Salt Sensitivity of Blood Pressure.

The year 2024 marks the centennial of the initiation of the American Heart Association. Over the past 100 years, the American Heart Association has led groundbreaking discoveries in cardiovascular disease including salt sensitivity of blood pressure, which has been studied since the mid-1900s. Salt sensitivity of blood pressure is an important risk factor for cardiovascular events, but the phenotype remains unclear because of insufficient understanding of the underlying mechanisms and lack of feasible diagnostic tools. In honor of this centennial, we commemorate the initial discovery of salt sensitivity of blood pressure and chronicle the subsequent scientific discoveries and efforts to mitigate salt-induced cardiovascular disease with American Heart Association leading the way. We also highlight determinants of the pathophysiology of salt sensitivity of blood pressure in humans and recent developments in diagnostic methods and future prospects.

The Rise and Fall of Universal Salt Iodization in Vietnam: Lessons Learned for Designing Sustainable Food Fortification Programs With a Public Health Impact.

BACKGROUND: In 2005, more than 90% of Vietnamese households were using adequately iodized salt, and urinary iodine concentration among women of reproductive age was in the optimal range. However, household coverage declined thereafter to 45% in 2011, and urinary iodine concentration levels indicated inadequate iodine intake. OBJECTIVE: To review the strengths and weaknesses of the Vietnamese universal salt iodization program from its inception to the current day and to discuss why achievements made by 2005 were not sustained. METHODS: Qualitative review of program documents and semistructured interviews with national stakeholders. RESULTS: National legislation for mandatory salt iodization was revoked in 2005, and the political importance of the program was downgraded with consequential effects on budget, staff, and authority. CONCLUSIONS: The Vietnamese salt iodization program, as it was initially designed and implemented, was unsustainable, as salt iodization was not practiced as an industry norm but as a government-funded activity. An effective and sustainable salt iodization program needs to be reestablished for the long-term elimination of iodine deficiency, building upon lessons learned from the past and programs in neighboring countries. The new program will need to include mandatory legislation, including salt for food processing; industry responsibility for the cost of fortificant; government commitment for enforcement through routine food control systems and monitoring of iodine status through existing health/nutrition assessments; and intersectoral collaboration and management of the program. Many of the lessons would apply equally to universal salt iodization programs in other countries and indeed to food fortification programs in general.

History of U.S. iodine fortification and supplementation.

Iodine is a micronutrient required for thyroid hormone production. This review highlights the history of the discovery of iodine and its uses, discusses the sources of iodine nutrition, and summarizes the current recommendations for iodine intake with a focus on women of childbearing age.

El consumo de sal: ¿Riesgo o necesidad? / Salt intake: a risk or need?

Se realizó una revisión acerca del consumo de sal y sus usos en las diferentes etapas de la historia de la humanidad. Se abordan elementos relacionados con su presencia en el organismo, las funciones fisiológicas esenciales para el mantenimiento homeostático en la vida, así como las complicaciones cuando sus niveles son inferiores a los límites fisiológicos, o superiores a estos. Se analizaron diferentes estudios y sus contradicciones sobre los daños que ocasiona a la salud el consumo de sal. Se precisan los grupos poblacionales sal sensibles (SS) y sal resistentes (SR), pautados por estudios realizados, así como las posibles causas de sus variaciones. Se emiten conclusiones en cuanto a riesgo y beneficio del consumo de sal. Se recomienda intervenir en un equilibrado consumo, tanto para los individuos como para las poblaciones(AU)

A literary review on salt intake and its uses throughout the different stages in the history of mankind was conducted. It addresses issues related to salt concentrations in the human body, its physiological functions that are essential for homeostatic control, as well as the complications when salt levels are below or over the physiological limits. Different studies were analyzed including the contradictions they all present on the damage that salt intake can cause to human health. Population groups are defined as salt sensitive (SS) and salt resistant (SR) according to study that was conducted as well as to the possible causes for their variations. Conclusions are drawn on the risks and benefits of salt intake. Intervention is recommended for balanced consumption, both for individuals and for populations(AU)

O sal como solução? Políticas de saúde e endemias rurais no Brasil (1940-1960) / Salt as solution? Health policies and endemic rural diseases in Brazil (1940-1960)

O objetivo deste artigo é analisar e comparar as políticas acerca do uso do sal no tratamento de duas doenças graves que assolaram a Amazônia e as áreas rurais do Brasil durante o período desenvolvimentista: o bócio endêmico e a malária. Apesar de serem doenças muito diferentes – a primeira é uma doença carencial, e a segunda uma doença parasitária – a luta dos médicos e nutricionistas para tornar obrigatória a iodação do sal de cozinha consumido no país inspirou aidéia de um sal misturado com cloroquina, a ser distribuído livremente em zonas de malária, onde o uso de DDT (Dicloro-Difenil-Tricloroetano) não seria eficaz. O que seria um método simples – e, portanto, eficaz – para controlar e até mesmo eliminar tais doenças, o uso do sal de cozinha como veículo para fornecer iodo e uma droga antimalárica para a população, esbarra em fatores cognitivos, econômicos, sociais e culturais. Algumas variáveis contribuem para a análise histórica desses programas de saúde: o consenso quanto à etiologia da doença, o grau de institucionalização da comunidade de especialistas e a sua organização, a importânciada doença na agenda das organizações internacionais de saúde, o locus dedecisão política, a existência de uma liderança científica envolvida na formulaçãoe gestão das políticas de saúde, e os padrões de consumo das populações-alvo. (AU)

INCAP studies of endemic goiter and its prevention.

The high prevalence of goiter among adults in its member countries of Central America and Panama was observed as soon as INCAP began field studies. This led to systematic studies of goiter in schoolchildren in all of the countries as described, beginning with Guatemala where the rate was 38% nationally. However, efforts to eliminate the consequences of iodine with iodized salt using the water soluble potassium iodate and a process that had proved successful in Switzerland and the United States could not be used with the crude moist salt of the region. INCAP identified potassium iodate that is insoluble in water, and in four schools (two each in El Salvador and Guatemala) proved that the iodine in this compound was as available as that in potassium iodate. It remained evenly distributed in moist salt. When added to salt in Guatemala, goiter rate dropped to 15% in four years and less than 5% in eight years. Compulsory iodation of salt in other developing countries followed with comparable results. This method is now used in worldwide campaigns against iodine deficiency in developing countries.

The story of the Croatian village of Rude after fifty years of compulsory salt iodination in Croatia.

The village of Rude is situated near Zagreb, the capital of Croatia in the last Alpine valley on Balkan. In the past, the village was well-known area of severe iodine deficiency disorders (IDD). In 1952', distinguished Croatian endocrinologist Professor Josip Matovinovic carried out detailed village survey. Goiter prevalence in school-age children was 85.0% (with 2.3% of cretins in the village). In 1953, the first regulation on compulsory salt iodination with 10 mg of KI/kg of salt was established in former Yugoslavia. Ten years later a dramatic decrease in goiter prevalence was recorded in all endangered areas of the country and no new cretins appeared. However, at the beginning of 1990' mild to moderate iodine deficiency still persisted in Croatia. In 1991, the village of Rude survey demonstrated goiter prevalence in school-age children of 35.0% and median of urinary iodine excretion (UIE) of 7.4 microg/dL. In 1996, the new obligatory regulation with 25 mg of KI/kg of salt was established in Croatia. The study aim was to monitor IDD status in the village after the new law on compulsory salt iodination. Measurements of UIE and thyroid volumes (Tvol) by ultrasound were performed in 7-11-y-old schoolchildren living in the village of Rude. Medians of UIE and body surface area (BSA)-adjusted Tvol in boys and girls were calculated. The study included 84 children in 1997, 132 in 2000, 72 in 2002, 85 in 2003 and 46 in 2004 for UIE measurement. Thyroid volumes were measured in 1999 (43 boys and 26 girls) and in 2005 (22 boys and 26 girls). Data were compared with the new WHO/ICCIDD reference values. Medians of UIE in schoolchildren from the village of Rude demonstrated rising values in microg/dL: 11.4 in 1997, 14.3 in 2000, 17.3 in 2002, 15.4 in 2003 and 19.0 in 2004. Significant decrease in BSA-adjusted Tvol was recorded from 1999-2005 in boys and girls from the village of Rude and in 2005 Tvol were within the normal range according to the new international reference values for Tvol in iodine-sufficient schoolchildren. As a result of increased iodine prophylaxis, IDD no longer exist in Croatia. Monitoring of IDD status in the village of Rude after new law on compulsory salt iodination in Croatia demonstrated rising medians of UIE together with significant reduction of Tvol. In 2005, Tvol in schoolchildren from the village of Rude were within the normal range according to the new international reference values for Tvol in iodine-sufficient schoolchildren.

Overview of salt fluoridation in Switzerland since 1955, a short history.

After an early start in 1955, the introduction and acceptance of fluoridated salt (FS) for domestic use was slow in Switzerland because up to around 1980 there was no consistent strategy for the support of the use of FS. Part of the dental community still supported water fluoridation, while others criticized the insufficient concentration of fluoride in the salt (90 ppm). All Swiss cantons have a historical monopoly on salt trade, and until 1983 most cantonal governments resolved to authorize the sale of fluoridated domestic salt. Some of the cantonal governments made fluoridated salt the only available type of "kitchen salt" in 1-kg packages. After the concentration had been increased to 250 ppm in 1983, the use of FS gained further acceptance. A temporary setback occurred in 1992-1994, but was successfully met with by making the FS available in several package sizes, while other types of salt (with or without iodine) were available in 500 g packages only. By 2004, the market share of fluoridated domestic salt reached 88%. Further endeavours aim at increasing the use of FS by large kitchens. FS is available in portions of 12.5 kg (since 2001) and 25 kg (since 1976).

[Salt and hypertension--100 years of unresolved issues]. / Salt og høyt blodtrykk--et dilemma i 100 år.

BACKGROUND: In recent years, criticism against the so-called "salt hypothesis" has gained momentum. We give a brief review of important data related to this issue, in particular of the evidence-based documentation supporting a general recommendation of reduced salt intake. MATERIAL AND METHODS: We searched in PubMed, Ovid and HighWire for papers relating to salt intake, blood pressure and cardiovascular disease. RESULTS: Most studies in favour of the salt hypothesis rely on short-term (about 30 days) intervention trials. The possible benefit of salt restriction on hypertension and hypertension-related morbidity and mortality is not firmly established. INTERPRETATION: A general recommendation of a reduction in salt intake among Norwegians to 5 g/day or less is not scientifically justified. More studies on salt intake in the general Norwegian population as well as intervention trials spanning years are warranted.