Sodium and potassium intake and risk of cardiovascular events and all-cause mortality: the Rotterdam Study

The Impact of 24 h Urinary Potassium Excretion on High-Density Lipoprotein Cholesterol and Chronic Disease Risk in Chinese Adults: A Health Promotion Study

BACKGROUND

Research into the pivotal role of potassium in chronic diseases and their comorbidities remains scarce. Our aim is to elucidate the relationship between potassium and chronic diseases, including comorbid conditions, and to provide evidence-based recommendations for potassium intake in patients.

METHODS

This study is anchored in a representative, population-based survey conducted in Zhejiang Province, China, in 2017, encompassing participants aged 18 to 69 years. Data collection included questionnaire responses, physical measurements, and biological samples, obtained through a multistage cluster random sampling method. A subset of 1496 participants provided complete 24 h urine samples.

RESULTS

The median age of the participants was 48.0 years (interquartile range [IQR] 24.0), with 51.1% being female, and hypertension was identified in more than one third (35.6%) of the participants. The prevalence of diabetes was approximately 9.0%, dyslipidemia was found in 34.2%, and microalbuminuria in 8.8%. The 24 h urinary excretion levels were 3613.3 mg/24 h (IQR 2161.7) for sodium and 1366.0 mg/24 h (IQR 824.9) for potassium, respectively. Potassium excretion exhibited an inverse relationship with blood pressure. Furthermore, a positive correlation was observed between potassium excretion and high-density lipoprotein cholesterol (HDL-C) levels, with an elevation of 0.03 mmol/L (95% confidence interval [CI] 0.00 to 0.05). In binary logistic regression analysis, individuals in the fourth quartile of potassium excretion (Q4) exhibited an odds ratio (OR) of 0.56 (95% CI 0.36-0.87) for hypertension compared to those in the first quartile (Q1). Urinary potassium excretion was inversely associated with low HDL-C levels, with Q4 individuals having 0.62 times the odds of having low HDL-C levels (OR, 0.62; 95% CI 0.39-1.00) compared to Q1.

CONCLUSIONS

Potassium excretion demonstrated a direct negative correlation with certain comorbidities. This study underscores the pivotal role of potassium in the management of chronic diseases and associated comorbidities, thereby highlighting the significance of potassium in both public health initiatives and clinical practice.

Association between admission serum potassium concentration and the island sign on cranial CT in HICH patients: a cross-sectional study

Objective

This study aimed to explore the correlation between serum potassium (K+) concentration upon admission and the presence of the Island Sign (IS) in cranial CT scans of patients diagnosed with Hypertensive Intracerebral Hemorrhage (HICH), including the potential presence of a non-linear relationship.

Methods

This investigation constituted a single-center cross-sectional study. We systematically gathered comprehensive general clinical characteristics, biological indicators, and imaging data from a cohort of 330 patients diagnosed with HICH. These patients received treatment within the neurosurgery department of Chongqing Emergency Medical Center during the period spanning from July 1, 2018, to July 7, 2023. Our primary objective was to scrutinize the potential connection between serum K+ concentration upon admission and the presence of the IS observed in cranial CT scans. To meticulously address this inquiry, we employed logistic regression modeling, thereby meticulously evaluating the correlation aforementioned. Moreover, in order to delve deeper into the intricacies of the relationship, we extended our analysis by employing a smoothed curve-fitting model to meticulously authenticate the potential non-linear interrelation between these two critical variables.

Results

In this investigation, a total of 330 patients diagnosed with HICH were ultimately enrolled, exhibiting an average age of 58.4 ± 13.1 years, comprising 238 (72.1%) males and 92 (27.9%) females. Among these participants, 118 individuals (35.7%) presented with the IS upon admission cranial CT scans, while 212 patients (64.3%) did not exhibit this characteristic. Upon comprehensive multifactorial adjustments, a non-linear association was uncovered between serum K+ concentration and the presence of IS. Notably, an inflection point was identified at approximately 3.54 mmol/L for serum K+ concentration. Prior to the patient's serum K+ concentration reaching around 3.54 mmol/L upon admission, a discernible trend was observed-every 0.1 mmol/L increment in serum K+ concentration was associated with an 8% decrease in the incidence of IS (OR: 0.914, 95% CI: 0.849-0.983, p = 0.015).

Conclusion

The findings of this study underscore a negative association between reduced serum K+ concentration upon admission and the occurrence of the IS on cranial CT scans among patients diagnosed with hypertensive cerebral hemorrhage. Furthermore, this negative correlation appears to manifest within the realm of a non-linear relationship. This study elucidates the potential significance of serum K+ concentration levels among patients with HICH, highlighting the role they play. Moreover, the maintenance of a physiological equilibrium in serum K+ concentrations emerges as a conceivable protective factor for individuals within the stroke population.

The Guidelines for use and promotion of low sodium salt in China

AIM

Both excessive intake of sodium and inadequate intake of potassium are associated with blood pressure elevation and subsequent increase in the risk of cardiovascular disease, which accounts for the largest number of deaths in China and worldwide. Low sodium salt, a mixture of mainly sodium chloride and potassium chloride, has shown its great potential as a promising population strategy for sodium intake reduction through multiple large-scale, multicenter, randomized controlled trials among populations including patients with cardiovascular disease, individuals with and without hypertension, older and younger adults, and men and women in China and other countries. This Guidelines aims to provide expert recommendations for promotion and use of low sodium salt in China, based on the current available scientific evidence regarding the effectiveness, safety, cost-effectiveness, and acceptability of low sodium salts in various population groups and different application scenarios. The suggestions to key stakeholders are also made.

METHODS

A working group, an expert review committee and an advisory committee were established to be responsible for formulating the guidelines' scope and key questions to be addressed, for searching, synthesizing, and evaluating research evidence, proposing and reviewing the recommendations. The consensus on the final recommendations was reached using the GRADE grid method.

RESULTS

The working group summarized current available evidence of salt substitution regarding its effectiveness, safety, cost-effectiveness, acceptability, availability, suitability, etc. The Guidelines provided six recommendations advising different populations how to use low sodium salt, four recommendations on the application of low sodium salts in different scenarios, and five suggestions for key stakeholders to promote salt substitution.

CONCLUSION

The first evidence-based guidelines on promotion and use of low sodium salts covers all key questions in relevance and would play a critical role in prevention and control of hypertension and cardiovascular disease in China and worldwide.

Potassium - a scoping review for Nordic Nutrition Recommendations 2023

Potassium (K) is an essential mineral that is necessary for normal cell and membrane function and for maintaining both fluid balance and acid-base balance. Potassium is furthermore very important for normal excitation, for example in nerves and muscle. It is widely available in several food products, with the most important dietary sources being potatoes, fruits, vegetables, cereal and cereal products, milk and dairy products, and meat and meat products. Potassium deficiency and toxicity is rare in healthy people, but dietary potassium is associated with other health outcomes. Results from observational studies have shown that a potassium intake above 3500 mg/day (90 mmol/day) is associated with a reduced risk of stroke. Similarly, intervention studies provide evidence that this level of potassium intake has a beneficial effect on blood pressure, particularly among persons with hypertension and in persons with a high sodium intake (>4 g/day, equivalent to >10 g salt/day).

Development and Validation of a Prediction Model for Incident Hypothyroidism in a National Chronic Kidney Disease Cohort

CONTEXT

Hypothyroidism is a common yet under-recognized condition in patients with chronic kidney disease (CKD), which may lead to end-organ complications if left untreated.

OBJECTIVE

We developed a prediction tool to identify CKD patients at risk for incident hypothyroidism.

METHODS

Among 15 642 patients with stages 4 to 5 CKD without evidence of pre-existing thyroid disease, we developed and validated a risk prediction tool for the development of incident hypothyroidism (defined as thyrotropin [TSH] > 5.0 mIU/L) using the Optum Labs Data Warehouse, which contains de-identified administrative claims, including medical and pharmacy claims and enrollment records for commercial and Medicare Advantage enrollees as well as electronic health record data. Patients were divided into a two-thirds development set and a one-third validation set. Prediction models were developed using Cox models to estimate probability of incident hypothyroidism.

RESULTS

There were 1650 (11%) cases of incident hypothyroidism during a median follow-up of 3.4 years. Characteristics associated with hypothyroidism included older age, White race, higher body mass index, low serum albumin, higher baseline TSH, hypertension, congestive heart failure, exposure to iodinated contrast via angiogram or computed tomography scan, and amiodarone use. Model discrimination was good with similar C-statistics in the development and validation datasets: 0.77 (95% CI 0.75-0.78) and 0.76 (95% CI 0.74-0.78), respectively. Model goodness-of-fit tests showed adequate fit in the overall cohort (P = .47) as well as in a subcohort of patients with stage 5 CKD (P = .33).

CONCLUSION

In a national cohort of CKD patients, we developed a clinical prediction tool identifying those at risk for incident hypothyroidism to inform prioritized screening, monitoring, and treatment in this population.

Potassium status and the risk of type 2 diabetes, cardiovascular diseases, and mortality: a meta-analysis of prospective observational studies

Epidemiological evidence on the association between potassium and cardiometabolic outcomes remains controversial. This study aimed to examine associations of dietary intake and blood and urinary levels of potassium with risk of type 2 diabetes, cardiovascular disease (CVD), and mortality. Relevant prospective studies were retrieved through a comprehensive search of four electronic databases up to July 1, 2023. Random-effects models were used to pool the study-specific relative risks (RRs) and 95% confidence intervals (CIs). Fifty-six studies were included in this meta-analysis. A higher intake of potassium was significantly associated with a 16% lower risk of CVD (RR: 0.84, 95% CI: 0.78-0.90). Similar inverse associations were also observed between potassium intake and mortality. Each 1.0 g/d increment in potassium intake was associated with a decreased risk of CVD (RR: 0.85, 95% CI: 0.80-0.91) and all-cause mortality (RR: 0.93, 95% CI: 0.88-0.99). For blood and urinary potassium levels, higher level of blood potassium increased the risk of all-cause mortality by 23% (RR: 1.23, 95% CI: 1.11-1.36). The association of blood potassium levels with mortality was nonlinear (Pnon-linearit<0.001). However, urinary potassium levels were inversely associated with the risk of all-cause mortality (RR: 0.84, 95% CI: 0.76-0.93). Our findings support the benefits of moderate potassium consumption for primary prevention of chronic diseases and premature death.

Effect of freezing-thawing on the quality changes of large yellow croaker treated by low-salt soaking during frozen storage

Introduction

The production of the large yellow croaker has seasonal and regional characteristics, which is typically preserved on ice, possibly leading to its deterioration in a short time. Therefore, in this study, we focused on the effect of temperature fluctuation on the quality changes of the large yellow croaker during frozen storage.

Methods

In this experiment, the large yellow croaker was soaked in a low-salt solution, and physical and chemical properties, water-holding capacity, color, and protein characteristics of the muscle were investigated after repeated freeze-thaw (F-T) cycles and frozen storage.

Results and discussion

The results show the deterioration of muscle quality of large yellow croaker after low-salt treatment was lower than that of the salt-free soaking group. The salting treatment significantly (P < 0.05) enhanced the yield of large yellow croaker, which was 24.3% greater than the salt-free soaking group after 6 weeks of frozen storage. The microstructure of the salted muscle was more stable and maintained its cellular structure after F-T cycles and frozen storage. The b* value of the salt-free soaking group increased from b* value of the low-salt soaking group decreased from acceptable range. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis indicates the content of 17 kDa peptide decreased in the low-salt soaking group, and the peptides at 21 and 24 kDa increased during frozen storage. The results of the present study provide guidance for the optimal processing, transport, and storage of large yellow croaker, but the effect of salting on lipid oxidation and protein oxidation requires further study.

Association between dietary sodium, potassium, and the sodium-to-potassium ratio and mortality: A 10-year analysis

There is inconclusive evidence of the association between dietary sodium, potassium, and the sodium-to-potassium ratio and all-cause and cardiovascular disease mortality. To investigate the association between dietary sodium, potassium, and the sodium-to-potassium ratio and all-cause and cardiovascular disease mortality risks. Data from 143,050 adult participants were analyzed from prospective 10-year community-based cohort analysis. Dietary sodium, potassium, and the sodium-to-potassium ratio at baseline were assessed by a food frequency questionnaire. In Cox proportional hazards regression models, the association between dietary sodium, potassium, and their ratio and all-cause and cardiovascular disease mortality was estimated using hazard ratios and 95% confidence intervals, and their predictive ability as mortality predictors was evaluated using Harrell's c-index. During the mean (range) 10.1 (0.2-15.9) years of follow-up, 5,436 participants died, of whom 985 died of cardiovascular causes. After adjustment for age, sex, body mass index, alcohol intake, smoking, regular exercise, total calorie intake, dyslipidemia, hypertension, diabetes, chronic kidney diseases (CKDs), and potassium or sodium intake, respectively, sodium intake was unassociated with all-cause mortality whereas potassium intake was significantly associated inversely with all-cause (Quintile-5 vs. Quintile-1, hazard ratio, 95% confidence interval, 1.09, 0.97-1.22, and 0.79, 0.69-0.91, respectively). The sodium-to-potassium ratio was not significantly associated with all-cause mortality in the adjusted model, and similar trends were observed for cardiovascular disease mortality.

Comparative study of micronutrient content in soft rice beverages based on green and black tea

Soft beverages based on rice (“rice milk”) are hypoallergenic, increase immunity, supply the body with energy, and normalize the nervous system. Earlier, we developed soft rice beverage recipes based on boiled rice filtrate, green (black) tea water concentrate, stevia extract as a natural sweetener. Physico-chemical analysis of the content of micronutrients in soft rice-tea beverages was carried out. Comparative analysis of content of vitamins E (alpha-tocopherol) and C (ascorbic acid) showed that vitamins are presented in both types of beverages during production, but in different amounts. The rice beverage combined with green tea concentrate contains 1.33 times more potassium ions and 1.13 times less magnesium ions than the beverage based on black tea. The rice beverage combined with black tea contains 3.81 times more sodium ions compared to the beverage based on green tea. There were no significant differences in the number of magnesium ions. Both samples contained traces of manganese and iron ions. The produced soft rice-tea beverages with stevia extract could be recommended as a functional food.

Dietary Reference Intakes of sodium for Koreans: focusing on a new DRI component for chronic disease risk reduction

Sodium is a physiologically essential nutrient, but excessive intake is linked to the increased risk of various chronic diseases, particularly cardiovascular. It is, therefore, necessary to accomplish an evidence-based approach and establish the Korean Dietary Reference Intakes (KDRIs) index, to identify both the nutritional adequacy and health effects of sodium. This review presents the rationale for and the process of revising the KDRIs for sodium and, more importantly, establishing the sodium Chronic Disease Risk Reduction Intake (CDRR) level, which is a new specific set of values for chronic disease risk reduction. To establish the 2020 KDRIs for dietary sodium, the committee conducted a systematic literature review of the intake–response relationships between the selected indicators for sodium levels and human chronic diseases. In this review, 43 studies published from January 2014 to December 2018, using databases of PubMed and Web of Science, were finally included for evaluating the risk of bias and strength of evidence (SoE). We determined that SoE of the relationship between dietary sodium and cardiovascular diseases, cerebrovascular disease, and hypertension, was moderate to strong. However, due to insufficient scientific evidence, we were unable to establish the estimated average requirement and the recommended nutrient intake for dietary sodium. Therefore, the adequate intake of sodium for adults was established to be 1,500 mg/day, whereas the CDRR for dietary sodium was established at 2,300 mg/day for adults. Intake goal for dietary sodium established in the 2015 KDRIs instead of the tolerable upper intake level was not presented in the 2020 KDRIs. For the next revision of the KDRIs, there is a requirement to pursue further studies on nutritional adequacy and toxicity of dietary sodium, and their associations with chronic disease endpoint in the Korean population.

High Adherence to Mediterranean Diet Is Not Associated with an Improved Sodium and Potassium Intake

Prevention and control of hypertension and cerebro-cardiovascular diseases are associated with adequate sodium and potassium intake and adherence to a Mediterranean dietary pattern. The aim of this study was to assess the association between adherence to a Mediterranean diet (MD) and the excretion of sodium and potassium as surrogate measures of intake. This is a cross-sectional analysis as part of a larger study (the iMC SALT randomized controlled trial) among workers of a public university. A food frequency questionnaire was used to assess the adherence to MD, using the alternative Mediterranean diet (aMED) score; sodium and potassium excretions were estimated by 24-h urine collections. Sociodemographic and other lifestyle characteristics were also obtained. The associations between the adherence to MD and Na and K excretion were calculated by logistic regression, adjusting for confounding variables. From the 109 selected participants, seven were excluded considering urine screening and completeness criteria, leaving a final sample of 102 subjects (48% male, average age 47 years). Mean sodium and potassium excretion were 3216 mg/day and 2646 mg/day, respectively. Sodium and potassium excretion were significantly higher in men, but no differences were found according to different levels of MD adherence. In logistic regression analysis, sodium, potassium, and sodium-to-potassium ratio urinary excretion tertiles were not associated with MD adherence (low/moderate versus high), even after adjustment for confounding variables. A high adherence to MD was thus not associated with a different level of sodium and potassium intake.

Differing Nutrient Intake and Dietary Patterns According to the Presence of Hyper-Low-Density Lipoprotein Cholesterolemia or Hypertriglyceridemia

Dietary choices may have differing effects on low-density lipoprotein cholesterol or triglyceride levels. The aim of this study was to investigate daily nutrient intake and dietary patterns of individuals with hyper-low-density lipoprotein cholesterolemia (hLDL) and hypertriglyceridemia (hTG) in a large Korean population-based study using propensity score (PS) matching. This study used data from the Korea National Health and Nutrition Examination Survey. Propensity score values for the predicted probability of patients with hLDL or hTG were estimated using logistic regression analysis, with age, sex, body mass index, alcohol consumption, smoking status, physical activity status, hypertension, and diabetes. After PS matching, intake of carbohydrates (%) was significantly lower (p = 0.021), and intake of fats (%) and saturated fatty acids (%) was significantly higher in the hLDL group than in the non-hLDL group (p = 0.025 and p = 0.013, respectively). The percentage of individuals with a high score for the Korean Healthy Eating Index (KHEI) "whole grains" or "saturated fatty acids" components was higher in the non-hLDL group than in the hLDL group (p < 0.05 for both). Dietary sodium/potassium ratio was significantly higher in the hTG than in the non-hTG (p = 0.049). Our results suggest that individualized dietary information and counseling require consideration of a person's specific lipid levels.

Sodium and Potassium Intake, the Sodium to Potassium Ratio, and Associated Characteristics in Older Adults, NHANES 2011-2016

BACKGROUND

Sodium, potassium, and the balance between these 2 nutrients are associated with hypertension and cardiovascular disease, and prevalence of these conditions increases with age. However, limited information is available on these intakes among older adults.

OBJECTIVE

Our aim was to explore the socioeconomic and health factors associated with usual sodium and potassium intakes and the sodium to potassium (Na:K) ratio of older adults.

DESIGN

This was a cross-sectional, secondary analysis of the 2011-2012, 2013-2014, and 2015-2016 National Health and Nutrition Examination Survey.

PARTICIPANTS/SETTING

This study included the data of 5,104 adults 50 years and older, with at least one reliable 24-hour dietary recall and an estimated glomerular filtration rate ≥60 mL/min/1.73 m².

MAIN OUTCOME MEASURES

Sodium and potassium intake, as absolute intake, density (per 1,000 kcal) and ratio of Na:K intake.

STATISTICAL ANALYSES

We used t tests and χ² tests to examine significant differences in intakes on a given day by characteristics. Linear and logistic regression models were used to assess associations of socioeconomic and health characteristics with usual sodium and potassium intakes, determined using the National Cancer Institute method.

RESULTS

Only 26.2% of participants consumed <2,300 mg sodium (16.2% of men and 35.2% of women) and 36.0% of men and 38.1% of women consumed at least 3,400 mg and 2,600 mg of potassium, respectively. Fewer than one-third of participants consumed a Na:K ratio of <1.0. Women, those with lower blood pressure, and those with a lower body mass index were more likely to have a ratio <1.0.

CONCLUSIONS

Participants consumed too much sodium and not enough potassium, based on current recommendations. A higher Na:K ratio was significantly associated with established risk factors for cardiovascular disease. The study findings suggest that more research on cardiovascular health should include both sodium and potassium, as well as balance between these nutrients.

Dietary Potassium Intake and Mortality in a Prospective Hemodialysis Cohort

OBJECTIVES

Among hemodialysis patients, clinical practice guidelines recommend dietary potassium restriction given concerns about potential hyperkalemia leading to malignant arrhythmias and mortality. However, there are sparse data informing recommendations for dietary potassium intake in this population. We thus sought to examine the relationship between dietary potassium intake and death risk in a prospective cohort of hemodialysis patients.

DESIGN AND METHODS

Among 415 hemodialysis patients from the prospective "Malnutrition, Diet, and Racial Disparities in Chronic Kidney Disease" cohort recruited across 16 outpatient dialysis clinics, information regarding dietary potassium intake was obtained using Food Frequency Questionnaires administered over October 2011 to March 2015. We first examined associations of baseline dietary potassium intake categorized as tertiles with mortality risk using Cox regression. We then examined clinical characteristics associated with low dietary potassium intake (defined as the lowest tertile) using logistic regression.

RESULTS

In expanded case-mix Cox analyses, patients whose dietary potassium intake was in the lowest tertile had higher mortality (ref: highest tertile) (adjusted hazard ratio 1.74, 95% confidence interval 1.14-2.66). These associations had even greater magnitude of risk following adjustment for laboratory and nutritional covariates (adjusted hazard ratio 2.65, 95% confidence interval 1.40-5.04). In expanded case-mix restricted cubic spline analyses, there was a monotonic increase in mortality risk with incrementally lower dietary potassium intake. In expanded case-mix logistic regression models, female sex; higher serum bicarbonate; and lower dietary energy, protein, and fiber intake were associated with low dietary potassium intake.

CONCLUSIONS

In a prospective cohort of hemodialysis patients, lower dietary potassium intake was associated with higher mortality risk. These findings suggest that excessive dietary potassium restriction may be deleterious in hemodialysis patients, and further studies are needed to determine the optimal dietary potassium intake in this population.

The association of carotid artery atherosclerosis with the estimated excretion levels of urinary sodium and potassium and their ratio in Chinese adults

Background

Arterial stiffness is an independent cardiovascular risk factor. However, the association between sodium/potassium intake and vascular stiffness was inconsistent. Therefore, a large community-based cross-sectional study was performed to try and achieve more definitive conclusion.

Methods

Urinary sodium, potassium, and creatinine levels were tested in spot urine samples during physical examinations of each recruited participant. The 24-h estimated urinary sodium excretion (eUNaE) and estimated urinary potassium excretion (eUKE) levels were determined using the Kawasaki formula (used as a surrogate for intake). Carotid intima-media thickness (IMT) and plaques were measured using ultrasound.

Results

In 13,523 subjects aged 18–80 years, the relationships between carotid plaques and IMT with eUNaE, eUKE and their ratios were analyzed. Overall, 30.2% of participants were diagnosed with carotid artery plaques. The ratio of estimated sodium vs. potassium excretion (Na/K ratio) of the individuals with carotid artery plaques was significantly higher than that of participants without plaque (2.14 ± 0.73 vs. 2.09 ± 0.61, P < 0.01). After adjusting for age, gender, and other lifestyle covariates, a significant positive relation was found between carotid plaque and Na/K ratios (OR = 1.06, P < 0.05). In participants without plaque, a similar positive association was observed between Na/K ratios and increased bifurcation carotid IMT (β = 0.008, P < 0.01), especially in the females (P_interaction < 0.01).

Conclusions

In this study, in which sodium intake was estimated on the basis of measured urinary excretion, high estimated excretion levels of urinary sodium and/or low estimated excretion levels of urinary potassium might be associated with an increased presence of carotid atherosclerosis in Chinese individuals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-021-00710-8.

Geospatial Analysis of Sodium and Potassium Intake: A Swiss Population-Based Study

Inadequate sodium and potassium dietary intakes are associated with major, yet preventable, health consequences. Local public health interventions can be facilitated and informed by fine-scale geospatial analyses. In this study, we assess the existence of spatial clustering (i.e., an unusual concentration of individuals with a specific outcome in space) of estimated sodium (Na), potassium (K) intakes, and Na:K ratio in the Bus Santé 1992–2018 annual population-based surveys, including 22,495 participants aged 20–74 years, residing in the canton of Geneva, using the local Moran’s I spatial statistics. We also investigate whether socio-demographic and food environment characteristics are associated with identified spatial clustering, using both global ordinary least squares (OLS) and local geographically weighted regression (GWR) modeling. We identified clear spatial clustering of Na:K ratio, Na, and K intakes. The GWR outperformed the OLS models and revealed spatial variations in the associations between explanatory and outcome variables. Older age, being a woman, higher education, and having a lower access to supermarkets were associated with higher Na:K ratio, while the opposite was seen for having the Swiss nationality. Socio-demographic characteristics explained a major part of the identified clusters. Socio-demographic and food environment characteristics significantly differed between individuals in spatial clusters of high and low Na:K ratio, Na, and K intakes. These findings could guide prioritized place-based interventions tailored to the characteristics of the identified populations.

Salt Replacement Changed the Bacterial Community Composition and Physicochemical Characteristics of Sodium-Reduced Fermented Sausages during Fermentation and Ripening

The impact on fermented sausages with 25% replacement of the sodium chloride content by 14% potassium chloride, 10% calcium ascorbate and 1% calcium glutamate during fermentation and ripening was evaluated based on the bacterial community composition and physicochemical and sensory characteristic analysis. Our results showed that the use of salt replacement varied the composition of the bacterial community and reduced the diversity of that in sodium-reduced fermented sausages. Moreover, the decrease in pH and the moisture content of fermented sausages with salt replacement accelerated the drying and ripening processes. The texture profile and color analysis did not reveal marked differences between normal fermented sausages and sodium-reduced products with salt replacement; however, salt replacement reduced resilience and lightness of fermented sausages. In addition, as shown in the principal component analysis, the comprehensive parameters of the fermented sausages with salt replacement were similar to those of normal salt products. These results indicate that the complex blends of salt replacement have great potential to be used to produce sodium-reduced fermented sausages.

Dietary Potassium Intake and 20-Year All-Cause Mortality in Older Adults: The Rancho Bernardo Study

We examined the association between dietary potassium intake and all-cause and cause-specific mortality among community-dwelling older adults. Potassium intake was assessed with a food frequency questionnaire administered to 1,363 older adults (mean age 71.0 ± 10.6 years). Cox proportional hazard regressions estimated hazard ratios for sex-specific quintiles of calorie-adjusted potassium in relation to all-cause and cause-specific (cardiovascular disease, CVD, and stroke) mortality, adjusting for numerous covariates. There were 855 deaths (63% mortality) during the 20-year follow-up. Relative to the third quintile, potassium intake in the lowest quintile only was associated with increased risk of all-cause mortality (fully-adjusted hazard ratio 1.33; 95% CI 1.06, 1.67). Potassium intake was not significantly associated with CVD or stroke mortality. These results suggest that low potassium intake is associated with increased risk of mortality independent of overall health status. Ensuring adequate potassium in the diet may be an important strategy for reducing risk of earlier mortality among older adults.

Effects of low sodium diet versus high sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterol, and triglyceride

BACKGROUND

Recent cohort studies show that salt intake below 6 g is associated with increased mortality. These findings have not changed public recommendations to lower salt intake below 6 g, which are based on assumed blood pressure (BP) effects and no side-effects.

OBJECTIVES

To assess the effects of sodium reduction on BP, and on potential side-effects (hormones and lipids) SEARCH METHODS: The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials up to April 2018 and a top-up search in March 2020: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also contacted authors of relevant papers regarding further published and unpublished work. The searches had no language restrictions. The top-up search articles are recorded under "awaiting assessment."

SELECTION CRITERIA

Studies randomizing persons to low-sodium and high-sodium diets were included if they evaluated at least one of the outcome parameters (BP, renin, aldosterone, noradrenalin, adrenalin, cholesterol, high-density lipoprotein, low-density lipoprotein and triglyceride,.

DATA COLLECTION AND ANALYSIS

Two review authors independently collected data, which were analysed with Review Manager 5.3. Certainty of evidence was assessed using GRADE.

MAIN RESULTS

Since the first review in 2003 the number of included references has increased from 96 to 195 (174 were in white participants). As a previous study found different BP outcomes in black and white study populations, we stratified the BP outcomes by race. The effect of sodium reduction (from 203 to 65 mmol/day) on BP in white participants was as follows: Normal blood pressure: SBP: mean difference (MD) -1.14 mmHg (95% confidence interval (CI): -1.65 to -0.63), 5982 participants, 95 trials; DBP: MD + 0.01 mmHg (95% CI: -0.37 to 0.39), 6276 participants, 96 trials. Hypertension: SBP: MD -5.71 mmHg (95% CI: -6.67 to -4.74), 3998 participants,88 trials; DBP: MD -2.87 mmHg (95% CI: -3.41 to -2.32), 4032 participants, 89 trials (all high-quality evidence). The largest bias contrast across studies was recorded for the detection bias element. A comparison of detection bias low-risk studies versus high/unclear risk studies showed no differences. The effect of sodium reduction (from 195 to 66 mmol/day) on BP in black participants was as follows: Normal blood pressure: SBP: mean difference (MD) -4.02 mmHg (95% CI:-7.37 to -0.68); DBP: MD -2.01 mmHg (95% CI:-4.37, 0.35), 253 participants, 7 trials. Hypertension: SBP: MD -6.64 mmHg (95% CI:-9.00, -4.27); DBP: MD -2.91 mmHg (95% CI:-4.52, -1.30), 398 participants, 8 trials (low-quality evidence). The effect of sodium reduction (from 217 to 103 mmol/day) on BP in Asian participants was as follows: Normal blood pressure: SBP: mean difference (MD) -1.50 mmHg (95% CI: -3.09, 0.10); DBP: MD -1.06 mmHg (95% CI:-2.53 to 0.41), 950 participants, 5 trials. Hypertension: SBP: MD -7.75 mmHg (95% CI:-11.44, -4.07); DBP: MD -2.68 mmHg (95% CI: -4.21 to -1.15), 254 participants, 8 trials (moderate-low-quality evidence).   During sodium reduction renin increased 1.56 ng/mL/hour (95%CI:1.39, 1.73) in 2904 participants (82 trials); aldosterone increased 104 pg/mL (95%CI:88.4,119.7) in 2506 participants (66 trials); noradrenalin increased 62.3 pg/mL: (95%CI: 41.9, 82.8) in 878 participants (35 trials); adrenalin increased 7.55 pg/mL (95%CI: 0.85, 14.26) in 331 participants (15 trials); cholesterol increased 5.19 mg/dL (95%CI:2.1, 8.3) in 917 participants (27 trials); triglyceride increased 7.10 mg/dL (95%CI: 3.1,11.1) in 712 participants (20 trials); LDL tended to increase 2.46 mg/dl (95%CI: -1, 5.9) in 696 participants (18 trials); HDL was unchanged -0.3 mg/dl (95%CI: -1.66,1.05) in 738 participants (20 trials) (All high-quality evidence except the evidence for adrenalin).

AUTHORS' CONCLUSIONS

In white participants, sodium reduction in accordance with the public recommendations resulted in mean arterial pressure (MAP) decrease of about 0.4 mmHg in participants with normal blood pressure and a MAP decrease of about 4 mmHg in participants with hypertension. Weak evidence indicated that these effects may be a little greater in black and Asian participants. The effects of sodium reduction on potential side effects (hormones and lipids) were more consistent than the effect on BP, especially in people with normal BP.

24-h urinary sodium excretion and the risk of adverse outcomes

AIMS

The objective was to evaluate whether sodium intake, assessed with the gold standard 24-h urinary collections, was related to long-term incidence of death, cardiovascular disease (CVD) and diabetes mellitus (DM).

METHODS

A cohort of 4630 individuals aged 25-64 years collected 24-h urine samples in 1979-2002 and were followed up to 14 years for the incidence of any CVD, coronary heart disease (CHD), stroke, heart failure (HF) and DM event, and death. Cox proportional hazards models were used to estimate the association between the baseline salt intake and incident events and adjusted for baseline age, body mass index, serum cholesterol, prevalent DM, and stratified by sex and cohort baseline year.

RESULTS

During the follow-up, we observed 423 deaths, 424 CVD events (288 CHD events, 142 strokes, 139 HF events) and 161 DM events. Compared with the highest quartile of salt intake, persons in the lowest quartile had a lower incidence of CVD (hazard ratio [HR] 0.70; 95% confidence interval [CI], 0.51-0.95, p = .02), CHD (HR 0.63 [95% CI 0.42-0.94], p = .02) and DM (HR 0.52 [95% CI 0.31-0.87], p = .01). The results were non-significant for mortality, HF, and stroke.

CONCLUSION

High sodium intake is associated with an increased incidence of CVD and DM.

Dietary Sodium Intake and Risk of Cardiovascular Disease: A Systematic Review and Dose-Response Meta-Analysis

Dietary sodium intake has received considerable attention as a potential risk factor of cardiovascular disease. However, evidence on the dose-response association between dietary sodium intake and cardiovascular disease risk is unclear. Embase and PubMed were searched from their inception to 17 August 2020 and studies that examined the association between sodium intake and cardiovascular disease in adolescents were not included in this review. We conducted a meta-analysis to estimate the effect of high sodium intake using a random effects model. The Newcastle-Ottawa Scale assessment was performed. A random-effects dose-response model was used to estimate the linear and nonlinear dose-response relationships. Subgroup analyses and meta-regression were conducted to explain the observed heterogeneity. We identified 36 reports, which included a total of 616,905 participants, and 20 of these reports were also used for a dose-response meta-analysis. Compared with individuals with low sodium intake, individuals with high sodium intake had a higher adjusted risk of cardiovascular disease (Rate ratio: 1.19, 95% confidence intervals = 1.08–1.30). Our findings suggest that there is a significant linear relationship between dietary sodium intake and cardiovascular disease risk. The risk of cardiovascular disease increased up to 6% for every 1 g increase in dietary sodium intake. A low-sodium diet should be encouraged and education regarding reduced sodium intake should be provided.

Assessment of Sodium Knowledge and Urinary Sodium Excretion among Regions of the United Arab Emirates: A Cross-Sectional Study

Non-communicable diseases (NCDs) such as cardiovascular disease, cancer and diabetes, are increasing worldwide and cause 65% to 78% of deaths in the Gulf Cooperation Council (GCC). A random sample of 477 healthy adults were recruited in the United Arab Emirates (UAE) in the period March-June 2015. Demographic, lifestyle, medical, anthropometric and sodium excretion data were collected. A questionnaire was used to measure knowledge, attitude and practice regarding salt. Mean sodium and potassium excretion were 2713.4 ± 713 mg/day and 1803 ± 618 mg/day, respectively, significantly higher than the World Health Organization (WHO) recommendations for sodium (2300 mg/day) and lower for potassium (3150 mg/day). Two-thirds (67.4%) exceeded sodium guidelines, with males 2.6 times more likely to consume excessively. The majority of the participants add salt during cooking (82.5%) and whilst eating (66%), and 75% identified processed food as high source of salt. Most (69.1%) were aware that excessive salt could cause disease. Most of the UAE population consumes excess sodium and insufficient potassium, likely increasing the risk of NCDs. Despite most participants being aware that high salt intake is associated with adverse health outcomes, this did not translate into salt reduction action. Low-sodium, high-potassium dietary interventions such as the Mediterranean diet are vital in reducing the impact of NCDs in the UAE.

Sodium-calcium exchanger 1 is the key molecule for urinary potassium excretion against acute hyperkalemia

The sodium (Na⁺)-chloride cotransporter (NCC) expressed in the distal convoluted tubule (DCT) is a key molecule regulating urinary Na⁺ and potassium (K⁺) excretion. We previously reported that high-K⁺ load rapidly dephosphorylated NCC and promoted urinary K⁺ excretion in mouse kidneys. This effect was inhibited by calcineurin (CaN) and calmodulin inhibitors. However, the detailed mechanism through which high-K⁺ signal results in CaN activation remains unknown. We used Flp-In NCC HEK293 cells and mice to evaluate NCC phosphorylation. We analyzed intracellular Ca²⁺ concentration ([Ca²⁺]_in) using live cell Ca²⁺ imaging in HEK293 cells. We confirmed that high-K⁺-induced NCC dephosphorylation was not observed without CaN using Flp-In NCC HEK29 cells. Extracellular Ca²⁺ reduction with a Ca²⁺ chelator inhibited high-K⁺-induced increase in [Ca²⁺]_in and NCC dephosphorylation. We focused on Na⁺/Ca²⁺ exchanger (NCX) 1, a bidirectional regulator of cytosolic Ca²⁺ expressed in DCT. We identified that NCX1 suppression with a specific inhibitor (SEA0400) or siRNA knockdown inhibited K⁺-induced increase in [Ca²⁺]_in and NCC dephosphorylation. In a mouse study, SEA0400 treatment inhibited K⁺-induced NCC dephosphorylation. SEA0400 reduced urinary K⁺ excretion and induced hyperkalemia. Here, we identified NCX1 as a key molecule in urinary K⁺ excretion promoted by CaN activation and NCC dephosphorylation in response to K⁺ load.

Does micronutrients intake modulate the risk of coronary heart disease?

Purpose

The purpose of this study was to examine the relationship between micronutrient intake and coronary heart disease (CHD) in middle-aged Jordanian participants.

Design/methodology/approach

A case-control study was conducted among patients referring for elective coronary angiography. A total of 400 patients were enrolled in this study. Face-to-face interview was used to complete food frequency questionnaire from which the authors derived usual daily intake of micronutrients. The mean age of participates was 52 years and their average BMI was 30.7 kg/m2. Multinomial logistic regression model and linear logistic regression model were used to calculate odd ratios (OR) and its 95 per cent confidence interval (CI) and p-value for trend, respectively. The association between the risk of CHD and micronutrients intake was adjusted for the age, gender, BMI, smoking, physical activity, total energy intake, occupation, education level, marital status and family history.

Findings

The study results showed no significant differences between cases and controls for dietary intakes of micronutrients, except for the intake of calcium (p < 0.005), magnesium (p < 0.025), phosphorus (p < 0.023) and potassium (p < 0.006) which were lower in cases than controls. Although no significant trend was observed between most of the dietary intake of micronutrients and the risk of developing CHD, a significant protective effect of magnesium [OR 0.52; 95 per cent CI (0.29-0.95)], phosphorus [OR 0.44; 95 per cent CI (0.24-0.80)] and potassium [OR 0.41; 95 per cent CI (0.22-0.74)] against the risk of CHD was detected.

Originality/value

The findings from this study provide strong evidence that the intake of micronutrients such as calcium, magnesium, phosphorus and potassium has no significant associations with the risk of CHD.

Joint association of urinary sodium and potassium excretion with cardiovascular events and mortality: prospective cohort study

OBJECTIVE

To evaluate the joint association of sodium and potassium urinary excretion (as surrogate measures of intake) with cardiovascular events and mortality, in the context of current World Health Organization recommendations for daily intake (<2.0 g sodium, >3.5 g potassium) in adults.

DESIGN

International prospective cohort study.

SETTING

18 high, middle, and low income countries, sampled from urban and rural communities.

PARTICIPANTS

103 570 people who provided morning fasting urine samples.

MAIN OUTCOME MEASURES

Association of estimated 24 hour urinary sodium and potassium excretion (surrogates for intake) with all cause mortality and major cardiovascular events, using multivariable Cox regression. A six category variable for joint sodium and potassium was generated: sodium excretion (low (<3 g/day), moderate (3-5 g/day), and high (>5 g/day) sodium intakes) by potassium excretion (greater/equal or less than median 2.1 g/day).

RESULTS

Mean estimated sodium and potassium urinary excretion were 4.93 g/day and 2.12 g/day, respectively. After a median follow-up of 8.2 years, 7884 (6.1%) participants had died or experienced a major cardiovascular event. Increasing urinary sodium excretion was positively associated with increasing potassium excretion (unadjusted r=0.34), and only 0.002% had a concomitant urinary excretion of <2.0 g/day of sodium and >3.5 g/day of potassium. A J-shaped association was observed of sodium excretion and inverse association of potassium excretion with death and cardiovascular events. For joint sodium and potassium excretion categories, the lowest risk of death and cardiovascular events occurred in the group with moderate sodium excretion (3-5 g/day) and higher potassium excretion (21.9% of cohort). Compared with this reference group, the combinations of low potassium with low sodium excretion (hazard ratio 1.23, 1.11 to 1.37; 7.4% of cohort) and low potassium with high sodium excretion (1.21, 1.11 to 1.32; 13.8% of cohort) were associated with the highest risk, followed by low sodium excretion (1.19, 1.02 to 1.38; 3.3% of cohort) and high sodium excretion (1.10, 1.02 to 1.18; 29.6% of cohort) among those with potassium excretion greater than the median. Higher potassium excretion attenuated the increased cardiovascular risk associated with high sodium excretion (P for interaction=0.007).

CONCLUSIONS

These findings suggest that the simultaneous target of low sodium intake (<2 g/day) with high potassium intake (>3.5 g/day) is extremely uncommon. Combined moderate sodium intake (3-5 g/day) with high potassium intake is associated with the lowest risk of mortality and cardiovascular events.

Association of Dietary Potassium Intake with the Development of Chronic Kidney Disease and Renal Function in Patients with Mildly Decreased Kidney Function: The Korean Multi-Rural Communities Cohort Study

Background

Dietary potassium has negative outcomes in patients with mildly impaired kidney function, while having positive outcomes in patients with hypertension. The association of dietary potassium intake with chronic kidney disease (CKD) development, with presence of hypertension, was studied in the Korean rural population with mildly impaired kidney function.

Material/Methods

From 3 rural areas of Korea, 5064 participants age ≥40 with CKD stage 2 at baseline were recruited. Patients were classified according to the quartile of dietary potassium intake. Newly developed CKD, defined as estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m² at the time of follow-up, and eGFR decline, defined as eGFR decrease >15% at follow-up, were studied. The effect of dietary potassium on CKD development and eGFR decline were studied by Cox proportional hazard models. The association of potassium with blood pressures and C-reactive protein was also studied to examine the underlying mechanisms.

Results

Compared to 8.6% in normotensives, 15.7% of hypertensives developed CKD. The hazard ratio (HR) (95% confidence interval) of CKD was lower in high potassium diet only in hypertensives, with 0.60 (0.37–0.99) in the highest quartile. The eGFR decline was also lower in patients with higher potassium diet, with 0.70 (0.50–0.98) in Q3 and 0.54 (0.34–0.85) in Q4. Potassium intake has also been shown to decrease high diastolic blood pressure development (>90 mmHg) in hypertensives at 0.45 (0.25–0.83).

Conclusions

Dietary potassium was associated with lower risk of CKD development and eGFR decline, and this association was observed only in hypertensives.

Impact of partial substitution of NaCl by KCl, and MgCl2 on physicochemical and sensory properties of cooked sausages during storage

Objective

To determine the effect of three salting treatments (control, 100% NaCl; T1, 60% NaCl and 40% KCl; T2, 50% NaCl, 40% KCl, and 10% MgCl₂) on meat quality of sausages during storage.

Methods

Various types of curing salts were used for processing of salamis. Physico-chemical and sensory evaluation of the sausages were analyzed during 4 weeks of ripening.

Results

The pH values and salinity contents were the highest in control, while they were the lowest in T2 at 4 weeks (p<0.05). Control and T1 had less thiobarbituric acid reactive substances than T2 at 2 weeks (p<0.05). The volatile basic nitrogen levels in T1 were similar to control and lower than T2 at 2 and 4 weeks (p<0.05). Moreover, T1 samples were redder and had a higher saturation index (C*) value when compared to the others. T2 showed greater hardness, gumminess and chewiness when compared with the control (p<0.05). Control was comparable to T1 for sensory attributes.

Conclusion

Sodium chloride may be partially substituted with potassium chloride without negatively influencing meat quality of sausages up to 4 weeks of storage. These results could help to develop low-sodium sausages.

Association of Low Urinary Sodium Excretion With Increased Risk of Stroke

The positive relationship between sodium intake and blood pressure is well established. However, results of observational studies on dietary sodium intake and risk of stroke are inconsistent. Moreover, prospective studies with multiple 24-hour urine samples for accurate estimation of habitual sodium intake are scarce. We examined the association of urinary sodium excretion (UNaV) as an accurate estimate of intake with risk of stroke. We studied 7330 individuals free of cardiovascular events at baseline in the Prevention of Renal and Vascular End-stage Disease (PREVEND) study, a prospective, population-based cohort of Dutch men and women. The UNaV was measured in two 24-hour urine specimens at baseline (1997-1998) and two specimens during follow-up (2001-2003). Baseline median UNaV was 137 mmol/24 h (interquartile range, 106-171 mmol/24 h). During a median follow-up of 12.5 years (interquartile range, 11.9-12.9 years), a total of 183 stroke events occurred. An inverse association between UNaV and risk of stroke was observed after adjustment for age and sex (hazard ratio [HR] per 1-SD [51 mmol/24 h] decrement, 1.36; 95% CI, 1.11-1.65), which remained independent of additional adjustment for anthropometric, dietary, lifestyle, and other potential confounding factors (HR, 1.44; 95% CI, 1.14-1.82). After adjustment for potential mediators (systolic blood pressure and antihypertensive medication, plasma renin, aldosterone, and sodium levels), the association of UNaV with risk of stroke remained unchanged, with HRs (95% CIs) of 1.44 (1.14-1.82), 1.50 (1.18-1.90), 1.54 (1.21-1.97), and 1.49 (1.17-1.90), respectively. This prospective study revealed an association of low UNaV with an increased risk of stroke.

Can pre-diagnostic serum levels of sodium and potassium predict prostate cancer survival?

There is evidence that derangement in serum electrolytes like sodium and potassium is associated with increased morbidity and mortality among hospitalized critically ill patients, but their role in the context of cancer survival remains poorly understood. We sought to investigate the association of pre-diagnostic serum sodium and potassium with risk of overall, cancer-specific, and cardiovascular (CV) death among 11,492 men diagnosed with prostate cancer (PCa) from the Swedish AMORIS study. Multivariable Cox proportional hazards regression was used to assess the risk of death by clinical categories of pre-diagnostic serum sodium and potassium. During a mean follow-up of 5.7 years, 1649 men died of PCa. Serum levels of sodium were not indicative of PCa-specific or CV death. A weak positive association was found between pre-diagnostic higher serum potassium (> 5 mEq/L) and overall death [HR: 1.26 (95% CI: 1.01-1.59)] as compared to low/normal levels of clinical cut-offs. The current study did not find strong evidence for a role of electrolytes in PCa mortality. To further disentangle the potential role of electrolytes in cancer development, future studies should use repeated measurement of serum electrolytes.This research project was reviewed and approved by the Stockholm Ethical Committee (Dnr 2010/1:7).

Dose-response association of dietary sodium intake with all-cause and cardiovascular mortality: a systematic review and meta-analysis of prospective studies

OBJECTIVE

High Na intake has been associated with different health problems. However, serious controversies exist over studies investigating associations of Na intake with mortality from all-causes and CVD. The present systematic review and meta-analysis was done to investigate, for the first time, the dose-response association of dietary Na intake with all-cause and CVD mortality among prospective studies.

DESIGN

Relevant papers published up to August 2017 were searched in MEDLINE, EMBASE and Google Scholar databases. Prospective cohort studies on the association of dietary Na intake with all-cause or/and CVD mortality were included. Linear and non-linear dose-response associations between Na intake and CVD and all-cause mortality were examined.

RESULTS

Overall, twenty publications met inclusion criteria. A significant non-linear association (P&lt;0·001) was found between Na intake and CVD mortality risk among studies assessing urinary Na excretion, with a relatively steep slope at Na intakes above 2400mg/d. However, the association was not significant in studies using dietary Na intake (P=0·61). Additionally, the non-linear association of Na intake with all-cause mortality was also non-significant. No linear association (effect size; 95 % CI; I 2) was seen between 100mg/d increment in Na intake and CVD mortality (1·01; 0·97, 1·05; 98·4 %) or all-cause mortality (1·01; 1·00, 1·02; 89·2 %). Following subgroup analyses, the association between Na intake and CVD mortality was observed only among studies conducted in the USA (0·99; 0·99, 1·00; 20·0 %).

CONCLUSIONS

The study showed a direct association between urinary Na excretion and CVD mortality which was more considerable at intakes above 2400mg/d. In contrast, no significant association was found between Na intake and all-cause mortality. Further long-term prospective studies on different populations are required to confirm these findings.

Dietary sodium, sodium-to-potassium ratio, and risk of stroke: A systematic review and nonlinear dose-response meta-analysis

BACKGROUND & AIMS

The association of high sodium intake with risk of stroke has been accepted. But considering the proposed J/U-shaped association between sodium intake and risk of all-cause mortality, the shape of the dose-response relationship has not been determined yet. This study aimed to test the dose-response association of dietary sodium and sodium-to-potassium ratio with risk of stroke in adults aged 18 years or older.

METHODS

We performed a systematic search using PubMed and Scopus, from database inception up to October 2017. Prospective and retrospective observational studies reporting risk estimates of stroke for three or more quantitative categories of dietary sodium or sodium-to-potassium ratio were included. Studies that reported results as continuous were also included. Two independent authors extracted the information and assessed the quality of included studies. Pooled relative risk (RR) was calculated using a random-effects model. Publication bias was tested. Sensitivity and subgroup analyses were done.

RESULTS

Of initial 20,412 studies identified, 14 prospective cohort studies, one case-cohort study, and one case-control study (total n = 261,732) with 10,150 cases of stroke were included. The Pooled RRs of stroke were 1.06 (95%CI: 1.02, 1.10; I² = 60%, n = 14 studies) for a 1 gr/d increment in dietary sodium intake, and 1.22 (95%CI: 1.04, 1.41; I² = 60%, n = 5 studies) for a one-unit increment in dietary sodium-to-potassium ratio (mmol/mmol). The risk of stroke increased linearly with increasing dietary sodium intake, and also along with the increase in dietary sodium-to-potassium ratio. No evidence of a J/U-shaped association was found in the analyses of total stroke, stroke incidence, and stroke mortality. High sodium intake was associated with a somewhat worse prognosis among Asian countries as compared to westerns.

CONCLUSION

Higher sodium intake and higher dietary sodium-to-potassium ratio were associated with a higher risk of stroke. Reducing dietary sodium-to-potassium ratio can be considered as a supplementary approach in parallel with the decrease in sodium intake in order to decrease stroke risk. The interpretation of the results is limited by observational nature of studies examined.

The taste of KCl - What a difference a sugar makes

Dramatic increase in NaCl consumption lead to sodium intake beyond health guidelines. KCl substitution helps reduce sodium intake but results in a bitter-metallic off-taste. Two disaccharides, trehalose and sucrose, were tested in order to untangle the chemical (increase in effective concentration of KCl due to sugar addition) from the sensory effects. The bitter-metallic taste of KCl was reduced by these sugars, while saltiness was enhanced or unaltered. The perceived sweetness of sugar, regardless of its type and concentration, was an important factor in KCl taste modulation. Though KCl was previously shown to increase the chemical activity of trehalose but not of sucrose, we found that it suppressed the perceived sweetness of both sugars. Therefore, sensory integration was the dominant factor in the tested KCl-sugar combinations.

Fluorescence spectroscopy coupled with independent components analysis to monitor molecular changes during heating and cooling of Cantal-type cheeses with different NaCl and KCl contents

BACKGROUND

Reduction of NaCl content of cheeses has received considerable attention by research during the past decades because of its health effects. Nonetheless, NaCl reduction is a challenge since it plays an important role in cheese quality, such as structure, texture and functional properties. Several methods were used to evaluate the effect of NaCl on these attributes. In this study, Cantal-type cheeses with different salts (NaCl and KCl) were analyzed for their structure at a molecular level and rheological properties during heating (20-60 °C) and cooling (60-20 °C). The structure was investigated by synchronous fluorescence spectroscopy (SFS) and the rheological properties by small-amplitude oscillatory test.

RESULTS

Independent components analysis (ICA) gave three independent components that were attributed to coenzyme/Maillard reaction products (IC1), tryptophan (IC2) and vitamin A (IC3). Signal proportions of each IC depicted information regarding the changes in those fluorophores with salts, heating and cooling. In addition, canonical correlation analysis (CCA) of the IC proportions and rheological measurements related modifications at a molecular level evaluated by fluorescence to cheese texture (0.34 < R² < 0.99).

CONCLUSION

This study demonstrated that SFS can monitor and characterize modification of Cantal-type cheeses at a molecular level, based on the analysis of the fluorescence spectra by ICA. The nature of correlation between signal proportions and the rheological parameters depicted that rheological attributes of cheeses observed at the macroscopic level can be derived from fluorescence spectra. © 2017 Society of Chemical Industry.

Associations of urinary sodium and sodium to potassium ratio with hypertension prevalence and the risk of cardiovascular events in patients with prehypertension

The aim of this study was to investigate the effects of urinary sodium and sodium to potassium ratio on inflammatory cytokines, hypertension, and cardiovascular disease in patients with prehypertension. The authors observed 627 patients with prehypertension in the General Hospital of Shenyang Military Region. Rank correlation analysis revealed that interleukin 6 expression exhibited significant positive correlations with urinary sodium (R = .13) and sodium to potassium ratio (R = .13). The multivariate-adjusted hazard ratio of 24-hour urinary sodium was 1.01 (95% confidence interval, 1.00 - 1.01) for hypertension and 1.01 (95% confidence interval, 1.00 - 1.02) for cardiovascular disease, whereas the hazard ratio for 24-hour urinary sodium to potassium ratio was 1.13 (95% confidence interval, 1.08 - 1.19) for hypertension and 1.10 (95% confidence interval, 1.04 - 1.17) for cardiovascular disease. The study suggests that a high-salt diet may lead to increased interleukin 6 levels and may contribute to hypertension. In addition, a high sodium to potassium ratio and high sodium levels are associated with increased risks of cardiovascular disease and hypertension in patients with prehypertension.

Dietary Sodium to Potassium Ratio and Risk of Stroke in a Multiethnic Urban Population: The Northern Manhattan Study

BACKGROUND AND PURPOSE

There is growing evidence that increased dietary sodium (Na) intake increases the risk of vascular diseases, including stroke, at least in part via an increase in blood pressure. Higher dietary potassium (K), seen with increased intake of fruits and vegetables, is associated with lower blood pressure. The goal of this study was to determine the association of a dietary Na:K with risk of stroke in a multiethnic urban population.

METHODS

Stroke-free participants from the Northern Manhattan Study, a population-based cohort study of stroke incidence, were followed-up for incident stroke. Baseline food frequency questionnaires were analyzed for Na and K intake. We estimated the hazard ratios and 95% confidence intervals for the association of Na:K with incident total stroke using multivariable Cox proportional hazards models.

RESULTS

Among 2570 participants with dietary data (mean age, 69±10 years; 64% women; 21% white; 55% Hispanic; 24% black), the mean Na:K ratio was 1.22±0.43. Over a mean follow-up of 12 years, there were 274 strokes. In adjusted models, a higher Na:K ratio was associated with increased risk for stroke (hazard ratio, 1.6; 95% confidence interval, 1.2-2.1) and specifically ischemic stroke (hazard ratio, 1.6; 95% confidence interval, 1.2-2.1).

CONCLUSIONS

Na:K intake is an independent predictor of stroke risk. Further studies are required to understand the joint effect of Na and K intake on risk of cardiovascular disease.

Estimating 24-h urinary sodium/potassium ratio from casual ('spot') urinary sodium/potassium ratio: the INTERSALT Study

Background

Association between casual and 24-h urinary sodium-to-potassium (Na/K) ratio is well recognized, although it has not been validated in diverse demographic groups. Our aim was to assess utility across and within populations of casual urine to estimate 24-h urinary Na/K ratio using data from the INTERSALT Study.

Methods

The INTERSALT Study collected cross-sectional standardized data on casual urinary sodium and potassium and also on timed 24-h urinary sodium and potassium for 10 065 individuals from 52 population samples in 32 countries (1985-87). Pearson correlation coefficients and agreement were computed for Na/K ratio of casual urine against 24-h urinary Na/K ratio both at population and individual levels.

Results

Pearson correlation coefficients relating means of 24-h urine and casual urine Na/K ratio were r = 0.96 and r = 0.69 in analyses across populations and individuals, respectively. Correlations of casual urine Na/creatinine and K/creatinine ratios with 24-h urinary Na and K excretion, respectively, were lower than correlation of casual and 24-h urinary Na/K ratio in analyses across populations and individuals. The bias estimate with the Bland-Altman method, defined as the difference between Na/K ratio of 24-h urine and casual urine, was approximately 0.4 across both populations and individuals. Spread around, the mean bias was higher for individuals than populations.

Conclusion

With appropriate bias correction, casual urine Na/K ratio may be a useful, low-burden alternative method to 24-h urine for estimation of population urinary Na/K ratio. It may also be applicable for assessment of the urinary Na/K ratio of individuals, with use of repeated measurements to reduce measurement error and increase precision.

Urinary Sodium and Potassium Excretion and Dietary Sources of Sodium in Maputo, Mozambique

This study aimed to evaluate the urinary excretion of sodium and potassium, and to estimate the main food sources of sodium in Maputo dwellers. A cross-sectional evaluation of a sample of 100 hospital workers was conducted between October 2012 and May 2013. Sodium and potassium urinary excretion was assessed in a 24-h urine sample; creatinine excretion was used to exclude unlikely urine values. Food intake in the same period of urine collection was assessed using a 24-h dietary recall. The Food Processor Plus^® was used to estimate sodium intake corresponding to naturally occurring sodium and sodium added to processed foods (non-discretionary sodium). Salt added during culinary preparations (discretionary sodium) was computed as the difference between urinary sodium excretion and non-discretionary sodium. The mean (standard deviation) urinary sodium excretion was 4220 (1830) mg/day, and 92% of the participants were above the World Health Organization (WHO) recommendations. Discretionary sodium contributed 60.1% of total dietary sodium intake, followed by sodium from processed foods (29.0%) and naturally occurring sodium (10.9%). The mean (standard deviation) urinary potassium excretion was 1909 (778) mg/day, and 96% of the participants were below the WHO potassium intake recommendation. The mean (standard deviation) sodium to potassium molar ratio was 4.2 (2.4). Interventions to decrease sodium and increase potassium intake are needed in Mozambique.

Effects of low sodium diet versus high sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterol, and triglyceride

BACKGROUND

In spite of more than 100 years of investigations the question of whether a reduced sodium intake improves health is still unsolved.

OBJECTIVES

To estimate the effects of low sodium intake versus high sodium intake on systolic and diastolic blood pressure (SBP and DBP), plasma or serum levels of renin, aldosterone, catecholamines, cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials up to March 2016: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 3), MEDLINE (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also searched the reference lists of relevant articles.

SELECTION CRITERIA

Studies randomising persons to low-sodium and high-sodium diets were included if they evaluated at least one of the above outcome parameters.

DATA COLLECTION AND ANALYSIS

Two review authors independently collected data, which were analysed with Review Manager 5.3.

MAIN RESULTS

A total of 185 studies were included. The average sodium intake was reduced from 201 mmol/day (corresponding to high usual level) to 66 mmol/day (corresponding to the recommended level).The effect of sodium reduction on blood pressure (BP) was as follows: white people with normotension: SBP: mean difference (MD) -1.09 mmHg (95% confidence interval (CI): -1.63 to -0.56; P = 0.0001); 89 studies, 8569 participants; DBP: + 0.03 mmHg (MD 95% CI: -0.37 to 0.43; P = 0.89); 90 studies, 8833 participants. High-quality evidence. Black people with normotension: SBP: MD -4.02 mmHg (95% CI:-7.37 to -0.68; P = 0.002); seven studies, 506 participants; DBP: MD -2.01 mmHg (95% CI:-4.37 to 0.35; P = 0.09); seven studies, 506 participants. Moderate-quality evidence. Asian people with normotension: SBP: MD -0.72 mmHg (95% CI: -3.86 to 2.41; P = 0.65); DBP: MD -1.63 mmHg (95% CI:-3.35 to 0.08; P =0.06); three studies, 393 participants. Moderate-quality evidence.White people with hypertension: SBP: MD -5.51 mmHg (95% CI: -6.45 to -4.57; P < 0.00001); 84 studies, 5925 participants; DBP: MD -2.88 mmHg (95% CI: -3.44 to -2.32; P < 0.00001); 85 studies, 6001 participants. High-quality evidence. Black people with hypertension: SBP MD -6.64 mmHg (95% CI:-9.00 to -4.27; P = 0.00001); eight studies, 619 participants; DBP -2.91 mmHg (95% CI:-4.52, -1.30; P = 0.0004); eight studies, 619 participants. Moderate-quality evidence. Asian people with hypertension: SBP: MD -7.75 mmHg (95% CI:-11,44 to -4.07; P < 0.0001) nine studies, 501 participants; DBP: MD -2.68 mmHg (95% CI: -4.21 to -1.15; P = 0.0006). Moderate-quality evidence.In plasma or serum, there was a significant increase in renin (P < 0.00001), aldosterone (P < 0.00001), noradrenaline (P < 0.00001), adrenaline (P < 0.03), cholesterol (P < 0.0005) and triglyceride (P < 0.0006) with low sodium intake as compared with high sodium intake. All effects were stable in 125 study populations with a sodium intake below 250 mmol/day and a sodium reduction intervention of at least one week.

AUTHORS' CONCLUSIONS

Sodium reduction from an average high usual sodium intake level (201 mmol/day) to an average level of 66 mmol/day, which is below the recommended upper level of 100 mmol/day (5.8 g salt), resulted in a decrease in SBP/DBP of 1/0 mmHg in white participants with normotension and a decrease in SBP/DBP of 5.5/2.9 mmHg in white participants with hypertension. A few studies showed that these effects in black and Asian populations were greater. The effects on hormones and lipids were similar in people with normotension and hypertension. Renin increased 1.60 ng/mL/hour (55%); aldosterone increased 97.81 pg/mL (127%); adrenalin increased 7.55 pg/mL (14%); noradrenalin increased 63.56 pg/mL: (27%); cholesterol increased 5.59 mg/dL (2.9%); triglyceride increased 7.04 mg/dL (6.3%).

Dietary sodium and potassium intake in relation to non-alcoholic fatty liver disease

A few epidemiological data are available assessing the associations of intakes of sodium (Na) and potassium (K) with non-alcoholic fatty liver disease (NAFLD). We aimed to examine the associations of dietary intake of Na and K with the prevalence of ultrasound-diagnosed NAFLD. We performed a cross-sectional study of 100 177 participants (46 596 men and 53 581 women) who underwent a health screening examination and completed a FFQ at the Kangbuk Samsung Hospital Total Healthcare Centers, South Korea, between 2011 and 2013. NAFLD was defined by ultrasonographic detection of fatty liver in the absence of excessive alcohol intake or other known causes of liver disease. The proportion of NAFLD was 35·6 % for men and 9·8 % for women. Increasing prevalence of NAFLD was observed with increasing Na intake. The multivariable-adjusted prevalence ratios (PR) of NAFLD comparing the highest with the lowest quintile of energy-adjusted Na intake were 1·25 (95 % CI 1·18, 1·32; P trend<0·001) in men and 1·32 (95 % CI 1·18, 1·47; P trend <0·001) in women. However, when we additionally adjusted for body fat percentage, the association became attenuated; the corresponding PR of NAFLD were 1·15 (95 % CI 1·09, 1·21) in men and 1·06 (95 % CI 0·95, 1·17) in women. No inverse association was observed for energy-adjusted K intake. Our findings suggest that higher Na intake is associated with a greater prevalence of NAFLD in young and middle-aged asymptomatic adults, which might be partly mediated by adiposity.

Meta-Analysis of Potassium Intake and the Risk of Stroke

Background

The possibility that lifestyle factors such as diet, specifically potassium intake, may modify the risk of stroke has been suggested by several observational cohort studies, including some recent reports. We performed a systematic review and meta‐analysis of existing studies and assessed the dose–response relation between potassium intake and stroke risk.

Methods and Results

We reviewed the observational cohort studies addressing the relation between potassium intake, and incidence or mortality of total stroke or stroke subtypes published through August 6, 2016. We carried out a meta‐analysis of 16 cohort studies based on the relative risk (RR) of stroke comparing the highest versus lowest intake categories. We also plotted a pooled dose–response curve of RR of stroke according to potassium intake. Analyses were performed with and without adjustment for blood pressure. Relative to the lowest category of potassium intake, the highest category of potassium intake was associated with a 13% reduced risk of stroke (RR=0.87, 95% CI 0.80–0.94) in the blood pressure–adjusted analysis. Summary RRs tended to decrease when original estimates were unadjusted for blood pressure. Analysis for stroke subtypes yielded comparable results. In the spline analysis, the pooled RR was lowest at 90 mmol of potassium daily intake (RRs=0.78, 95% CI 0.70–0.86) in blood pressure–adjusted analysis, and 0.67 (95% CI 0.57–0.78) in unadjusted analysis.

Conclusions

Overall, this dose–response meta‐analysis confirms the inverse association between potassium intake and stroke risk, with potassium intake of 90 mmol (≈3500 mg)/day associated with the lowest risk of stroke.

Urinary Sodium and Potassium Excretion and Carotid Atherosclerosis in Chinese Men and Women

Limited studies have examined the association between sodium (Na) and potassium (K) levels and the risk of atherosclerosis. This study examined whether higher Na and Na/K levels and low K levels were independent risk factors for atherosclerosis. This community-based cross-sectional study included 3290 subjects (1067 men and 2223 women) 40 to 75 years of age in Guangzhou, China, between 2011 and 2013. Urinary excretion of Na and K were measured from the first morning void, and creatinine-adjusted values were used. The intima-media thickness (IMT) of the carotid common artery and the carotid bifurcation was measured with high-resolution B-mode ultrasonography. Dietary K and Na intake and other covariates were obtained by face-to-face interviews. A significant positive association was seen between urinary Na excretion and carotid atherosclerosis after adjustment for age, sex, and other lifestyle covariates. The odds ratios (OR) and 95% confidence interval (CI) of the highest (vs. lowest) quartile of urinary Na were 1.32 (1.04-1.66) for carotid plaques, 1.48 (1.18-1.87) for increased common carotid artery IMT, and 1.55 (1.23-1.96) for increased carotid bifurcation IMT (all p-trend < 0.01). A similar positive association was observed between urinary Na/K levels and carotid plaque and increased IMT, and between dietary Na intake and increased bifurcation IMT. Regarding potassium data, we only found a significantly lower presence of carotid plaque (OR 0.72, 95% CI 0.57-0.91) for quartile 2 (vs. 1) of urinary K. Our findings suggest that higher levels of urinary excretion Na and Na/K are significantly associated with greater presence of carotid atherosclerosis in Chinese adults.

Dietary sodium-to-potassium ratio as a risk factor for stroke, cardiovascular disease and all-cause mortality in Japan: the NIPPON DATA80 cohort study

OBJECTIVES

To evaluate the impact of dietary sodium and potassium (Na-K) ratio on mortality from total and subtypes of stroke, cardiovascular disease (CVD) and all causes, using 24-year follow-up data of a representative sample of the Japanese population.

SETTING

Prospective cohort study.

PARTICIPANTS

In the 1980 National Cardiovascular Survey, participants were followed for 24 years (NIPPON DATA80, National Integrated Project for Prospective Observation of Non-communicable Disease And its Trends in the Aged). Men and women aged 30-79 years without hypertensive treatment, history of stroke or acute myocardial infarction (n=8283) were divided into quintiles according to dietary Na-K ratio assessed by a 3-day weighing dietary record at baseline. Age-adjusted and multivariable-adjusted HRs were calculated using the Mantel-Haenszel method and Cox proportional hazards model.

PRIMARY OUTCOME MEASURES

Mortality from total and subtypes of stroke, CVD and all causes.

RESULTS

A total of 1938 deaths from all causes were observed over 176 926 person-years. Na-K ratio was significantly and non-linearly related to mortality from all stroke (p=0.002), CVD (p=0.005) and total mortality (p=0.001). For stroke subtypes, mortality from haemorrhagic stroke was positively related to Na-K ratio (p=0.024). Similar relationships were observed for men and women. The observed relationships remained significant after adjustment for other risk factors. Quadratic non-linear multivariable-adjusted HRs (95% CI) in the highest quintile versus the lowest quintile of Na-K ratio were 1.42 (1.07 to 1.90) for ischaemic stroke, 1.57 (1.05 to 2.34) for haemorrhagic stroke, 1.43 (1.17 to 1.76) for all stroke, 1.39 (1.20 to 1.61) for CVD and 1.16 (1.06 to 1.27) for all-cause mortality.

CONCLUSIONS

Dietary Na-K ratio assessed by a 3-day weighing dietary record was a significant risk factor for mortality from haemorrhagic stroke, all stroke, CVD and all causes among a Japanese population.