Effects of altered salt intake and diet on cytokines in humans: A 20-week randomized cross-over intervention study.

High sodium concentration alters leukocyte activation, and in particular T-helper (Th) lymphocyte polarization, and drives the development of autoimmune diseases in mouse studies. Similar results have been obtained with human leukocytes under in vitro settings and in few observational studies. Therefore, salt has been implicated as a risk factor for autoimmune diseases. Here, we examined whether physiologically relevant changes in salt intake or diet alter cytokine concentrations. In a 20-wk double-blinded, placebo-controlled study 106 participants were randomized to Habitual and Healthy Nordic diets, and further to Usual Sodium and Reduced Sodium intake groups using a cross-over setup. Plasma concentrations of 45 cytokines were measured at three different time-points using a multiplex assay. Repeated analyses of covariance revealed that high salt ingestion (or changes in the diet) did not induce significant changes in any of the signature cytokines controlling Th1, Th2 or Th17 polarization. Several other pro-inflammatory interleukins, chemokines and growth factors were also unaffected by the level of salt intake or changes in the diet. We conclude that in humans clinically relevant changes in salt intake or diet do not have reflections on the systemic concentrations of pro-inflammatory cytokines in vivo.

Adding salt to foods and risk of psoriasis: A prospective cohort study.

BACKGROUND: High salt intake may play a critical role in the etiology of psoriasis. Yet, evidence on the association of high salt intake with risk of psoriasis is limited. OBJECTIVE: To estimate the association between frequency of adding salt to foods and risk of psoriasis. METHODS: We conducted a prospective cohort study of 433,788 participants from the UK Biobank. Hazard ratios (HRs) and their 95 % confidence intervals (CIs) for risk of psoriasis in relation to frequency of adding salt to foods were estimated using multivariable Cox proportional hazards models. We further evaluated the joint association of adding salt to foods and genetic susceptibility with risk of psoriasis. We conducted a mediation analysis to assess how much of the effect of adding salt to foods on risk of psoriasis was mediated through several selected mediators. RESULTS: During a median of 14.0 years of follow-up, 4279 incident cases of psoriasis were identified. In the multivariable-adjusted model, a higher frequency of adding salt to foods was significantly associated with an increased risk of psoriasis ("always" versus "never/rarely" adding salt to foods, HR = 1.25, 95 % CI: 1.10, 1.41). The observed positive association was generally similar across subgroups. In the joint association analysis, we observed that participants with a high genetic risk (above the second tertile) and the highest frequency of adding salt to foods experienced 149 % higher risk of psoriasis, when compared with participants with a low genetic risk (below the first tertile) and the lowest frequency of adding salt to foods (HR = 2.49, 95 % CI: 2.05, 3.02). Mediation analysis revealed that 1.8 %-3.2 % of the positive association between frequency of adding salt and risk of psoriasis was statistically significantly mediated by obesity and inflammatory biomarkers such as C-reactive protein and systemic immune-inflammation index (all P values < 0.004). CONCLUSIONS: Our study demonstrated a positive association between frequency of adding salt to foods and risk of psoriasis. The positive association was independent of multiple other risk factors, and may be partially mediated through obesity and inflammation.

Is high salt intake inducing obesity via production of cortisol? A novel working hypothesis and pilot study.

PURPOSE: Evidence is growing that high salt intake is an independent risk factor for obesity, but the mechanisms are unknown. Our novel working hypothesis is that high salt intake drives cortisol production, which in turn, drives obesity. The current study aimed to demonstrate an acute cortisol response following a single high salt meal. METHODS: Eight participants (age 30.5 ± 9.8 years [mean ± SD], 50% female), consumed high salt (3.82 g; 1529 mg sodium) and low salt (0.02 g; 9 mg sodium) meals in a randomized cross-over design. RESULTS: Urinary and salivary cortisol and plasma adrenocorticotropic hormone (ACTH) demonstrated order effects. When high salt was given second, there was a peak above baseline for urinary cortisol (26.3%), salivary cortisol (9.4%) and plasma ACTH (4.1%) followed by a significant decline in each hormone (treatment*time, F[9, 18] = 2.641, p = 0.038, partial η2 = 0.569; treatment*time, F[12, 24] = 2.668, p = 0.020, partial η2 = 0.572; treatment*time, F[12, 24] = 2.580, p = 0.023, partial η2 = 0.563, respectively), but not when high salt was given first (p > 0.05 for all). CONCLUSION: These intriguing findings provide partial support for our hypothesis and support a need for further research to elucidate the role of high salt intake in cortisol production and, in turn, in the aetiology of obesity. TRIAL REGISTRATION NUMBER: ACTRN12623000490673; date of registration 12/05/2023; retrospectively registered.

Hypertension status and its risk factors in highlanders living in Ganzi Tibetan Plateau: a cross-sectional study.

BACKGROUND: The updated status of hypertension and its risk factors are poorly evaluated in Tibetan highland areas. We initiated a large-scale cross-sectional survey to provide updated status of hypertension and its risk factors (especially salt intake) in the Ganzi Tibetan Plateau, China. METHODS: Stratified multistage random sampling was performed to obtain a representative sample of 4,036 adult residents from 4 counties in the Ganzi Tibetan area. The whole survey population was used to present the epidemiology and risk factors of hypertension. The participants with blood and urine biochemistry data were used to analyze the relationship between salt intake parameters and hypertension. RESULTS: Stratified multistage random sampling was performed to obtain a representative sample of 4,036 adult residents. The overall prevalence rate of hypertension was 33.5% (the age-adjusted prevalence rate was 28.9%). A total of 50.9% of the hypertensive patients knew their conditions; 30.1% of them received antihypertensive treatment; and 11.2% of them had their blood pressure controlled. Age, male sex, living altitude ≥ 3500 m, overweight and abdominal obesity were positively correlated with hypertension. In addition, the adjusted odds ratio (OR) for hypertension was 1.33 (95% CI: 1.01-1.74) for drinking tea with salt, and 1.51 (95% CI: 1.32-1.72) for per SD increase in the estimation of 24-hour urinary sodium excretion (e24hUSE). Furthermore, per 100mmol/day increase in e24hUSE was associated with elevation of blood pressure (+ 10.16, 95% CI: 8.45-11.87 mmHg for SBP; +3.83, 95% CI: 2.74-4.93 mmHg for DBP) in this population. CONCLUSIONS: Our survey suggests a heavy disease burden of hypertension in the Ganzi Tibetan Plateau. Age, male sex, altitude of residence ≥ 3500 m, overweight, abdominal obesity, and excessive salt intake (shown as drinking tea with adding salt and a higher level of e24hUSE) all increased the risk of hypertension in this highland area.

Low-Chloride Diet Prevents the Development of Arterial Hypertension and Protects Kidney Function in Angiotensin II-Infused Mice.

INTRODUCTION: A comprehensive pathophysiological mechanism to explain the relationship between high-salt intake and hypertension remains undefined. Evidence suggests that chloride, as the accompanying anion of sodium in dietary salt, is necessary to develop hypertension. We evaluated whether reducing dietary Cl- while keeping a standard Na+ intake modified blood pressure, cardiac hypertrophy, renal function, and vascular contractility after angiotensin II (AngII) infusion. METHODS: C56BL/6J mice fed with standard Cl- diet or a low-Cl- diet (equimolar substitution of Cl- by a mixture of Na+ salts, both diets with standard Na+ content) received AngII (infusion of 1.5 mg/kg/day) or vehicle for 14 days. We measured systolic blood pressure (SBP), glomerular filtration rate (GFR), natriuretic response to acute saline load, and contractility of aortic rings from mice infused with vehicle and AngII, in standard and low-Cl- diet. RESULTS: The mice fed the standard diet presented increased SBP and cardiac hypertrophy after AngII infusion. In contrast, low-Cl- diet prevented the increase of SBP and cardiac hypertrophy. AngII-infused mice fed a standard diet presented hampered natriuretic response to saline load, meanwhile the low-Cl- diet preserved natriuretic response in AngII-infused mice, without change in GFR. Aortic rings from mice fed with standard diet or low-Cl- diet and infused with AngII presented a similar contractile response. CONCLUSION: We conclude that the reduction in dietary Cl- as the accompanying anion of sodium in salt is protective from AngII pro-hypertensive actions due to a beneficial effect on kidney function and preserved natriuresis.

Inadequate Dietary Education and Poor Adherence to a High Protein, Low Sodium Diet in Cirrhosis: Mixed Methods Approach.

BACKGROUND: Malnutrition in cirrhosis is associated with poor outcomes, leading to guidelines for a high protein, low sodium diet; however, there is no guidance regarding the implementation of diet education in clinical practice. METHODS: A mixed methods study enrolled 21 patients with cirrhosis and their caregivers. Semi-structured interviews on barriers and facilitators of dietary education and adherence were conducted. Demographic and clinical data were obtained, along with quantitative measures of dietary adherence, including 24-h food recall and spot urine sodium. Combined deductive and inductive coding was used to identify qualitative themes, along with a quantitative assessment of interviews. Quantitative data was reported using descriptive statistics with frequencies, mean and confidence intervals. RESULTS: Participants were mostly male (16/21) with a mean age 57.8 years (SE 2.8) and MELD-Na 9 (SE 1.2). 4 themes emerged: 1. More than 50% of participants and caregivers endorsed no or inadequate diet education 2. They reported mostly negative experiences with dietary adherence with largest impact on social life 3. Facilitators of adherence included the presence of household support and fear of complications of cirrhosis 4. Overwhelmingly desired non-generic handouts and information. Dietary adherence was poor with only one participant meeting protein and sodium requirements based on food recall. Four participants who adhered to < 2000 mg sodium had inadequate daily caloric intake. CONCLUSIONS: Dietary education is inadequate, and adherence to dietary recommendations is poor in patients with cirrhosis. Future studies should use these barriers and facilitators for intervention development.

Associations between estimation of salt intake and salt-restriction spoons and hypertension status in patients with poorly controlled hypertension: a community-based study from Huzhou City, Eastern China.

BACKGROUND: As the prevalence of hypertension increases in China, it is advised to use salt-restriction spoons (SRS) as a lifestyle modification. This study aimed to examine the associations between estimated salt consumption, SRS usage, and the hypertension status in individuals with poorly controlled hypertension. METHODS: Data was collected in Huzhou City, Zhejiang Province, in 2021 using convenience sampling. The analysis involved ordinal logistic regression and restricted cubic splines to assess the relevant factors. RESULTS: The study found that 73.34% of the 1215 patients had uncontrolled blood pressure (BP). Urinary excretion was assessed through the utilization of the Kawasaki, INTERSALT, and Tanaka formulas. The outcomes of these three methodologies revealed average daily sodium excretion values of 208.70 (65.65), 154.78 (33.91), and 162.61 (40.87) mmol, respectively. The prevalence of utilizing SRS was found to be 37.78% in this study. Despite the acknowledgment among SRS users of the potential hazards associated with excessive salt consumption, there exists a contradictory pattern of attitudes and behaviors concerning salt reduction. Among individuals with different levels of salt intake (quartiles 1-4, Q1 vs Q4), there was a positive association between limiting salt and hypertension status when controlling for other variables (Kawasaki adjusted OR = 0.58, 95% CI = 0.43-0.79; INTERSALT adjusted OR = 0.62, 95% CI = 0.41-0.92; Tanaka adjusted OR = 0.61, 95% CI = 0.45-0.92, p < 0.05). Our research also revealed that using or used SRS was a protective factor for blood BP control (adjusted OR = 0.79, 95% CI = 0.64-0.99, P < 0.05). The restricted cubic spline plots illustrated a monotonic upward relationship between estimated 24-h urinary Na and BP (P-overall association < 0.05; P-non-linear association > 0.05). CONCLUSIONS: The use of dietary SRS could result in decrease in daily salt intake for BP control in patients with poorly controlled hypertension. To reduce the impact of high BP in China, additional studies are required to create interventions that can enhance the results for patients.

Effects of salt reduction education from a salt questionnaire on inter-dialysis weight gain in patients on hemodialysis.

BACKGROUND: Heart failure is the leading cause of death in patients undergoing hemodialysis (HD), with fluid overload being the most common cause. Therefore, it is important for patients undergoing HD to reduce salt intake. We recently developed a highly accurate and simple self-administered salt questionnaire. Using this salt questionnaire, we aimed to determine whether salt intake and inter-HD weight gain decrease when patients with HD are instructed to reduce their salt intake. METHODS: Seventy-eight outpatients at a maintenance HD facility were assessed for dietary salt intake using a salt questionnaire. After one month of dietary guidance, salt intake was assessed again using the salt questionnaire. RESULTS: The mean age of the patients was 72.2 ± 11.9 years; 47 (60.3%) were men, 23 had diabetic nephropathy as the primary disease, and the median HD vintage was 74 months. Salt intake significantly decreased from 8.41 ± 2.43 g/day before the salt questionnaire intervention to 7.67 ± 2.60 g/day after the intervention (p = 0.010). Changes in salt intake before and after the intervention were significantly positively correlated with changes in weight gain before the start of HD sessions with an interval of 2 days (r = 0.24, p = 0.037). Furthermore, changes in salt intake significantly and positively correlated with changes in weight gain after adjusting for age, sex, and dry weight. CONCLUSION: The salt questionnaire may be an effective tool for reducing salt intake and controlling weight gain during HD.

Twenty-four hour urinary sodium and potassium excretion in adult population of Slovenia: results of the Manjsoli.si/2022 study.

OBJECTIVE: The objective of study was to assess 24-h urinary Na and K excretion and estimate the average salt and K intakes in a nationally representative sample of the adult population of Slovenia. DESIGN: A nationally representative cross-sectional study was conducted in four stages between September and November 2022: study questionnaire, physical measurements, 24-h urine collection and laboratory analysis. SETTING: Slovenia. PARTICIPANTS: We invited 2000 adult, non-institutionalised inhabitants of Slovenia, aged between 25 and 64 years. A stratified two-staged sample was selected from this population by the Statistical Office of Slovenia, using sampling from the Central Population Register. According to the WHO methodology, additional eligibility criteria were screened before participating. A total of 518 individuals participated in all four stages of the study, resulting in a response rate of 30 %. RESULTS: The mean 24-h urinary Na excretion was 168 mmol/d (95 % CI 156, 180), which corresponds to a mean estimated intake of 10·3 g salt/d (95 % CI 9·6, 11·1). Mean 24-h urinary K excretion was 65·4 mmol/d (95 % CI 63·2, 67·5), and the estimated mean K intake was 2·93 g/d (95 % CI 2·84, 3·03). There were statistically significant differences in mean intakes between males and females. The mean sodium-to-potassium ratio was 2·7 (95 % CI 2·5, 2·8). CONCLUSIONS: The study results highlighted that the salt intake in the adult population of Slovenia remains much higher than recommended by the WHO, and K intakes are insufficient, as most participants did not meet the recommendations.

No change in 24-h sodium intake estimated from spot urine in Norwegian adults from 2006 to 2019: the population-based Trøndelag Health Study (HUNT).

OBJECTIVE: Monitoring time trends in salt consumption is important for evaluating the impact of salt reduction initiatives on public health outcomes. There has so far not been available data to indicate if salt consumption in Norway has changed during the previous decade. We aimed to assess whether average 24-h salt intake estimated from spot urine samples in the adult population of mid-Norway changed from 2006-2008 to 2017-2019 and to describe variations by sex, age and educational level. DESIGN: Repeated cross-sectional studies. SETTING: The population-based Trøndelag Health Study (HUNT). PARTICIPANTS: In each of two consecutive waves (HUNT3: 2006-2008 and HUNT4: 2017-2019), spot urine samples were collected from 500 men and women aged 25-64 years, in addition to 250 men and women aged 70-79 years in HUNT4. Based on spot urine concentrations of Na, K and creatinine and age, sex and BMI, we estimated 24-h Na intake using the International Cooperative Study on Salt and Blood Pressure (INTERSALT) equation for the Northern European region. RESULTS: Mean (95 % CI) estimated 24-h salt intakes in men were 11·1 (95 % CI 10·8, 11·3) g in HUNT3 and 10·9 (95 % CI 10·6, 11·1) g in HUNT4, P = 0·25. Corresponding values in women were 7·7 (95 % CI 7·5, 7·9) g and 7·7 (95 % CI 7·5, 7·9) g, P = 0·88. Mean estimated salt intake in HUNT4 decreased with increasing age in women, but not in men, and it did not differ significantly across educational level in either sex. CONCLUSIONS: Estimated 24-h salt intake in adult men and women in mid-Norway did not change from 2006-2008 to 2017-2019.

Characteristics of and changes in the cardiometabolic measures of Japanese workers grouped according to their vegetables and salt intake through workplace cafeteria meals.

OBJECTIVE: This study aimed to objectively evaluate the diet consumed in a workplace cafeteria to group Japanese workers according to vegetables and salt intake and estimate the association of these groups with changes in cardiometabolic measurements. DESIGN: This longitudinal observational study estimated the food and nutrient intake of Japanese workers from data recorded in the cafeteria system of their workplace. The primary outcomes included cardiometabolic measures obtained via regular health check-ups conducted at the workplace. The participants were divided into four groups according to high or low vegetables and salt intake based on their respective medians and the association of each group with cardiometabolic measurement changes was estimated using robust regression with MM-estimation. SETTING: A Japanese automobile manufacturing factory. SUBJECTS: The study included 1,140 men and women workers with available cafeteria and health check-up data. RESULTS: An inverse marginal association was observed between changes in triglyceride levels and high vegetables and low salt intake (ß: -9.93, 95% confidence interval [CI]: -20.45, 0.59, p: 0.065) with reference to low vegetables and high salt intake. This association was stronger in participants who used the cafeteria more frequently (>71 days; ß: -13.55, 95% CI: -25.51, -1.60, p: 0.027). CONCLUSIONS: The participants in the higher vegetables and lower salt intake group were more likely to exhibit decreased triglyceride levels. These findings encourage using workplace cafeteria meals to promote the health of workers.

Effect of educational intervention based on the theory of planned behavior (TPB) on amount of salt intake in pregnant women with PreHypertension.

BACKGROUND: Prehypertension is one of the common disorders during pregnancy. Reducing salt intake is among the best cost-effective interventions to reduce the risk of hypertension. The present study aimed to explore the effect of an educational intervention based on the Theory of Planned Behavior (TPB) on amount of salt consumed by prehypertensive pregnant women. METHODS: The present quasi-experimental study was conducted in 2022 on 61 prehypertensive pregnant women visiting the Comprehensive Health Services Centers in Birjand, Iran. Pregnant women were selected through a convenience sampling method and randomly assigned to intervention and control groups. A blood pressure test and a 24-hour urine test were taken in 3 stages (before, immediately after, and one month after the intervention). A reliable and valid questionnaire based on the TPB was used to measure the cognitive variables. The intervention program included three training sessions based on the TPB held on an online platform (WhatsApp social network). Data were analyzed using repeated measures ANOVA and longitudinal marginal model with the GEE approach in SPSS19. The significance level for all statistical tests was set at p < 0 0.05. RESULTS: After intervention, the mean score of perceived behavioral control (p = 0.02), intention (p = 0.004), and salt consumption behavior (p = 0.03) increased significantly in the intervention group, and the mean score of systolic blood pressure (p < 0.001) and diastolic blood pressure (P < 0.01) decreased significantly in this group. In the control group, a statistically significant difference was observed in the systolic and diastolic blood pressure of the subjects (p < 0.01). However, the score of attitude, subjective norms, perceived behavioral control, intention, salt consumption behavior and the daily salt intake did not show a statistically significant difference over time (P < 0.05). CONCLUSION: The present findings showed that the perceived behavioral control, intention, behavior, systolic and diastolic blood pressure can be modifiable variables to improve the amount of salt consumed by pre-hypertensive pregnant women. Therefore, we recommend that the present model be used to develop interventions to improve health indicators in pregnant women as a highly susceptible group in society.

[Sodium depletion assessed by the urinary sodium/creatinine ratio in monitoring cystic fibrosis patients]. / Déplétion sodée évaluée par le ratio sodium/créatinine urinaire dans le suivi des patients atteints de mucoviscidose.

As a result of excessive salt loss, cystic fibrosis patients are at risk of dehydration, especially in hot weather. The urinary sodium/creatinine ratio is an easy and noninvasive tool for assessing whether dietary salt intake is adequate, whatever the patient's age. Recently, new reference values have been established, adapted to the patient's age. The objectives of this study are to investigate the impact of these new standards on the diagnosis of inadequate sodium intake and the variation in this ratio as a function of body mass index (BMI), outdoor temperature and the use of modulator therapy of CFTR protein. The present study included 40 patients and 335 urine samples. Adapting the urinary sodium/creatinine ratio with the new reference values reduced the number of patients with sodium deficiency by 11.8%. However, there were no significant differences in BMI, lung function or outdoor temperature between the sodium deficient and non-deficient groups. The CFTR modulator-treated group had a better mean urinary sodium/creatinine ratio compared with the group without modulators (p = 0.01), However, larger-scale studies are needed to provide a definitive answer to this question.

Suite à des pertes excessives en sel, les patients atteints de mucoviscidose sont à risque de déshydratation, surtout lors de fortes chaleurs. Le ratio sodium/créatinine urinaire est un outil simple et non invasif permettant d'évaluer l'adéquation des apports en sel dans l'alimentation du patient quel que soit son âge. Récemment, de nouvelles valeurs de référence ont été établies en fonction de l'âge. Les objectifs de cette étude sont d'étudier la répercussion de ces nouvelles normes sur le constat d'un apport sodé insuffisant pour le patient ainsi que la variation de ce ratio en fonction de l'indice de masse corporelle (IMC), de la température extérieure et de la prise d'un modulateur de la protéine CFTR. Cette étude comporte 40 patients et un total de 335 prélèvements urinaires. L'adaptation du ratio sodium/créatinine urinaire permet de réduire de 11,8 % le nombre de patients en déficit sodé. Il n'y a, par contre, pas de différences significatives concernant l'IMC, la fonction respiratoire et les températures extérieures, entre les groupes avec ou sans déficit sodé. Le groupe traité par un modulateur de la protéine CFTR a un meilleur ratio sodium/créatinine urinaire moyen en comparaison au groupe sans ce traitement (p = 0,01). Cependant, des études à plus large échelle sont nécessaires pour répondre de façon formelle à la question.

Excessive salt intake reduces bone density in the general female population.

BACKGROUND: Osteoporosis is a multifactorial disorder in which nutrition is associated with its onset and progression. Excessive salt intake is closely associated with the onset and progression of various diseases, such as osteoporosis and hypertension. We investigated the effects of dietary salt intake on bone density in the general female population. METHODS: In 884 female participants (60.1 ± 10.1 years old) who visited our hospital for an annual physical checkup, salt intake (g/day) was assessed using a spot urine sample, and bone density was evaluated as a speed of sound (m/s) of ultrasonic pulses in a calcaneus by quantitative ultrasound. We investigated the relationship between bone density and salt intake and the differences in bone density or salt intake between the presence and absence of lifestyle-related diseases such as hypertension, diabetes mellitus and dyslipidaemia. RESULTS: The average bone density and salt intake were 1497 ± 26 m/s and 8.5 ± 1.8 g/day, respectively. Univariate and multivariate regression analyses revealed that bone density was significantly negatively associated with salt intake. Bone density was lower, and salt intake was higher in participants with hypertension, diabetes mellitus and dyslipidaemia than in those without. After adjusting for age, hypertension, diabetes mellitus and dyslipidaemia, bone density was negatively correlated with salt intake. CONCLUSIONS: We confirmed that excessive salt intake reduces bone density independently of age and lifestyle-related diseases in the general female population. Since dietary salt intake is a modifiable factor, osteoporosis can be prevented by dietary intervention, including salt reduction.

Iodine intake assessment in the staff of a Porto region university (Portugal): the iMC Salt trial.

PURPOSE: Iodine deficiency disorder (IDD) is an ongoing worldwide recognized problem with over two billion individuals having insufficient iodine intake. School-aged children and pregnant women are often target groups for epidemiological studies, but there is a lack of knowledge on the general adult population. The aim of this study was to assess the iodine status among a Portuguese public university staff as a proxy for the adult working population. METHODS: The population study covered 103 adults within the iMC Salt randomized clinical trial, aged 24-69 years. Urinary iodine concentration was measured spectrophotometrically using the Sandell-Kolthoff reaction. Iodine food intake was assessed using a 24-h dietary recall. The contribution of discretionary salt to the iodine daily intake was assessed through 24-h urinary sodium excretion (UIE) and potentiometric iodine determination of household salt. RESULTS: The mean urine volume in 24 h was 1.5 L. The median daily iodine intake estimated from 24-h UIE was 113 µg/day, being lower among women (p < 0.05). Only 22% of participants showed iodine intake above the WHO-recommended cutoff (150 µg/day). The median daily iodine intake estimated from the 24-h dietary recall was 58 µg/day (51 and 68 µg/day in women and men, respectively). Dairy, including yoghurt and milk products, were the primary dietary iodine source (55%). Iodine intake estimated from 24-h UIE and 24-h dietary recall was moderately correlated (Spearman rank correlation coefficient r = 0.34, p < 0.05). The average iodine concentration in household salt was 14 mg I/kg, with 45% of the samples below the minimum threshold preconized by WHO (15 mg I/kg). The contribution of discretionary salt to the daily iodine intake was around 38%. CONCLUSION: This study contributes new knowledge about iodine status in Portuguese working adults. The results revealed moderate iodine deficiency, particularly in women. Public health strategies and monitoring programs are needed to ensure iodine adequacy in all population groups.

Sodium intake and urinary losses in children on dialysis: a European multicenter prospective study.

BACKGROUND: Sodium (Na) balance is unexplored in dialyzed children. We assessed a simplified sodium balance (sNaB) and its correlates in pediatric patients receiving maintenance dialysis. METHODS: Patients < 18 years old on hemodialysis (HD) or peritoneal dialysis (PD) in six European Pediatric Dialysis Working Group centers were recruited. sNaB was calculated from enteral Na, obtained by a 3-day diet diary, Na intake from medications, and 24-h urinary Na (uNa). Primary outcomes were systolic blood pressure and diastolic blood pressure standard deviation scores (SBP and DBP SDS), obtained by 24-h ambulatory blood pressure monitoring or office BP according to age, and interdialytic weight gain (IDWG). RESULTS: Forty-one patients (31 HD), with a median age of 13.3 (IQR 5.2) years, were enrolled. Twelve patients (29.3%) received Na-containing drugs, accounting for 0.6 (0.7) mEq/kg/day. Median total Na intake was 1.5 (1.1) mEq/kg/day, corresponding to 60.6% of the maximum recommended daily intake for healthy children. Median uNa and sNaB were 0.6 (1.8) mEq/kg/day and 0.9 (1.7) mEq/kg/day, respectively. The strongest independent predictor of sNaB in the cohort was urine output. In patients receiving HD, sNaB correlated with IDWG, pre-HD DBP, and first-hour refill index, a volume index based on blood volume monitoring. sNaB was the strongest predictor of IDWG in multiple regression analysis (ß = 0.63; p = 0.005). Neither SBP SDS nor DBP SDS correlated with sNaB. CONCLUSIONS: Na intake is higher than uNa in children on dialysis, and medications may be an important source of Na. sNaB is best predicted by urine output in the population, and it is a significant independent predictor of IDWG in children on HD. A higher resolution version of the Graphical abstract is available as Supplementary information.

Deleterious effect in endothelin receptor-mediated coronary artery smooth muscle contractility in high-salt diet rats.

BACKGROUND AND AIMS: High-salt diet has been suggested to increase the risk of heart disease. However, the mechanisms underlying coronary artery tension dysfunction caused by high-salt diet are unclear. Previous studies have shown that coronary artery spasm is often induced by endothelin-1 (ET-1) and thromboxane, leading to myocardial ischemia, while the store-operated Ca2+ entry (SOCE) function of coronary smooth muscle is very important in this process. METHODS AND RESULTS: Tension measurements of endothelium-denuded coronary artery ring segments showed that vasocontraction induced by U46619, ET-1, orSTIM1/Orai1-mediated SOCE was significantly lower in 4% high-salt diet rats than in control rats fed a regular diet. The results of western blotting and immunohistochemistry assays showed lower expression levels of endothelial receptors ETA and ETB, STIM1 and Orai1 in coronary artery of high-salt intake rats compared with control rats. Fibrosis was observed by using Masson's trichrome staining and picrosirius red staining. The plasma ET-1 concentration in high-salt diet rats was significantly higher than that of controls. The interventricular septum and posterior wall of high-salt diet rats were significantly thickened. CONCLUSION: Our findings indicated that coronary artery tension was significantly decreased in 4% high-salt diet rats and that this decrease may be due to the change of endothelin receptor and its downstream pathway SOCE related protein expression in coronary artery. Coronary fibrosis was observed in rats fed with high-salt diet. This study provides potential mechanistic insights into high-salt intake-induced heart disease.

Salt Restriction and Angiotensin-Converting Enzyme Inhibitor Improve the Responsiveness of the Small Artery in Salt-Sensitive Hypertension.

For salt-sensitive hypertension (SSH), salt restriction and angiotensin-converting enzyme (ACE) inhibitors are essential treatments, but their effect on the function of resistance arteries is unclear. Here, we present an intravital study to detect the effect of salt restriction and ACE inhibitors on the function of the mesenteric small artery (MSA) in SSH. Dahl salt-sensitive rats were randomized into the following groups: ACE inhibitor gavage, salt restriction, ACE inhibitor combined with salt restriction, and high-salt diet. After a 12-week intervention, the mesenteric vessels maintained their perfusion in vivo, and the changes in the diameter and blood perfusion of the MSAs to norepinephrine (NE) and acetylcholine (ACh) were detected. Switching from a high-salt diet to a low-salt diet (i.e., salt restriction) attenuated the vasoconstriction of the MSAs to NE and promoted the vasodilatation to ACh, while ACE inhibitor improved the vasodilatation more obviously. Pathologically, changes in local ACE, AT1R, and eNOS expression were involved in these processes induced by a high-salt diet. Our study suggests that salt restriction and ACE inhibitor treatment improve high salt intake-induced MSA dysfunction in SSH, and salt restriction is a feasible and effective treatment. Our findings may provide a scientific basis for the treatment of hypertension.

Excessive salt intake accelerates the progression of cerebral small vessel disease in older adults.

BACKGROUND: It is unclear whether excessive salt intake accelerates the progression of cerebral small vessel disease (CSVD). The major objective of this study was to investigate the harmful effect of excessive salt intake on the progression of CSVD in older individuals. METHODS: Between May 2007 and November 2010, 423 community-dwelling individuals aged 60 years and older were recruited from the Shandong area, China. Salt intake was estimated using 24-hour urine collection for 7 consecutive days at baseline. Participants were classified into low, mild, moderate and high groups according to the salt intake estimation. CSVD including white matter hyperintensities (WMHs), lacunes, microbleeds and an enlarged perivascular space (EPVS) were determined using brain magnetic resonance imaging. RESULTS: During an average of five years of follow-up, the WMH volume and WMH-to-intracranial ratio were increased in the four groups. However, the increasing trends in the WMH volume and WMH-to-intracranial ratio were significantly faster in the higher salt intake groups compared with the lower salt intake groups (Padjusted < 0.001). The cumulative hazard ratios of new-incident WMHs (defined as those with Fazekas scale scores ≥ 2), new-incident lacunes, microbleeds or an EPVS, as well as composites of CSVD, were respectively 2.47, 2.50, 3.33, 2.70 and 2.89 for the mild group; 3.72, 3.74, 4.66, 4.01 and 4.49 for the moderate group; and 7.39, 5.82, 7.00, 6.40 and 6.61 for the high group, compared with the low group after adjustment for confounders (Padjusted < 0.001). The risk of new-incident WMHs, lacunes, microbleeds or an EPVS, and composites of CSVD was significantly increased with each 1-standard-deviation increment in salt intake (Padjusted < 0.001). CONCLUSION: Our data indicates that excessive salt intake is an important and independent contributor to the progression of CVSD in older adults.

Increased cerebral vascular resistance underlies preserved cerebral blood flow in response to orthostasis in humans on a high-salt diet.

Cerebral blood flow autoregulation protects brain tissue from blood pressure variations and maintains cerebral perfusion pressure by changes in vascular resistance. High salt (HS) diet impairs endothelium-dependent vasodilation in many vascular beds, including cerebral microcirculation, and may affect vascular resistance. The aim of present study was to determine if 7-day HS diet affected the reactivity of middle cerebral artery (MCA) to orthostatic challenge in healthy human individuals, and if autoregulatory mechanisms and sympathetic neural regulation were involved in this phenomenon.Twenty-seven persons participated in study (F:21, M:6, age range 19-24). Participants consumed 7-day low-salt (LS) diet (< 2.3 g kitchen salt/day) and afterwards 7-day HS diet (> 11.2 g kitchen salt/day). Blood and urine analysis and anthropometric measurements were performed after each diet. Arterial blood pressure, heart rate and heart rate variability, and cerebral and systemic hemodynamic parameters were recorded simultaneously with transcranial Doppler ultrasound and The Task Force® Monitor in response to orthostatic test.Participants remained normotensive during HS diet. Following both, the LS and HS dietary protocols, mean cerebral blood flow (CBF), as well as the velocity time integral and diastolic blood pressure decreased, and cerebral pulsatility index increased after rising up. Importantly, cerebrovascular resistance significantly increased in response to orthostasis only after HS diet. Urine concentration of noradrenaline and vanillylmandelic acid, baroreflex sensitivity (BRS), and sympathetic neural control was significantly decreased in HS diet.Results suggest that CBF in response to orthostatic test was preserved in HS condition due to altered vascular reactivity of MCA, with increased cerebrovascular resistance and blunted BRS and sympathetic activity.