24-Hour Urinary Sodium and Potassium Excretion and Cardiovascular Risk.

BACKGROUND: The relation between sodium intake and cardiovascular disease remains controversial, owing in part to inaccurate assessment of sodium intake. Assessing 24-hour urinary excretion over a period of multiple days is considered to be an accurate method. METHODS: We included individual-participant data from six prospective cohorts of generally healthy adults; sodium and potassium excretion was assessed with the use of at least two 24-hour urine samples per participant. The primary outcome was a cardiovascular event (coronary revascularization or fatal or nonfatal myocardial infarction or stroke). We analyzed each cohort using consistent methods and combined the results using a random-effects meta-analysis. RESULTS: Among 10,709 participants, who had a mean (±SD) age of 51.5±12.6 years and of whom 54.2% were women, 571 cardiovascular events were ascertained during a median study follow-up of 8.8 years (incidence rate, 5.9 per 1000 person-years). The median 24-hour urinary sodium excretion was 3270 mg (10th to 90th percentile, 2099 to 4899). Higher sodium excretion, lower potassium excretion, and a higher sodium-to-potassium ratio were all associated with a higher cardiovascular risk in analyses that were controlled for confounding factors (P≤0.005 for all comparisons). In analyses that compared quartile 4 of the urinary biomarker (highest) with quartile 1 (lowest), the hazard ratios were 1.60 (95% confidence interval [CI], 1.19 to 2.14) for sodium excretion, 0.69 (95% CI, 0.51 to 0.91) for potassium excretion, and 1.62 (95% CI, 1.25 to 2.10) for the sodium-to-potassium ratio. Each daily increment of 1000 mg in sodium excretion was associated with an 18% increase in cardiovascular risk (hazard ratio, 1.18; 95% CI, 1.08 to 1.29), and each daily increment of 1000 mg in potassium excretion was associated with an 18% decrease in risk (hazard ratio, 0.82; 95% CI, 0.72 to 0.94). CONCLUSIONS: Higher sodium and lower potassium intakes, as measured in multiple 24-hour urine samples, were associated in a dose-response manner with a higher cardiovascular risk. These findings may support reducing sodium intake and increasing potassium intake from current levels. (Funded by the American Heart Association and the National Institutes of Health.).

Outcomes of sugar reduction policies, United Kingdom of Great Britain and Northern Ireland.

Poor diets are the major cause of death and disease globally, driving high levels of obesity and noncommunicable diseases. Cheap, heavily marketed, ultra-processed, energy-dense and nutrient-poor food and drinks that are high in fat, sugar and salt play a major role. The high-sugar content of these products leads to consumption levels much higher than recommended. The World Health Organization recommends that sugar intake should be reduced to just 5% of energy intake by using fiscal policies and food and drink reformulation strategies. Over the previous decade, the government of the United Kingdom of Great Britain and Northern Ireland has implemented several policies aimed at reducing sugar intake. We compare the soft drinks industry levy and the sugar reduction programme, examining how differences in policy design and process may have influenced the outcomes. Success has been mixed: the mandatory levy achieved a reduction in total sugar sales of 34.3%, and the voluntary reduction programme only achieved a 3.5% reduction in sugar levels of key contributors to sugar intake (despite a target of 20%). Both policies can be improved to enhance their impact, for example, by increasing the levy and reducing the sugar content threshold in the soft drinks industry levy, and by setting more stringent subcategory specific targets in the sugar reduction programme. We also recommend that policy-makers should consider applying a similar levy to other discretionary products that are key contributors to sugar intake. Both approaches provide valuable learnings for future policy in the United Kingdom and globally.

La malnutrition est l'une des principales causes de décès et de pathologies dans le monde, entraînant des taux élevés d'obésité et un grand nombre de maladies non transmissibles. Massivement commercialisés, les aliments et boissons bon marché, ultra-transformés, riches en énergie et pauvres en nutriments, à forte teneur en graisse, en sucre et en sel jouent un rôle majeur. La quantité de sucre contenue dans ces produits engendre une consommation qui dépasse largement les recommandations en la matière. L'Organisation mondiale de la Santé conseille de réduire la proportion de sucre afin que ce dernier ne représente plus que 5% de l'apport énergétique grâce à des politiques fiscales et des stratégies de révision de la composition des aliments et des boissons. Au cours des dix dernières années, le gouvernement du Royaume-Uni de Grande-Bretagne et d'Irlande du Nord a adopté plusieurs politiques visant à réduire la consommation de sucre. Dans le présent document, nous comparons la taxe sur l'industrie des sodas avec le programme de réduction du sucre, en examinant comment les différences de conception et de mise en œuvre des politiques pourraient avoir influencé les résultats. Le succès s'est révélé mitigé: la taxe obligatoire a permis de faire chuter le total des ventes de sucre de 34,3%, alors que le programme de baisse volontaire n'a pas permis de faire diminuer ce taux de plus de 3,5% chez les acteurs clés de l'apport en sucre (bien loin des 20% ciblés). Les deux politiques peuvent être améliorées pour renforcer leur impact, par exemple en augmentant la taxe et en réduisant la teneur en sucre maximale applicable à l'industrie des sodas, mais aussi en définissant des objectifs spécifiques plus stricts dans les sous-catégories du programme de réduction du sucre. Nous encourageons en outre les responsables politiques à instaurer une taxe similaire sur d'autres produits non essentiels qui contribuent eux aussi à la consommation de sucre. Les deux approches fournissent des renseignements précieux pour de futures mesures au Royaume-Uni et partout dans le monde.

Las dietas inadecuadas son la principal causa de muerte y enfermedad en todo el mundo. Además, impulsan altos niveles de obesidad y enfermedades no transmisibles. Los alimentos y las bebidas baratos, muy comercializados, ultraprocesados, hipercalóricos y pobres en nutrientes, con un alto contenido en grasas, azúcar y sal, desempeñan una función importante. El alto contenido en azúcar de estos productos conduce a niveles de consumo muy superiores a los recomendados. La Organización Mundial de la Salud recomienda reducir el consumo de azúcar a solo el 5% de la ingesta energética mediante políticas fiscales y estrategias de reformulación de alimentos y bebidas. En la última década, el gobierno del Reino Unido de Gran Bretaña e Irlanda del Norte ha aplicado varias políticas encaminadas a reducir la ingesta de azúcar. Comparamos el impuesto del sector de las bebidas no alcohólicas y el programa de reducción del azúcar, examinando cómo las diferencias en el diseño y el proceso de las políticas pueden haber influido en los resultados. El éxito ha sido desigual: el impuesto obligatorio logró una reducción de las ventas totales de azúcar del 34,3%, y el programa de reducción voluntaria solo consiguió una reducción del 3,5% en los niveles de azúcar de los principales contribuyentes a la ingesta de azúcar (a pesar de un objetivo del 20%). Se pueden mejorar ambas políticas para aumentar su impacto, por ejemplo, aumentando el impuesto y reduciendo el umbral de contenido de azúcar en el impuesto del sector de las bebidas no alcohólicas, y estableciendo objetivos específicos por subcategorías más estrictos en el programa de reducción de azúcar. También recomendamos a los responsables de formular las políticas que estudien la posibilidad de aplicar un impuesto similar a otros productos discrecionales que contribuyen decisivamente a la ingesta de azúcar. Ambos enfoques aportan valiosas enseñanzas para las futuras políticas del Reino Unido y del resto del mundo.

Salt reduction policy for out of home sectors: a supplementary document for the salt reduction strategy to prevent and control non-communicable diseases (NCDS) in Malaysia 2021-2025.

Cardiovascular diseases (CVDs) are the major cause of death among Malaysians. Reduction of salt intake in populations is one of the most cost-effective strategies in the prevention of CVDs. It is very feasible as it requires low cost for implementation and yet could produce a positive impact on health. Thus, salt reduction initiatives have been initiated since 2010, and two series of strategies have been launched. However, there are issues on its delivery and outreach to the target audience. Further, strategies targeting out of home sectors are yet to be emphasized. Our recent findings on the perceptions, barriers and enablers towards salt reduction among various stakeholders including policy-makers, food industries, food operators, consumers and schools showed that eating outside of the home contributed to high salt intake. Foods sold outside the home generally contain a high amount of salt. Thus, this supplementary document is being proposed to strengthen the Salt Reduction Strategy to Prevent and Control Non-communicable Diseases (NCDs) for Malaysia 2021-2025 by focussing on the strategy for the out-of-home sectors. In this supplementary document, the Monitoring, Awareness and Product (M-A-P) strategies being used by the Ministry of Health (MOH) are adopted with a defined outline of the plan of action and indicators to ensure that targets could be achieved. The strategies will involve inter-sectoral and multi-disciplinary approaches, including monitoring of salt intake and educating consumers, strengthening the current enforcement of legislation on salt/sodium labelling and promoting research on reformulation. Other strategies included in this supplementary document included reformulation through proposing maximum salt targets for 14 food categories. It is hoped that this supplementary document could strengthen the current the Salt Reduction Strategy to Prevent and Control NCDs for Malaysia 2021-2025 particularly, for the out-of-home sector, to achieve a reduction in mean salt intake of the population to 6.0 g per day by 2025.

Perceptions, barriers and enablers on salt reduction in the out-of-home sectors in Malaysia (MySaltOH) from the perspective of street food vendors, caterers and consumers.

OBJECTIVE: To explore the perspectives, barriers and enablers on salt reduction in out-of-home sectors in Malaysia among street food vendors, caterers and consumers. DESIGN: A qualitative study involving twenty-two focus group discussions and six in-depth interviews was conducted, recorded and transcribed verbatim. An inductive thematic analysis approach was employed to analyse the data. SETTING: Two in-depth interviews and twenty-two focus group discussions were conducted face-to-face. Four in-depth interviews were conducted online. PARTICIPANTS: Focus group discussions were conducted among twenty-three street food vendors, twenty-one caterers and seventy-six consumers of various eateries. In-depth interviews were conducted among two street food vendors and four caterers, individually. RESULTS: Consumers and food operators perceived a high-salt intake within Malaysia's out-of-home food sectors. Food operators emphasised the necessity for a comprehensive salt reduction policy in the out-of-home sector involving all stakeholders. Consumers faced limited awareness and knowledge, counterproductive practices among food operators and challenges in accessing affordable low-Na food products, whereas food operators faced the lack of standardised guidelines and effective enforcement mechanisms and uncooperative consumer practices. Both groups expressed that food quality and price of salt were also the barriers, and they advocated for awareness promotion, enhanced regulation of manufactured food products and stricter enforcement targeting vendors. Consumers also suggested promoting and recognising health-conscious food premises, whereas food operators suggested on knowledge enhancement tailored to them, strategies for gaining consumers acceptance and maintaining food quality. CONCLUSIONS: These findings provide valuable insights that serve as foundational evidence for developing and implementing salt reduction policies within Malaysia's out-of-home sectors.

Salt reduction to prevent hypertension: the reasons of the controversy.

There is a causal relationship between dietary salt intake and blood pressure. A reduction in salt intake from the current world average of ∼10 g/day to the WHO recommended level of <5 g/day, lowers blood pressure and reduces the risk of cardiovascular disease and all-cause mortality. However, a few cohort studies have claimed that there is a J-shaped relationship between salt intake and cardiovascular risk, i.e. both high and low salt intakes are associated with an increased risk. These cohort studies have several methodological problems, including reverse causality, and inaccurate and biased estimation of salt intake, e.g. from a single spot urine sample with formulas. Recent studies have shown that the formulas used to estimate salt intake from spot urine cause a spurious J-curve. Research with inappropriate methodology should not be used to refute the robust evidence on the enormous benefits of population-wide reduction in salt intake. Several countries, e.g. Finland, the UK, have successfully reduced salt intake, which has resulted in falls in population blood pressure and deaths from stroke and ischaemic heart disease. Every country should develop and implement a coherent, workable strategy to reduce salt intake. Even a modest reduction in salt intake across the whole population will lead to a major improvement in public health, along with huge cost-savings to the healthcare service.

24-hour sodium and potassium excretion in the Americas: a systematic review and meta-analysis.

Objective: To determine the 24-hour urinary sodium and potassium excretions in the Americas. Methods: A systematic review and meta-analysis were performed seeking for studies conducted between 1990 and 2021 in adults living in any sovereign state of the Americas in Medline, Embase, Scopus, SciELO, and Lilacs. The search was first run on October 26th, 2020 and was updated on December 15th, 2021. Of 3 941 abstracts reviewed, 74 studies were included from 14 countries, 72 studies reporting urinary sodium (27 387 adults), and 42 studies reporting urinary potassium (19 610 adults) carried out between 1990 and 2020. Data were pooled using a random-effects meta-analysis model. Results: Mean excretion was 157.29 mmol/24h (95% CI, 151.42-163.16) for sodium and 57.69 mmol/24h (95% CI, 53.35-62.03) for potassium. When only women were considered, mean excretion was 135.81 mmol/24h (95% CI, 130.37-141.25) for sodium and 51.73 mmol/24h (95% CI, 48.77-54.70) for potassium. In men, mean excretion was 169.39 mmol/24h (95% CI, 162.14-176.64) for sodium and 62.67 mmol/24h (95% CI, 55.41-69.93) for potassium. Mean sodium excretion was 150.09 mmol/24h (95% CI, 137.87-162.30) in the 1990s and 159.79 mmol/24h (95% CI, 151.63-167.95) in the 2010s. Mean potassium excretion was 58.64 mmol/24h (95% CI, 52.73-64.55) in the 1990s and 56.33 mmol/24/h (95% CI, 48.65-64.00) in the 2010s. Conclusions: These findings suggest that sodium excretions are almost double the maximum level recommended by the World Health Organization and potassium excretions are 35% lower than the minimum requirement; therefore, major efforts to reduce sodium and to increase potassium intakes should be implemented.

Comment on Hogas et al. Salt, Not Always a Cardiovascular Enemy? A Mini-Review and Modern Perspective. Medicina 2022, 58, 1175.

Hogas et al. recently published their perspective on dietary salt in a mini review [...].

Impact of color-coded and warning nutrition labelling schemes: A systematic review and network meta-analysis.

BACKGROUND: Suboptimal diets are a leading risk factor for death and disability. Nutrition labelling is a potential method to encourage consumers to improve dietary behaviour. This systematic review and network meta-analysis (NMA) summarises evidence on the impact of colour-coded interpretive labels and warning labels on changing consumers' purchasing behaviour. METHODS AND FINDINGS: We conducted a literature review of peer-reviewed articles published between 1 January 1990 and 24 May 2021 in PubMed, Embase via Ovid, Cochrane Central Register of Controlled Trials, and SCOPUS. Randomised controlled trials (RCTs) and quasi-experimental studies were included for the primary outcomes (measures of changes in consumers' purchasing and consuming behaviour). A frequentist NMA method was applied to pool the results. A total of 156 studies (including 101 RCTs and 55 non-RCTs) nested in 138 articles were incorporated into the systematic review, of which 134 studies in 120 articles were eligible for meta-analysis. We found that the traffic light labelling system (TLS), nutrient warning (NW), and health warning (HW) were associated with an increased probability of selecting more healthful products (odds ratios [ORs] and 95% confidence intervals [CIs]: TLS, 1.5 [1.2, 1.87]; NW, 3.61 [2.82, 4.63]; HW, 1.65 [1.32, 2.06]). Nutri-Score (NS) and warning labels appeared effective in reducing consumers' probability of selecting less healthful products (NS, 0.66 [0.53, 0.82]; NW,0.65 [0.54, 0.77]; HW,0.64 [0.53, 0.76]). NS and NW were associated with an increased overall healthfulness (healthfulness ratings of products purchased using models such as FSAm-NPS/HCSP) by 7.9% and 26%, respectively. TLS, NS, and NW were associated with a reduced energy (total energy: TLS, -6.5%; NS, -6%; NW, -12.9%; energy per 100 g/ml: TLS, -3%; NS, -3.5%; NW, -3.8%), sodium (total sodium/salt: TLS, -6.4%; sodium/salt per 100 g/ml: NS: -7.8%), fat (total fat: NS, -15.7%; fat per 100 g/ml: TLS: -2.6%; NS: -3.2%), and total saturated fat (TLS, -12.9%; NS: -17.1%; NW: -16.3%) content of purchases. The impact of TLS, NS, and NW on purchasing behaviour could be explained by improved understanding of the nutrition information, which further elicits negative perception towards unhealthful products or positive attitudes towards healthful foods. Comparisons across label types suggested that colour-coded labels performed better in nudging consumers towards the purchase of more healthful products (NS versus NW: 1.51 [1.08, 2.11]), while warning labels have the advantage in discouraging unhealthful purchasing behaviour (NW versus TLS: 0.81 [0.67, 0.98]; HW versus TLS: 0.8 [0.63, 1]). Study limitations included high heterogeneity and inconsistency in the comparisons across different label types, limited number of real-world studies (95% were laboratory studies), and lack of long-term impact assessments. CONCLUSIONS: Our systematic review provided comprehensive evidence for the impact of colour-coded labels and warnings in nudging consumers' purchasing behaviour towards more healthful products and the underlying psychological mechanism of behavioural change. Each type of label had different attributes, which should be taken into consideration when making front-of-package nutrition labelling (FOPL) policies according to local contexts. Our study supported mandatory front-of-pack labelling policies in directing consumers' choice and encouraging the food industry to reformulate their products. PROTOCOL REGISTRY: PROSPERO (CRD42020161877).

Labelling changes in response to a tax on sugar-sweetened beverages, United Kingdom of Great Britain and Northern Ireland.

OBJECTIVE: To evaluate the changes in sugar and energy labelling of carbonated sugar-sweetened soft drinks after the implementation of a tax on sugar-sweetened drinks in the United Kingdom of Great Britain and Northern Ireland. METHODS: We visited nine main supermarkets before (May 2014) and after (April 2018) the tax came into effect and obtained data from product packaging and nutrition information panels of carbonated sugar-sweetened soft drinks. We used the paired t-test to assess differences in sugar and energy content of the same products between 2014 and 2018. FINDINGS: We obtained data from 166 products in 2014 and 464 products in 2018, of which 83 products were the same in both years. Large variations in stated sugar content were found between the different carbonated sugar-sweetened soft drinks in both 2014 and 2018 for all products and for the 83 products. The mean sugar content of the 83 products decreased by 42% between 2014 and 2018, from 9.1 g/100 mL (standard deviation, SD: 3.3) to 5.3 g/100 mL (SD: 3.5; P < 0.001). The mean energy content decreased by 40%, from 38 kcal/100 mL (SD: 13) in 2014 to 23 kcal/100 mL (SD: 15) in 2018 (P < 0.001). CONCLUSION: The significant decreases in the labelling of sugar and energy content of carbonated sugar-sweetened soft drinks after the levy came into effect suggest this tax has been effective. The sugar content of drinks still varied considerably in 2018, suggesting further reductions in sugar content of these drinks is possible. The levy thresholds should be reduced and the tax increased to drive further reformulation of soft drinks to reduce their sugar content.

The sugar and energy in non-carbonated sugar-sweetened beverages: a cross-sectional study.

BACKGROUND: The consumption of non-carbonated sugar-sweetened beverages (NCSSBs) has many adverse health effects. However, the sugar and energy content in NCSSBs sold in China remain unknown. We aimed to investigate the sugar and energy content of NCSSBs in China and how these contents were labelled. METHODS: A cross-sectional survey was conducted in 15 supermarkets in Haidian District, Beijing from July to October 2017. The product packaging and nutrient information panels of NCSSBs were recorded to obtain type of products (local/imported), serving size, nutrient contents of carbohydrate, sugar and energy. For those NCSSBs without sugar content information, we used carbohydrate content as a replacement. RESULTS: A total of 463 NCSSBs met the inclusion criteria and were included in our analysis. The median of sugar content and energy content was 9.6 [interquartile range (IQR): 7.1-11.3] g/100 ml and 176 (IQR: 121-201) kJ/100 ml. The median of sugar contents in juice drinks, tea-based beverages, sports drinks and energy drinks were 10.4, 8.5, 5.0 and 7.4 g/100 ml. Imported products had higher sugar and energy content than local products. There were 95.2% products of NCSSBs receiving a 'red'(high) label for sugars per portion according to the UK criteria, and 81.6% products exceeding the daily free sugar intake recommendation from the World Health Organization (25 g). There were 82 (17.7%) products with sugar content on the nutrition labels and 60.2% of them were imported products. CONCLUSIONS: NCSSBs had high sugar and energy content, and few of them provided sugar content information on their nutrition labels especially in local products. Measures including developing better regulation of labelling, reducing sugar content and restricting the serving size are needed for reducing sugar intakes in China.

Salt and sugars content of breakfast cereals in the UK from 1992 to 2015.

OBJECTIVE: To study the salt and sugars content of breakfast cereals sold in the UK between 1992 and 2015. DESIGN: Cross-sectional surveys on salt and sugars content collected from the nutrition information panel of breakfast cereals in 1992, 2004, 2006, 2009, 2012 and 2015. SETTING: All major UK retailers operating at that moment in time (approximately ten). SUBJECTS: The salt and sugars content was collected from product packaging and the nutrition information panels. RESULTS: Cereals consistently surveyed across all five years (n22) showed a significant reduction in salt content of 47 % (P<0·001). Sugars content of breakfast cereals (n 15), however, did not show a significant change; 25·65 g/100 g in 1992 and 22·45 g/100 g in 2015 (P=0·170). There was a large variation in salt and sugars content between different categories and within the same type of category. CONCLUSIONS: The study shows the progressive reduction in salt content of breakfast cereals in the UK since 2004 as a result of the successful salt reduction programme, particularly the setting of incremental salt targets. Further reductions in salt content need to be made as cereals remain a major contributor to salt intake. Sugars content, however, has been consistently high due to the lack of a sugar reduction strategy. The research demonstrates that the sugars content of breakfast cereals in the UK is of concern, particularly in children's breakfast cereals, with a typical serving (30 g) containing a third of a 4-6-year-old's maximum daily recommendation (19 g/d) for free sugars intake in the UK. More can and should be done to reformulate, with an urgent need to set incremental sugar reduction targets.

Salt and sugar: their effects on blood pressure.

Both dietary salt and sugar are related to blood pressure (BP). The evidence for salt is much stronger, and various types of studies have consistently shown that salt is a major cause of raised BP, and a reduction from the current intake of ≈ 9-12 g/day in most countries of the world to the recommended level of 5-6 g/day lowers BP in both hypertensive and normotensive individuals, in men and women, in all age groups and in all ethnic groups. Countries such as Finland and the UK that have successfully reduced salt intake have demonstrated a reduction in population BP and cardiovascular mortality, with major cost savings to the health service. The mechanisms whereby salt raises BP are not fully understood. The traditional concepts focus on the tendency for an increase in extracellular fluid volume. Increasing evidence suggests that small increases in plasma sodium may play an important role. There are several other factors that also increase BP, one of which is added sugars. The current high intake of added sugars increases obesity which, in turn, raises BP. Recent studies also suggest that added sugars, particularly those in soft drinks, may have a direct effect on BP. However, the relationship between soft drink consumption and BP could be, at least partially, mediated by the effect of salt intake on increasing soft drink consumption. Actions to reduce salt and sugar intake across the whole population will have major beneficial effects on health along with major cost savings.

Sodium, blood pressure, and cardiovascular disease: further evidence supporting the American Heart Association sodium reduction recommendations.

Recent reports of selected observational studies and a meta-analysis have stirred controversy and have become the impetus for calls to abandon recommendations for reduced sodium intake by the US general population. A detailed review of these studies documents substantial methodological concerns that limit the usefulness of these studies in setting, much less reversing, dietary recommendations. Indeed, the evidence base supporting recommendations for reduced sodium intake in the general population remains robust and persuasive. The American Heart Association is committed to improving the health of all Americans through implementation of national goals for health promotion and disease prevention, including its recommendation to reduce dietary sodium intake to <1500 mg/d.

Altering plasma sodium concentration rapidly changes blood pressure during haemodialysis.

BACKGROUND: Plasma sodium is increased following each meal containing salt. There is an increasing interest in the effects of plasma sodium concentration, and it has been suggested that it may have direct effects on blood pressure (BP) and possibly influences endothelial function. Experimental increases of plasma sodium concentration rapidly raise BP even when extracellular volume falls. METHODS: Ten patients with end-stage renal failure established on haemodialysis were studied during the first 2 h of dialysis without fluid removal during this period. They were randomized to receive haemodialysis with (i) dialysate sodium concentration prescribed to 135 mmol/L and (ii) 145 mmol/L in random order in a prospective, single-blinded crossover study. BP measurements and blood samples were taken every 30 min. RESULTS: Pre-dialysis sitting BP was 137/76 ± 7/3 mmHg. Lower dialysate sodium concentration (135 mmol/L) reduced plasma sodium concentration [139.49 ± 0.67 to 135.94 ± 0.52 mmol/L (P < 0.001)], whereas plasma sodium concentration was not altered by higher dialysate sodium (145 mmol/L) (140.17 ± 0.66 mmol/L at baseline to 140.72 ± 0.43 mmol/L at 120 min). Systolic BP was lower with dialysate sodium concentration 135 mmol/L [area under the curve (AUC) 15823.50 ± 777.15 (mmHg)min] compared with 145 mmol/L [AUC 17018.20 ± 1102.17 (mmHg)min], mean difference 1194.70 ± 488.41 (mmHg)min, P < 0.05. There was a significant positive relationship between change in plasma sodium concentration and change in systolic BP. This direct relationship suggests that a fall of 1 mmol/L in plasma sodium concentration would be associated with a 1.7 mmHg reduction in systolic BP (P < 0.05). CONCLUSIONS: The potential mechanism for the increase in BP seen with salt intake may be through small but significant changes in plasma sodium concentration.

Effect of longer-term modest salt reduction on blood pressure.

BACKGROUND: A reduction in salt intake lowers blood pressure (BP) and, thereby, reduces cardiovascular risk. A recent meta-analysis by Graudal implied that salt reduction had adverse effects on hormones and lipids which might mitigate any benefit that occurs with BP reduction. However, Graudal's meta-analysis included a large number of very short-term trials with a large change in salt intake, and such studies are irrelevant to the public health recommendations for a longer-term modest reduction in salt intake. We have updated our Cochrane meta-analysis. OBJECTIVES: To assess (1) the effect of a longer-term modest reduction in salt intake (i.e. of public health relevance) on BP and whether there was a dose-response relationship; (2) the effect on BP by sex and ethnic group; (3) the effect on plasma renin activity, aldosterone, noradrenaline, adrenaline, cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL) and triglycerides. SEARCH METHODS: We searched MEDLINE, EMBASE, Cochrane Hypertension Group Specialised Register, Cochrane Central Register of Controlled Trials, and reference list of relevant articles. SELECTION CRITERIA: We included randomised trials with a modest reduction in salt intake and duration of at least 4 weeks. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers. Random effects meta-analyses, subgroup analyses and meta-regression were performed. MAIN RESULTS: Thirty-four trials (3230 participants) were included. Meta-analysis showed that the mean change in urinary sodium (reduced salt vs usual salt) was -75 mmol/24-h (equivalent to a reduction of 4.4 g/d salt), the mean change in BP was -4.18 mmHg (95% CI: -5.18 to -3.18, I (2)=75%) for systolic and -2.06 mmHg (95% CI: -2.67 to -1.45, I (2)=68%) for diastolic BP. Meta-regression showed that age, ethnic group, BP status (hypertensive or normotensive) and the change in 24-h urinary sodium were all significantly associated with the fall in systolic BP, explaining 68% of the variance between studies. A 100 mmol reduction in 24 hour urinary sodium (6 g/day salt) was associated with a fall in systolic BP of 5.8 mmHg (95%CI: 2.5 to 9.2, P=0.001) after adjusting for age, ethnic group and BP status. For diastolic BP, age, ethnic group, BP status and the change in 24-h urinary sodium explained 41% of the variance between studies. Meta-analysis by subgroup showed that, in hypertensives, the mean effect was -5.39 mmHg (95% CI: -6.62 to -4.15, I (2)=61%) for systolic and -2.82 mmHg (95% CI: -3.54 to -2.11, I (2)=52%) for diastolic BP. In normotensives, the mean effect was -2.42 mmHg (95% CI: -3.56 to -1.29, I (2)=66%) for systolic and -1.00 mmHg (95% CI: -1.85 to -0.15, I (2)=66%) for diastolic BP. Further subgroup analysis showed that the decrease in systolic BP was significant in both whites and blacks, men and women. Meta-analysis of hormone and lipid data showed that the mean effect was 0.26 ng/ml/hr (95% CI: 0.17 to 0.36, I (2)=70%) for plasma renin activity, 73.20 pmol/l (95% CI: 44.92 to 101.48, I (2)=62%) for aldosterone, 31.67 pg/ml (95% CI: 6.57 to 56.77, I (2)=5%) for noradrenaline, 6.70 pg/ml (95% CI: -0.25 to 13.64, I (2)=12%) for adrenaline, 0.05 mmol/l (95% CI: -0.02 to 0.11, I (2)=0%) for cholesterol, 0.05 mmol/l (95% CI: -0.01 to 0.12, I (2)=0%) for LDL, -0.02 mmol/l (95% CI: -0.06 to 0.01, I (2)=16%) for HDL, and 0.04 mmol/l (95% CI: -0.02 to 0.09, I (2)=0%) for triglycerides. AUTHORS' CONCLUSIONS: A modest reduction in salt intake for 4 or more weeks causes significant and, from a population viewpoint, important falls in BP in both hypertensive and normotensive individuals, irrespective of sex and ethnic group. With salt reduction, there is a small physiological increase in plasma renin activity, aldosterone and noradrenaline. There is no significant change in lipid levels. These results provide further strong support for a reduction in population salt intake. This will likely lower population BP and, thereby, reduce cardiovascular disease. Additionally, our analysis demonstrates a significant association between the reduction in 24-h urinary sodium and the fall in systolic BP, indicating the greater the reduction in salt intake, the greater the fall in systolic BP. The current recommendations to reduce salt intake from 9-12 to 5-6 g/d will have a major effect on BP, but are not ideal. A further reduction to 3 g/d will have a greater effect and should become the long term target for population salt intake.

Consumption of Soft Drinks and Overweight and Obesity Among Adolescents in 107 Countries and Regions.

Importance: Soft drink consumption is associated with weight gain in children and adolescents, but little is known about the association between soft drink consumption and prevalence of the overweight and obesity in adolescents. Objective: To investigate the association of soft drink consumption with overweight and obesity in adolescents enrolled in school (hereafter, school-going adolescents) using country-level and individual-level data. Design, Setting, and Participants: This cross-sectional study used data from 3 cross-sectional studies including 107 countries and regions that participated in the Global School-Based Student Health Survey (2009-2017), the European Health Behavior in School-Aged Children study (2017-2018), and the US Youth Risk Behavior Survey (2019). Exposure: Daily soft drink consumption (consuming soft drinks 1 or more times per day or not). Main Outcome and Measure: Overweight and obesity defined by the World Health Organization Growth Reference Data. Results: Among the 107 countries and regions, 65 were low- and middle-income, and 42 were high-income countries and regions, with a total of 405 528 school-going adolescents (mean [SD] age, 14.2 [1.7] years; 196 147 [48.4%] males). The prevalence of overweight and obesity among adolescent students varied from 3.3% (95% CI, 2.6 to 4.1) in Cambodia to 64.0% (95% CI, 57.0 to 71.6) in Niue, and the prevalence of adolescent students consuming soft drinks 1 or more times per day varied from 3.3% (95% CI, 2.9 to 3.7) in Iceland to 79.6% (95% CI, 74.0 to 85.3) in Niue. There was a positive correlation between the prevalence of daily soft drink consumption and the prevalence of overweight and obesity (R, 0.44; P < .001). The pooled analysis using individual-level data also showed a statistically significant association between daily soft drink consumption and overweight and obesity (daily soft drink consumption vs nondaily soft drink consumption), with an odds ratio of 1.14 (95% CI, 1.08 to 1.21) among school-going adolescents. Conclusions and Relevance: In this study of 107 countries and regions, the prevalence of daily consumption of soft drinks was associated with the prevalence of overweight and obesity among adolescent students. Our results, in conjunction with other evidence, suggest that reducing soft drink consumption should be a priority in combating adolescent overweight and obesity.