Estimation of salt intake by 24-hour urinary sodium excretion: a cross-sectional study in Yantai, China

Meta-analysis guided development of a standard artificial urine

In this study, we present the first meta-analysis of human urine reported in the literature, drawing data from a total of 35 articles with a combined participant count of 14,021. Through this analysis, we have developed an artificial urine (AU) composition that can be adjusted within typical physiological parameters for in vitro applications. Our findings demonstrate the utility of this AU in determining the solubility of nitrofurantoin, particularly in the context of crystalluria. Notably, we observe that in saline, nitrofurantoin solubility, within the framework of its urinary pharmacokinetics, suggests a risk of crystalluria. However, in AU, this risk is mitigated due to complexation with urea. More broadly, we anticipate that our developed formulation will serve as a foundation for translational studies across biomedical and pharmaceutical sciences.

Consistency between 3 days' dietary records and 24-h urine in estimating salt intake in children and adolescents

Purpose

This study aimed to evaluate the salt intake in boarding school students and the consistency between salt intake measurements based on 24-h urine and weighed dietary records over 3 consecutive days in this population.

Methods

This was a school-based cross-sectional study. Overweight (including obesity) or hypertensive students aged 6-14 years and their normal counterparts were recruited for this study at three boarding schools in China. Three consecutive 24-h urine samples were collected from all participants. During the collection period of 24-h urine, the weighed diet records were collected in children who had all three meals at the school canteens on weekdays. Incomplete 24-h urine or dietary records were excluded from the analysis.

Results

The median salt excretion was 6,218 [4,636, 8,290] mg by 24-h urine and 120 (82.2%) consumed excess salt among the participants. The median salt intake was 8,132 [6,348, 9,370] mg by dietary records and 112 (97.4%) participants consumed excess salt than recommended in participants who have all three meals in the school canteens. In children with complete dietary records and 24-h urine, the level of salt intake estimated by 24-h urine accounted for 79.6% of the dietary records.

Conclusion

Our study showed that boarding school students consumed excessive salt from school canteens. Thus, policies or strategies targeting school canteens are urgently needed. Weighed dietary records are recommended if feasible.

Association of Salt-Reduction Knowledge and Behaviors and Salt Intake in Chinese Population

Objective

Excessive salt intake is causally associated with an increased risk of cardiovascular disease. Salt-reduction strategies have been rapidly deployed across China since 2017. This study aimed to investigate the association of salt-reduction knowledge and behaviors and salt intake in Chinese population.

Study Design

This study was a national cross-sectional study in China.

Methods

This cross-sectional study was based on data collected during a Chinese adult chronic disease and nutrition surveillance program in 2018 with 7,665 study participants. Salt intake was assessed by calculating 24 h urine sodium from morning urine samples. Logistic regression and mean impact value (MIV) based on the back propagation (BP) artificial neural network were used to screen the potential influencing factors.

Results

A total of 7,665 participants were included in the analysis, with an average age of 54.64 ± 13.26 years, and with men accounting for 42.6%. Only 19.3% of the participants were aware of the Chinese Dietary Guidelines, and only 7.3% of them could accurately identify the level of salt intake recommended in the Chinese Dietary Guidelines. Approximately 41% of the participants adopted salt-reduction behaviors, among whom the number of participants who used less salt when cooking was the highest, and the number of participants who used low sodium salt was the lowest. In the logistic regression, only "No extra salt was added at the table" group showed the effect of salt-reduction, the odds ratio (OR) being 0.78 (95% confidence interval [CI]: 0.64-0.95). The MIV result based on the BP neural network showed that the most important salt-reduction behavior was using less salt when cooking, while reducing eating-out behavior and using salt-limiting tools were the least important.

Conclusion

The research shows that the popularization of salt-reduction knowledge and behaviors can reduce the population's salt intake. However, there is still considerable scope for promoting salt-reduction knowledge and behaviors, while the promotion of salt-reduction tools and low-sodium salt still needs to be strengthened.

Validation and reproducibility of a semi-qualitative food frequency questionnaire for assessment of sodium intake in Iranian population

Background

Few semi-quantitative food frequency questionnaires (SFFQ)s has yet been developed to assess sodium intake in Middle East region. This study was performed to validate a SFFQ for assessment of sodium consumption and food groups΄ contribution to sodium intake.

Methods

This study was performed on 219 healthy participants including 113 adults aged ≥19 years and 106 children aged 6–18 years in Isfahan, Iran. They were administered two SFFQ at the beginning and after 1 year to evaluate the reproducibility. The validity of SFFQ for assessment of sodium intake was compared with 24-h urine sodium and twelve 24-h dietary recalls which were completed monthly during a year as two standard methods.

Results

Correlation coefficient between the contribution of food groups to sodium intake based on SFFQ and 24-h dietary recalls varied from 0.04 for legumes (P = 0.667) to 0.47 for added salt (P < 0.001). There was a significant correlation between the estimated total sodium intake based on SFFQ and both standard methods (P < 0.01). Intraclass correlation coefficient (95% CI) between first and second SFFQ had a diverse range from 0.10 (-0.05, 0.17) for fats and oils to 0.49 (0.28, 0.69) for bread. According to the Bland-Altman plots, we observed an acceptable level of agreement between the two methods for sodium intake.

Conclusions

The SFFQ was a relatively valid and reproducible method for estimating sodium intake. Combination of this SFFQ with a valid prediction of 24-h urinary sodium excretion can be useful in achieving more accurate results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-021-00749-7.

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.

Urinary Sodium Excretion and Adherence to the Mediterranean Diet in Older Adults

Despite the well-known benefits of the Mediterranean Diet (MedDiet), data on the sodium intake is scarce. This study aimed to quantify the association between sodium excretion and the adherence to the MedDiet in the elderly. A representative sample of 1500 Portuguese adults (≥65 years) was assessed (1321 were eligible for the present analysis). A 24 h urine sample was collected and analysed for creatinine and sodium. Excessive sodium intake was defined as above 2000 mg/day. The adherence to the MedDiet was assessed by the PREDIMED. A binary logistic regression model was conducted to evaluate the association between urinary sodium excretion and the adherence to the MedDiet. Odds Ratios (OR) and respective 95% Confidence Intervals (95% CI) were calculated. Excessive sodium excretion was observed in 80.0% of men and 91.5% of women whereas a high adherence to the MedDiet was reported by 42.2% of women and 46.4% of men. After adjusting for confounders, excessive sodium excretion was associated with a high adherence to the MedDiet in men (OR = 1.94; 95% CI: 1.03–3.65) but not in women. These results show that the MedDiet can be an important source of sodium and highlight the need for implementing strategies to reduce sodium intake when following a MedDiet.

Estimation of sodium and potassium intakes assessed by two 24-hour urine collections in a city of Indonesia

Intakes of excess Na and insufficient K are two major contributors of heart diseases and stroke development. However, no precise study has previously been carried out on Na and K intakes among Indonesian adults. The present study aimed to estimate the Na and K intakes using two consecutive 24-h urine collections. Participants were community-dwelling adults aged between 20 and 96 years, randomly selected from a pool of resident registration numbers. Of the 506 participants, 479 (240 men and 239 women) completed urine collections. The mean Na excretion was 102·8 and 100·6 mmol/d, while the mean K excretion was 25·0 and 23·4 mmol/d for men and women, respectively. Na and K excretions were higher in participants with a higher BMI. A higher K excretion was associated only with younger age. More than 80 % of the participants consumed more than 5 g/d of salt (the upper limit recommended by the Indonesian government), whereas none of them consumed more than 3510 mg/d of K (the lower limit). The high Na and low K intakes, especially high Na among participants with high BMI, should be considered when future intervention programmes are planned in this country.

Impact of self-monitoring of salt intake by salt meter in hypertensive patients: A randomized controlled trial (SMAL-SALT)

Salt intake over reference level would result in elevated blood pressure (BP) and long‐term morbidity. Salt meter is a device used to detect sodium content in daily food. This study aimed to evaluate the efficacy of salt‐meter addition to dietary education. The authors conducted a randomized‐controlled trial in hypertensive patients with uncontrolled BP (systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg). Patients were randomized to receive salt meter plus dietary education (group A) or education only (group B), and followed up for 8 weeks. The primary endpoint was change in 24‐h urinary sodium excretion. Changes in BP, salt taste sensitivity, cardio‐ankle vascular index (CAVI) were also analyzed. There were total number of 90 patients who had complete follow‐up, 45 in each group. Mean age was 62.9 years and 53% were females. Mean baseline 24‐h urine sodium was 151.6 mmol/24 h and mean SBP and DBP were 152.8 and 83.4 mmHg, respectively. Baseline characteristics were similar between two groups. At 8 weeks, mean change in urine sodium were –31.83 mmol/24 h and 0.36 mmol/24 h in group A and group B, respectively (p = .006). Mean decrease in BP were SBP, 14.44 versus 8.22 mmHg (p = .030), and DBP 5.53 versus 1.93 mmHg (p = .032). The salt sensitivity was improved more in group A. There was no different between change in CAVI. From this study, salt meter in conjunction with dietary education, for self‐monitoring of salt intake is superior to education alone in hypertensive patients, and provided better blood pressure control. Salt meter should be considered in uncontrolled hypertensive patients.

Urinary sodium excretion and dietary sources of sodium intake in community-dwelling Chinese adults aged 50 years and over

OBJECTIVE

This study examined Na intake and identified the major food sources of Na in healthy Chinese adults aged ≥50 years in Hong Kong.

DESIGN

Participants who completed a baseline assessment of a randomised controlled trial assessing the effectiveness of exercise and nutrition supplementation on improving physical and cognitive functions were included. A single 24-h urine sample and a 3-d diet record were used to measure urinary Na excretion and dietary intake, respectively. The compliances to the WHO (<5 g/d) and China Nutrition Society (<6 g/d) recommendations for salt intake were assessed based on the urinary Na excretion. The relative contribution of sixteen food groups to the dietary Na intake was expressed as percentages. Associations between food groups and urinary Na excretion were analysed using multiple linear regression.

SETTING

Community facilities.

PARTICIPANTS

Totally, 114 healthy Chinese adults (mean age 60·6 years, 55 % women).

RESULTS

The mean urinary Na excretion over 24-h was 2876·6 ± 1249·4 mg/d (7·3 ± 3·2 g salt/d). Overall, 22·8 % of participants met the WHO recommendation and 34·2 % met the Chinese Nutrition Society recommendation for salt intake. The major food sources of dietary Na intake were condiments (42·4 %), cereals and their products (16·8 %) and soups (13·5 %). Higher intakes of seafood and nuts were associated with lower urinary Na excretion.

CONCLUSIONS

Public health strategies should target healthy Chinese adults in Hong Kong to modify the current patterns of Na intake. Targeting condiments, cereals and their products and soups will be an important strategy to reduce their Na intake.

Estimation of salt intake assessed by 24-h urinary sodium level among adults speaking different dialects from the Chaoshan region of southern China

OBJECTIVE

Dietary salt intake may vary depending on different lifestyles. We aimed to estimate the different salt intakes and evaluate the knowledge and self-awareness about salt among people speaking the Teochew, Teochew-Hakka and Hakka dialects in the Chaoshan region of southern China.

DESIGN

The study followed a cluster sampling of residents in Chaoshan region. General characteristics, lifestyles, health status as well as knowledge and self-awareness related to salt intake were investigated using a questionnaire. Anthropometric variables as well as Na and K excretion in a 24-h urine collection were measured.

SETTING

Chaoshan region of China.

PARTICIPANTS

Four hundred fifteen adults who spoke only one of these three dialects.

RESULTS

The salt intake of adults who spoke the Teochew, Teochew-Hakka and Hakka dialects was 7·19 (interquartile range (IQR) 5·29-10·17), 9·03 (IQR 6·62-11·54) and 10·12 (IQR 7·61-12·82) g/d, respectively, with significant differences between Teochew and Teochew-Hakka speakers and between Teochew and Hakka speakers (both P < 0·05). The Na:K ratio for adults who spoke the three dialects was 3·00 (IQR 2·00-4·11), 3·50 (IQR 2·64-4·82) and 4·52 (IQR 3·35-5·97), respectively, and differed significantly among the groups (all P < 0·05). Multiple linear regression analysis showed increased Na:K ratio associated with hypertension (β = 0·71, P = 0·043) in Hakka speakers. Knowledge and self-awareness about salt intake were poor in this population.

CONCLUSIONS

Salt intake was closely related to lifestyles and was higher than the upper limit (5 g/d) recommended by the WHO in adults of Chaoshan, especially those speaking the Hakka dialect.

C, Galloway D, Schweizer ML, Guclu H, Cousins J, Lingle C, Yearwood GMH, Li K, Calderone P, Noble E, Gao H, Rainey J, Uzicanin A, Read JM. Age-specific social mixing of school-aged children in a US setting using proximity detecting sensors and contact surveys

Comparisons of the utility and accuracy of methods for measuring social interactions relevant to disease transmission are rare. To increase the evidence base supporting specific methods to measure social interaction, we compared data from self-reported contact surveys and wearable proximity sensors from a cohort of schoolchildren in the Pittsburgh metropolitan area. Although the number and type of contacts recorded by each participant differed between the two methods, we found good correspondence between the two methods in aggregate measures of age-specific interactions. Fewer, but longer, contacts were reported in surveys, relative to the generally short proximal interactions captured by wearable sensors. When adjusted for expectations of proportionate mixing, though, the two methods produced highly similar, assortative age-mixing matrices. These aggregate mixing matrices, when used in simulation, resulted in similar estimates of risk of infection by age. While proximity sensors and survey methods may not be interchangeable for capturing individual contacts, they can generate highly correlated data on age-specific mixing patterns relevant to the dynamics of respiratory virus transmission.

Elevated Salt Taste Threshold Is Associated with Increased Risk of Coronary Heart Disease

High salt intake has been associated with coronary heart disease (CHD). The salt taste threshold could affect the salt intake, but its role in CHD is uncertain. We studied the association of salt taste threshold with CHD. In this study, the levels of salt detection threshold, recognition threshold, and taste preference were higher in CHD than in controls. The salt taste recognition threshold was significantly associated with CHD, and the significant association persisted after adjustment for traditional risk factors. Individuals with high level of salt taste recognition threshold were at a greater risk of CHD. Coincident occurrence of high level of salt taste recognition threshold, hypertension, and diabetes increased the risk of CHD. Thus, a high level of salt taste recognition threshold increases the risk of CHD, and the concurrence of high level of salt taste recognition threshold, hypertension, and diabetes further increases the risk of CHD.

Practical Method for Salt Intake Follow-Up in Hypertensive Patients

Background: Obese and hypertensive (HT) patients should restrict salt intake. In excessive salt intake, ouabain-like compounds inhibit Na/K-ATPase (Na+ pump), which increases intracellular Na+ and Ca2+. Ca2+ has a vasotonic effect on arteries and an inotropic effect on the heart and may cause cortical opacities in the lens. To our knowledge, there is still no practical method for salt intake follow-up. This study tested whether salt intake follow-up can be performed with the help of opacity tracking. Methods: In total, 400 HT patients (age 30-69 years) with cortical lens opacities were included in the study. Changes in opacities based on biomicroscopic examination at baseline and after 3 months were recorded digitally with the help of imaging software. Salt intake at 1 and 3 months was evaluated with a 24-hr urine Na assay. Changes in opacities were compared among group 1 (∼50% salt reduction), group 2 (∼10% salt reduction), and group 3 (∼15% salt increase). Results: Age and changes in small opacity diameter (SOD) and large opacity diameter (LOD) were the most important determinants of the 50% salt reduction in the third month. For changes in LOD, the sensitivity was 88.5% [confidence interval (95% CI) 85.2-91.7] and specificity was 95.5% (95% CI 93.1-98.7) for predicting a 50% salt restriction during the 3-month period. For SOD, the values were 85% (95% CI 82.5-87) and 95% (95% CI 92.3-97.5), respectively. Conclusions: Opacity changes are a practical method for predicting a 50% reduction in salt intake over a 3-month period in 30- to 59-year-old HT patients.

Sodium Intake, Blood Pressure and Cardiovascular Disease

Sodium intake reduction has been emphasized because sodium adversely impacts health, especially blood pressure (BP), and the cardiovascular (CV) disease risk. However, data obtained from several cohort studies have raised questions regarding the effects of high sodium intake on BP and the CV disease risk. In the present study, we systematically reviewed the literature to evaluate these associations. Studies showing negative associations between urine sodium and BP and CV outcomes relied on estimated 24-hour urine sodium from spot urine that is inappropriate for determining sodium intake at an individual level. Furthermore, controversy about the association between 24-hour urine sodium and BP may have been caused by different characteristics of study populations, such as age distribution, ethnicity, potassium intake and the inclusion of patients with hypertension, the different statistical methods and BP measurement methods. Regarding the association between sodium intake and the CV disease risk, studies showing negative or J- or U-shaped associations used a single baseline measurement of 24-hour urine sodium in their analyses. However, recent studies that employed average of subsequently measured 24-hour urine sodium showed positive, linear associations between sodium intake and CV outcomes, indicating that controversies are caused by the different sodium intake measurement methods and analytic designs. In conclusion, the study shows that positive associations exist between sodium intake and BP, CV outcomes, and mortality, and that the argument that reducing sodium intake is dangerous is invalid. Sodium intake reduction should be recommended to all, and not limited to patients with hypertension or CV disease.

Dietary Vitamin C Deficiency Is Associated With Health-Related Quality of Life and Cardiac Event-free Survival in Adults With Heart Failure

BACKGROUND

Vitamin C deficiency is prevalent in adults with heart failure (HF). Little is known about the relationship of dietary vitamin C deficiency with health outcomes in adults with HF.

OBJECTIVE

The study's aim was to determine the relationships of vitamin C deficiency measured at baseline with health-related quality of life (HRQOL) and cardiac event-free survival in patients with HF measured 1 year later.

METHOD

A total of 251 patients with HF completed a 4-day food diary. Dietary vitamin C deficiency was defined as daily intake less than the estimated average requirement from the Institute of Medicine of 75 mg/d for men and 60 mg/d for women. Health-related quality of life was assessed using the Minnesota Living with Heart Failure Questionnaire at 12 months. Patients were followed for a median of 1 year to determine time to the first event of cardiac-related hospitalization or death. Data were analyzed by hierarchical linear and Cox proportional hazards regressions.

RESULTS

One hundred patients (40%) had vitamin C deficiency. Dietary vitamin C deficiency was associated with poorer HRQOL at 12 months (β = 0.16, P = .02) after controlling for demographic and clinical variables. During the follow-up period, 59 patients (24%) had cardiac events. In Cox regression, vitamin C deficiency predicted shorter cardiac event-free survival after adjusting for the same covariates (hazards ratio, 1.95; 95% confidence interval, 1.08-3.51).

CONCLUSION

Vitamin C deficiency was associated with poorer HRQOL and shorter cardiac event-free survival in patients with HF. The findings suggest that encouraging patients with HF to consume a diet rich in fruits/vegetables to prevent vitamin C deficiency may lead to better health outcomes.

Mean dietary salt intake in Nepal: A population survey with 24-hour urine collections

High salt (sodium chloride) intake raises blood pressure and increases the risk of developing hypertension, a major risk factor for cardiovascular disease. Little is known about salt intake in Nepal, and no study has estimated salt consumption from 24-hour urinary sodium excretion. Participants (n = 451) were recruited from the Community-Based Management of Non-Communicable Diseases in Nepal (COBIN) cohort in 2018. Salt intake was estimated by analyzing 24-hour urinary sodium excretion. Multivariate linear regression was used to estimate differences in salt intake. The mean (±SD) age and salt intake were 49.6 (±9.8) years and 13.3 (±4.7) g/person/d, respectively. Higher salt intake was significantly associated with male gender (β for female = -2.4; 95% CI: -3.3, -1.4) and younger age (β_10 years  = -1.4; 95% CI: -1.4, -0.5) and higher BMI (β = 0.1; 95% CI: 0.0, 0.2). A significant association was also found between increase in systolic blood pressure and higher salt intake (β = 0.3; 95% CI: 0.0, 0.7). While 55% reported that they consumed just the right amount of salt, 98% were consuming more than the WHO recommended salt amount (<5 g/person/d). Daily salt intake in this population was over twice the limit recommended by the WHO, suggesting a substantial need to reduce salt intake in this population. It also supports the need of global initiatives such as WHO's Global Hearts Initiative SHAKE technical package and Resolves to Save Lives for sodium reduction in low- and middle-income countries like Nepal.

A survey of Chinese consumers' knowledge, beliefs and behavioural intentions regarding salt intake and salt reduction

OBJECTIVE

Globally, China is among the 'saltiest' nations. In order to support current nationwide salt reduction initiatives, we investigated Chinese consumers' knowledge, beliefs and behaviours related to salt intake and salt reduction.

DESIGN

A cross-sectional face-to-face survey was carried out, focusing on salt knowledge, beliefs and behaviours related to salt intake and salt reduction, perceptions of salt reduction responsibility and support for different national strategies.

SETTING

The survey was carried out in China mainland.

PARTICIPANTS

Consumers (n 2444) from six of seven major geographical regions in China participated in the survey. After data cleaning, a sample of 2430 was included in the final analysis.

RESULTS

A majority of Chinese consumers believed that salt added during home cooking was the biggest contributor to their salt intake. Knowledge gaps existed in the awareness of salt hidden in certain foods and flavouring products. Chinese consumers in general were interested in lowering their salt intake. They were aware of salt reduction tools, but the adoption level was low. Consumers expressed strong support for promotion of salt-restriction spoons and public education, but not fiscal policies (e.g. salt-related tax or subsidies). In terms of individual differences, education status demonstrated a substantial impact on salt reduction knowledge and behaviour.

CONCLUSIONS

There is still big room to 'shake' Chinese consumers' salt habit. The present study provides important evidence and consumer insights to support China's efforts to meet its salt reduction targets.

A town level comprehensive intervention study to reduce salt intake in China: protocol for a cluster randomised controlled trial

INTRODUCTION

Salt intake in China (≈12 g/day) is more than twice the upper limit recommended by the WHO (5 g/day). To reduce salt intake, Action on Salt China (ASC) was launched in 2017. As one of four randomised controlled trials (RCTs) in the ASC programme, a comprehensive intervention study was designed to test whether all the components of the interventions adopted by other RCTs are acceptable, scalable and effective when provided to a region in the real world.

METHODS AND ANALYSIS

Using a cluster RCT design, 2688 participants were selected from 48 towns (clusters) in 12 counties in 6 provinces and assigned to the intervention group or the control group. Randomisation was performed after the baseline survey was completed. Information on salt-related knowledge, attitude and practice (KAP), blood pressure and 24-hour urinary sodium were collected. The intervention includes government engagement, health education and other intervention components targeting restaurants, home cooks and primary school students and their families that have been used in other RCTs. The control group will not receive the intervention. The project will be followed up for 2 years, with the intervention being carried out for the first year only. The primary outcome is salt intake measured by 24-hour urinary sodium excretion after 1 year. The secondary outcomes are the long-lasting effectiveness on salt intake and blood pressure measured by the same method, as well as salt-related KAP and blood pressure at the 1-year and 2-year follow-ups. Process evaluation and health economics analysis will be conducted as well.

ETHICS AND DISSEMINATION

The study was reviewed and approved by the Institutional Review Board of the National Center for Chronic and Noncommunicable Disease Control and Prevention, the Chinese Center for Disease Control and Prevention, and Queen Mary Research Ethics Committee. Results will be disseminated through presentations, publications and social media.

TRIAL REGISTRATION NUMBER

ChiCTR1800018119.

Salt content of sauces in the UK and China: cross-sectional surveys

OBJECTIVES

(1) To assess the changes in the salt content of sauces in the UK in the past 10 years; (2) to compare the salt content of sauces in China with equivalent products sold in the UK and (3) to calculate the proportion of sauce products meeting the salt targets set by the UK Department of Health (DoH).

DESIGN

Cross-sectional surveys from the nutrition information panels of sauces.

SETTING

Major retailers in London, Beijing and Shijiazhuang operating at data collection times.

MAIN OUTCOME MEASURE

Salt content of sauces.

RESULTS

Relative change in the median salt content of UK products ranged from -70.6% to +3.0% in sauces for which salt targets were set, whereas it ranged from -27.1% to +111.5% in sauces without targets. Median salt contents were on average 4.4-fold greater in Chinese sauces compared with their UK equivalents surveyed during the same period (2015-2017). Only 13.4% of the Chinese products met the UK 2017 salt targets, compared with 70.0% of UK products.

CONCLUSION

In the UK, the target-based approach contributed to the reduction in the salt content of sauces over the course of the past 10 years. Currently, large variations in salt content exist within the same categories of sauces and 70% of the products have met DoH's 2017 targets, demonstrating that further reductions are possible and lower salt targets should be set. In China, salt content of sauces is extremely high with similarly large variations within same categories of sauces, demonstrating the feasibility of reducing their salt content. As processed foods (including sauces) are expected to become an important contributor to salt intake in China, national salt reduction efforts such as setting salt targets would be a valuable, proactive strategy.

Relationship between 24-hour urinary sodium excretion and blood pressure in the adult population in Shandong, China

The main objective of this study was to determine baseline salt intake levels in a sample of the adult population of Shandong province and to establish the relationship between urinary sodium excretion and blood pressure. A total of 512 participants were recruited, and all the participants provided complete 24‐hour urine collections. Physical assessment and socioeconomic status of participants were collected at the same time. The mean 24‐hour urinary sodium excretion of all subjects was 228.0 ± 127.5 mmol/24 hours. Estimated salt intake was higher in obese subjects (17.6 ± 8.8 g/d) compared with overweight subjects (15.6 ± 8.0 g/d) and those with a normal BMI (13.9 ± 6.8 g/d). Likewise, urinary sodium excretion of hypertensive participants was dramatically higher than that of non‐hypertensive ones, the equivalent of 18.2 ± 9.1 g/d vs 13.3 ± 6.8 g/d. Urinary sodium was significantly associated with SBP (β = 1.08, P = .018) after adjustment for potential confounders. In summary, we found significantly high levels of salt intake in Shandong Province, particularly in obese and hypertension subjects. It is quite important to improve public education about reducing salt intake to control blood pressure among Shandong people.

Twenty-Four-Hour Urinary Sodium and Potassium Excretion in China: A Systematic Review and Meta-Analysis

Background

In China, high sodium and low potassium intakes result in elevated blood pressure, a major cause of cardiovascular disease, yet the intake estimates lack accuracy and nutritional strategies remain limited.

Methods and Results

We aimed to determine sodium and potassium intake by systematically searching for and quantitatively summarizing all published 24‐hour urinary sodium and potassium data (ie, the most accurate method). MEDLINE, EMBASE, Scopus, China National Knowledge Infrastructure, and Wanfang were searched up to February 2019. All studies reporting 24‐hour urinary sodium or potassium in China were included; hospitalized patients were excluded. Data were pooled using random‐effects meta‐analysis and heterogeneity was explored with meta‐regression. Sodium data were reported in 70 studies (n=26 767), 59 of which also reported potassium (n=24 738). Mean sodium and potassium excretions were 86.99 mmol/24 h (95% CI, 69.88–104.10) and 14.65 mmol/24 h (95% CI, 11.10–18.20) in children aged 3 to 6 years, 151.09 mmol/24 h (95% CI, 131.55–170.63) and 25.23 mmol/24 h (95% CI, 22.37–28.10) in children aged 6 to 16 years, and 189.07 mmol/24 h (95% CI, 182.14–195.99) and 36.35 mmol/24 h (95% CI, 35.11–37.59) in adults aged >16 years. Compared with southern China, sodium intake was higher in northern China (P<0.0001) but is declining (P=0.0066).

Conclusions

Average sodium intake in all age groups across China is approximately double the recommended maximum limits, and potassium intake is less than half that recommended. Despite a decline, sodium intake in northern China is still among the highest in the world, and the North–South divide persists. Urgent action is needed to simultaneously reduce sodium and increase potassium intake across China.

Evaluation of an education program based on the theory of planned behavior for salt intake in individuals at risk of hypertension

This study was conducted to evaluate an education program based on the theory of planned behavior (TPB) for salt intake in individuals at risk of hypertension. This randomized controlled trial was conducted from February 2017 to December 2017 in Shahediyeh, Yazd Province, Iran. For this purpose, 140 people were selected and assigned to two groups of 70 each, namely, intervention and control. Data were gathered by a self-administered TPB based questionnaire, and also 24-h urinary sodium and potassium levels and systolic and diastolic blood pressure were measured. The intervention group received TPB based on a training package, while the control group received no intervention. Post-test was administered 2 months after completion of the intervention. Independent and paired t-tests, χ2 and analysis of covariance (ANCOVA) were used for data analysis. All mean scores on TPB constructs increased significantly except motivation to comply and power of control for intervention group. Average salt intake decreased in intervention group compared with the control group (-4.73 g/day �0.73 versus -0.24 g/day �0.94, P < 0.001), but systolic and diastolic blood pressure did not change significantly in intervention group compared with control group. TPB can be implemented along with other approaches in educational programs to reduce salt intake. Code: IRCT201701108803N3.

Salt, Hypertension, and the Lens

BACKGROUND

Salt is important in the pathogenesis of hypertension (HT). Salt-sensitive hypertension (SSH) accounts for about half of all HT cases. In SSH, sodium/potassium adenosine triphosphatase (Na⁺/K⁺-ATPase) activity is impaired. Impaired Na⁺/K⁺-ATPase activity in the lens epithelium results in cortical opacities in the peripheral equator of the lens. We investigated the sensitivity of cortical lens opacities in detecting SSH.

METHODS

The study included 191 SSH and 159 non-SSH, salt-resistant HT (SRH) patients (350 HT patients total), aged 40-80 years. One hundred twenty-four sex- and age-matched patients without a HT diagnosis made up the control group. Daily salt intake of all groups was calculated from 24-hr urinary Na excretion. SSH was diagnosed when the difference in mean arterial blood pressure values obtained during high- and low-Na diets was ≥10%. Non-SSH, SRH was diagnosed when the difference was <10%.Two researchers examined the presence of cortical lens opacities biomicroscopically using the diffuse, direct, Scheimpflug, and retroillumination from fundus methods.

RESULTS

Total lens opacity was predictive of SSH among all cases (P < 0.001), with a sensitivity and specificity of 75.4% [95% confidence interval (CI): 68.6-81.3] and 83.6% (95% CI: 77.0-89.0), respectively. Its positive and negative predictive values were 84.7% (95% CI: 79.4-88.8) and 73.9% (95% CI: 68.6-78.5), respectively.

CONCLUSIONS

Lens opacities can be used as a finding that can be easily observed in the detection of SSH and excess salt intake.

Associations of urinary sodium levels with overweight and central obesity in a population with a sodium intake

Background

Previous studies have reported an association between dietary sodium intake and overweight/central obesity. However, dietary survey methods were prone to underestimate sodium intake. Therefore, this study investigated the associations of calculated 24-h urinary sodium excretion, an index of dietary sodium intake, with various obesity parameters including body mass index (BMI) and waist circumference (WC) in a population with a relatively high sodium intake.

Methods

A total of 16,250 adults (aged ≥19 years) and 1476 adolescents (aged 10-18 years), with available information on spot urine sodium levels and anthropometric measurements from the Korea National Health and Nutrition Examination Survey (KNHANES) were included in this study. We calculated 24-h urine sodium excretion levels from spot urine sodium levels using the Tanaka formula.

Results

In adults, those with high sodium excretion levels (≥ 3200 mg) showed increased odds of overweight and central obesity compared to those with low urinary sodium excretion level (< 2200 mg) (odds ratio [OR] = 2.17, 95% confidence interval [CI] = 1.90-2.49 for overweight; OR = 2.50, 95% CI = 2.13-2.94 for central obesity). These associations were also observed in adolescents (OR = 5.80, 95% CI = 3.17-10.60 for overweight; OR = 4.19, 95% CI = 1.78-9.89 for central obesity).

Conclusions

The present study suggests that reducing salt intake might be important for preventing overweight and central obesity, especially in adolescents. However, because the present study was conducted with cross-sectional study design, further longitudinal studies are warranted to confirm the causal relationship between urinary sodium excretion and overweight/central obesity.

Sodium excretion and associated factors in urine samples of African descendants in Alcântara, Brazil: a population based study

In most countries, salt intake has been excessive and constitutes one of the main risk factors for disease development, especially hypertension. Factors such as age, gender, sedentary lifestyle, smoking, African descent, obesity, dietary habits and family history of hypertension may be associated with high blood pressure. Studies show a positive association between the excretion of sodium and increased blood pressure. We evaluated the urinary excretion of sodium and associated factors in isolated urine samples of African descendants from remaining Quilombos. We performed a cross-sectional, population-based study with 1162 African descendants living in remaining quilombos in Alcântara, Maranhão, Brazil. Demographic, nutritional, clinical and laboratory data were analyzed. Urinary sodium excretion was estimated using the Kawasaki equation. A multivariate linear regression model was used to identify the variables related to sodium excretion. The average age was 37.6 ± 11.8 years and 51.2% were women. The prevalence of hypertension was 21.3%. The average urinary excretion of sodium was high, especially among the hypertensive (217.9 ± 90.1 vs. 199.2 ± 83.0 mmol/d; p = .002). After an adjusted analysis, only the waist circumference (odds ratios (OR) = 1.16; confidence intervals(CI)95%: 1.03-1.30), triglyceride (OR = 1.13; CI95%: 1.05-1.22), systolic blood pressure (OR = 1.19; CI95%: 1.08-1.32) and Chronic Kidney Disease Epidemiology (CKD-EPI;OR = 1.24; CI95%: 1.15-1.35) remained related to urinary sodium excretion. African descendants had a high rate of sodium excretion, especially among those who had hypertension. Abdominal adiposity, triglyceride and systolic blood pressure levels and renal function by CKD-EPI equation were associated to urinary sodium excretion.

Constituent analysis of iodine intake in Armenia

OBJECTIVE

We sought to assess the universal salt iodization (USI) strategy in Armenia by characterizing dietary iodine intake from naturally occurring iodine, salt-derived iodine in processed foods and salt-derived iodine in household-prepared foods.

DESIGN

Using a cross-sectional cluster survey model, we collected urine samples which were analysed for iodine and sodium concentrations (UIC and UNaC) and household salt samples which were analysed for iodine concentration (SI). SI and UNaC data were used as explanatory variables in multiple linear regression analyses with UIC as dependent variable, and the regression parameters were used to estimate the iodine intake sources attributable to native iodine and iodine from salt in processed foods and household salt.

SETTING

Armenia is naturally iodine deficient; in 2004, the government mandated a USI strategy.

SUBJECTS

We recruited school-age children (SAC), pregnant women (PW) and non-pregnant women of reproductive age (WRA).

RESULTS

From thirteen sites covering all provinces, sufficient urine and table salt samples were obtained from 312 SAC, 311 PW and 332 WRA. Findings revealed significant differences between groups: contribution of native iodine ranged from 81% in PW to 46% in SAC, while household salt-derived iodine contributed from 19% in SAC to 1% in PW.

CONCLUSIONS

Differences between groups may reflect differences in diet. In all groups, household and processed food salt constituted a significant part of total iodine intake, highlighting the success and importance of USI in ensuring iodine sufficiency. There appears to be leeway to reduce salt intake without adversely affecting the iodine status of the population in Armenia.

Salt Intake of Lactating Women as Assessed by Modified Food Weighted Records

OBJECTIVE

High salt intake among lactating women can increase the risk of hypertension and cardiovascular disease in infants/offspring. However, considering the limited salt intake data in lactating women, the aims of this study were to compare the salt intake assessed by modified food weighted records (FWR) with that estimated by 24-h urinary sodium excretion and to investigate the salt intake of lactating women.

METHODS

In total, 30 lactating women aged 20-39 years who were 2 to 4 months postpartum were recruited from the cities of Tianjin and Luoyang in China. The household salt intakes of the lactating women were collected by modified FWR for 3 days. Information on the gender, age, eating behaviours and labour intensity of the family members and guests dining at home during the 3 days was recorded. Meanwhile, 24-h urine samples of lactating women were collected.

RESULTS

The salt intakes of the lactating women estimated by modified FWR and 24-h urinary sodium excretion were 8.50 ± 5.32 g/d and 9.34±3.74 g/d (t=-1.29, P=0.207), respectively, which exceeded the WHO recommendation of 5 g/d. There was a significant correlation (r=0.628, P < 0.001) between the salt intakes assessed by the two methods. A Bland-Altman plot showed no significant mean difference between the two methods (salt intake measured by 24-h urinary sodium excretion-salt intake assessed by modified FWR=0.46 g/d, P=0.207).

CONCLUSIONS

The modified FWR is a reliable tool to assess the salt intake of lactating women. The salt intake of lactating women in China remains higher than the WHO recommendation and should be restricted through further efforts.

Alarming prevalence and clustering of modifiable noncommunicable disease risk factors among adults in Bhutan: a nationwide cross-sectional community survey

BACKGROUND

Bhutan is currently facing a double burden of non-communicable (NCDs) and communicable diseases, with rising trends of NCDs. The 2014 STEPS survey identified high prevalence of several NCD risk factors; however, associations with socio-demographic characteristics as well as clustering of risk factors were not assessed. This study aimed to determine the distribution and clustering of modifiable NCD risk factors among adults in Bhutan and their demographic and social determinants.

METHODS

This was secondary analysis of data from NCD Risk Factors WHO STEPS Survey 2014 in Bhutan. A weighted analysis was conducted to calculate the prevalence of NCD risk factors, and associations were explored using weighted log-binomial regression models.

RESULTS

This study included 2822 Bhutanese aged 18-69 years; 52% were 18-39 years, 62% were female, and 69% were rural resident. Prevalence of high salt intake, unhealthy diet and tobacco use were 99, 67 and 25% respectively. Raised blood pressure was the commonest (36%) modifiable biological risk factor followed by overweight (33%). The median NCD risk factors per person was 3 (Inter Quartile Range: 2-4); 52.5%% had > = 3 risk factors. A statistically significant difference was found between male vs. female in alcohol consumption(aPR 0.71, 95% CI: 0.53-0.97), low physical activity(aPR 2.06, 95% CI: 1.54-2.75), impaired fasting glycaemia(aPR 1.24, 95% CI: 1.01-1.52), and being overweight(aPR 1.46, 95% CI: 1.31-1.63). Low physical activity was more common among those with secondary and above education level vs. those without any formal education(aPR 1.71, 95% CI: 1.24-2.35), and among those residing in urban areas vs. those in rural(aPR 3.43, 95% CI: 2.27-5.18). Older participants and urban residents were more likely to have > = 3 NCD risk factors compared to younger(aPR 1.46, 95% CI: 1.35-1.58) and rural residents(aPR 1.21, 95% CI: 1.10-1.32).

CONCLUSION

Lifestyle modifications at the population level are urgently required in Bhutan as several NCD risk factors such as high salt intake, unhealthy diet, overweight, and high blood pressure were alarmingly high and frequently clustered. Moreover there is a need to consider policy and socio-political and economic factors that have undermined global and national progress to address the rise of NCDs and their risk factors in Bhutan as elsewhere.

Prevalence of severe early childhood caries and associated socioeconomic and behavioral factors in Xinjiang, China: a cross-sectional study

BACKGROUND

This study assessed the prevalence and severity of early childhood caries (ECC) and identified socioeconomic and behavioral correlates of the disease in preschool children living in Xinjiang.

METHODS

For this cross-sectional survey, 1727 children aged 3-5 years in Xinjiang were randomly recruited using a three-stage cluster sampling procedure. The "dmft" index according to the WHO 1997 criteria was used to assess ECC and severe ECC (S-ECC). A questionnaire was completed by caregivers. Variables included sociodemographic characteristics, dietary and oral hygiene behaviors, and access to dental services. The statistical associations of variables with ECC, S-ECC, and dmft were evaluated by univariate and multiple logistic regression analyses.

RESULTS

The prevalence of ECC was 78.2% and that of S-ECC was 41.2%; mean dmft scores were 5.61 ± 3.56 and 8.17 ± 2.94, respectively. The prevalence of ECC was significantly higher in children from Ining (OR 2.747; 95% CI 2.033-3.713), those whose caregivers had caries (OR 1.78; 95% CI 1.245-2.547), those with a dental visit in the past (OR 2.023; 95% CI 1.429-2.865), and those whose parents had received instructions on oral health care (OR 2.171; 95% CI 1.44-3.272), and increased significantly at age 4 years (OR 2.09; 95% CI 1.506-2.901) and 5 years (OR 2.666; 95% CI 1.855-3.833) and in children who starting tooth brushing at a young age (OR 1.363; 95% CI 1.171-1.587), and decreased significantly in children with a more educated mother (OR 0.817; 95% CI 0.688-1), those from high-income families (OR 0.667; 95% CI 0.582-0.765), those with low consumption of sweets (OR 0.66; 95% CI 0.57-0.763), and those who seldom ate before sleep (OR 0.557; 95% CI 0.437-0.712).

CONCLUSIONS

ECC and S-ECC remain a serious problem among preschool children in Xinjiang. Caries rates were associated with sociodemographic and behavioral factors, which could be modified by public health strategies, including protection of primary dentition, extension of insurance to cover oral preventive services, improvement of the oral health care system, and public health education.

Preoperative selective vs non-selective α-blockade in PPGL patients undergoing adrenalectomy

PURPOSE

Preoperative preparation for adrenalectomy for pheochromocytomas and paragangliomas (PPGL) is universally recognized as necessary, while the optimal strategy remains controversial. Our aims were to increase intraoperative hemodynamic stability, expedite postoperative recovery, decrease side effects and reduce costs for patients with PPGL undergoing adrenalectomy.

METHODS

We identified 526 patients undergoing open adrenalectomy for PPGL in the West China Hospital of Sichuan University between May, 2007 and December, 2016. 149 patients received preoperative selective α-blockade with phenoxybenzamine, and 377 patients received non-selective α-blockade with prazosin, doxazosin or terazosin. There were no statistical differences between groups regarding preoperative patient and tumor characteristics. Operations were planned once hypertensive patients were well-controlled with blood pressure ≤130/85 mmHg. Intraoperatively, all patients received arterial blood pressure monitoring, and indwelling urinary catheters to record urine output. We recorded intraoperative hemodynamics, status in the postanesthesia or intensive care unit, postoperative recovery and complications.

RESULTS

Patients in the non-selective group showed a more significant decline in postoperative systolic blood pressure than the selective group (P = 0.041). Also, patients in the non-selective group appeared to receive a long-term anti-hypertensive effect, especially for diastolic blood pressure (P = 0.037), which was a novel finding, based on the current literature.

CONCLUSIONS

Our results confirmed that non-selective α-blockade produced a more significant anti-hypertensive effect than selective α-blockade. However, we found no significant difference in intraoperative hemodynamic instability, postoperative recovery and postoperative complications between groups.

Validation and Assessment of Three Methods to Estimate 24-h Urinary Sodium Excretion from Spot Urine Samples in High-Risk Elder Patients of Stroke from the Rural Areas of Shaanxi Province

Background: 24-h urine collection is regarded as the "gold standard" for monitoring sodium intake at the population level, but ensuring high quality urine samples is difficult to achieve. The Kawasaki, International Study of Sodium, Potassium, and Blood Pressure (INTERSALT) and Tanaka methods have been used to estimate 24-h urinary sodium excretion from spot urine samples in some countries, but few studies have been performed to compare and validate these methods in the Chinese population. Objective: To compare and validate the Kawasaki, INTERSALT and Tanaka formulas in predicting 24-h urinary sodium excretion using spot urine samples in 365 high-risk elder patients of strokefrom the rural areas of Shaanxi province. Methods: Data were collected from a sub-sample of theSalt Substitute and Stroke Study. 365 high-risk elder patients of stroke from the rural areas of Shaanxi province participated and their spot and 24-h urine specimens were collected. The concentrations of sodium, potassium and creatinine in spot and 24-h urine samples wereanalysed. Estimated 24-h sodium excretion was predicted from spot urine concentration using the Kawasaki, INTERSALT, and Tanaka formulas. Pearson correlation coefficients and agreement by Bland-Altman method were computed for estimated and measured 24-h urinary sodium excretion. Results: The average 24-h urinary sodium excretion was 162.0 mmol/day, which representing a salt intake of 9.5 g/day. Three predictive equations had low correlation with the measured 24-h sodium excretion (r = 0.38, p < 0.01; ICC = 0.38, p < 0.01 for the Kawasaki; r = 0.35, p < 0.01; ICC = 0.31, p < 0.01 for the INTERSALT; r = 0.37, p < 0.01; ICC = 0.34, p < 0.01 for the Tanaka). Significant biases between estimated and measured 24-h sodium excretion were observed (all p < 0.01 for three methods). Among the three methods, the Kawasaki method was the least biased compared with the other two methods (mean bias: 31.90, 95% Cl: 23.84, 39.97). Overestimation occurred when the Kawasaki and Tanaka methods were used while the INTERSALT method underestimated 24-h sodium excretion. Conclusion: The Kawasaki, INTERSALT and Tanaka methods for estimation of 24-h urinary sodium excretion from spot urine specimens were inadequate for the assessment of sodium intake at the population level in high-risk elder patients of stroke from the rural areas of Shaanxi province, although the Kawasaki method was the least biased compared with the other two methods.

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.

Salt intake, blood pressure, and socioeconomic disparities among government employees in Sri Lanka: a cross-sectional study

Our study estimated salt intake, examined the association between blood pressure (BP) and salt intake, and explored the socioeconomic variations in salt intake among administrators (government employees). This is a cross-sectional study. We studied 168 randomly selected administrators aged 30-60 years attached to government offices in Colombo, Sri Lanka. Self-administered questionnaire gathered information on socio-demographic, work-related information, lifestyle practices, and medical history. BP, 24-hour urine collection, and anthropometric indices were measured. Mean salt intake levels measured by 24-hour Sodium (Na) excretion in hypertensives and non-hypertensives were 202.56 (SD ± 85.45) mmol/day and 176.79 (SD ± 82.02) mmol/day, respectively. A 100-mmol increase in sodium was associated with an average increase of 3.1 (95 per cent CI 2-4.2) mmHg in systolic BP and 1.8 (95 per cent CI 0.89-2.6) mmHg in diastolic BP. Higher salt intake was found in managerial assistants (12.38 ± 5.0 g) compared with senior officers (10.84 ± 4.9 g). Salt intake among these administrators was alarmingly high. High salt intake was positively associated with hypertension and more prevalent in lower socioeconomic strata.

Salt reduction in China: a state-of-the-art review

Objective

This study aimed to reveal the latest evidence on salt reduction initiatives in China in order to identify the contextual cost-effective interventions, as well as the barriers encountered during China’s long march to reach its population salt reduction goal.

Background

Population-based salt reduction has been considered as one of the most cost-effective strategies in the world for the prevention and control of noncommunicable diseases. China, along with its sustained economic growth, faces increasing burdens from chronic diseases such as cardiovascular and kidney diseases. With policy support and cross-sector collaboration, various salt reduction initiatives have been adopted in China in order to reduce such dietary risk, especially since the beginning of this millennium.

Methods

This study conducted structured literature reviews in both English and Chinese databases and synthesized the latest evidence on the association of salt intake and health, as well as salt intake among Chinese and population-based salt reduction strategies in China and around the world.

Findings

Dietary salt restriction has been found to contribute to the reduction of blood pressure among both the normotensives and hypertensives bringing associated reduced disease burdens and great public health benefits. With gender, ethnic, and regional variations, salt intake levels in the population in China are well above the recommended threshold and physiological need. Admittedly, excessive salt intake precipitates the high prevalence of hypertension and cardiovascular disease among the Chinese. Considering that the majority of the dietary salt is added during cooking in China, salt substitutes, salt restriction tools, and health education are the most common salt reduction initiatives with varying levels of effectiveness and acceptability among the Chinese population.

Implication

Overwhelming evidence is in support of a well-coordinated nationwide salt restriction initiative as a key public health strategy for the prevention and control of hypertension and its related diseases. Orchestrated efforts from the government, industries, academia, health professionals, and the general public are required to achieve China’s long-term goal for salt reduction.

Does the Theory of Planned Behavior Predict Dietary Sodium Intake in Patients With Heart Failure?

Sodium intake in heart failure (HF) is a crucial but poorly understood phenomenon. Theoretical models promote understanding and provide a context for rational appraisal of complex situations. The purpose of this study was to determine which factors were associated with sodium intake in HF patients using theory of planned behavior (TPB). In this study, patients’ ( N = 244) attitudes, subjective norms, and perceived behavioral control (tenets of the TPB) were assessed using the Dietary Sodium Restriction Questionnaire. Sodium intake was estimated objectively by 24-hr urinary sodium excretion (UNa). The average UNa was 3,811 mg. Subjective norms, gender, and New York Heart Association functional class were associated with sodium intake ( p < .001). Thus, it is important for health care providers to clearly express their approval of following low-sodium diet to their HF patients, and include significant others in interventions to help patients develop/maintain a positive subjective norm to decrease sodium intake and reduce HF exacerbations.

School based education programme to reduce salt intake in children and their families (School-EduSalt): cluster randomised controlled trial

OBJECTIVE

To determine whether an education programme targeted at schoolchildren could lower salt intake in children and their families.

DESIGN

Cluster randomised controlled trial, with schools randomly assigned to either the intervention or control group.

SETTING

28 primary schools in urban Changzhi, northern China.

PARTICIPANTS

279 children in grade 5 of primary school, with mean age of 10.1; 553 adult family members (mean age 43.8).

INTERVENTION

Children in the intervention group were educated on the harmful effects of salt and how to reduce salt intake within the schools' usual health education lessons. Children then delivered the salt reduction message to their families. The intervention lasted for one school term (about 3.5 months).

MAIN OUTCOME MEASURES

The primary outcome was the difference between the groups in the change in salt intake (as measured by 24 hour urinary sodium excretion) from baseline to the end of the trial. The secondary outcome was the difference between the two groups in the change in blood pressure.

RESULTS

At baseline, the mean salt intake in children was 7.3 (SE 0.3) g/day in the intervention group and 6.8 (SE 0.3) g/day in the control group. In adult family members the salt intakes were 12.6 (SE 0.4) and 11.3 (SE 0.4) g/day, respectively. During the study there was a reduction in salt intake in the intervention group, whereas in the control group salt intake increased. The mean effect on salt intake for intervention versus control group was -1.9 g/day (95% confidence interval -2.6 to -1.3 g/day; P<0.001) in children and -2.9 g/day (-3.7 to -2.2 g/day; P<0.001) in adults. The mean effect on systolic blood pressure was -0.8 mm Hg (-3.0 to 1.5 mm Hg; P=0.51) in children and -2.3 mm Hg (-4.5 to -0.04 mm Hg; P<0.05) in adults.

CONCLUSIONS

An education programme delivered to primary school children as part of the usual curriculum is effective in lowering salt intake in children and their families. This offers a novel and important approach to reducing salt intake in a population in which most of the salt in the diet is added by consumers.Trial registration ClinicalTrials.gov NCT01821144. .

Salt intake, knowledge of salt intake, and blood pressure control in Chinese hypertensive patients

A cross-sectional study involving 2502 subjects was conducted to evaluate salt intake, knowledge of salt intake, and blood pressure control in hypertensive patients. The blood pressure control rate was 33.5% among the hypertensive patients. Of the patients, 69.9% had salt intake higher than 6 g/d. Overall 35.0% knew the recommended salt intake, and 94.9% knew that "excess salt intake can result in hypertension." Altogether, 85.8% of patients had received health education related to a low-salt diet at some time. Patients who consumed less than 6 g/d of salt had a higher control rate than those who consumed more than 6 g/d (48.7% vs. 27.0%; χ(2) = 111.0; P < .001). Patients with knowledge of the recommended salt intake had a higher control rate than those without (45.8% vs. 26.9%; χ(2) = 91.3; P < .001). Our findings suggest a high salt intake and low blood pressure control rate among Chinese hypertensive patients. Knowledge of recommended salt intake is inappropriate for patients with education of a low-salt diet.

Estimation of daily salt intake through a 24-hour urine collection in Pohang, Korea

There is an established relationship between a high salt diet and public health problems, especially hypertension and cardiovascular disease. We estimated daily salt intake in a group of adults and assessed its association with related variables in Pohang, Korea. We conducted a cross-sectional survey in 2013 with 242 adults. Urine was collected for 24 hr to estimate daily salt intake, and questionnaires about salt preference were administered. The mean daily salt intake was 9.9±4.6 g. There was no difference in salt intake between high systolic blood pressure (SBP) participants and normal SBP participants (10.5±4.7 g/d vs. 9.6±4.3 g/d, P=0.339), but high diastolic blood pressure (DBP) participants reported more salt intake than normal DBP participants (10.4±4.9 g/d vs. 9.7±4.1 g/d, P=0.049). Salt intake and body mass index demonstrated a positive correlation (P=0.001). A preference for Korean soup or stew was associated with high salt intake (P=0.038). Dietary salt intake in Korean adults is still higher than the recommendation from the World Health Organization. More efforts should be made to reduce the salt consumption of Korean adults.

Analysis of correlation between 24-hour urinary sodium and the degree of blood pressure control in patients with chronic kidney disease and non-chronic kidney disease

We investigated the association between 24-hr urinary sodium (24UNA) and adequacy of blood pressure (BP) control in patients with chronic kidney disease (CKD) and nonCKD. All data were collected retrospectively by accessing the electrical medical records in patients with 24-hr urine collection and serum creatinine. Enrolled 400 subjects were subgrouped by the amount of 24UNA, or CKD stage. The appropriate BP was defined as BP < 130/80 mmHg for subjects with proteinuria, and BP < 140/90 mmHg for subjects without proteinuria. The mean level of 24UNA was 166±76 mEq/day. The 24UNA group was an independently related factor to diastolic BP as a continuous variable. The rate of appropriate BP control in patients with proteinuria was highest in 24UNA <100 mEq/L (P=0.012). The odds to fail achievement of BP target in subjects with 24UNA≥90 mEq/day was 2.441 (1.249-4.772, P=0.009) higher than that of 24UNA <90 mEq/day among participants with proteinuria. There was difference in the amount of 24UNA between CKD and non-CKD except each stage of CKD group. In conclusion, salt intake estimated by 24-hr urine sodium excretion is a risk factor to achieve appropriate BP control.