Biglycan reduces body weight by regulating food intake in mice and improves glucose metabolism through AMPK/AKT dual pathways in skeletal muscle.

While biglycan (BGN) is suggested to direct diverse signaling cascades, the effects of soluble BGN as a ligand on metabolic traits have not been studied. Herein, we tested the effects of BGN on obesity in high-fat diet (HFD)-induced obese animals and glucose metabolism, with the underlying mechanism responsible for observed effects in vitro. Our results showed that BGN administration (1 mg/kg body weight, intraperitoneally) significantly prevented HFD-induced obesity, and this was mainly attributed to reduced food intake. Also, intracerebroventricular injection of BGN reduced food intake and body weight. The underlying mechanism includes modulation of neuropeptides gene expression involved in appetite in the hypothalamus in vitro and in vivo. In addition, BGN regulates glucose metabolism as shown by improved glucose tolerance in mice as well as AMPK/AKT dual pathway-driven enhanced glucose uptake and GLUT4 translocation in L6 myoblast cells. In conclusion, our results suggest BGN as a potential therapeutic target to treat risk factors for metabolic diseases.

Hypoxia-inducible factor 2α is a novel inhibitor of chondrocyte maturation.

Hypoxic environment is essential for chondrocyte maturation and longitudinal bone growth. Although hypoxia-inducible factor 1 alpha (Hif-1α) has been known as a key player for chondrocyte survival and function, the function of Hif-2α in cartilage is mechanistically and clinically relevant but remains unknown. Here we demonstrated that Hif-2α was a novel inhibitor of chondrocyte maturation through downregulation of Runx2 stability. Mechanistically, Hif-2α binding to Runx2 inhibited chondrocyte maturation by Runx2 degradation through disrupting Runx2/Cbfß complex formation. The Hif-2α-mediated-Runx2 degradation could be rescued by Cbfß transfection due to the increase of Runx2/Cbfß complex formation. Consistently, mesenchymal cells derived from Hif-2α heterozygous mice were more rapidly differentiated into hypertrophic chondrocytes than those of wild-type mice in a micromass culture system. Collectively, these findings demonstrate that Hif-2α is a novel inhibitor for chondrocyte maturation by disrupting Runx2/Cbfß complex formation and consequential regulatory activity.

Risk of Osteoarthritis is Positively Associated with Vitamin D Status, but Not Bone Mineral Density, in Older Adults in the United States.

OBJECTIVE: We examined the risk of osteoarthritis (OA) according to vitamin D status and bone mineral density (BMD) using a cross-sectional nationally representative database. METHODS: National Health and Nutrition Examination Survey (NHANES) data from 2007 to 2010 were used to assess the relationship between OA and vitamin D status in adults aged ≥40 years (n = 2934). NHANES data from 2005 to 2010 and 2013 to 2014 were analyzed to investigate the association between OA and BMD (n = 5949). Vitamin D status was categorized as serum 25-hydroxyvitamin D (25OHD) <20 ng/mL or ≥20 ng/mL. Bone health was classified according to T-score (normal, osteopenia, or osteoporosis) and BMD tertile. Risk of OA was assessed using logistic regression and adjusted for covariates. RESULTS: Participants with serum 25OHD <20 ng/mL had a 37% lower risk of OA (95% confidence interval (CI) [0.39-0.99], P = 0.046). When stratified by sex, the odds ratio for OA in men with lower vitamin D status was 0.35 (95% CI [0.15-0.81], P = 0.02). No association was found in women. The risk for OA did not differ according to BMD tertile or T-score classification. CONCLUSIONS: The risk of OA is lower in older men with 25OHD less than 20 ng/mL but not in older women. Bone mineral density is not associated with OA risk in older adults in the United States.

Core Binding Factor ß Plays a Critical Role During Chondrocyte Differentiation.

Core binding factor ß (Cbfß) is a partner protein of Runx family transcription factors with minimally characterized function in cartilage. Here we address the role of Cbfß in cartilage by generating chondrocyte-specific Cbfß-deficient mice (Cbfb(Δch/Δch) ) from Cbfb-floxed mice crossed with mice expressing Cre from the Col2a1 promoter. Cbfb(Δch/Δch) mice died soon after birth and exhibited delayed endochondral bone formation, shorter appendicular skeleton length with increased proliferative chondrocytes, and nearly absent hypertrophic chondrocyte zones. Immunohistochemical and quantitative real-time PCR analyses showed that the number and size of proliferative chondrocytes increased and the expression of chondrocyte maturation markers at the growth plates, including Runx2, osterix, and osteopontin, significantly diminished in Cbfb(Δch/Δch) mice compared to wild type mice. With regard to signaling pathways, both PTHrP-Ihh and BMP signaling were compromised in Cbfb(Δch/Δch) mice. Mechanistically, Cbfß deficiency in chondrocytes caused a decrease of protein levels of Runx transcription factors by accelerating polyubiquitination-mediated proteosomal degradation in vitro. Indeed, Runx2 and Runx3, but not Runx1, decreased in Cbfb(Δch/Δch) mice. Collectively, these findings indicate that Cbfß plays a critical role for chondrocyte differentiation through stabilizing Runx2 and Runx3 proteins in cartilage.

Habitual dietary intake of ß-carotene, vitamin C, folate, or vitamin E may interact with single nucleotide polymorphisms on brachial-ankle pulse wave velocity in healthy adults.

PURPOSE: The interaction between genetics and diet may explain the present disagreement in the protective role of vitamin intake on cardiovascular disease. We cross-sectionally assessed the interaction of habitual dietary intake of ß-carotene, vitamin C, folate, and vitamin E with single nucleotide polymorphisms (SNPs) on brachial-ankle pulse wave velocity (baPWV), a measure of arterial stiffness. METHODS: Dietary intakes of ß-carotene, vitamin C, folate, and vitamin E were quantified by a food frequency questionnaire in 3198 healthy men and women (≥ 40 years) from the Korea Multi-Rural communities Cohort study. baPWV was measured, and 19 SNPs were genotyped. The associations and interactions between dietary vitamin intake, SNP genotype, and baPWV were assessed using general linear models. RESULTS: In both men and women, dietary intake of ß-carotene, vitamin C, folate, or vitamin E and baPWV were not directly associated. Vitamin C, folate, and vitamin E intake had an interaction with rs4961 (ADD1) genotype on baPWV in men. rs4961 also interacted with folate intake on baPWV in women. In women, rs10817542 (ZNF618) and rs719856 (CD2AP) had an interaction with ß-carotene and folate intake and rs5443 (GNB3) had an interaction with vitamin E intake on baPWV. In general, minor allele homozygotes with low vitamin intake had higher baPWV than other subgroups. Results were similar when supplement users were excluded. CONCLUSIONS: Higher intake of dietary vitamin C, folate, and vitamin E may be related to high baPWV in healthy Korean men who are minor allele homozygotes of rs4961. In healthy Korean women, dietary folate, ß-carotene, and vitamin E intake may affect baPWV differently according to rs4961, rs10817542, rs719856, or rs5443 genotype. Greater dietary intake of these nutrients may protect those that are genetically vulnerable to stiffening of the arteries.

Risk of all-cause mortality is associated with multiple health-related lifestyle behaviors and does not differ between urban and rural areas in Korea.

BACKGROUND/OBJECTIVES: Urban-rural inequities in health and mortality exist in Korea, a highly centralized developed country. The potential impact of multiple health-related lifestyle behaviors on mortality and difference between urban and rural areas is not fully understood. This study aimed to investigate the effect of high-risk health behaviors on all-cause mortality among residents living in urban and rural in Korea. SUBJECTS/METHODS: Cross-sectional analyses were conducted on 8,298 adults aged 40 yrs and older from the Korea National Health and Nutrition Examination Survey 2013-2015. High-risk behaviors were defined as having poor diet quality, current smoking, high-risk drinking, or insufficient physical activity. Mortality status was linked to the Cause of Death data followed up to December 31, 2019. The associations between all-cause mortality and high-risk behaviors were evaluated using Cox proportional hazard regression models adjusted for age, sex, education, income, and survey year. Population attributable fractions (PAFs) were calculated, and effect modification analysis was conducted. Participants were stratified by residential area (urban or rural). RESULTS: During the follow-up (median: 5.4 yrs), 313 deaths occurred. A higher proportion of rural residents than urban residents engaged in multiple high-risk behaviors (28.9% vs. 22.6%; P < 0.0001). As individual factors, a greater risk of mortality was associated with poor diet quality, current smoking, and inadequate physical activity, and these tendencies persisted in rural residents, especially for diet quality. Multiple high-risk behaviors were positively associated with a higher risk of mortality in Koreans living in urban and rural areas. PAF (95% confidence interval) was 18.5% (7.35-27.9%) and 29.8% (16.1-40.2%) in urban and rural residents, respectively. No additive or multiplicative effect of the region was observed. CONCLUSION: The higher prevalence of multiple high-risk lifestyle behaviors in rural residents may explain the higher mortality in rural areas compared to urban areas. Comprehensive public health policies to improve health-related behaviors in rural populations may be needed.

Korean Working Group on Sarcopenia Guideline: Expert Consensus on Sarcopenia Screening and Diagnosis by the Korean Society of Sarcopenia, the Korean Society for Bone and Mineral Research, and the Korean Geriatrics Society.

Despite the introduction of a diagnostic code and acceptance of a diagnostic process for sarcopenia as a new health technology in Korea, many practitioners remain unfamiliar with the evaluation of sarcopenia. Thus, the Korean Working Group on Sarcopenia (KWGS) developed clinical practice guidelines for the diagnosis of sarcopenia in older Korean adults. A two-phase Delphi interview comprising 19 questions was conducted with 40 expert panelists, 22 of whom participated in the first round between June and August 2022. The second round of the Delphi interview included the remaining 11 questions that were not agreed upon in the first round. The screening process for sarcopenia includes various questionnaires and examinations used in different research and clinical settings. The diagnostic process for sarcopenia was simplified by combining the steps of case finding and assessment. The Short Physical Performance Battery test was given particular emphasis owing to its multifaceted nature. Regardless of muscle mass, having low muscle strength with low physical performance is considered clinically relevant and newly defined as "functional sarcopenia." Comprehensive geriatric assessment is important for diagnosing sarcopenia. The KWGS's clinical guideline aims to facilitate the early detection of sarcopenia by allowing various screening tools to be used in a unified process and reducing confusion about which tools to use for diagnosis. This recommendation expands the conceptual definition of sarcopenia as a complex pathophysiological state in line with the concept of frailty and aims to stimulate further research on the diagnosis and management of sarcopenia in clinical settings.

Low Vitamin D Status Is Associated with Increased Risk of Mortality in Korean Men and Adults with Hypertension: A Population-Based Cohort Study.

Background Recent randomized controlled trials (RCTs) have shown no effect of vitamin D supplementation on cardiovascular disease, cancer events and mortality or all-cause mortality in Western populations. However, there has been a lack of research on populations with low vitamin D status, including Asians. In addition, there have been indications that an individual's sex or hypertension status may affect the relationship between vitamin D status and mortality. In this study, we retrospectively assessed the association between vitamin D status and all-cause, cardiovascular, and cancer mortality in Koreans using a national database, and stratified participants according to sex and hypertension status. Methods Participants in the Korean Health and Nutrition Examination Survey 2008−2014, who consented to their data being synthesized with mortality data (up to December 2019), were included (n = 22,742; mean follow-up: 8.9 years). Participants' level of serum 25-hydroxyvitamin D (25(OH)D) was measured by radioimmunoassay and categorized as <12, 12−19.9, and ≥20 ng/mL. A Cox proportional hazard model was used to assess the risk of mortality. Results In the total sample, risk of all-cause, cancer, and cardiovascular mortality was greater in adults with a serum 25(OH)D level below 12 and 12−19.9 ng/mL than those with ≥20 ng/mL. Men and adults with hypertension, who had low vitamin D status, had a higher risk of cancer and cardiovascular mortality, but not women or adults without hypertension. Similar results were observed when various cutoffs for 25(OH)D were employed, or extrinsic deaths were excluded. Conclusions Vitamin D status below 20 ng/mL is associated with a higher risk of mortality in Korean adults, especially in men and those with hypertension, on the basis of data from a nationally representative sample. Further RCTs on Asian adults with low vitamin D status are warranted.

Position Statement: Vitamin D Intake to Prevent Osteoporosis and Fracture in Adults.

Adequate vitamin D status is essential for bone health. New randomized controlled trials investigating the effect of vitamin D supplementation on bone health have recently been published. This position statement updates and expands on the previous 2015 position statement of the Korean Society for Bone and Mineral Research on the adequate vitamin D status for healthy older adults (age ≥ 70 years) and those at high risk of osteoporosis and fracture (adults on osteoporosis medications) to maintain serum 25-hydroxy-vitamin D (25[OH]D) levels ≥ 20 ng/mL but < 50 ng/mL. A serum 25(OH)D level of 30 ng/mL may be beneficial for those on anti-resorptives. Vitamin D can be obtained from ultraviolet light exposure and diet. To reach the target vitamin D status through intake, adults must consume at least 400 IU/day to reach 20 ng/mL and 800 to 1,000 IU/day to reach 30 ng/mL. Foods familiar to the Korean diet that are high in vitamin D content or consumed frequently enough to positively impact vitamin D status are introduced in addition to the amount required to help reach one's target vitamin D status.

Higher food literacy scores are associated with healthier diet quality in children and adolescents: the development and validation of a two-dimensional food literacy measurement tool for children and adolescents.

BACKGROUND/OBJECTIVES: Most child and adolescent food literacy measurement tools focus on nutrition and food safety. However, the importance of aspects related to the food system such as food distribution and food waste and their effects on environmental sustainability is growing. We therefore developed and validated a two-dimensional tool for children (8-12 years old) and adolescents (13-18 years old) that can comprehensively measure food literacy. The association of food literacy with diet quality and self-reported health was assessed. SUBJECTS/METHODS: First, we developed a food literacy conceptual framework that contains food system and literacy dimensions through a literature review, focus group interviews, and expert review. After a face validity study, we conducted the main survey (n = 200) to validate the questionnaire. Construct validity and reliability were assessed using exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and Cronbach's alpha. RESULTS: As a result of the Delphi study, content validity was confirmed for the remaining 30 items after two items were excluded (content validity ratio = 0.86). Eleven items were excluded from the EFA results, while the CFA results indicated appropriate fit indices for the proposed model (comparative fit index = 0.904, root mean square error of approximation = 0.068). The final food literacy questionnaire consisted of 19 questions and comprised 5 factors: production, distribution, selection, preparation and cooking, and intake. Food literacy was positively associated with diet quality, as assessed by the Nutrition Quotient score, in both children and adolescents and with self-reported health in adolescents. CONCLUSIONS: Based on this integrated conceptual framework, a two-dimensional 19-item food literacy measurement tool was developed and verified for practical use to improve the diet quality and food-related environmental sustainability awareness of children and adolescents.

Prolonged or Transition to Metabolically Unhealthy Status, Regardless of Obesity Status, Is Associated with Higher Risk of Cardiovascular Disease Incidence and Mortality in Koreans.

The risk of chronic disease and mortality may differ by metabolic health and obesity status and its transition. We investigated the risk of cardiovascular disease (CVD) and cancer incidence and mortality according to metabolic health and obesity status and their transition using the nationally representative Korea National Health and Nutrition Examination Survey (KNHANES) and the Ansan-Ansung (ASAS) cohort of the Korean Genome and Epidemiology Study. Participants that agreed to mortality linkage (n = 28,468 in KNHANES and n = 7530 adults in ASAS) were analyzed (mean follow-up: 8.2 and 17.4 years, respectively). Adults with no metabolic risk factors and BMI <25 or ≥25 kg/m2 were categorized as metabolically healthy non-obese (MHN) or metabolically healthy obese (MHO), respectively. Metabolically unhealthy non-obese (MUN) and metabolically unhealthy obese (MUO) adults had ≥1 metabolic risk factor and a BMI < or ≥25 kg/m2, respectively. In KNHANES participants, MUN, and MUO had higher risks for cardiovascular mortality, but not cancer mortality, compared with MHN adults. MHO had 47% and 35% lower risks of cancer mortality and all-cause mortality, respectively, compared to MHN. Similar results were observed in the ASAS participants. Compared to those persistently MHN, the risk of CVD was greater when continuously MUN or MUO. Transitioning from a metabolically healthy state to MUO also increased the risk of CVD. Few associations were found for cancer incidence. Using a nationally representative cohort and an 18-year follow-up cohort, we observed that the risk of CVD incidence and mortality and all-cause mortality, but not cancer incidence or mortality, increases with a continuous or a transition to an unhealthy metabolic status in Koreans.

Perspectives on the systematic review for the 2020 Dietary Reference Intakes for Koreans for calcium.

An accurate assessment of the recommended calcium (Ca) intake may contribute to reducing the risk of fractures and chronic diseases, ultimately improving quality of life. This review was performed to summarize key findings of Ca studies, investigate the effect of Ca intake on health outcomes, and determine the adequacy of evidence to revise the 2015 Dietary Reference Intakes for Koreans (KDRIs) for Ca in 2020. Databases were searched for intervention studies that assessed health outcomes by providing Ca in diets or as supplements. The framework of the systematic review comprised conducting literature searches, data extraction, quality assessment of the literature, and summarizing key findings relevant to set the Estimated Average Requirement (EAR) and Tolerable Upper Intake Level (UL) for Ca for the 2020 KDRI. The final search was performed in June 2019. A total of 13,309 studies were identified through databases and manual search. Sixtyfive studies were included in the final quality assessment and were summarized according to health indicators. As bone health was used as an indicator of the EAR for Ca, literature reports on bone health were further categorized by the life-cycle stage of the participants. This systematic review did not find new evidence that could be applied to the general Korean adult population, including postmenopausal women, for defining a new EAR for Ca in the 2020 KDRIs. Evidence in most of the reviewed literature was considered weak; however, some evidence was found that could improve the criteria on how the EAR for Ca was determined in children and adolescents. A review of the literature for the 2020 KDRIs for Ca did not find strong evidence in order to change the recommended values of the 2015 KDRIs. More clinical interventions are required among Koreans to strengthen the body of evidence to warrant the revision of the KDRIs.

A short education session increases the accuracy of estimated food records in young Korean women during a controlled-feeding study.

BACKGROUND/OBJECTIVES: Despite the widespread use of dietary assessment tools, the validity of food records has not been evaluated in Koreans. We assessed the accuracy of estimated food records and the effect of a short education session in young Korean women. SUBJECTS/METHODS: Thirty women (aged 18-23 yrs) each completed 3 food records during a controlled-feeding study. One educational session was provided on day 2 of the study. Food records were analyzed for the accuracy of food items and portion size estimation according to food group (grains; meat, fish, eggs, and beans; vegetables; fruit; dairy; and oils and sugars) and type of dish (rice, kimchi, soup, side dishes, spreads, beverages, and snacks). Reported food items were categorized as exact, close, or far matches, exclusions, or intrusions. Portion sizes were evaluated as accurate, similar, or inaccurate estimates, or missing. The means of days 2 and 3 were used to assess post-education results. Paired t-tests were performed to assess the effects of the education session. RESULTS: The mean percentages of exact matches, close matches, far matches, and exclusions on day 1 were 80.9%, 10.9%, 2.0%, and 6.2%, respectively, and mean intrusions observed were 0.1. The education session slightly increased the accuracy of recorded food items. The percentages of accurate, similar, and inaccurate estimates, and missing portion sizes were 11.7%, 19.8%, 12.2%, and 56.3%, respectively, at baseline. The percentage of missing portion size estimates decreased to 14.0% after the education session, resulting in an increase in the percentages of all other estimates. An increase was observed in the accuracy of reported portion sizes of vegetables, rice, and kimchi. CONCLUSIONS: In young Korean women, estimated food records are highly accurate for food items but not for portion size estimates without prior education. A short education session can improve the accuracy of portion size estimation. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0003307.

Short Term Intake of Undaria pinnatifida Does Not Affect Bone Biomarkers in Young Korean Women with Low Calcium Intake.

Calcium intake is essential for bone health, but young Korean women have low calcium intakes. Seaweeds have high calcium content, which may affect calcium metabolism. Twenty nine females aged 18-39 years with low calcium intake (< 400 mg/day) participated in a 19-day open-label randomized controlled trial. During the first five days, participants adhered to a controlled-feeding protocol followed by a two-week supplementation period in free-living conditions. The treatment group (n = 14) received an additional 200 mg Ca/day through Undaria pinnatifida and Porphyra in meals during the controlled-feeding period, and as U. pinnatifida noodles during days 6-19. Mineral intake (Ca, P, Mg, Na, and K) was assessed from diet composites and three 24-hour recalls during the controlled-feeding and free-living periods, respectively. Fasting serum levels of calcium, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D (1,25[OH]D), phosphorus, parathyroid hormone (PTH), and alkaline phosphatase (ALP) were assessed at baseline, day 6, and day 19. Statistical analyses were performed by Student's t-test and mixed ANOVA. Mean intakes of all minerals during days 1-5 and mean Ca and Mg intakes during days 6-19 were greater in the treatment group compared to the control group. No group effect or group and time interaction was observed in serum biomarkers. Serum 1,25(OH)D increased while PTH and ALP tended to decrease on day 6 but returned to baseline values on day 20. Short-term intake of U. pinnatifida and Porphyra does not affect calcium metabolism in young Korean women with low calcium intakes. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0003307.

Smoking May Affect Pulmonary Function through DNA Methylation: an Epigenome-Wide Association Study in Korean Men.

Smoking is a risk factor for various disease outcomes and is one of the modifiers of DNA methylation. We aimed to identify smoking-related DNA methylation sites (CpG-sites) and test whether one identified CpG-site is associated with smoking-related traits and pulmonary function. We obtained DNA methylation data of 209 men from the Korean Genome and Epidemiology Study analyzed by Illumina's HumanMethylation450 array. To identify smoking-related DNA methylation sites, epigenome-wide association analysis of smoking status was conducted, adjusting for age, area, current drinking status, and body mass index. We assessed the association between smoking intensity and DNA methylation of cg05951221 (AHRR), the CpG showing the strongest largest difference in DNA methylation among the 5 hypomethylated CpGs in current smokers compared to never smokers. The association between DNA methylation and pulmonary function was examined longitudinally resulting in a positive association between DNA methylation and forced expiratory volume in 1 second/forced vital capacity, regardless of adjustment for smoking status. This suggests that DNA methylation associates with long-term pulmonary function. Our study contributes to explaining the relationship between smoking and pulmonary function via DNA methylation.

Marine Healing, but Not Additional Intake of Undaria pinnatifida, Benefits Physical and Emotional Exhaustion Symptoms of Menopause.

Menopausal symptoms can persist or worsen even years after menopause and affect women's quality of life. We investigated whether menopausal symptoms were alleviated through a marine healing program and if sea mustard intake additionally benefits these symptoms. A total of 42 menopausal women self-selected to participate as the marine (n = 22) or city group (n = 20). The marine group participated in a 5-day marine healing program consisting of a balanced diet, exercise, and mind-body practices using ocean resources. The city group continued one's daily routine without any intervention. Within the marine group, participants were randomly assigned to consume sea mustard (Undaria pinnatifida) (15.4 g dry weight/day; n = 11) or control (n = 11). Changes in menopausal symptoms were measured using the Menopause Rating Scale (MRS) before, immediately after, and 2 weeks after the end of the marine healing program. The city group completed the MRS at baseline and on day 20. Within subject differences of menopausal symptoms between baseline and immediately after the marine healing program were assessed using paired t-test. Intervention effects were assessed by mixed analysis of variance. Somatic, psychological, and urogenital symptoms were immediately alleviated after the marine healing program. No effect of sea mustard was detected in the marine group. After 2 weeks, the effect of marine healing persisted in physical and mental exhaustion only. A 5-day integrated marine healing program, but not additional sea mustard intake, temporarily alleviated menopausal symptoms. The reduction in physical and mental exhaustion after marine healing can be maintained for 2 weeks. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0004025.

Development of a Comprehensive Food Literacy Measurement Tool Integrating the Food System and Sustainability.

The concept of food literacy is evolving and expanding, increasing the need for a comprehensive measurement tool for food literacy. This study aimed to develop a validated food literacy questionnaire based on an expanded conceptual framework for food literacy. A literature review of existing frameworks and questionnaires for food literacy and focus group interviews (n = 12) were conducted to develop a conceptual framework and candidate questions. A Delphi study (n = 15) and pilot survey (n = 10) to test the preliminary questionnaire's content and face validity were conducted, which were followed by the main survey (n = 200). Construct validity and reliability were assessed using exploratory factor analysis (EFA) and Cronbach's alpha, respectively. Criterion validity was assessed by comparing food literacy scores with food knowledge scores (FN-score) and nutrient quotient scores (NQ-score). By integrating and revising the six existing conceptual frameworks and focus group interview results, we proposed a two-dimensional conceptual framework comprising a literacy dimension and a food system dimension. After reviewing 560 items and categorizing them into 18 domains (3 in the literacy dimension × 6 in the food system dimension), 32 questions were selected. As a result of the Delphi study, two items were deleted, and content validity was confirmed for the remaining 30 items (content validity ratio (CVR) = 0.92). Ten items were revised during the face validation process, and five items were excluded as a result of the EFA. The final food literacy questionnaire comprised 25 questions related to five factors: production, selection, preparation and cooking, intake, and disposal. Food literacy scores were positively associated with FN- and NQ-scores, confirming the reliability and criterion validity of the final questionnaire. The two-dimensional food literacy conceptual framework developed in this study systematically encompasses complex food literacy concepts by adding a food systems dimension (production, selection, preparation and cooking, intake, and disposal domain) to the existing literacy dimension (functional, interactive, and critical literacy domain). Based on this integrated conceptual framework, a 25-item food literacy questionnaire was developed and validated for practical use.

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.

Modulation of Gut Microbiota in Korean Navy Trainees following a Healthy Lifestyle Change.

Environmental factors can influence the composition of gut microbiota, but understanding the combined effect of lifestyle factors on adult gut microbiota is limited. Here, we investigated whether changes in the modifiable lifestyle factors, such as cigarette smoking, alcohol consumption, sleep duration, physical exercise, and body mass index affected the gut microbiota of Korean navy trainees. The navy trainees were instructed to stop smoking and alcohol consumption and follow a sleep schedule and physical exercise regime for eight weeks. For comparison, healthy Korean civilians, who had no significant change in lifestyles for eight weeks were included in this study. A total of 208 fecal samples were collected from navy trainees (n = 66) and civilians (n = 38) at baseline and week eight. Gut flora was assessed by sequencing the highly variable region of the 16S rRNA gene. The α-and ß -diversity of gut flora of both the test and control groups were not significantly changed after eight weeks. However, there was a significant difference among individuals. Smoking had a significant impact in altering α-diversity. Our study showed that a healthy lifestyle, particularly cessation of smoking, even in short periods, can affect the gut microbiome by enhancing the abundance of beneficial taxa and reducing that of harmful taxa.