Association between High Blood Pressure and Intakes of Sodium and Potassium among Korean Adults: Korean National Health and Nutrition Examination Survey, 2007-2012

Association between plant-based diets and risk of metabolic dysfunction-associated steatotic liver disease in Korean adults: A prospective cohort study

OBJECTIVES

Few studies have investigated the correlation between plant-based diet indices (PDIs) and the risk of metabolic dysfunction-associated steatotic liver disease (MASLD) in the Korean population. Therefore, this study aimed to investigate the association between PDIs and the risk of MASLD in Korean adults.

METHODS

This cohort study utilized data from the Health Examinees Study conducted in the South Korean population. Dietary and nutrient intake were assessed at baseline and follow-up using a food frequency questionnaire and the Korean Food Consumption Table. Food items were categorized into overall PDI, healthy PDI (hPDI), and unhealthy PDI (uPDI), with MASLD defined using the fatty liver index. Baseline characteristics and food intake groups were evaluated based on PDI quintiles and stratified by sex. Further analyses involved stratification by age, body mass index, alcohol intake, and physical activity in men and women.

RESULTS

Over a median follow-up period of 4.2 y, MASLD occurred in 1532 participants. Both men and women in the highest hPDI quintile had a reduced risk of MASLD (men: HR: 0.71, 95% CI: 0.55-0.91, p = 0.0031; women: HR: 0.61, 95% CI: 0.48-0.78, p < 0.0001). Conversely, the highest uPDI quintile was associated with a higher risk of MASLD.

CONCLUSIONS

This cohort study revealed an association of the overall PDI and hPDI with a lower risk of MASLD, highlighting the importance of adhering to these types of plant-based diets to prevent MASLD among Korean adults.

Calcium- and Sodium-Rich Food Intake among Koreans with and without Metabolic Syndrome: Cross-Sectional Analysis of the Korean Genome and Epidemiology Study

BACKGROUND

The prevalence of metabolic syndrome (MetS) is increasing. While calcium and sodium are known nutritional factors used for managing MetS, few studies have focused on food-based analyses. This cross-sectional study examined the distribution of calcium- and sodium-rich food intake among Koreans with MetS.

METHODS

This cross-sectional analysis evaluated 130,423 participants from the Health Examinees-Gem cohort study. Foods contributing up to 90% of the calcium and sodium intake were selected from the semi-quantitative food frequency questionnaire, and consumption levels were calculated. MetS was defined as satisfying three or more criteria from the National Cholesterol Education Program Adult Treatment Panel III. The results are presented as odds ratios (OR) with an interquartile range (ORIQR) and 95% confidence interval.

RESULTS

Participants with MetS showed a low calcium intake (ORIQR = 0.95 and 0.92 for men and women, respectively), low consumption of dairy products (ORIQR = 0.92 and 0.89), beverages except for coffee or green tea (ORIQR = 0.97 and 0.96), and bread (ORIQR = 0.96 and 0.94). Men with MetS consumed high total sodium (ORIQR = 1.04), and large amounts of Kimchi (ORIQR = 1.03), fermented paste (ORIQR = 1.04), and noodles (ORIQR = 1.07). Women with MetS consumed more Kimchi than those without MetS (ORIQR = 1.04). The odds ratio for the low calcium and high sodium group compared to the high calcium and low sodium group was 1.26.

CONCLUSION

The MetS group consumed less calcium-rich foods and more sodium-rich foods than those without MetS. Patients with MetS might benefit from precise recommendations of high calcium-rich and low sodium-rich foods.

Inverse association of daily fermented soybean paste (“Jang”) intake with metabolic syndrome risk, especially body fat and hypertension, in men of a large hospital-based cohort

Introduction

Jang is a fermented soybean paste containing salt and is traditionally used as a substitute for salt to enhance the flavor of foods in Korea. It has been speculated that regular consumption of Jang may lower the risk of metabolic syndrome (MetS). We hypothesized that Jang intake was associated with the risk of MetS and its components after adjusting for potential confounders, including sodium intake. The hypothesis was investigated according to gender in a large city hospital-based cohort (n = 58,701) in Korea.

Methods

Jang intake, calculated as the sum of the intakes of Chungkookjang, Doenjang, Doenjang soup, and Ssamjang (a mixture of Doenjang and Kochujang), was included in the semi-quantitative food frequency questionnaire (SQFFQ) administered to the cohort, and the daily Jang intake was estimated. The participants were categorized into low-Jang and high-Jang groups by 1.9 g daily Jang intake. MetS was defined according to 2005 revised United States National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) criteria modified for Asians.

Results

The participants in the low-Jang and high-Jang groups consumed an average of 0.63 g and 4.63 g Jang daily; their total sodium intake was about 1.91 and 2.58 g/day, respectively. The participants in the high-Jang group had higher energy, fiber, calcium, vitamin C, vitamin D, and potassium intake than those in the low-Jang group. After adjusting for covariates, the participants with the highest sodium intake (≥3.31 g/day) were positively associated with MetS risk in the quintiles of men and women. Among the MetS components, waist circumference, fat mass, and hypo-high-density lipoprotein (HDL)-cholesterolemia were positively associated with sodium intake in all participants and women. Unlike the association seen with sodium intake, Jang intake (≥1.9 g/day) was inversely associated with MetS components, including waist circumference, fat mass, serum glucose concentrations, and hypo-HDL-cholesterolemia in all participants and men, after adjusting for covariates including sodium intake.

Discussion

Substituting salt for Jang in cooking may be recommended to prevent and alleviate MetS incidence, and its efficacy for MetS risk was better in men than women. The results can be applied to sodium intake in Asian countries where salt is used to promote flavor.

Effect of low sodium and high potassium diet on lowering blood pressure

Background: Hypertension is the leading factor of cardiovascular mortality and morbidity. Although antihypertensive medical treatment is the cornerstone of blood pressure control, lifestyle modification, including optimal diet therapy, such as dietary approaches to stop hypertension (DASH), cannot be overemphasized.Current Concepts: Due to the mismatch between sodium intake and excretion process being the key mechanisms according to physiologic principles, low sodium and high potassium intakes are the critical components of DASH. If the patient has a sensitive elevation of blood pressure following increased sodium intake, a low sodium diet could be essential for optimal blood pressure control. Salt sensitivity is increased by the activated reninangiotensin system, sympathetic nervous activity, sodium channels disorder, and endothelial dysfunction and frequently observed in the elderly and patients with obesity and chronic kidney disease. Increased potassium intake could attenuate sodium absorption by affecting the intracellular chloride and WNK4 activity, especially in patients with salt sensitivity or high salt intake.Discussion and Conclusion: For low sodium and high potassium intakes, the Na/K diet ratio could be a good target for intervention, and this approach is a critical component of DASH.

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.

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.

Facile Synthesis of In Situ Formable Alginate Composite Hydrogels with Ca2+-Induced Healing Ability

Dental caries have plagued humans for many years. At present, photocrosslinking resin is commonly used in clinics to repair narrow tooth defects, but the ultraviolet light used in this process has unavoidable cytotoxicity. In situ hydrogels with a similar structure to that of the natural extracellular matrix have gradually attracted attention in the field of hard tissue repair engineering. The injectable molding properties of hydrogel also give it the potential to fill irregularly shaped or fine tissue defects. Through a rapid and facile Michael addition reaction, we prepared maleic chitosan (CS-maleic anhydride [MA]) and thiolated alginate (sodium alginate [SA]-SH) to form a CS-MA/SA-SH hydrogel. To endue its mineralize ability, β-glycerophosphate calcium phosphate and calcium carbonate as the precursor of hydroxyapatite (HAp) were premixed in the hydrogel at certain ratios. This kind of hydrogel can quickly form into different shapes within 10 min. It is worth noting that external Ca²⁺ can react with the residual carboxyl groups of SA and provide the hydrogel with a self-healing ability. At the same time, we creatively propose a method that uses alkaline phosphatase to promote the mineralization of HAp in hydrogels, to achieve the purpose of regenerating hard tissue in situ. By examining the properties of hydrogels at different concentrations of calcium and phosphorus salts, we find that the CS-MA/SA-SH hydrogel with 50% (wt.%) inorganic matter presented the best self-healing properties, excellent mineralization of highly crystallized Hap, and has ideal cell compatibility. The potential application of the CS-MA/SA-SH hydrogel in repairing exposed dentin tubules in decayed teeth was explored through preliminary in vitro dental restoration experiments. Obviously, the penetration depth through dentin tubules was better than that of commercial dental sensitizers. In addition, the HAp morphology was affected by the local environment. We believe that this hydrogel can utilize tissues for dental regeneration and mineralization, and the healing ability provides the hydrogel flexibility for further application in hard tissue regeneration.

Mineral Intake Status of Community-Dwelling Elderly from Urban and Rural Areas of South Korea: A Cross-Sectional Study Based on Korean National Health and Nutrition Examination Survey, 2013~2016

We aimed to evaluate the intake of minerals (calcium, phosphorous, sodium, and potassium) in the urban and rural elderly and explore the adequacy of intake and food sources for each mineral using nationwide big data. The study used data from the Korea National Health and Nutrition Examination Survey (KNHANES) between 2013 and 2016. We analyzed 5292 elderly individuals that were aged 65 years and older (2271 men, 3021 women). Daily calcium, phosphorous, sodium, and potassium intake, and they were analyzed using the 24-h dietary recall method. Additionally, the adequacy of intake and food sources for each mineral was analyzed. Blood triglyceride level was significantly higher in rural elderly than in urban elderly. The intake of calcium and potassium per 1000 kcal of energy intake was significantly lower in the rural elderly, and the proportion of participants with calcium intake below the Estimated Average Requirement was significantly higher in the rural elderly than in the urban elderly. The intake of calcium, phosphorous, and potassium in the rural elderly was lower than that in the urban elderly. These results can be used as basic data when making social and environmental policies for the health of the elderly and when providing targeted dietary education for the management of chronic diseases for the elderly.

Association between dietary sodium intake and disease burden and mortality in Koreans between 1998 and 2016: The Korea National Health and Nutrition Examination Survey

BACKGROUND/OBJECTIVES

Sodium intake is positively associated with blood pressure, which may increase the risk for cardiovascular disease (CVD). Therefore, we assessed the disease burden of CVD attributable to sodium intakes above 2,000 mg/day and prospectively investigated the association between dietary/urinary sodium levels and the risk of all-cause and CVD-mortality using the Korea National Health and Nutrition Examination Survey (KNHNES).

SUBJECTS/METHODS

A total of 68,578 and 33,113 participants were included for comparative risk assessment (CRA) analysis and mortality analysis, respectively, and mean follow-up time for mortality was 5.4 years. CRA analysis was used to quantify attributable incidences of stroke, ischemic heart disease (IHD), and deaths attributable to sodium intake between 1998 and 2016. Cox proportional hazard regression model was used to determine the association between sodium intake and all-cause and CVD-mortality.

RESULTS

Mean dietary sodium intake decreased over time, reaching 3,647 mg/day in 2016. Similarly, the population attributable fractions of stroke and IHD, and the number of CVD-associated deaths attributable to high sodium intake/excretion also decreased. In terms of association with mortality, when participants were grouped into quartiles (Q) by energy-adjusted sodium intake, those in Q2 had a lower risk of all-cause mortality than those in Q1 with lower intakes. The risk of CVD-associated mortality was higher only in females with high sodium intake in Q4 than those in Q1.

CONCLUSIONS

This nationwide data indicates that, in line with previous studies of multiple cohorts, both low and high sodium intakes may be associated with an increased risk of mortality; therefore, the optimal sodium intake for Koreans needs to be revised.

Associations of Dietary Sodium, Potassium, and Sodium to Potassium Ratio with Blood Pressure- Regional Disparities in China

High dietary sodium and low potassium intake increase blood pressure and risk of hypertension, but whether the relationship between dietary sodium and potassium and risk of hypertension is different in North China and South China remains unclear. We used data from the longitudinal China Health and Nutrition Survey (CHNS) and selected 6705 adults who participated in at least two waves in 2009, 2011, and 2015 and had no hypertension in baseline. We performed multiple linear regression analysis and multiple logistic regressions stratified by area for the present study design. Sodium and potassium intake were higher in North China (4343.4 and 1624.8 mg/day, respectively) than in South China (4107.8 and 1516.1 mg/d, respectively) (p < 0.05). Multiple linear regression revealed that a positive correlation of sodium intake (β = 0.026, p < 0.05) and ratio of sodium to potassium (Na-K) intake (β = 0.041, p < 0.01) with diastolic blood pressure (DBP) was found in North China, and the association of sodium, potassium, and Na-K intake ratio with blood pressure was different in South China. Multiple logistic regressions documented a similar significant inverse association between dietary potassium intake and risk of hypertension in both North China and South China (risk ratio (RR): 0.63, 95%CI: 0.50–0.79; RR: 0.80, 95%CI: 0.66–0.98, respectively). The risk of hypertension increased in the fourth quartile of dietary sodium and Na-K intake ratio (RR: 1.20, 95%CI: 1.00–1.44; RR: 1.35, 95%CI: 1.13–1.62, respectively) in North China but no association was observed in South China. The current study indicates a different association of dietary sodium and Na-K intake ratio with systolic blood pressure (SBP), DBP, and risk of hypertension in North China and South China.

Association between blood pressure and dietary intakes of sodium and potassium among US adults using quantile regression analysis NHANES 2007-2014

Hypertension has become a major public health challenge, and previous studies have observed associations between hypertension and sodium, potassium, and sodium to potassium ratio. However, little is known about how the whole continuum of blood pressure (BP) is related to dietary intake of sodium and potassium. This study aims to examine quantile-specific associations of blood pressure with dietary intake of sodium and potassium. It is based on national-level, cross sectional data for US adults aged ≥18 years from the National Health and Nutrition Examination Survey (NHANES) 2007-2014. A total of 11,095 eligible subjects were included in this study. Quantile regression (QR) models were used to investigate distributional effects in the dietary intake of sodium and potassium on blood pressure by adjusting the confounding factors. We observed some evidence indicating distributional effects of dietary intake of sodium and potassium on systolic blood pressure (SBP) and diastolic blood pressure (DBP). QR showed that the consumption of sodium was positively associated with SBP (P₁₀) and DBP (P₁₀) in males, and positively associated with DBP (P₈₀-P₉₀) alone in females. Intake of potassium was, however, negatively associated with SBP (P₂₀-P₃₀, P₇₀-P₈₀) in males, and also negatively associated with SBP (P₁₀-P₈₀) and DBP(P₂₀-P₅₀) in females. Sodium to potassium ratio was positively associated with SBP (P₁₀-P₅₀, P₈₀) and DBP (P₇₀-P₉₀) in males, and was positively associated with SBP(P₁₀-P₇₀, P₉₀) in females. QR models provided a more detailed view on associations of SBP and DBP with the dietary intake of sodium and potassium and uncovered the quantile-related patterns.

Fast food consumption and its associations with obesity and hypertension among children: results from the baseline data of the Childhood Obesity Study in China Mega-cities

BACKGROUND

China has seen rapid increase in obesity and hypertension prevalence and fast food consumption over the past decade. We examined status and risk factors for Western- and Chinese fast food consumption and their associations with health outcomes in Chinese children, and examined how maternal factors were associated with child health outcomes.

METHODS

Data of 1626 students aged 7-16 (11.6 ± 2.0) years and their parents in four mega-cities across China (Beijing, Shanghai, Nanjing, and Xi'an) were collected in the 2015 baseline survey of the Childhood Obesity Study in China Mega-cities. Weight, height, waist circumference, and blood pressure were measured. Food intake was assessed using questionnaire. Mixed models were used to examine the associations.

RESULTS

Among the children, 11.1% were obese, 19.7% were centrally obese, and 9.0% had hypertension. Obesity prevalence was much higher in boys than in girls (15.2% vs. 6.9% and 27.4% vs. 11.7%, respectively, both P < 0.001). About half (51.9% and 43.6%) of children consumed Western and Chinese fast food, respectively, over the past 3 months. Compared to those with college or above maternal education level, those with elementary school or below maternal education level were 49% more likely to consume Western fast food (odds ratio [OR] and 95% confidence interval [CI]: 1.49 [1.10-2.03]). Chinese fast food consumption rate increased by 12% with each year of increase in child's age (OR and 95% CI: 1.12 [1.02-1.23]). No significant associations between fast food consumption and health outcomes were detected. Adjusting for Western fast food consumption, children with lower maternal education were 71% and 43% more likely to have obesity and central obesity (ORs and 95% CIs: 1.71 [1.12-2.61] and 1.43 [1.00-2.03], respectively), and maternal body mass index was positively associated with child obesity, central obesity, and hypertension (ORs and 95% CIs: 1.11 [1.06-1.17], 1.12 [1.07-1.17], and 1.09 [1.03-1.15], respectively). Results were similar when Chinese fast food consumption was adjusted for.

CONCLUSIONS

The prevalence of fast food consumption, obesity and hypertension is high among children in major cities in China. Maternal factors affect child outcomes.

Psychosocial Factors and Dietary Practices in Korean Americans

This study was to identify the role of demographics and social support from family and friends in predicting self-efficacy for a healthy diet and healthy dietary practices. A descriptive, cross-sectional study was conducted with a sample of 112 Korean American adults in the southwestern United States. Most were college educated (85.3%), with mean age of 54.0 (± 10.6), and women (66.4%). The findings indicate that gender and education played a moderating role between family support and self-efficacy for a healthy diet, whereas age and education were moderators between support from family and friends and healthy dietary practices. Diet interventions tailored to demographic subgroups may increase self-efficacy, promote healthy dietary practices, and ultimately contribute to a reduction in the rates of critical health conditions and health costs in the community.

The science of salt: A regularly updated systematic review of salt and health outcomes (December 2015-March 2016)

The purpose of this review was to identify, summarize, and critically appraise studies on dietary salt relating to health outcomes that were published from December 2015 to March 2016. The search strategy was adapted from a previous systematic review on dietary salt and health. Overall, 13 studies were included in the review: one study assessed cardiovascular events, nine studies assessed prevalence or incidence of blood pressure or hypertension, one study assessed kidney disease, and two studies assessed other health outcomes (obesity and nonalcoholic fatty liver disease). Four studies were selected for detailed appraisal and commentary. One study met the minimum methodologic criteria and found an increased risk associated with lower sodium intake in patients with heart failure. All other studies identified in this review demonstrated positive associations between dietary salt and adverse health outcomes.

The Association between Urinary Sodium Excretion and Metabolic Syndrome in Korean Adults from the 2010-2011 Korean National Health and Nutrition Examination Survey

Background

The sodium intake of Koreans was higher than that recommended by the World Health Organization. Urinary sodium, which is correlated with sodium intake, can be easily calculated by the Tanaka's equation. This study aimed to evaluate the association between urinary sodium and metabolic syndrome in Korean adults using the 2010–2011 Korean National Health and Nutrition Examination Survey (KNHANES).

Methods

A total of 5,870 participants from the 2010–2011 KNHANES were included in this study. Twenty-four hour urinary sodium was calculated by the Tanaka's equation using spot urine. Participants were divided into tertiles based on urinary sodium levels. The association between urinary sodium and metabolic syndrome was analyzed using multivariate logistic regression analysis.

Results

The odds ratios (ORs) and 95% confidence intervals (CIs) of metabolic syndrome for the 2nd and 3rd tertile of urinary sodium levels was 1.51 (1.16–1.97) and 1.56 (1.23–1.97) compared to the lowest tertile of urinary sodium in men. The ORs and 95% CIs of metabolic syndrome in women were 1.20 (0.95–1.51) for the 2nd tertile and 2.16 (1.68–2.78) for the 3rd tertile. These associations remained statistically significant, even after adjusting for multiple covariates such as age, education, regular exercise, smoking, and alcohol consumption.

Conclusion

These findings indicate that urinary sodium is significantly associated with metabolic syndrome in Korean adults.