Differential association of dietary carbohydrate intake with metabolic syndrome in the US and Korean adults: data from the 2007-2012 NHANES and KNHANES

Low-carbohydrate diet score and chronic obstructive pulmonary disease: a machine learning analysis of NHANES data

Background

Recent research has identified the Low-Carbohydrate Diet (LCD) score as a novel biomarker, with studies showing that LCDs can reduce carbon dioxide retention, potentially improving lung function. While the link between the LCD score and chronic obstructive pulmonary disease (COPD) has been explored, its relevance in the US population remains uncertain. This study aims to explore the association between the LCD score and the likelihood of COPD prevalence in this population.

Methods

Data from 16,030 participants in the National Health and Nutrition Examination Survey (NHANES) collected between 2007 and 2023 were analyzed to examine the relationship between LCD score and COPD. Propensity score matching (PSM) was employed to reduce baseline bias. Weighted multivariable logistic regression models were applied, and restricted cubic spline (RCS) regression was used to explore possible nonlinear relationships. Subgroup analyses were performed to evaluate the robustness of the results. Additionally, we employed eight machine learning methods-Boost Tree, Decision Tree, Logistic Regression, MLP, Naive Bayes, KNN, Random Forest, and SVM RBF-to build predictive models and evaluate their performance. Based on the best-performing model, we further examined variable importance and model accuracy.

Results

Upon controlling for variables, the LCD score demonstrated a strong correlation with the odds of COPD prevalence. In compared to the lowest quartile, the adjusted odds ratios (ORs) for the high quartile were 0.77 (95% CI: 0.63, 0.95), 0.74 (95% CI: 0.59, 0.93), and 0.61 (95% CI: 0.48, 0.78). RCS analysis demonstrated a linear inverse relationship between the LCD score and the odds of COPD prevalence. Furthermore, the random forest model exhibited robust predictive efficacy, with an area under the curve (AUC) of 71.6%.

Conclusion

Our study of American adults indicates that adherence to the LCD may be linked to lower odds of COPD prevalence. These findings underscore the important role of the LCD score as a tool for enhancing COPD prevention efforts within the general population. Nonetheless, additional prospective cohort studies are required to assess and validate these results.

The association between dietary carbohydrate intake and the risk of hyperlipidemia among reproductive-aged women in the US: A cross-sectional study

BACKGROUND

The association between dietary carbohydrate intake and hyperlipidemia remained incompletely understood. This study aimed to explore the association between dietary carbohydrate intake and the risk of hyperlipidemia among reproductive-aged women in the US.

METHODS

The study utilized data from the National Health and Nutrition Examination Survey (NHANES) conducted from 2005 to 2020. Dietary intake information was assessed via interviews using 24-hour dietary recall interviews, and hyperlipidemia diagnosis adhered to the National Cholesterol Education Program guidelines. Univariate and multivariate logistic regression analyses, along with restricted cubic splines (RCS) and stratified analyses, were conducted to investigate the association between dietary carbohydrate intake and the risk of hyperlipidemia.

RESULTS

A total of 6,791 women of reproductive age, with a mean age of 34.87 (±8.57) years, were included in the final analysis. In the multivariate logistic regression model adjusting for covariates, a higher percentage of energy from carbohydrate was positively correlated with the risk of hyperlipidemia (adjusted odds ratio (AOR): 1.014, 95% CI: 1.004-1.024). Analyzing the percentage of energy from carbohydrate as a categorical variable, compared to the lowest quartile, the third quartile (AOR: 1.263, 95% CI: 1.031-1.546) and the highest quartile (AOR: 1.411, 95% CI: 1.083-1.839) were associated with increased hyperlipidemia risk. Additionally, a linear relationship (P for nonlinearity = 0.088) existed between the percentage of energy from carbohydrate and the risk of hyperlipidemia, with an inflection point identified at 49.64.

CONCLUSIONS

This study found that elevated dietary carbohydrate intake was associated with an increased the risk of hyperlipidemia in reproductive-aged women. These findings implied that reproductive-aged women should pay closer attention to reducing their carbohydrate intake.

Carbohydrate Intake Levels and the Risk of Metabolic Syndrome in Korean Populations: A Prospective Study

In Korea and other Asian countries, traditional high-carbohydrate diets are increasingly associated with metabolic syndrome (MetS) and its complications. As dietary patterns shift, there is a growing need to assess the effect of these changes on health outcomes related to MetS. This study aimed to investigate the prospective relationship between carbohydrate consumption and the risk of MetS and its components. We analyzed data from 7902 participants from the Korean Association Resource, part of the Korean Genome and Epidemiology Study Dietary intakes, including carbohydrates and fiber, were assessed using a validated semi-quantitative food frequency questionnaire, allowing for the calculation of the proportion of total energy from carbohydrates (P_CARB) and the carbohydrate-to-fiber ratio to assess carbohydrate quality. Blood samples were collected after at least eight hours of fasting for laboratory analysis. We employed Cox proportional hazards models to estimate hazard ratios and 95% confidence intervals, focusing on the relationship between the P_CARB and the risk of developing MetS and its individual components, while adjusting for carbohydrate quality. In the fully adjusted model, which accounted for carbohydrate quality as a covariate, individuals in the highest percentile of the P_CARB showed a significantly increased risk of MetS, hypertriglyceridemia, hypo-high density lipoprotein cholesterolemia, dyslipidemia, and high blood pressure, compared to those in the lowest P_CARB group. Spline curve analyses indicated that the risks for MetS and its components consistently escalated with increasing P_CARB, with all p-values for nonlinearity exceeding 0.05. The findings suggest that higher levels of P_CARB are associated with an increased risk of MetS and related conditions, except for high fasting glucose. These results highlight the importance of dietary awareness and potential adjustments for populations consuming high-carbohydrate diets.

Long-term health outcomes by cancer diagnosed age among adolescent and young adult: multinational representative database

BACKGROUND

The cancer experienced in adolescent and young adult (AYA) could disturb developmental changes and long-term life. The current AYA guidelines and research for survivorship were developed and reported according to the general age range of 15-39 years; however, expected life events vary by diagnosed age. We aimed to examine the social, psychological, and physical well-being of AYA cancer survivors by age at diagnosis using a multinational representative dataset focusing on age at diagnosis.

METHODS

We conducted a cross-sectional study using the US and Korean National Health and Nutrition Examination Surveys from 2007 to 2018. Participants diagnosed with any cancer aged 15-39 years and were aged > 18 years at the survey year were defined as AYA cancer survivors. AYA were classified into three groups based on their diagnosed age: adolescent survivors (diagnosed between the ages of 15 and 19, n = 45), young adult survivors (diagnosed between the ages of 20 and 29, n = 238), and late young adult survivors (diagnosed between the ages of 30 and 39, n = 539). We also selected an age-, sex-, race-, and survey year-matched general population with 1:5 ratio among participants without cancer (N = 4110).

RESULTS

The average age of the survey was 29.1, 43.7, and 48.7 years for AYA survivors diagnosed during adolescence, young adulthood, and late young adulthood, respectively. Adolescent survivors had more non-couple marital status (adjusted odds ratio (aOR), 1.34; 95% CI, 1.10-1.64) and unemployed (aOR, 1.30; 95% CI, 1.05-1.61) compared to late young adult survivors. Comparing with the matched general, adolescent survivors were more in poor general health (aOR, 4.65; 95% CI, 2.09-10.38) and unemployed (aOR, 2.17; 95% CI, 1.12-4.24) and late young adult survivors were more non-couple (aOR, 1.40; 95% CI, 1.05-1.86).

CONCLUSION

This study provides evidence for future studies on long-term health, which may vary according to age at the time of diagnosis among AYA with cancer.

Lifestyle Factors Influencing Metabolic Syndrome after Adjusting for Socioeconomic Status and Female Reproductive Health Indicators: A National Representative Survey in Korean Pre- and Postmenopausal Women

Metabolic syndrome (MetS) is increasing markedly among postmenopausal women. Although studies suggest multiple risk factors for its development, few have investigated changes in socioeconomic status (SES), female reproductive health indicators (menarche age, experience of pregnancy, delivery, breastfeeding, and postmenopausal status), and lifestyle factors. This study investigated lifestyle factors affecting MetS prevalence among pre- and post-menopausal women after adjusting for SES and female reproductive health indicators. Data from the Korea National Health and Nutrition Examination Survey VII (2016-2018) on 2856 pre- and postmenopausal women aged 40-59 years were analyzed. Differences in SES (e.g., age, education, and household income), female reproductive health indicators (e.g., age of menarche and menopause), and lifestyle (e.g., total calorie intake, fats, and proteins, percentage of energy from carbohydrates, fats, and proteins, smoking, physical activity, and obesity) between MetS and non-MetS groups were calculated by performing χ2 or t-tests. Consequently, current smoking, physical inactivity, overweight, and obesity were significantly associated with increased MetS after adjusting for SES and female reproductive health indicators using logistic regression analysis. Hence, health policies and programs focusing on modifiable MetS risk factors-encouraging healthy eating habits, smoking cessation, and regular exercise-must be formulated to prevent the development of MetS in pre- and postmenopausal women.

Nutrient composition of plant-based fast-food meals and their omnivore counterparts: A cross-sectional analysis of e-menus

OBJECTIVES

Fast food chains have introduced many plant-based meals to their menus. We aimed to compare the nutrient composition and allergenic content of plant-based (vegan or vegetarian) meals in fast food chains with their animal-based equivalents.

METHODS

E-menus from 50 fast food chains across 5 countries (Australia, Canada, Poland, the UK, and the US) were analyzed. Data on meal type, weight, calories, macronutrients, sodium, fiber, and allergen presence were gathered. Plant-based meals were matched with meat counterparts, where the latter shared the same meal type, originated from the same country and chain, and showed a weight difference of less than 10%. Multivariate logistic regression analysis was performed.

RESULTS

From n = 2455 records, n = 1868 unique meals were matched. Plant-based meals showed lower odds ratios (OR) for protein (OR, 0.10; 95% confidence interval [CI], 0.08-0.14) and sodium (OR, 0.70; 95% CI, 0.55-0.90) and higher odds for carbohydrates (OR, 1.87; 95% CI, 1.41-2.49), sugar (OR, 1.43; 95% CI, 1.12-1.82), and fiber (OR, 4.87; 95% CI, 3.60-6.63) compared with omnivorous meals, adjusted for country, meal type, and meal weight. Notably, plant-based and omnivorous meals were not associated with total caloric content. Separate analyses of vegetarian and vegan meals yielded similar results. Omnivorous meals more frequently contained allergens such as dairy, eggs, fish, shellfish, and mustard, whereas plant-based meals more likely contained allergens such as sesame, seeds, and nuts.

CONCLUSIONS

Plant-based fast food meals were more likely to contain more carbohydrates, sugar, and fiber and less protein and sodium than their animal-based counterparts. These findings emphasize the importance of informed food choices in the fast food context.

Body mass index as a dominant risk factor for metabolic syndrome among indonesian adults: a 6-year prospective cohort study of non-communicable diseases

BACKGROUND

Non-communicable diseases (NCDs), notably cardiovascular disease and type 2 diabetes mellitus, are largely driven by metabolic syndrome (MetS), a cluster of critical risk factors. Despite extensive research, the progression of MetS, especially in Indonesia, has received limited attention. This research tracks adult MetS risk dynamics in a populous Bogor District cohort, providing crucial insights into its evolving nature.

METHODS

This prospective open cohort study analysed secondary data from the Special Research - Cohort Study of Non-Communicable Diseases by the Ministry of Health, Republic of Indonesia from 2011 to 2018. The final sample was 1,376 Indonesian adult participants, all residents of Bogor District. MetS outcome, dietary assessment, physical activity, and biomarkers were analysed every two consecutive years.

RESULTS

The risk of overweight and obese participants developing MetS was 2.4 and 4.4 times higher, respectively (95% CI: 1.176-3.320 and 3.345-5.740) than those with body mass index (BMI) in the normal range. Participants who reported less intentional physical exercise had a MetS risk 1.5 times higher (95% CI: 1.034-2.109) than those with more intentional physical exercise. The role of diet is also significant, evidenced by a 30% reduction in MetS risk for people with fat intakes in the 2nd quartile compared to the 1st quartile (95% CI: 0.505-0.972). Meanwhile, a carbohydrate intake in the 2nd quartile increased the risk of MetS 1.5 times (95% CI: 1.063-2.241) in comparison with the 1st quartile.

CONCLUSIONS

Notably, participants with underweight BMI exhibited the highest cumulative survival of MetS, while those with obese BMI recorded the lowest cumulative survival. There is an urgent need for strategic interventions to enhance the existing early detection and NCD monitoring program. This involves a targeted focus on promoting a community-based healthy lifestyle in the Bogor District. The study emphasizes the importance of tailored public health measures to address specific risk factors identified in the local context, aiming to mitigate the prevalence and impact of MetS in the population.

Association of daily carbohydrate intake with intermuscular adipose tissue in Korean individuals with obesity: a cross-sectional study

BACKGROUND/OBJECTIVES

The prevalence of obesity, a worldwide pandemic, has been increasing steadily in Korea. Reports have shown that increased intermuscular adipose tissue (IMAT) is associated with an increased risk of cardiovascular disease, independent of body mass index. However, the relationship between dietary intake and IMAT accumulation in the Korean population remains undetermined. The objective of this study was to evaluate regional fat compartments using advanced magnetic resonance imaging (MRI) techniques. We also aimed to investigate the association between IMAT amounts and dietary intake, including carbohydrate intake, among Korean individuals with obesity.

SUBJECTS/METHODS

This cross-sectional study, performed at a medical center in South Korea, recruited 35 individuals with obesity (15 men and 20 women) and classified them into 2 groups according to sex. Anthropometry was performed, and body fat distribution was measured using MRI. Blood parameters, including glucose and lipid profiles, were analyzed using commercial kits. Linear regression analysis was used to test whether the IMAT was associated with daily carbohydrate intake.

RESULTS

Carbohydrate intake was positively associated with IMAT in all individuals, with adjustments for age, sex, height, and weight. No significant differences in blood indicators were found between the sexes.

CONCLUSIONS

Regardless of sex and age, higher carbohydrate intake was strongly correlated with greater IMAT accumulation. This suggests the need to better understand sex differences and high carbohydrate diet patterns in relation to the association between obesity and metabolic risk, which may help reduce obesity prevalence.

Effect of weight change on the association between overall and source of carbohydrate intake and risk of metabolic syndrome: Tehran lipid and glucose study

BACKGROUND

In this prospective cohort study, we aimed to evaluate the association between dietary carbohydrates, whole grains, refined grains, and simple sugar with the risk of metabolic syndrome (MetS) and assess the effect of weight change on these associations.

METHODS

This study was conducted within the framework of the Tehran Lipid and Glucose Study (TLGS). We included 1915 healthy participants with complete demographic, anthropometric and dietary measurements, among whom 591 developed MetS during 8.9 years of follow-up. Intake of dietary carbohydrates, whole grains, refined grains, and simple sugar was assessed with a validated semi-quantitative food frequency questionnaire. Multivariable adjusted Cox regression was used to estimate hazard ratios (HRs) for MetS events across tertiles of dietary variables. Using joint classification, the effect of weight change on the association between dietary variables and risk of MetS was assessed by Cox regression.

RESULTS

Carbohydrate intake was not associated with the risk of MetS in multivariable-adjusted models. Whole grains intake was inversely associated with the risk of MetS (HR: 0.78, CI: 0.63-0.98), while this association disappeared after adjustment for weight change. The risk of MetS increased by 11% (1.11, 1.09-1.14) for each 3% energy increment from simple sugar, and by 5% (1.05, 1.03-1.08) for each 1 serving/day increment in refined grains. Consumption of refined grains increased the risk of MetS; an effect modification of this association was found by weight change. Among subjects with weight loss, intake of refined grains < median intake decreased the risk of MetS (0.59, 0.41-0.87). However, consumption of refined grains ≥ median intake increased the risk of MetS in individuals with weight gain (1.47, 1.08-2.01). Simple sugar was positively associated with an increased risk of MetS, after adjustment for weight change (3.00, 2.37-3.82). In joint classification, intake of simple sugar greater than median intake increased the risk of MetS, independent of weight change.

CONCLUSION

Our findings suggest an effect modification by weight change on the association between carbohydrates, and refined grains intake and the risk of MetS. Weight loss along with lower consumption of carbohydrates, and refined grains reduced the risk of MetS. However, simple sugar intake, regardless of weight change, was associated with an increased risk of MetS.

Associations of Dietary Intakes of Total and Specific Types of Fat with Blood Lipid Levels in the Filipino Women's Diet and Health Study (FiLWHEL)

Background

Limited evidence exists on the association between dietary fat intake and lipid profiles in Southeast Asian populations.

Objectives

We aimed to examine the cross-sectional associations of dietary intake of total and specific types of fat with dyslipidemia in Filipino immigrant women in Korea.

Methods

We included 406 Filipino women married to Korean in the Filipino Women's Diet and Health Study (FiLWHEL). Dietary fat intake was assessed using 24-hour recalls. Impaired blood lipid profiles were defined as high total cholesterol (TC) (≥200 mg/dL), high triglyceride (TG) (≥150 mg/dL), high LDL Cholesterol (LDL-C) (≥ 130 mg/dL), or low HDL cholesterol (HDL-C) (<50 mg/dL). The genomic DNA samples were genotyped using DNA chip. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariate logistic regression.

Results

Substituting carbohydrates with dietary saturated fat (SFA) intake was associated with increased prevalence of dyslipidemia; ORs (95% CIs) for subsequent tertiles compared to the first tertile were 2.28 (1.19-4.35), and 2.88 (1.29-6.39) (P for trend = 0.02). When we examined individual markers, ORs (95% CIs, P for trend) comparing the third to the first tertile were 3.62 (1.53-8.55, 0.01) for high TC, 1.46 (0.42-5.10, 0.72) for high TG, 4.00 (1.48-10.79, 0.02) for high LDL-C, and 0.69 (0.30-1.59, 0.36) for low HDL-C. When we examined the interaction by LDL-C-related polymorphisms, the association with dyslipidemia was more pronounced among participants with CC alleles than among those with T alleles of rs6102059 (P for interaction = 0.01).

Conclusions

High dietary SFA intake was significantly associated with a high prevalence of dyslipidemia in Filipino women in Korea. Further prospective cohort studies are warranted to determine risk factors for CVD in Southeast Asian populations.

Associations between Dietary Patterns and Metabolic Syndrome: Findings of the Korean National Health and Nutrition Examination Survey

Metabolic syndrome (MetS) is a multifactorial cluster of metabolic disorders related to cardiovascular disease and type 2 diabetes mellitus. Diet and dietary patterns are significant factors in the development and management of MetS. The associations between dietary patterns (i.e., high-carbohydrate [HCHO], high-fat [HF], and high-protein [HP] diets) and the prevalence of MetS in Koreans were examined using data from the Korean National Health and Nutrition Examination Survey, collected between 2018 and 2020. The study included data from 9069 participants (3777 men and 5292 women). The percentage of participants with MetS was significantly higher in the HCHO diet group than in the normal diet group in women. Women with HCHO diet were positively associated with elevated blood pressure and triglyceride levels based on a comparison with the normal diet group (p = 0.032 and p = 0.005, respectively). Men with an HF diet were negatively associated with elevated fasting glucose levels based on a comparison with the normal diet group (p = 0.014). Our findings showed that HCHO intake was strongly associated with a higher risk of MetS, especially elevated blood pressure and triglyceride levels in women, and an HF diet was negatively associated with elevated fasting glucose levels in men. Further prospective studies of the impact of dietary carbohydrate, fat, and protein proportions on metabolic health are needed. The optimal types and proportions of these dietary components, as well as the underlying mechanisms through which suboptimal proportions can lead to MetS, should also be investigated.

A Positive Causal Relationship between Noodle Intake and Metabolic Syndrome: A Two-Sample Mendelian Randomization Study

The controversy over the link between noodle consumption and metabolic syndrome (MetS) persists. Using a two-sample Mendelian randomization (MR) approach, we aimed to examine the potential causal relationship between noodle consumption and the risk of MetS and its components in adult populations of city hospital-based (n = 58,701) and Ansan/Ansung plus rural (AAR; n = 13,598) cohorts. The instrumental variables were assigned with genetic variants associated with low- and high-noodle intake (cutoff: 130 g/day) by a genome-wide association study (GWAS) with p < 5 × 10⁻⁵ and linkage disequilibrium (r² = 0.001), following adjustment for covariates related to MetS, in the city cohort. MR-Egger, inverse-variance weighted (IVW), and weighted median were applied to investigate the causal association of noodle intake with MetS risk in the AAR. The quality of the MR results was checked with leave-one-out sensitivity and heterogeneity analyses. A higher energy intake with lower carbohydrates and higher fats, proteins, and higher sodium and a lower intake of calcium, vitamin D, vitamin C, and flavonoids were shown in the high-noodle group, indicating poor diet quality. The glycemic index and glycemic load of daily meals were much higher in the high-noodle intake group than in the low-noodle intake group. In the observational studies, not only the total noodle intake but also the different types of noodle intake were also positively associated with MetS risk. In the MR analysis, high-noodle intake elevated MetS, hypertension, dyslipidemia, hyperglycemia, hypertriglyceridemia, and abdominal obesity in an IVW model (p < 0.05) but not the MR-Egger model. No single genetic variant among the instrumental variables changed their relationship in the leave-one-out sensitivity analysis. No likelihood of horizontal pleiotropy and heterogeneity was exhibited in the association between noodle intake and MetS. In conclusion, noddle intake had a positive causal association with MetS and its components in Asian adults.

Carbohydrate Intake and Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis of Prospective Studies

The purpose of this study is to understand the conflicting results from previous studies on the association between carbohydrate intake and cardiovascular disease (CVD) by conducting a systematic review and meta-analysis to summarize the most recent scientific evidence. A systematic review used three electronic databases to gather literature on the association between carbohydrate intake and CVD. Considering the discrepancies, either fixed or random effect models were chosen to determine the effect size, and sensitivity analysis results, as well as publication bias, were also presented. The meta-analysis found that individuals with the highest carbohydrate intake had a 1.15-fold increased risk of CVD compared to those with the lowest intake (hazard ratio, HR: 1.15, 95% confidence interval, CI: 1.07-1.23). Further subgroup analysis revealed that this association was only present in Asia, with a 1.52-fold increased risk (HR: 1.52, 95% CI: 1.17-1.97), while no associations were seen in the Americas, Europe, and Oceania. The relationship between carbohydrate intake and CVD was non-linear, with a marked escalation beyond 60% of total energy from carbohydrates. Our findings suggest that a high-carbohydrate diet may raise the risk of CVD, particularly in Asian populations. This association may be due to the higher carbohydrate consumption and genetic variations found in Asia.

Association of plant-based diets with adropin, atherogenic index of plasma, and metabolic syndrome and its components: A cross-sectional study on adults

Background

Little is known about the association of plant-based diet indices with metabolic syndrome (MetS) and its novel predictive biomarkers, including the atherogenic index of plasma (AIP) and adropin. We aimed to investigate the association of plant-based diets with adropin, atherogenic index of plasma, and MetS and its components in adults.

Methods

The present population-based cross-sectional study was conducted on a representative sample of adults aged 20-60 years in Isfahan, Iran. Dietary intake was obtained through a validated 168-item semi-quantitative food frequency questionnaire (FFQ). Peripheral blood was obtained after an overnight fast of at least 12 h from each participant. MetS was identified based on the Joint Interim Statement (JIS). AIP was calculated as a logarithmically transformed ratio of triglyceride (TG)/high-density lipoprotein cholesterol (HDL-c), and serum levels of adropin were measured by an ELISA kit.

Results

A total of 28.7% of subjects had MetS. No significant association was found between the overall plant-based diet index (PDI) and the healthful plant-based diet index (hPDI) with MetS. However, a non-linear association was observed between hPDI and MetS. Subjects in the third quartile of the unhealthful plant-based diet index (uPDI) had higher odds of MetS compared to the first quartile (OR: 2.39; 95% CI: 1.01, 5.66). The highest quartile of PDI (OR: 0.46; 95% CI: 0.21, 0.97) and the third quartile of hPDI (OR: 0.40; 95% CI: 0.18, 0.89) were associated with decreased odds of having high-risk AIP compared to the first quartile, after adjusting for potential confounders. No linear association was found between quartiles of plant-based diet indices and serum levels of adropin.

Conclusion

Plant-based diet index (PDI) and hPDI were not associated with the prevalence of MetS in adults, while moderate adherence to uPDI increased the prevalence of MetS. In addition, high adherence to PDI and moderate adherence to hPDI were associated with decreased odds of high-risk AIP. No significant association was found between plant-based diet indices and serum adropin levels. To confirm these findings, further studies with prospective designs are warranted.

Higher Intake of Total Dietary Essential Amino Acids Is Associated with a Lower Prevalence of Metabolic Syndrome among Korean Adults

We hypothesized that a well-balanced intake of total essential amino acids (EAAs) may be associated with lower prevalence of metabolic syndrome among Korean adults. This population-based cross-sectional study included 25,787 participants aged ≥30 years from the 2008-2019 Korea National Health and Nutrition Examination Survey. Dietary information was obtained from 24 h recall data. Demographic and lifestyle factors were assessed using self-administered questionnaires, and metabolic biomarkers were obtained from a health examination. Total essential amino acid score (EAAS) was calculated to determine whether essential amino acid (EAA) intake meets the recommended nutrient intake (RNI). Multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression models. After adjusting for multiple confounding factors, participants with higher EAAS had a significantly lower prevalence of high blood pressure (OR: 0.86, 95% CI: 0.75-0.98), hypertriglyceridemia (OR: 0.86, 95% CI: 0.76-0.98), and Metabolic syndrome (MetS) (OR: 0.86, 95% CI: 0.74-0.996). Spline regression analysis confirmed linearity of the association between total EAAS and MetS. EAA intake and MetS are associated with an inverse dose-response relationship in which metabolic disease may be prevented when the overall EAA intake meets the RNI.

"Planeterranea": An attempt to broaden the beneficial effects of the Mediterranean diet worldwide

Non-communicable diseases (NCDs) lead to a dramatic burden on morbidity and mortality worldwide. Diet is a modifiable risk factor for NCDs, with Mediterranean Diet (MD) being one of the most effective dietary strategies to reduce diabetes, cardiovascular diseases, and cancer. Nevertheless, MD transferability to non-Mediterranean is challenging and requires a shared path between the scientific community and stakeholders. Therefore, the UNESCO Chair on Health Education and Sustainable Development is fostering a research project-"Planeterranea"-aiming to identify a healthy dietary pattern based on food products available in the different areas of the world with the nutritional properties of MD. This review aimed to collect information about eating habits and native crops in 5 macro-areas (North America, Latin America, Africa, Asia, and Australia). The information was used to develop specific "nutritional pyramids" based on the foods available in the macro-areas presenting the same nutritional properties and health benefits of MD.

Dietary Patterns Derived from Reduced Rank Regression Are Associated with the 5-Year Occurrence of Metabolic Syndrome: Aichi Workers' Cohort Study

The aim of the present study was to derive dietary patterns to explain variation in a set of nutrient intakes or in the measurements of waist circumference (WC) and fasting blood glucose (FBG) using reduced rank regression (RRR) and to prospectively investigate these patterns in relation to the risk of developing metabolic syndrome (MetS) and its components during the follow-up. The study participants were comprised of 2944 government employees aged 30−59 years without MetS. RRR was applied with 38 food groups as predictors and with two sets of response variables. The first set included intake of putatively beneficial nutrients, and the first factor retained was named the Healthy Dietary Pattern (HDP). The second one included baseline WC and FBG, and the first factor was named the Unhealthy Dietary Pattern (UHDP). Multivariable Cox proportional hazard model was used to estimate hazard ratio and 95% confidence intervals with adjustments for age, sex, total energy consumption and other potential confounders. During the 5-year median follow-up, we ascertained 374 cases of MetS. The HDP score was inversely associated with the incidence of MetS (p-trend = 0.009) and hypertension (p-trend = 0.002) and marginally significantly associated with elevated triglyceride and decreased high-density lipoprotein cholesterol (p-trend = 0.08). The UHDP score was linearly positively associated with the incidence of MetS and all its components (all p-trend < 0.05). Both the HDP and UHDP predicted the development of MetS and its components.

Association of Dietary Factors With Grip Strength, Body Fat, and Prevalence of Sarcopenic Obesity in Rural Korean Elderly With Cardiometabolic Multimorbidity

Background and Aims

Aging accompanied by cardiometabolic multimorbidity (CM) promotes chronic low-grade inflammation, increased oxidative stress, and insulin resistance (IR), which result in loss of muscle mass and functional impairment. Better quality diets have been directly associated with muscle health and decreased risk of all-cause mortality. However, no study has investigated the relationship of dietary factors with grip strength, body composition, and prevalence of sarcopenic obesity (SO) in Korean rural residents according to their CM pattern. Therefore, we aimed to examine this association among this population.

Materials and Methods

This cross-sectional study utilized data from 932 rural residents aged ≥ 65 years. An exploratory tetrachoric factor analysis revealed four multimorbidity patterns: CM, inflammatory disease, respiratory disease, and cancer and other diseases. All participants were categorized into the CM and non-CM groups. Skeletal muscle mass and the prevalence of sarcopenia were estimated using bioelectrical impedance analysis (BIA). Dietary assessment was analyzed using a validated 106-item food frequency questionnaire. Adjusted multiple linear regression and multivariate logistic regression were employed to examine the association of dietary factors with muscle strength, quality, and SO prevalence ratio in elderly participants.

Results

The mean age of the participants was 71.8 ± 0.1 years (65.8% women). Dietary fat and protein intake were positively correlated with handgrip strength in women with CM, after adjusting for covariates (p = 0.001). Similarly, protein intake (g/kg) was positively associated with appendicular skeletal muscle mass (ASM; kg/m²) and ASM (%) in both sexes in the CM and non-CM groups. Regarding the tertiles of wheat intake (g/d), 2.1-fold increase in SO prevalence ratios [prevalence ratio (PR): 2.149, confidence intervals (CIs): 1.134–4.071] was observed in the highest tertile (T3: 269.1 g/d), compared to the lowest tertile (Q1: 8.6 g/d) in the CM group. Higher tertile of meat intake (T2: 34.8 g/d, T3: 99.5 g/d) had a 2-fold increase in SO (PR: 1.932, CIs: 1.066–3.500) compared to the lowest tertile (T1: 9.2 g/d) in the CM group.

Conclusion

Overconsumption of wheat and meat negatively impacted the development of SO, while protein intake was positively associated with grip strength and skeletal muscle mass in elderly Koreans with CM.

Low-carbohydrate diet score is associated with improved blood pressure and cardio-metabolic risk factors among obese adults

Obesity is associated with numerous co-morbidities and diet, is one of the modifiable risk factors for prevention against these obesity-related metabolic disorders. In the current study, we aimed to evaluate the association between adherence to low carbohydrate diet (LCD) score and serum lipids, glycemic markers, blood pressure, and anthropometric parameters among obese individuals. The current cross-sectional study is a combination of two projects with total participants of 359 obese individuals (body mass index [BMI] ≥ 30 kg/m2 ) aged 20-50 years were included. Dietary intake was assessed by a validated semi-quantitative food frequency questionnaire (FFQ) of 132 food items. Low carbohydrate diet score was estimated by deciles of dietary intakes. Metabolic syndrome (MetS) was defined based on the guidelines of the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III). Enzymatic methods were used to assess serum lipids, glucose, and insulin concentrations. Blood pressure was measured by sphygmomanometer and body composition with bioelectrical impedance analysis (BIA). Higher adherence to LCD score was associated with significantly lower DBP and triglyceride (TG) concentrations and increased high density lipoprotein (HDL)-C levels after adjustment for the confounders (p < 0.05). A non-significant reduction in systolic blood pressure (SBP) and total cholesterol (TC) values were also observed. Also, high adherence to LCD score was associated with reduced prevalence of metabolic syndrome (p < 0.05). Higher BMI, fat mass, and lower fat-free mass were also accompanied with higher adherence to LCD score. According to our study, low carbohydrate diet score was associated with more favorable cardio-metabolic risk factors independent of some confounders like age, BMI, sex, and physical activity level. Further studies in different communities will help for generalization of our findings.

Habitual- and Meal-Specific Carbohydrate Quality Index and Their Relation to Metabolic Syndrome in a Sample of Iranian Adults

AIM

Most studies on diet quality have focused on the habitual and overall intake of foods without considering intakes at specific eating occasions. This study aimed to assess the association between habitual- and meal-specific carbohydrate quality index (CQI) and metabolic syndrome (MetS) in Iranian adults.

METHODS

In this cross-sectional study, data from 850 participants were analyzed. Dietary information was obtained from a 3-day nonconsecutive 24 h recall. CQI was calculated from three criteria: dietary fiber, glycemic index, and solid carbohydrate/total carbohydrate ratio. The association between CQI and MetS was assessed by logistic regression.

RESULTS

The prevalences of MetS in the lowest and highest tertile of CQI were 30.1 and 33.7, respectively (P = 0.6). In habitual diet and all the three meals, we failed to find any significant association between tertiles of CQI and MetS either before or after adjustment for covariates. However, in the habitual meals [odds ratio (OR): 0.69, 95% CI: 0.47-0.96] and lunch meals (OR: 0.66; 95% CI: 0.47-0.94), the highest CQI in comparison to the lowest one, significantly decreased the low high-density lipoprotein (HDL). In addition, the trend of low-HDL with CQI in habitual meal and lunch meal was statistically significant.

CONCLUSION

The results of this study showed that CQI was not associated with MetS and its components. Further investigations into the mechanisms underlying the role of carbohydrate quality in developing metabolic disorders are warranted.

Household-specific physical activity levels and energy intakes according to the presence of metabolic syndrome in Korean young adults: Korean National Health and nutrition examination survey 2016-2018

BACKGROUND

Participation in exercise, and dietary and nutritional intakes have an impact on the risk and prevalence of metabolic syndrome (MetS), but these effects may differ according to whether a person lives alone or in a multi-person household. We analyzed differences in physical activity (PA) levels and energy intake according to household-type and MetS presence among young adults, to investigate the relationships among these factors.

METHODS

Data of 3974 young adults (aged > 19 years and < 40 years) were obtained from the Korean National Health and Nutrition Examination Survey (2016-2018). We analyzed PA levels (occupational and recreational PA, and transport) and energy intake (total, carbohydrate, protein, and fat).

RESULTS

Logistic regression data showed that low PA levels and higher energy intake were associated with MetS incidence and its components in young adults, after adjusting for body mass index, smoking, household-type, and sex. Overall, there was no significant difference in PA level between the MetS and non-MetS group. The total energy intake was higher in the MetS than in the non-MetS group (p <  0.05). These results were similar to those found in multi-person households. In single-person households, the MetS group had significantly lower PA levels (p <  0.01) and total energy intake (p <  0.05) than the non-MetS group.

CONCLUSIONS

We found significant association among low PA levels, high energy intake, and MetS components in young Korean adults, but with patterns differing according to household type. Energy intake was higher in young adults with than those without MetS, who lived in multi-person households, while young adults with MetS who lived alone had lower PA levels and lower energy intake than those without MetS. These findings highlight the need for different approaches of implementing PA and nutrition strategies according to the type of household in order to prevent MetS.

Lipid Accumulation Product Index Predicts New-Onset Type 2 Diabetes Among Non-Obese Koreans: A 12-Year Longitudinal Study

PURPOSE

The lipid accumulation product (LAP) has been a potential indicator of central lipid accumulation status. This study aimed to assess the longitudinal association between LAP index and incident type 2 diabetes among non-obese Korean adults using a large, community-based Korean cohort observed over 12 years.

PATIENTS AND METHODS

This study included 4281 non-diabetic adults without generalized obesity and abdominal obesity and aged 40-69 years from the Korean Genome and Epidemiology Study. The participants were divided into four groups according to LAP index quartiles, calculated as (waist circumference [cm] - 65) x (triglycerides [mmol/L]) in men and (waist circumference [cm] - 58) x (triglycerides [mmol/L]) in women. We prospectively assessed hazard ratios (HRs) with 95% confidential intervals (CIs) for incident type 2 diabetes using multivariate Cox proportional hazard regression models.

RESULTS

Overall, 608 (14.2%) participants developed type 2 diabetes during the follow-up period. HRs for incident type 2 diabetes in the second, third, and fourth LAP quartile were 1.32 (95% CI: 0.97-1.79), 1.51 (95% CI: 1.11-2.06), and 2.14 (95% CI: 1.56-2.94), respectively, after adjusting for age, sex, body mass index, smoking status, alcohol intake, physical activity, mean arterial blood pressure, family history of diabetes, and impaired glucose tolerance.

CONCLUSION

A high LAP index can be an additional indicator for new-onset T2DM among middle-aged and elderly non-obese Koreans.

Lifestyle Modification in the Management of Metabolic Syndrome: Statement From Korean Society of CardioMetabolic Syndrome (KSCMS)

Metabolic syndrome (MetS) is highly prevalent and is associated with worse cardiovascular outcome. Lifestyle modification is the most effective way to reduce the incidence of cardiovascular complications caused by MetS. Here, we would like to review the effects and specific methods of the 6 lifestyle modifications (weight control, smoking cessation, alcohol drinking in moderation, diet control, exercise and physical activity, and cognitive behavioral therapy) and control of blood pressure, dyslipidemia, and blood sugar based on evidence in the management of MetS.

With the recent rapid increase in obesity worldwide, metabolic syndrome (MetS) has gained significant importance. MetS is a cluster of obesity-related cardiovascular risk factors including abdominal obesity, atherogenic dyslipidemia, high blood pressure and impaired glucose tolerance. MetS is highly prevalent and strongly associated with an increased risk of developing diabetes and cardiovascular disease, putting a great burden on human society. Therefore, it is very important to reduce MetS risk, which can improve patients’ cardiovascular prognosis. The primary and most effective strategy to control each component of MetS is lifestyle change such as losing body weight, keeping regular exercise, adopting a healthy diet, quitting smoking and alcohol drinking in moderation. Many studies have shown that lifestyle modification has improved all components of MetS, and reduces the incidence of diabetes and cardiovascular disease. Here, the Korean Society of CardioMetabolic Syndrome has summarized specific and practical methods of lifestyle modification in the management of MetS in the healthcare field.

Comparative analysis of energy intake and physical activity according to household type and presence of metabolic syndrome in middle-aged men based on data from the 7th Korea national health and nutrition examination survey (KNHANES) (2016-2018)

[Purpose]

This study analyzed data from the 7^th Korean National Health and Nutrition Examination Survey (2016‒2018) to compare the differences in energy intake and physical activity (PA) levels in middle-aged Korean men aged 40-59 years according to household type and the presence of metabolic syndrome (MetS).

[Methods]

Data from 2,266 young adults (aged >39 years and <60 years) were obtained from the KNHANES. We analyzed the differences in energy intake and PA levels according to household type and MetS. The presence or absence of MetS was determined by measuring waist circumference, blood pressure, fasting blood glucose, triglyceride, and HDL-C levels.

[Results]

Regarding total nutritional intake, no relationship with MetS was observed regardless of household type (interaction between MetS and household type: p = 0.875). No differences in total PA were observed between multiple- and single-person households (interaction between MetS and household type: p = 0.122). The relationship between MetS and MetS components according to nutritional intake showed that participants with a higher energy intake had a 27% lower prevalence of low high-density lipoprotein cholesterol (HDL-C) (p < 0.05) and a 36% higher prevalence of high blood pressure (p < 0.01). The relationship between MetS and MetS components according to the PA level showed significantly reduced prevalence of MetS by approximately 39%, 35%, and 43% (p < 0.01, 0.01, and 0.001) in subjects who were somewhat active, active, and very active, respectively, compared to inactivity.

[Conclusion]

Middle-aged men showed no difference in nutritional intake and PA between multiple- and single-person households. However, the risk of MetS was significantly higher in participants with approximately 1.5 times the energy intake compared to the group with the lowest energy intake. Moreover, higher levels of PA had a marked positive effect on the risk factors and prevalence of MetS. Therefore, we suggest that reducing the total energy intake and increasing total PA are important for preventing MetS in middle-aged men regardless of household type.

Macronutrient Intake in Adults Diagnosed with Metabolic Syndrome: Using the Health Examinee (HEXA) Cohort

Macronutrient intake is important in the prevention and management of metabolic syndrome (MetS). This study aimed to evaluate total energy and macronutrient intake of participants diagnosed with MetS at recruitment of the health examinees (HEXA) cohort, considering the plant and animal sources of each macronutrient. We included 130,423 participants aged 40-69 years for analysis. Odds ratios (OR) and 95% confidence intervals (CI) were estimated to evaluate the intake of macronutrients stratified by gender. Energy and macronutrient intake were estimated by linking food frequency questionnaire data to the Korean food composition database, and were calculated separately for plant and animal foods. Low energy (men: OR = 0.95, 95% CI: 0.92-0.98; women: OR = 0.97, 95% CI: 0.95-0.99), and fat intake (men: OR = 0.93, 95% CI: 0.90-0.96; women: OR = 0.80, 95% CI: 0.77-0.83) were observed. Only postmenopausal women had lower intake of total energy (OR = 0.95, 95% CI: 0.92-0.97), whereas low fat intake was observed in all women (OR = 0.80, 95% CI: 0.77-0.83). For carbohydrate intake, the OR were 1.14 (95% CI: 1.08-1.22) and 1.17 (95% CI: 1.08-1.27) among women in their 50s and 60s, respectively. Protein intake was low (OR = 0.90, 95% CI: 0.86-0.95; and OR = 0.88, 95% CI: 0.82-0.94) among women in their 50s and 60s, respectively. High intake of plant carbohydrates in women (OR = 1.16, 95% CI: 1.12-1.20), and plant protein in both genders (OR = 1.09, 95% CI: 1.05-1.13) were observed, but low intake of total energy, fat, and animal-source carbohydrates in both genders was also observed. Fat intake was low regardless of food source. In conclusion, high consumption of plant-source macronutrients, and low consumption of animal-source macronutrients was observed in Korean adults diagnosed with MetS. Attention should be directed to plant sources of carbohydrates and proteins when designing population interventions for metabolic syndrome reduction in Korea.

Low-Carbohydrate Diets in Korea: Why Does It Matter, and What Is Next?

In recent years, low-carbohydrate diets have become highly popular in Korea as a means to lose weight. People following this regime believe that fat and protein can be consumed in unlimited quantities, as long as carbohydrate intake is strictly restricted. However, low-carbohydrate diets are more complex than simply reducing carbohydrate intake. Meta-analyses of randomized controlled trials revealed that low-carbohydrate diets are at least as effective as low-fat diets in terms of weight loss, but their cardiovascular effects vary. Low-carbohydrate diets confer more beneficial effects on weight loss and lipid profiles such as triglycerides and high-density lipoprotein cholesterol but exhibited detrimental effects on lipid profiles such as total and low-density lipoprotein cholesterol. Korean diets are typically high in carbohydrates, where carbohydrate intake is in the range of 50%-80% of total energy. Within this range of carbohydrate intake, high carbohydrate intake was associated with an increased risk of elevated triglyceride and high-density lipoprotein cholesterol levels but with a reduced risk of elevated total and low-density lipoprotein-cholesterol levels. The optimal range of carbohydrate intake was depicted by a U-shaped relationship between carbohydrate intake and mortality, with 50%-60% of energy from carbohydrates having the lowest mortality risk. The distribution of macronutrients varied greatly according to age and sex groups in Korea. There is no single diet that can be recommended to all individuals, especially if focusing only on the quantity of macronutrients as opposed to their quality. The health benefits of low-carbohydrate or low-fat diets may depend on the source of protein and fat and the carbohydrate quality.

Association between Carbohydrate Intake and the Prevalence of Metabolic Syndrome in Korean Women

Carbohydrates consist of a large proportion of calories in the Asian diet. Therefore, we aimed to investigate the association between carbohydrate intake and metabolic syndrome in Korean women. A cross-sectional analysis was conducted with a total of 4294 Korean women aged 40–69 years from the Korean Genomic and Epidemiology Study (KoGES). Carbohydrate intake was calculated based on a validated food frequency questionnaire. Metabolic syndrome was defined by using the National Cholesterol Education Program, Adult Treatment Panel III (NCEPIII). Logistic regression was used to estimate the association of carbohydrate intake with metabolic syndrome and its components. In this study, high carbohydrate intake seemed to be associated with low socioeconomic status and an imbalanced diet. After adjusting for confounding factors, subjects with higher carbohydrate intake showed an increased risk of metabolic syndrome (odds ratio (OR) 1.34, 95% confidence interval (CI) 1.08–1.66, p-trend = 0.004, highest vs. lowest quartile [≥75.2 vs. <67.0% of energy]), particularly elevated waist circumference. This association was stronger among those with low levels of C-reactive protein (CRP) and those with low dairy intake. In conclusion, higher carbohydrate intake is associated with a higher risk of metabolic syndrome, particularly abdominal obesity, in Korean women. This association may differ according to individuals’ CRP level and dairy intake.

Dietary carbohydrates interact with AMY1 polymorphisms to influence the incidence of type 2 diabetes in Korean adults

The relationship between AMY1 single nucleotide polymorphisms (SNPs), dietary carbohydrates, and the risk of type 2 diabetes is unclear. We aimed to evaluate this association using an ongoing large-scale prospective study, namely the Korean Genome and Epidemiology Study. We selected six genetic variants of the AMY1 gene: rs10881197, rs4244372, rs6696797, rs1566154, rs1930212, and rs1999478. Baseline dietary data were obtained using a semi-quantitative food frequency questionnaire. Type 2 diabetes was defined according to the criteria of the World Health Organization and American Diabetes Association. During an average follow-up period of 12 years (651,780 person-years), 1082 out of 4552 (23.8%) patients had type 2 diabetes. Three AMY1 SNPs were significantly associated with diabetes incidence among patients with carbohydrate intake > 65% of total energy: rs6696797, rs4244372, and rs10881197. In multivariable Cox models, Korean women with the rs6696797 AG or AA genotype had 28% higher incidence of type 2 diabetes (hazard ratio 1.28, 95% confidence interval 1.06-1.55) than Korean women with the rs6696797 GG genotype. We did not observe significant associations between AMY1 SNPs, dietary carbohydrates, and diabetes incidence in Korean men. We conclude that AMY1 genetic variants and dietary carbohydrate intake influence the incidence of type 2 diabetes in Korean women only. Korean women who are minor carriers of the AMY1 rs6696797, rs4244372, and rs10881197 genotypes may benefit from a low-carbohydrate diet to prevent the future risk of type 2 diabetes.

Association of Carbohydrate and Fat Intake with Prevalence of Metabolic Syndrome Can Be Modified by Physical Activity and Physical Environment in Ecuadorian Adults: The ENSANUT-ECU Study

The associations of lifestyle and environment with metabolic syndrome (MetS) and cardiovascular disease have recently resulted in increased attention in research. This study aimed to examine interactive associations among carbohydrate and fat intake, physical environment (i.e., elevation and humidity), lifestyle, and MetS among Ecuadorian adults. We used data from the Ecuador National Health and Nutrition Survey 2012 (ENSANUT-ECU), with a total of 6023 participants aged 20 to 60 years included in this study. Logistic regression was used to determine the association of status of carbohydrate and fat intake, low-carbohydrate high-fat diet (LCHF) and medium-carbohydrate and fat (MCF) diet with MetS, where the high-carbohydrate low-fat (HCLF) diet was used as a reference. Women with LCHF and MCF diets showed lower prevalence of increased blood pressure (OR = 0.34, 95% CI: 0.19–0.59; OR = 0.50, 95% CI: 0.32–0.79, respectively). Women with MCF diet also showed lower prevalence of elevated fasting glucose (OR = 0.58, 95% CI: 0.37–0.91). Moreover, there were negative associations between MetS and reduced HDL cholesterol in women with MCF diet residing in low relative humidity (OR = 0.66, 95% CI: 0.45–0.98) and in women with LCHF diet residing at a high elevation (OR = 0.37, 95% CI: 0.16–0.86). Additionally, higher prevalence of increased waist circumference was observed in men with both MFC and LCHF diets who were physically inactive (OR = 1.89, 95% CI: 1.12–3.20; OR = 2.34, 95% CI: 1.19–4.60, respectively) and residing in high relative humidity (OR = 1.90, 95% CI: 1.08–2.89; OR = 2.63, 95% CI: 1.32–5.28, respectively). Our findings suggest that LCHF intake is associated with lower blood pressure, while MCF intake is associated with lower blood pressure and fasting glucose in Ecuadorian women. Furthermore, the associations of carbohydrate and fat intake with prevalence of MetS can be modified by physical activity, relative humidity, and elevation. The obtained outcomes may provide useful information for health programs focusing on dietary intake and lifestyle according to physical environment of the population to promote health and prevent metabolic diseases.

Effects of macronutrient intake in obesity: a meta-analysis of low-carbohydrate and low-fat diets on markers of the metabolic syndrome

The metabolic syndrome (MetS) comprises cardiometabolic risk factors frequently found in individuals with obesity. Guidelines to prevent or reverse MetS suggest limiting fat intake, however, lowering carbohydrate intake has gained attention too. The aim for this review was to determine to what extent either weight loss, reduction in caloric intake, or changes in macronutrient intake contribute to improvement in markers of MetS in persons with obesity without cardiometabolic disease. A meta-analysis was performed across a spectrum of studies applying low-carbohydrate (LC) and low-fat (LF) diets. PubMed searches yielded 17 articles describing 12 separate intervention studies assessing changes in MetS markers of persons with obesity assigned to LC (<40% energy from carbohydrates) or LF (<30% energy from fat) diets. Both diets could lead to weight loss and improve markers of MetS. Meta-regression revealed that weight loss most efficaciously reduced fasting glucose levels independent of macronutrient intake at the end of the study. Actual carbohydrate intake and actual fat intake at the end of the study, but not the percent changes in intake of these macronutrients, improved diastolic blood pressure and circulating triglyceride levels, without an effect of weight loss. The homeostatic model assessment of insulin resistance improved with both diets, whereas high-density lipoprotein cholesterol only improved in the LC diet, both irrespective of aforementioned factors. Remarkably, changes in caloric intake did not play a primary role in altering MetS markers. Taken together, these data suggest that, beyond the general effects of the LC and LF diet categories to improve MetS markers, there are also specific roles for weight loss, LC and HF intake, but not reduced caloric intake, that improve markers of MetS irrespective of diet categorization. On the basis of the results from this meta-analysis, guidelines to prevent MetS may need to be re-evaluated.

Triglyceride glucose (TyG) index as a predictor of incident type 2 diabetes among nonobese adults: a 12-year longitudinal study of the Korean Genome and Epidemiology Study cohort

The rate of undiagnosed type 2 diabetes tends to increase in lean Koreans, while the triglyceride glucose (TyG) index has been proposed as a surrogate marker of peripheral insulin resistance. We investigated the longitudinal relationship between TyG and incident type 2 diabetes among apparently healthy Korean adults. We assessed 4285 lean adults without diabetes aged 40-69 years from the Korean Genome and Epidemiology Study. Participants were divided into 4 groups according to quartiles of TyG index, calculated as ln [fasting triglycerides (mg/dL) × fasting plasma glucose (mg/dL)/2]. We prospectively assessed the hazard ratios (HRs) with 95% confidence intervals (CIs) for incident type 2 diabetes, based on the American Diabetes Association criteria, using multivariate Cox proportional hazards regression models, over 12 years after the baseline survey. During the follow-up period, 631 (14.7%) participants had newly developed type 2 diabetes. The HRs of incident type 2 diabetes in each TyG index quartile were 1.00, 1.63 (95%CI, 1.18-2.24), 2.30 (95%CI, 1.68-3.14), and 3.67 (95%CI, 2.71-4.98), respectively, after adjusting for age, sex, body mass index, waist circumference, smoking status, alcohol intake, and physical activity. Higher TyG index precedes and significantly predicts type 2 diabetes among community-dwelling middle aged and elderly lean Koreans.

The triglyceride-glucose index predicts ischemic heart disease risk in Koreans: a prospective study using National Health Insurance Service data

Background

Ischemic heart disease (IHD) without diabetes is considered an important challenge to human health and is associated with a poor prognosis, as well as a lack of health awareness. We prospectively investigated the relationship between the triglyceride-glucose (TyG) index, a surrogate marker of early insulin resistance, and incident IHD risk in a large cohort of nondiabetic Korean adults using National Health Insurance Service data.

Methods

We assessed 16,455 participants (8426 men and 8029 women) without diabetes using data from a health risk assessment study (HERAS) and Korea Health Insurance Review and Assessment (HIRA) data. The participants were divided into four groups according to TyG index quartiles, calculated as ln [fasting triglycerides (mg/dL) × fasting plasma glucose (mg/dL)/2]. We prospectively assessed hazard ratios (HRs) with 95% confidence intervals (CIs) for IHD using multivariate Cox proportional-hazards regression models over a 50-month period that followed the baseline survey.

Results

During the follow-up period, 322 (2.0%) participants developed IHD. HRs of IHD for TyG index quartiles 2–4 were 1.61 (95% CI 1.05–2.48), 1.85 (95% CI 1.21–2.81), and 2.29 (95% CI 1.50–3.51), respectively, after adjusting for age, sex, body mass index, smoking status, alcohol intake, and physical activity.

Conclusions

A higher TyG index precedes and significantly predicts future IHD among nondiabetic Koreans. Accordingly, the TyG index may be a useful measure in assessing cardiovascular risk for nondiabetic adults in the preclinical stage.

Animal Protein Intake Is Positively Associated with Metabolic Syndrome Risk Factors in Middle-Aged Korean Men

Few studies have examined the relationship of protein intake by food source with metabolic syndrome in Korean adults, even though animal food intake has increased. This study examined the association between plant and animal protein intake and metabolic syndrome among middle-aged Korean adults. A total of 13,485 subjects aged 30-64 years were selected from the 2013-2018 Korea National Health and Nutrition Examination Survey. Protein intake was assessed using 24-h dietary recall data and divided into quintiles. Men had a higher percentage of energy intake from animal protein (7.4%) than plant protein (6.9%). Men in the highest quintile group of animal protein intake had a higher prevalence of abdominal obesity (OR: 1.30, 95% CI: 1.00-1.70), reduced high-density lipoprotein cholesterol (HDL-C) (OR: 1.43, 95% CI: 1.07-1.90), and elevated fasting glucose (OR: 1.32, 95% CI: 1.01-1.74), after adjusting for covariates. Furthermore, stronger associations of animal protein intake with abdominal obesity were shown in men who consumed less than estimated energy requirements (OR: 1.60, 95% CI: 1.11-2.31). Plant protein intake was negatively associated with increased blood pressure in men. Neither animal nor plant protein intakes were significantly associated with any of the metabolic syndrome risk factors in women. The results imply that lower animal protein intake may be a beneficial factor for metabolic syndrome management in middle-aged Korean men.

Association of the Healthy Eating Index with Estimated Cardiovascular Age in Adults from the KNHANES 2013-2017

In this paper, we hypothesized that the gap between estimated cardiovascular age (eCV-age) and chronological age had a gender-wise correlation with the Korean Healthy Eating Index (KHEI). We tested the hypothesis in adults aged 20-64 years old using the KNHANES 2013-2017 data. eCV-age was estimated based on the designated risk factors of cardiovascular disease (CVD) and age-gap was calculated by subtracting the eCV-age from the chronological age in 12,317 adults. Adjusted odds ratios for the age-gap were measured according to KHEI, while controlling for covariates to influence risk factors of CVD, using logistic regression analysis with the complex sample survey design. Age-gaps were divided into four groups: >4 (High), 0-4 (Moderate), -4-0 (Mild), and <-4 years (Low). The higher the age-gap, the lower the cardiovascular risk. Persons included in the following categories belonged to the high and moderate age-gap groups: young (<40 years), women, urban living, better than high school education, higher income, lean, mild drinking, and exercising regularly. KHEI scores were overall higher in women than men (p < 0.01). Having breakfast and saturated fat intake were primary factors that influenced the age-gap for men, whereas fresh fruit intake and carbohydrate intake influenced the age-gap in women. The KHEI scores positively correlated with nutrient intake, especially fiber and vitamin C intake in women (p < 0.05). Participants with high KHEI scores increased their chances of belonging to the high age-gap group by 2.16 times for men and 2.10 for women after adjusting for covariates of sex, age, and residence. However, after adding the covariates of education, income, marriage, and obesity, in conjunction with smoking, alcohol, and regular exercise, this reduced to 1.34 times in women. In conclusion, both genders had a positive correlation between age-gap and overall KHEI scores.

East Asian diet-mimicking diet plan based on the Mediterranean diet and the Dietary Approaches to Stop Hypertension diet in adults with type 2 diabetes: A randomized controlled trial

Aims/Introduction

Using an investigational diet plan based on the Mediterranean diet and the Dietary Approaches to Stop Hypertension diet comprised of substitute ingredients that mimic the average East Asian diet, this study assessed the glycemic benefits in comparison with a food exchange system‐based diet in established type 2 diabetes patients.

Materials and Methods

This was a 12‐week, open‐label randomized clinical trial carried out among 60 Korean adults with type 2 diabetes having a median body mass index of 23.5 kg/m². Glycemic benefits in the investigational diet (group A) were compared with those obtained with a food exchange system‐based diet, either in the form of ready meals provided to participants (group B) or not (group C). The primary end‐point was changes in glycated hemoglobin from baseline to week 12.

Results

Changes in glycated hemoglobin (%) from baseline to week 12 were −0.97 ± 0.97 in group A (vs group B, P = 0.085 in the full analysis set, and P = 0.028 in the per‐protocol set; vs group C, P = 0.030 in the full analysis set and P = 0.020 in the per‐protocol set), −0.51 ± 0.65 in group B (vs group C, P > 0.05 in the full analysis set and the per‐protocol set), and −0.36 ± 0.74 in group C. Decreases from baseline in body mass index, waist circumference and blood pressure were greater in group A than in group C.

Conclusion

With the provision of ready meals, the glycemic benefits of the investigational diet plan were demonstrable over a self‐prepared food exchange system‐based diet in Korean adults with established type 2 diabetes.

A moderate-carbohydrate diet with plant protein is inversely associated with cardiovascular risk factors: the Korea National Health and Nutrition Examination Survey 2013-2017

Background

Because a moderate-carbohydrate diet reportedly has minimal risks, the substitution of carbohydrate for protein has been emphasized. Few studies have explored the effect of moderate-carbohydrate diets with higher protein intake in Asians, who typically consume a high-carbohydrate low-fat diet. Therefore, this study evaluated the associations of moderate- versus high- carbohydrate diets with cardiovascular risk factors among Korean adults by protein source.

Methods

This study included 7965 adults (3196 men, 4769 women) aged ≥ 19 years who participated in the 2013–2017 Korea National Health and Nutrition Examination Survey. Dietary intake was assessed by a 24-h recall method and four types of diet were defined: a moderate-carbohydrate diet with plant protein (MCP) or animal protein (MCA) and a high-carbohydrate diet with plant protein (HCP) or animal protein (HCA).

Results

Compared with the MCP group, men in the other three groups had significantly higher odds ratios (ORs) for elevated total cholesterol, reduced high-density lipoprotein (HDL)-cholesterol, and metabolic syndrome. Among women, only the HCP group had an increased OR for reduced HDL-cholesterol, compared with the MCP group. Similar associations were observed in younger adults (19–49 years). In addition, younger adults in the MCA group exhibited higher ORs for elevated triglycerides in men and elevated total cholesterol in women, compared with those in the MCP group.

Conclusions

A moderate-carbohydrate diet with a high intake of plant protein was inversely associated with cardiovascular risk factors, especially among younger Korean adults. Further intervention studies are required to confirm this relationship and develop the optimal diet for cardiovascular health in the Korean population.

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.

LMX1B rs10733682 Polymorphism Interacts with Macronutrients, Dietary Patterns on the Risk of Obesity in Han Chinese Girls

Previous studies have found that LMX1B rs10733682 polymorphism is associated with Body Mass Index (BMI) in European and American Indian adults. In this study, the association of rs10733682 polymorphism with obesity-related indicators, and its interaction with macronutrients and dietary patterns (DPs) were explored in Chinese children (n = 798). The rs10733682 polymorphism was genotyped by improved Multiple Ligase Detection Reaction (iMLDR). Four DPs were identified by factor analysis. The AA genotype had a higher incidence of overweight/obesity than GG+GA genotypes (P = 0.010) in girls (n = 398), but no difference in boys. The AA genotype in girls could interact with intake of energy, fat and carbohydrate, causing an increased triglyceride (TG), (P = 0.021, 0.003, 0.002, respectively), and also could interact with energy from protein, causing an elevated BMI (P = 0.023) and waist (P = 0.019). Girls inclining to the HED (high-energy density)-DP were associated with increased TG (P = 0.033), and girls inclining to the VEF (vegetables, eggs, and fishes based)-DP were associated with decreased total cholesterol (TC, P = 0.045) and decreased low density lipoprotein cholesterin (LDL, P = 0.016). The findings indicated that the AA genotype of rs10733682 and the HED-DP are potential risk factors of obesity in Chinese girls.

Trends of Premature and Early Menopause: a Comparative Study of the US National Health and Nutrition Examination Survey and the Korea National Health and Nutrition Examination Survey

BACKGROUND

While evidence shows a tendency toward delays in menopause worldwide, whether prevalence of premature (< 40 years) or early menopause (40-44 years) is also reduced in different ethnic groups is uncertain. The aim of this study was to explore birth cohort effect in the prevalence of premature and early menopause in United States (US) and Korea.

METHODS

This is a retrospective study using the National Health and Nutrition Examination Survey (NHANES, 1999-2014) and the Korea NHANES (KNHANES, 2007-2012). We analyzed prevalence of premature and early menopause in three ethnic groups of US and Korea. We restricted our analysis to women aged ≥ 45 years at the time of the survey born between 1920 and 1969. The data of both eligible 9,209 US women and 9,828 Korean was included in final analysis. We calculated odds ratios (OR) for each outcome adjusting for biological and socioeconomic factors, respectively.

RESULTS

Prevalence of premature menopause was 1.7% in US, 2.8% in Korean women. Early menopause occurred in 3.4% and 7.2% of US and Korean, respectively. In US women, prevalence of premature and early menopause did not change and did not differ across three ethnicities. Korean women showed highest and consistently decreasing prevalence (P < 0.001). When we adjusted for covariates, birth lower risk for premature menopause was evident in US Non-Hispanic black born in 1950s and in Korean born between 1940s and 1960s compared to those born in 1920s. In the analysis of early menopause, excluding premature menopause patients, lower risk of more recent generation (born in 1940s and later) was evident in Korean women.

CONCLUSION

The trend and birth cohort effect in occurrence of premature and early menopause among the US and Korea women are different. Prevalences of premature and early menopause decrease only in Korean.

Rate of inappropriate energy and micronutrient intake among the Korean working population

OBJECTIVE

Adequate energy and nutrient intakes are important for workers who spend at least one-third of their day working. We investigated differences in these intakes among Korean workers because few studies have reported on energy or nutrient intakes, related to working conditions (long working hours, shift work and non-standard work).

DESIGN

Dietary intake was assessed using 1-d 24-h recall. Energy and nutrient intakes were evaluated using age- and sex-specific dietary reference intakes for Korean citizens. Occupational characteristics were obtained from self-reported Korean National Health and Nutritional Examination Survey (KNHANES) data (occupational classification, working hours, shift work and non-standard workers). An age, education and household income-adjusted logistic regression model was applied to investigate differences in inappropriate energy and nutrient intakes, by sex and occupation.

SETTING

Cross-sectional study.

PARTICIPANTS

From KNHANES (2007-2016), 11 145 participants (5401 males; 5744 females) were included, finally.

RESULTS

Males with long working hours had higher inappropriate carbohydrate, protein, water, vitamin B2 and phosphate intakes than those who worked ≤60 h/week. Long working hours among females were significantly associated with total energy and nutrient 'under-intake'. Male shift and non-standard workers had higher inappropriate protein, water, mineral and vitamin intakes. Multivariate logistic regression revealed that white- and male pink-collar workers had significantly increased risks of water and vitamins A, C, B1 and niacin 'under-intake'.

CONCLUSIONS

We found different rates of inappropriate energy and micronutrient intakes according to working conditions. Younger workers with long hours and shift work schedules were vulnerable to inappropriate energy and nutrient intakes.

Dietary and Health Characteristics of Korean Adults According to the Level of Energy Intake from Carbohydrate: Analysis of the 7th (2016-2017) Korea National Health and Nutrition Examination Survey Data

The purpose of this study was to examine the association between the level of energy intake from carbohydrate and the dietary and health characteristics among Korean adults. We examined the diet quality and health conditions of Korean adults by segmenting them into eight groups according to the level of energy intake from carbohydrate (<45%, 45–50%, 50–55%, 55–60%, 60–65%, 65–70%, 70–75%, and ≥75%). From the data of the 7th (2016–2017) Korea National Health and Nutrition Examination Survey (KNHANES), 7566 subjects aged 19 to 64 years were analyzed. Diet quality was much lower in the groups whose energy intake from carbohydrate was <50% or ≥65%, compared to the groups whose energy intake from carbohydrate was 50–65%. Hypertension or low HDL-cholesterolemia was associated with low (<45%) or high (≥70%) energy intake from carbohydrate. We found no considerable difference in the diet quality and health conditions between the groups whose energy intake from carbohydrate was 50–55% and 55–65%. In conclusion, it is suggested to expand the current acceptable macronutrient distribution range (AMDR) for carbohydrate for Korean adults (i.e., 55% to 65%) to include 50–55%.

Associations of Dietary Intake with Cardiovascular Disease, Blood Pressure, and Lipid Profile in the Korean Population: a Systematic Review and Meta-Analysis

OBJECTIVE

Previous studies have separately reported the contributions of dietary factors to the risk of cardiovascular disease (CVD) and its markers, including blood pressure (BP) and lipid profile. This study systematically reviewed the current evidence on this issue in the Korean population.

METHODS

Sixty-two studies from PubMed and Embase were included in this meta-analysis. We performed a random-effects model to analyze pooled odds ratios (ORs) and hazard ratios (HRs) and their 95% confidence intervals (CIs) for the consumption of 14 food items, three macro- and eight micro-nutrients, two dietary patterns, and three dietary indices.

RESULTS

An analysis of pooled effect sizes from at least four individual study populations showed significant associations between coffee consumption and CVD (OR/HR, 0.71; 95% CI, 0.52-0.97) and elevated/high triglycerides (TG) (OR, 0.84; 95% CI, 0.78-0.90), sugar-sweetened beverage intake and elevated BP (OR/HR, 1.20; 95% CI, 1.09-1.33), and milk and dairy intake and elevated/high TG and low high-density lipoprotein cholesterol (HDL-C) (OR/HR, 0.82; 95% CI, 0.76-0.89 for both). Carbohydrate consumption and the low-carbohydrate-diet score were consistently related to an approximately 25% risk reduction for elevated TG and low HDL-C. A lower risk of elevated total cholesterol, but not low-density lipoprotein, was additionally observed for those with a higher low-carbohydrate-diet score. A healthy dietary pattern was only associated with a reduced risk of elevated TG in the Korea National Cancer Screenee Cohort (OR, 0.81; 95% CI, 0.67-0.98).

CONCLUSION

This study showed that milk and dairy and coffee had protective effects for CVD and its risk factors, such as BP and lipid profile, while sugar-sweetened beverages exerted harmful effects.

Comparison of Trends in Blood Pressure and the Prevalence of Obesity Among Korean and American Adolescents: A 12-Years Cross-sectional Study

OBJECTIVES

This study was conducted to explore recent trends in the prevalence of pediatric elevated blood pressure and hypertension (HTN) in Korea and the United States, applying the new HTN reference values for adolescents.

METHODS

This study analyzed 17 339 (8755 Korean and 8584 American) adolescents aged 10 to 17 who participated in the Korea National Health and Nutrition Examination Survey and the National Health and Nutrition Examination Survey, respectively, between 2005 and 2016. HTN was defined using percentile-based reference values for non-overweight adolescents from 7 nations, and obesity was defined by body mass index (BMI) based on country-specific growth charts. All analyses were stratified by sex and year-over-year changes were evaluated by calculating the p for trend.

RESULTS

Systolic blood pressure showed a statistically meaningful upward trend in Korean boys and girls, while diastolic blood pressure did not show any significant changes. Both systolic and diastolic blood pressure levels declined among United States boys and girls. The prevalence of elevated blood pressure and HTN remained similar in Korean adolescents, but declined in both sexes among United States adolescents. BMI increased in both sexes among Korean adolescents, although the overweight and obesity rates stayed the same. No significant trends were found in any obesity indices among United States adolescents. The prevalence of elevated blood pressure and HTN by obesity level was higher among Korean adolescents than among their United States peers in both sexes, and the gap became higher at more severe levels of obesity.

CONCLUSIONS

Despite the strong correlation between obesity and HTN, recent trends in the prevalence of HTN and obesity among Korean and United States adolescents were strikingly different. Follow-up studies are necessary to determine why the prevalence of HTN was more than twice as high among Korean adolescents than among their United States counterparts.

Carbohydrate intake and risk of metabolic syndrome: A dose-response meta-analysis of observational studies

BACKGROUND AND AIMS

Epidemiological association studies have reported inconsistent findings on the relationship between carbohydrate intake and risk of metabolic syndrome (MetS). Therefore, we aimed to conduct the first dose-response meta-analysis to investigate this effect.

METHODS AND RESULTS

A systematic search in PubMed and Web of Science databases from their inception to June 01, 2019, together with relevant literature scrutiny, was performed to identify related studies for inclusion into the meta-analysis. We calculated the odds ratios (ORs) with 95% confidence intervals (CIs) using a random effects model. Furthermore, subgroup, sensitivity, heterogeneity, and publication bias analyses were performed. This meta-analysis included 14 cross-sectional and four cohort studies, totaling 284,638 participants and 69,554 MetS cases. The highest versus the lowest carbohydrate intake values were associated with an increased risk of MetS (OR: 1.253, 95% CI: 1.147-1.368), with moderate heterogeneity (I² = 54.5%). Using dose-response analysis, we found a linear association between carbohydrate consumption and MetS risk with a corresponding OR of 1.026 (95% CI, 1.004-1.048) and with significant heterogeneity (I² = 82.0%) at 5% energy intake from carbohydrates. We have found similar results using subgroup analyses for major study characteristics and adjustment for confounders. Sensitivity analysis further enhanced the robustness of the results, and no publication bias was detected.

CONCLUSION

Carbohydrate intake is associated with an increased risk of developing MetS. Therefore, additional large prospective cohort studies are warranted to confirm our findings.

Normative range of blood biochemical parameters in urban Indian school-going adolescents

Adolescence is the most critical phase of human growth that radically alters physiology of the body and wherein any inconsistency can lead to serious health consequences in adulthood. The timing and pace at which various developmental events occur during adolescence is highly diverse and thus results in a drastic change in blood biochemistry. Monitoring the physiological levels of various biochemical measures in ample number of individuals during adolescence can call up for an early intervention in managing metabolic diseases in adulthood. Today, only a couple of studies in different populations have investigated blood biochemistry in a small number of adolescents however, there is no comprehensive biochemical data available worldwide. In view, we performed a cross-sectional study in a sizeable group of 7,618 Indian adolescents (3,333 boys and 4,285 girls) aged between 11–17 years to inspect the distribution of values of common biochemical parameters that generally prevails during adolescence and we observed that various parameters considerably follow the reported values from different populations being 3.56–6.49mmol/L (fasting glucose), 10.60–199.48pmol/L (insulin), 0.21–3.22nmol/L (C–peptide), 3.85–6.25% (HbA₁c), 2.49–5.54mmol/L (total cholesterol), 1.16–3.69mmol/L (LDL), 0.78–1.85mmol/L (HDL), 0.33–2.24mmol/L (triglycerides), 3.56–11.45mmol/L (urea), 130.01–440.15μmol/L (uric acid) and 22.99–74.28μmol/L (creatinine). Barring LDL and triglycerides, all parameters differed significantly between boys and girls (p< 0.001). Highest difference was seen for uric acid (p = 1.3 x10^-187) followed by C–peptide (p = 6.6 x10^-89). Across all ages during adolescence, glycemic and nitrogen metabolites parameters varied markedly with gender. Amongst lipid parameters, only HDL levels were found to be significantly associated with gender following puberty (p< 0.001). All parameters except urea, differed considerably in obese and lean adolescents (p< 0.0001). The present study asserts that age, sex and BMI are the essential contributors to variability in blood biochemistry during adolescence. Our composite data on common blood biochemical measures will benefit future endeavors to define reference intervals in adolescents especially when the global availability is scarce.

Association between carbohydrate intake and body composition: The Korean National Health and Nutrition Examination Survey

OBJECTIVE

Several studies have investigated the effects of dietary carbohydrate intake on body composition. However, the results are controversial and few studies have been conducted on an Asian population. The aim of this study was to investigate whether dietary carbohydrate intake is associated with body composition in Korean adults.

METHODS

The present study used data from the Korean National Health and Nutrition Examination Survey, a cross-sectional survey of Korean civilians, conducted from 2008 to 2011. The study analyzed 9594 participants. Carbohydrate intake was defined as the proportion of energy consumed from carbohydrate. Waist circumference, body mass index, and lean and fat mass using a whole-body dual-energy x-ray absorptiometry scanner were measured as body composition parameters.

RESULTS

After adjusting for age, household income, smoking, alcohol consumption, physical activity, history of diabetes, hypertension, dyslipidemia, and intake of energy and fiber per day, the proportion of carbohydrate intake was positively correlated with total limb lean mass in men (β = 0.141, P = 0.046), and in women, the proportion of carbohydrate intake was positively associated with appendicular skeletal muscle mass index (β = 0804, P = 0.003) but negatively associated with trunk fat percentage (β = -0.075, P = 0.026). Total limb lean mass and appendicular skeletal muscle mass index in women showed an increasing trend as the proportion of carbohydrate intake increased.

CONCLUSIONS

No positive association was found between the proportion of carbohydrate intake and any measure of obesity or body fat mass in either men or women. Further studies are needed to evaluate the effects of quantity and quality of carbohydrate intake on body composition.

Low-carbohydrate diet and the risk of metabolic syndrome in Korean adults

BACKGROUND & AIMS

The association of low-carbohydrate diet with weight loss and the risk of cardiovascular diseases has recently been the focus of increasing research attention. However, studies on low-carbohydrate diet in the Asian population are limited. The present study was aimed to examine the association between low-carbohydrate diet and metabolic syndrome among Korean adults.

METHODS AND RESULTS

A total of 16,349 participants aged 30 years or older who participated in a 24-h dietary recall survey of the fifth and sixth Korea National Health and Nutrition Examination Survey were included in this study. Low-carbohydrate diet was evaluated using the low-carbohydrate-diet score, which was calculated based on the percentage of energy from carbohydrate, protein, and fat by sex. The association between the low-carbohydrate-diet score and metabolic syndrome was analyzed using multiple logistic regression analysis. A low-carbohydrate diet was not associated with metabolic syndrome and its components such as waist circumference, blood pressure, and triglyceride levels. However, women in the highest decile of the animal- or plant-based low-carbohydrate-diet score showed a decreased risk of reduced high-density lipoprotein (HDL)-cholesterol levels, and men in the highest decile of the animal-based low-carbohydrate-diet score showed a decreased risk of reduced HDL-cholesterol levels than those in the lowest decile of the low-carbohydrate-diet score.

CONCLUSION

These findings indicate that, in Korea, a low-carbohydrate diet did not increase the risk of metabolic syndrome among adults who typically consume a high-carbohydrate low-fat diet. However, it may moderately decrease the risk of reduced HDL-cholesterol levels.

Nutrition Trends in Kidney Transplant Recipients: the Importance of Dietary Monitoring and Need for Evidence-Based Recommendations

Many physiological properties of the renal system influence nutrient metabolism, elimination, and homeostasis. Kidney failure poses significant challenges to maintaining adequate nutrition, most of which transplantation ameliorates. Comprehensive recommendations for managing nutritional derangements for patients with chronic kidney disease and end stage renal disease exist; however, there are only sparse guidelines for post-transplant malnutrition and adverse outcomes. Not only are guidelines limited, but little is known about dietary trends of post-kidney transplant recipients. This review describes guidelines for prevalent metabolic and nutritional complications post-kidney transplantation and also evaluates changes in caloric intake and diet composition after transplantation. This topic is important because nutrition influences allograft function and a number of cardiovascular risk factors including blood pressure, dyslipidemia, weight, and diabetes. In addition, many dietary recommendations and modifiable lifestyle changes should be tailored for specific complications of transplant patients, namely immunosuppression side effects, dietary restrictions, and electrolyte imbalances.

Total energy intake according to the level of skeletal muscle mass in Korean adults aged 30 years and older: an analysis of the Korean National Health and Nutrition Examination Surveys (KNHANES) 2008-2011

BACKGROUND/OBJECTIVES

Since gain or loss of skeletal muscle mass is a gradual event and occurs due to a combination of lifestyle factors, assessment of dietary factors related to skeletal muscle is complicated. The aim of this study was to investigate the changes in total energy intake according to the level of skeletal muscle mass.

SUBJECTS/METHODS

A total of 8,165 subjects ≥ 30 years of age from the Korean National Health and Nutrition Examination Surveys (KNHANES) 2008-2011 were included in the analysis, and multivariate-adjusted regression analyses were performed to analyze the association of the quartiles of sarcopenia index (SI) with energy intake of the study population after adjusting for age and metabolic parameters.

RESULTS

The increase in SI quartile was in proportion to the gradual decrease in systemic lipids and the anthropometric measurement of fat accumulation (P < 0.001). Subjects in higher SI quartiles tended to consume more total energy and energy-producing nutrients than those in lower quartiles (P < 0.001). After age, body weight, alcohol consumption, and metabolic parameters were adjusted in the analysis, total energy intake gradually increased according to the increase in SI quartile, and the association between total energy intake and SI was more pronounced in men. However, the risk (odd ratio) of having a low SI was not affected by any single macronutrient intake.

CONCLUSIONS

In this study, total energy intake was positively associated with SI and relative skeletal mass in both men and women. However, no significant association or a weak association was observed between any single macronutrient intake and skeletal muscle mass. The data indicated that acquiring more energy intake within the normal range of energy consumption may help to maintain skeletal muscle mass.

Toenail Chromium Concentration and Metabolic Syndrome among Korean Adults

Although in vivo and in vitro studies have shown that chromium has protective effects against metabolic diseases, few studies have examined this association in humans. The present study examined chronic chromium (Cr) exposure among Koreans based on the measurement of toenail Cr concentrations, and analyzed the associations between toenail Cr concentrations and metabolic syndrome (MetS) and its components. We conducted a cross-sectional analysis using baseline data from the prospective cohort study in the Yeungnam area of South Korea that included 232 men and 268 women. Toenail Cr concentration was quantified by neutron activation analysis, and metabolic biomarker levels were obtained through medical examinations. The odd ratios (OR) of prevalent MetS and its components in correlation with Cr concentrations were calculated using multivariable logistic regression. After multiple confounding variables were adjusted for, participants with higher concentrations of Cr had a prevalence rate of MetS similar to those with lower concentrations (OR, 1.84; 95% confidence interval, 0.65-5.23). Our results do not support an association between long-term exposure to Cr and a lower prevalence of MetS in Koreans, whose Cr concentrations are relatively low compared to those of populations in Europe and the United States.