observed over 10 years for both genders, and all age, body mass index (BMI) and educational classes. CONCLUSIONS: The average daily salt intake of the Italian general adult population remains higher than the WHO recommended level, but a significant reduction of 12% in men and 13% in women has occurred in the past ten years. These results encourage the initiatives undertaken by the Italian Ministry of Health aimed at the reduction of salt intake at the population level.

Low intake of iodized salt and iodine containing supplements among pregnant women with apparently insufficient iodine status - time to change policy?

BACKGROUND: Iodine is an essential nutrient for human health throughout the life cycle, especially during early stages of intrauterine life and infancy, to ensure adequate neurocognitive development. The growing global reliance on desalinated iodine-diluted water raises the specter of increased iodine deficiency in several regions. The case of Israel may be instructive for exploring the link between iodine status and habitual iodine intake in the setting of extensive national reliance on desalinated water. The aim of this study was to explore the relationship between iodine intake, including iodized salt and iodine-containing supplements intake, and iodine status among pregnant women residing in a sub-district of Israel that is highly reliant on desalinated iodine-diluted water. METHODS: A total of 134 consecutive pregnant women were recruited on a voluntary basis from the obstetrics department of the Barzilai University Medical Center during 2018. Blood was drawn from participants to determine levels of serum thyrotropin (TSH), thyroid peroxidase antibodies (TPOAb), thyroglobulin antibodies (TgAb) and thyroglobulin (Tg). An iodine food frequency questionnaire (sIFFQ) was used to assess iodine intake from food, IS and ICS. A questionnaire was used to collect data on demographic and health characteristics. RESULTS: A total of 105 pregnant women without known or reported thyroid disease were included in the study. Elevated Tg values (≥ 13 µg/L), were found among 67% of participants, indicating insufficient iodine status. The estimated iodine intake (median, mean ± SD 189, 187 ± 106 µg/d by sIFFQ) was lower than the levels recommended by the World Health Organization and the Institute of Medicine (250 vs. 220 µg/day respectively). The prevalence of iodized salt intake and iodine containing supplement intake were 4 and 52% (respectively). Values of Tg > 13 µg/L were inversely associated with compliance with World Health Organization and Institute of Medicine recommendations. CONCLUSIONS: While the Israeli Ministry of Health has recommended the intake of iodized salt and iodine containing supplements, this is apparently insufficient for achieving optimal iodine status among Israeli pregnant women. The evidence of highly prevalent probable iodine deficiency in a sample of pregnant women suggests an urgent need for a national policy of iodized salt regulation, as well as guidelines to promote iodine containing supplements and adherence to them by caregivers. In addition, studies similar to this one should be undertaken in additional countries reliant on desalinated iodine-diluted water to further assess the impact of desalinization on maternal iodine status.

Mapping and Analysis of US State and Urban Local Sodium Reduction Laws.

CONTEXT: Excessive sodium consumption contributes to high blood pressure, which is a risk factor for cardiovascular disease. OBJECTIVES: To (1) identify state and urban local laws addressing adult or general population sodium consumption in foods and beverages and (2) align findings to a previously published evidence classification review, the Centers for Disease Control and Prevention Sodium Quality and Impact of Component (QuIC) evidence assessment. DESIGN: Systematic collection of sodium reduction laws from all 50 states, the 20 most populous counties in the United States, and the 20 most populous cities in the United States, including Washington, District of Columbia, effective on January 1, 2019. Relevant laws were assigned to 1 or more of 6 interventions: (1) provision of sodium information in restaurants or at point of purchase; (2) consumer incentives to purchase lower sodium foods; and provision of lower sodium offerings in (3) workplaces, (4) vending machines, (5) institutional meal services, and (6) grocery, corner, and convenience stores. The researchers used Westlaw, local policy databases or city Web sites, and general nutrition policy databases to identify relevant laws. RESULTS: Thirty-nine sodium reduction laws and 10 state laws preempting localities from enacting sodium reduction laws were identified. Sodium reduction laws were more common in local jurisdictions and in the Western United States. Sodium reduction laws addressing meal services (n = 17), workplaces (n = 12), labeling (n = 13), and vending machines (n = 11) were more common, while those addressing grocery stores (n = 2) or consumer incentives (n = 6) were less common. Laws with high QuIC evidence classifications were generally more common than laws with low QuIC evidence classifications. CONCLUSIONS: The distribution of sodium laws in the US differed by region, QuIC classification, and jurisdiction type, indicating influence from public health and nonpublic health factors. Ongoing research is warranted to determine how the strength of public health evidence evolves over time and how those changes correlate with uptake of sodium reduction law.

Changes in Consumer Attitudes toward Broad-Based and Environment-Specific Sodium Policies-SummerStyles 2012 and 2015.

We examined temporal changes in consumer attitudes toward broad-based actions and environment-specific policies to limit sodium in restaurants, manufactured foods, and school and workplace cafeterias from the 2012 and 2015 SummerStyle surveys. We used two online, national research panel surveys to conduct a cross-sectional analysis of 7845 U.S. adults. Measures included self-reported agreement with broad-based actions and environment-specific policies to limit sodium in restaurants, manufactured foods, school cafeterias, workplace cafeterias, and quick-serve restaurants. Wald Chi-square tests were used to examine the difference between the two survey years and multivariate logistic regression was used to obtain odds ratios. Agreement with broad-based actions to limit sodium in restaurants (45.9% agreed in 2015) and manufactured foods (56.5% agreed in 2015) did not change between 2012 and 2015. From 2012 to 2015, there was a significant increase in respondents that supported environment-specific policies to lower sodium in school cafeterias (80.0% to 84.9%; p < 0.0001), workplace cafeterias (71.2% to 76.6%; p < 0.0001), and quick-serve restaurants (70.8% to 76.7%; p < 0.0001). Results suggest substantial agreement and support for actions to limit sodium in commercially-processed and prepared foods since 2012, with most consumers ready for actions to lower sodium in foods served in schools, workplaces, and quick-serve restaurants.

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

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

Fibroblast growth factor 23 and the antiproteinuric response to dietary sodium restriction during renin-angiotensin-aldosterone system blockade.

BACKGROUND: Residual proteinuria during renin-angiotensin-aldosterone system (RAAS) blockade is a major renal and cardiovascular risk factor in chronic kidney disease. Dietary sodium restriction potentiates the antiproteinuric effect of RAAS blockade, but residual proteinuria remains in many patients. Previous studies linked high fibroblast growth factor 23 (FGF-23) levels with volume overload; others linked higher serum phosphate levels with impaired RAAS-blockade efficacy. We hypothesized that FGF-23 reduces the capacity of dietary sodium restriction to potentiate RAAS blockade, impairing the antiproteinuric effect. STUDY DESIGN: Post hoc analysis of cohort data from a randomized crossover trial with two 6-week study periods comparing proteinuria after a regular-sodium diet with proteinuria after a low-sodium diet, both during background angiotensin-converting enzyme inhibition. SETTING & PARTICIPANTS: 47 nondiabetic patients with CKD with residual proteinuria (median protein excretion, 1.9 [IQR, 0.8-3.1] g/d; mean age, 50±13 [SD] years; creatinine clearance, 69 [IQR, 50-110] mL/min). PREDICTOR: Plasma carboxy-terminal FGF-23 levels. OUTCOMES: Difference in residual proteinuria at the end of the regular-sodium versus low-sodium study period. Residual proteinuria during the low-sodium diet period adjusted for proteinuria during the regular-sodium diet period. RESULTS: Higher baseline FGF-23 level was associated with reduced antiproteinuric response to dietary sodium restriction (standardized ß=-0.46; P=0.001; model R(2)=0.71). For every 100-RU/mL increase in FGF-23 level, the antiproteinuric response to dietary sodium restriction was reduced by 10.6%. Higher baseline FGF-23 level was a determinant of more residual proteinuria during the low-sodium diet (standardized ß=0.27; P=0.003) in linear regression analysis adjusted for baseline proteinuria (model R(2)=0.71). There was no interaction with creatinine clearance (P interaction=0.5). Baseline FGF-23 level did not predict changes in systolic or diastolic blood pressure upon intensified antiproteinuric treatment. LIMITATIONS: Observational study, limited sample size. CONCLUSIONS: FGF-23 levels are associated independently with impaired antiproteinuric response to sodium restriction in addition to RAAS blockade. Future studies should address whether FGF-23-lowering strategies may further optimize proteinuria reduction by RAAS blockade combined with dietary sodium restriction.

Interested in developing a national programme to reduce dietary salt?

High dietary salt is a major contributor to increased blood pressure, the leading risk for death worldwide. In several countries, national programmes to reduce dietary salt have been implemented with leadership and involvement of hypertension experts. Other hypertension experts may be interested in assisting or leading a national programme to reduce dietary salt, however, may not have the experience or training to do so. The article is based on the experiences of three hypertension experts who have led the development of national dietary salt reduction programmes in the United Kingdom, Australia and Canada. The article advises developing leadership and a coalition, conducting a nation-specific environmental scan of facilitators and barriers, estimating the national health and financial costs of high dietary salt and the benefits of reducing salt intake, obtaining core documents to provide the scientific rational for the programme, developing a policy statement to outline the required actions to be undertaken, engaging government and industry, using media to gain public support, overcoming industry supported opposition and sustaining the effort long term. Resources and potential sources for international collaboration are provided as well as caveats for developing the programme within the specific nations' context and overall effort to improve health. Developing and leading a national salt reduction programme is a major commitment, however, reducing dietary salt is estimated to be one of the most effective strategies to improve a nation's health.

High-salt diet and hypertension: focus on the renin-angiotensin system.

A high-salt diet is one of the major risk factors in the development and maintenance of hypertension. Numerous experimental and observational studies have confirmed the association of sodium intake with blood pressure levels. The effects of a high-salt diet are related to the function of the renin-angiotensin system, which is normally suppressed by a high-salt diet. Endothelial dysfunction probably plays an important role in the influence of high sodium intake on blood pressure, although the exact mechanisms remain elusive. Genetic factors are known to be very important, and various consomic and congenic rat strains as animal models have proven to be very useful in bringing us a step closer to understanding the interaction between salt intake and hypertension. In this article, experimental data obtained in studies on animals and humans, as well as epidemiological data are reviewed.

Yanomamos: ingestión de sal e hipertensión arterial / Yanomamos: salt intake and arterial hypertension

La nación yanomama es un grupo indigena aislado y autosuficiente que reside en la selva lluviosa al sur de Venezuela y norte de Brasil que ha logrado vivir en armonia con su ambiente y que ha mostrado ancestral respecto a la naturaleza sin producir basura ni contaminación. Deparam la sal que necesitan de un àrbol de la misma región llamado Tavarí. El Estudio Intersalt es una investigación observacional que ha demostrado una asociación entre la presión arterial y el consumo de sal de la dieta a través de la medición de su excreción urinaria. Los hallazgos encontrados en este grupo poblacional fueron extraordinarios: Niveles de presión arterial muy bajos que no se incrementaron con la edad, niveles de colesterol muy reducidos, ausencia de alcoholismo u obesidad. Constituyen un experimento de la naturaleza digno de seguir; desafortunadamente el mundo occidental ha tenido un impacto negativo en sus vidas y cultura

The nation yanomami is an isolated and self-sufficient indigenous group who reside in the rainy forest to the south of Venezuela and north of Brazil that has managed to live in harmony with its atmosphere and that has shown ancestral respect to the nature without producing any sweepings or contamination. They obtain the salt that needs from a local tree of called Tavarí. The Intersalt Study is an observational investigation that has demostrated an association between the arterial pressure and the consumption of salt of the diet through the measurement of its urinary excretion. The findings found in this population group were extraordinary: very low levels of pressure arterial that are not increased with the age, cholesterol levels very reduced, absence of alcoholism or obesity, very low sodium excretion. They constitute an experiment of the nature worthy to follow; unfortunately western world had much of a negative impact on their lives or culture

Dietary management of feline chronic renal failure: where are we now? In what direction are we headed?

Dietary modification is of primary importance in managing cats with chronic renal failure. Diets designed for cats with chronic renal failure are typically formulated to be pH neutral and contain reduced quantities of protein, phosphorus and sodium and an increased quantity of potassium. These changes in diet formulation are designed to ameliorate clinical signs of renal failure by adapting dietary intakes to meet the limited ability of failing kidneys to adapt to the normal range of dietary intakes. Important recent clinical trials support the therapeutic value of dietary therapy in cats with chronic renal failure.

Drug and dietary intervention in hypertension.

Antihypertensive drug treatment has been shown to be efficacious in reducing mortality, morbidity, and end-organ damage from hypertension. However, the health care consequences of providing continued antihypertensive therapy for approximately one-fourth of the adult population has led to inquiry into the potential of nutritional change as an alternative therapy. The relapse rate for the return of hypertension after withdrawal of antihypertensive drugs is greater in the obese than in the nonobese patient. The relapse rate is also much greater if the hypertension was severe before antihypertensive drugs were started. A programmed course of dietary instruction enabled participants to drop sodium excretion by 50%, and to lose approximately 5% of body weight in 32 weeks. Adequate large-scale trials to determine the therapeutic success rate of dietary modification in mild hypertension have yet to be done. Studies have been initiated in the United States and Finland to determine the feasibility of dietary modifications as a means of preventing the occurrence of hypertension. This endeavor deserves the highest priority, for the magnitude of the problem threatens to overwhelm conventional means of provision of medical care.

A community-based intervention study on the feasibility and effects of the reduction of salt intake in North Karelia, Finland.

A community-based programme to reduce salt consumption to lower general blood pressure levels has been started in North Karelia, a county eastern Finland with high hypertension and CVD rates. The programme is based on the previous activity in the community to control CVD risk factors (the North Karelia Project). Previously, however, salt reduction was not included among the objectives. The aim of the study is to evaluate the feasibility and effects of this new community programme to reduce salt intake. The study period is from spring 1979 to spring 1982. At the outset and at the end cross-sectional random population samples, ages 14 to 65, are examined both in North Karelia and a matched reference community. The surveys include among other measurements 24-hour urine collection (for Na, K and creatinine excretion) and blood pressure. The effect evaluation is concerned whether the programme reduced the general salt intake and whether this was associated with reduction in blood pressure levels among the population. Principles and methods of intervention are presented. Preliminary results from the baseline survey confirmed the high salt intake of the population: the mean 24-hour urinary Na excretion was 215-218 mmol among men and 171-173 mmol among women. The respective K excretion values were 89-91 mmol and 72-72 mmol, and Na/K ratios 2.5-2.6 and 2.4-2.5.