Dietary Sodium Intake in People with Diabetes in Korea: The Korean National Health and Nutrition Examination Survey for 2008 to 2010

Salt Intake in Adults with Diabetes and Hypertension: The Longitudinal Study of Adult Health-Brasil Study

Background and Objective: Hypertension and type-2 diabetes are strong risk factors for cardiovascular diseases, and their management requires lifestyle changes, including a shift in dietary habits. The consumption of salt has increased in the last decades in some countries, but its association with type-2 diabetes remains unknown. Thus, we aimed to estimate the amount of salt intake among adults with and without diabetes and to assess whether concomitant hypertension and diabetes are associated with higher salt intake. Methods: Data from 11,982 adults 35-74 years of age enrolled in the baseline of the Longitudinal Study of Adult Health-Brasil study (2008-2010) were studied. A clinical and anthropometric evaluation was performed, and their daily salt intake was estimated by the overnight 12-hr urine sodium excretion. Results: Salt intake (gram per day) was higher in participants with diabetes as compared with those without diabetes, regardless of sex (men: 14.2 ± 6.4 vs. 12.4 ± 5.6, P < 0.05; women: 10.5 ± 4.8 vs. 9.1 ± 4.1, P < 0.05). However, salt intake is high in participants with fasting glucose ≥126 mg/dL or HbA1c ≥6.5%, but not in participants with blood glucose 2 hr after the glucose tolerance test ≥200 mg/dL. When hypertension and diabetes coexisted, salt consumption was higher than among people without these conditions. The prevalence of hypertension increased with increasing salt intake in women with diabetes, but not in men with this condition. Conclusions: Our findings highlight the high consumption of salt in individuals with diabetes and/or hypertension, and the need for effective strategies to reduce salt consumption in these groups of increased risk for major cardiovascular events, especially in women.

Dietary patterns and the risk of diabetes in Korean adults: A cross-sectional and prospective cohort study

OBJECTIVE

The aim of this study was to identify dietary patterns associated with diabetes in Korean adults and to investigate their association with diabetes risk in both a cross-sectional and prospective study.

METHODS

Predefined food groups collected by the Korea National Health and Nutrition Examination Survey (KNHANES 2015-2018, n = 19 721) were entered in a reduced rank regression (RRR) model, followed by stepwise linear regression analyses to identify the most predictive dietary patterns. We evaluated the construct validity of dietary patterns in two independent samples from KNHANES 2019 to 2021 (n = 14 223) and the Health Examinees (HEXA) cohort study (n = 30 013). Associations between dietary patterns and diabetes risk were examined using multivariable regression and multivariable-adjusted Cox proportional hazard models, respectively.

RESULTS

A dietary pattern was identified with high positive loadings for refined white rice, kimchi and salted vegetables, wheat flour and bread, and seasonings, and high negative loadings for whole grains, legumes with tofu and soymilk, poultry, eggs, and plant oils. The higher pattern scores were significantly associated with diabetes risk in KNHANES 2015 to 2018 (male: odds ratio [OR]: 1.59; 95% confidence interval [CI]: 1.35, 1.88; female: OR: 1.37; 95% CI: 1.18, 1.52), KNHANES 2019 to 2021 (male: OR: 1.47; 95% CI: 1.01, 1.69; female: OR: 1.37; 95% CI: 1.18, 1.54), and HEXA study (male: hazard ratio [HR]: 1.10; 95% CI: 1.01, 1.34; female: HR: 1.24; 95% CI: 1.02, 1.52).

CONCLUSIONS

Dietary patterns derived by RRR followed by stepwise linear regression analyses were associated with increased risks of diabetes among Korean adults.

Dietary salt intake predicts future development of metabolic syndrome in the general population

Excessive dietary salt consumption is one of the most important risk factors for hypertension. Metabolic disorders often coexist with hypertension, and excess salt intake has been reported to underlie metabolic disorders, such as insulin resistance. Therefore, we tested the hypothesis that excessive dietary salt causes metabolic syndrome in the general population. In total, 13886 subjects who participated in our medical checkup were enrolled, and salt intake was assessed using a spot urine sample. The characteristics of participants with metabolic syndrome (n = 1630) were examined at baseline, and then participants without metabolic syndrome (n = 12256) were followed up with the endpoint being the development of metabolic syndrome. The average estimated salt intake in our participants was 8.72 ± 1.93 g/day. A significant association between salt intake and metabolic syndrome was obtained from the logistic regression analysis, and salt intake increased as the number of metabolic disorders in an individual increased at baseline (P < 0.001). During the median follow-up period of 52 months, 1669 participants developed metabolic syndrome. Kaplan-Meier analysis demonstrated an increased risk of metabolic syndrome across quartiles of baseline salt intake (log-rank, P < 0.001). In the Cox proportional hazard regression analysis where salt intake was taken as a continuous variable, salt intake at baseline was an independent predictor of developing metabolic syndrome. These results suggest that excessive salt intake is significantly associated with the development of metabolic syndrome in the general population. Salt may play an important role in the development of metabolic disorders and hypertension.

Determinants of Type 2 Diabetes Mellitus Among Adults in Dill-Chora Referral Hospital, Dire Dawa, East Ethiopia

Introduction

Ethiopia has been exhibiting trends that are shifting the populace's way of life toward urbanization. As a result, the country's primary focus is on treating infectious diseases, whereas chronic noncommunicable diseases receive less attention. Type 2 diabetes has emerged as a major noncommunicable disease that is endangering African nations' economic, social, and cultural underpinnings. There has been research mostly on prevalence, factors associated, and glycemic control of diabetes but not adequate on the causes of T2DM in Ethiopia, particularly in the study region.

Objective

To identify the determinants of type 2 diabetes mellitus among adults at Dill-Chora hospital, from August 30 to October 30, 2021.

Methods

An unmatched case-control study was carried out at Dill-Chora referral hospital using face-to-face interviews. The data was collected, cleaned, coded, and entered to epi data version 3.1 before being exported to SPSS version 23 for analysis. The analyses used were descriptive and logistic regression.

Results

The study included 331 individuals, 113 cases and 218 controls. Cigarette smoking (AOR: 3.15, 95% CI: 1.24-7.96), extra salt consumption (AOR: 5.52, 95% CI: 2.33-13.05), low fruit consumption (AOR: 5.28, 95% CI: 2.12-13.16), infrequent physical activity (AOR: 3.72, 95% CI: 1.65-8.39), waist to hip ratio (AOR: 18.88, 95% CI: 7.35-48.42), and triglyceride level (AOR: 2.93, 95% CI: 1.34-6.32) were strongly linked to the onset of type 2 diabetes mellitus.

Conclusion and Recommendation

This study discovered a variety of risk factors for type 2 diabetes, including triglyceride levels, fruit consumption, smoking, increased salt consumption, irregular exercise, and waist to hip ratio. By focusing preventative efforts on these risk factors, the occurrence of type 2 diabetes may be reduced. Furthermore, diabetes mellitus screening is crucial, particularly in those with a high waist-to-hip ratio, a smoking history, and high triglyceride levels.

Effects of different diets on glycemic control among patients with type 2 diabetes: A literature review

Background: Globally, type 2 diabetes mellitus (T2DM) is one of the most common diseases, and the incidence is gradually increasing. Diet management could improve the elevated HbA1c levels. Aim: This review aims to examine the effects of different types of diets on glycemic control in patients with T2DM. Methods: PubMed and Google scholar databases were searched. Reports published from the years 1991 to 2021 that focused on the effect of different diets on diabetes control were selected. Results: All the studies reported that the type of diet can affect insulin secretion and glycemic control in patients with diabetes. The recommended macronutrient distribution for patients with diabetes is 30% of fat, 45-60% of carbohydrates, and 15-35% of protein. Consuming more or less of these macronutrients may lead to changes in glucose metabolism and may affect insulin secretion. In fact, following alow-fat diet improves glycemic control and decreases HbA1c levels. Studies reported that a low-carbohydrate diet had the greatest effect on improving glycemic control and insulin parameters. A low-calorie diet reduced fasting plasma glucose, while a very low-calorie diet resulted in a long-term decrease in HbA1c level. A healthy diet free of processed foods and sugar, and rich in nutrients such as fiber, vitamins, and minerals contributed to maintaining controlled blood sugar and lipid plasma levels. Although studies show a low-salt diet improves blood pressure, which is common inT2DM, other findings show that restricting salt intake is associated with increased sugar consumption. Conclusion: Healthy diet with adequate intake of energy and low-fat and low-sugar foods can enhance the glycemic control and reduce T2DM complications.

Trends of Dietary Intakes and Metabolic Diseases in Japanese Adults: Assessment of National Health Promotion Policy and National Health and Nutrition Survey 1995–2019

Health Japan 21 is Japan’s premier health promotion policy encompassing preventive community health measures for lifestyle-related diseases. In this repeated cross-sectional survey, we report 24-year trends of type 2 diabetes mellitus (T2DM), obesity, hypertension, and their association with dietary intakes to evaluate Health Japan 21’s impact and identify gaps for future policy implementation. We analyzed data from 217,519 and 232,821 adults participating in the physical examination and dietary intake assessment, respectively, of the National Health and Nutrition Survey 1995–2019. Average HbA1c and BMI have significantly increased along with the prevalence of T2DM and overweight/obesity among males. Despite a significant decrease in daily salt intake, the decline in the combined prevalence of Grades 1–3 hypertension was non-significant. Seafood and meat intakes showed strong opposing trends during the study period, indicating a dietary shift in the Japanese population. Neither salt nor vegetable/fruit intake reached the target set by Health Japan 21. Metabolic disease trend differences between males and females highlight the need for a gender-specific health promotion policy. Future Health Japan 21 implementation must also consider locally emerging dietary trends.

Association of rheumatoid arthritis and high sodium intake with major adverse cardiovascular events: a cross-sectional study from the seventh Korean National Health and Nutrition Examination Survey

OBJECTIVES

High salt intake has a harmful effect on hypertension; however, the association between major adverse cardiovascular events (MACE) and salt intake is still controversial. Rheumatoid arthritis (RA) is also characterised by excess cardiovascular risk. However, few studies have investigated the combined role of salt intake and RA in MACE in the general Korean population. Here, we evaluated this relationship among the Korean adult population.

DESIGN

Retrospective, cross-sectional.

SETTING

Population-based survey in Korea.

METHODS

This study was based on the data of the seventh Korean National Health and Nutrition Examination Survey (2016-2018). The estimated 24-hour urinary sodium excretion (24HUNa), a surrogate marker for daily sodium intake, was calculated using the Tanaka equation and was stratified into five groups (<3, 3-3.999, 4-4.999, 5-5.999 and ≥6 g/day). Finally, data from 13 464 adult participants (weighted n=90 425 888) were analysed; all analyses considered a complex sampling design. Multivariable logistic regression for MACE as primary dependent variable was performed and adjusted for potential covariates.

RESULTS

Participants with MACE had higher 24HUNa levels and RA proportion than those without MACE (p<0.001). The association of MACE with 24HUNa was J-shaped with a gradual increase from about 3 g/day. The highest 24HUNa (≥6 g/day) group was significantly associated with increased prevalence of MACE compared with the reference group (3-3.999 g/day) after adjusting for all associated covariates (OR 6.75, 95% CI 1.421 to 32.039). In the multivariate logistic regression analysis, RA (OR 2.05, 95% CI 1.283 to 3.264) and the highest 24HUNa group (OR 6.35, 95% CI 1.337 to 30.147) were significantly associated with MACE even after adjusting for baseline covariates.

CONCLUSIONS

These nationally representative data suggest that RA and extremely high sodium intake are associated with MACE in the general adult Korean population. Avoiding extremely high salt intake and considering RA as an important risk factor for MACE might help promote public cardiovascular health.

Dietary sodium and cardiovascular morbidity/mortality: a brief commentary on the 'J-shape hypothesis'

The last decade, a growing number of evidence support J-shape or inverse - instead of positive linear -- associations between dietary sodium intake and cardiovascular morbidity/mortality. A careful evaluation of these studies leads to the following observations: less accurate methods for dietary sodium assessment are usually used; most studies included high-risk participants, enhancing the possibility of a 'reverse causality' phenomenon. However, these limitations do not explain all the findings. Few carefully designed randomized clinical trials comparing different levels of sodium intake that address the issue of the optimal and safe range exist; therefore, current guidelines recommend a higher cut-off instead of a safe range of intake. Given the demonstrated harmful effects of very low sodium diets leading to subclinical vascular damage in animal studies, the 'J-shape hypothesis' cannot yet be either neglected or verified. There is a great need of well-designed general population-based prospective randomized clinical trials to address the issue.

Associations of Dietary Salt and Its Sources with Hemoglobin A1c in Patients with Type 2 Diabetes Not Taking Anti-Diabetic Medications: Analysis Based on 6-Month Intervention with a Moderate Low-Carbohydrate Diet

OBJECTIVE

Based on biological studies, the hyperglycemic effect mediated by sodium-glucose co-transporter 1 in the intestine is stronger for foods containing more sodium chloride. Observational studies have demonstrated that type 2 diabetes (T2DM) incidence increases as salt intake increases. We aimed to elucidate associations of total salt and its sources with hemoglobin A1c (HbA1c) in patients with T2DM.

METHODS

We conducted an observational study using data from a 6-month moderate low-carbohydrate dietary intervention in 245 outpatients with T2DM (138 men) without antidiabetic medication. Intakes of total salt and its sources, carbohydrate and total energy were assessed at baseline and 6 months based on 3-day dietary records. Multiple regression analyses were performed to examine associations of Δtotal salt or its sources with ΔHbA1c.

RESULTS

Salt intake significantly decreased in men (change: -0.92 ± 3.53 g/day) but not in women (0.11 ± 2.28). HbA1c (men: -1.5 ± 1.6%; women: -0.9 ± 1.3%), carbohydrate (men: -115 ± 104 g/day; women: -64 ± 71) and total energy (men: -439 ± 660 kcal/day; women: -192 ± 438) significantly decreased in both sexes. Multiple regression analysis revealed that reducing intakes of total salt and salt from salty snacks, meat processed foods, Chinese noodles with soup and table salt by 1.0 g was associated with decreases in HbA1c of 0.11% 1.18% 0.47% 0.38% and 0.26%, respectively, in men, while reducing salt from miso by 1.0 g was associated with a decrease in HbA1c of 0.30% in women. The associations were dependent on Δcarbohydrate or Δtotal energy in men, while the association of Δsalt from miso in women was independent of them.

CONCLUSION

Reducing total salt and its sources had differential associations with HbA1c. Individual associations depended on Δcarbohydrate or Δtotal energy in men, while that of salt from miso in women was independent of them.

Dietary Sodium Intake and Health Indicators: A Systematic Review of Published Literature between January 2015 and December 2019

As the science surrounding population sodium reduction evolves, monitoring and evaluating new studies on intake and health can help increase our understanding of the associated benefits and risks. Here we describe a systematic review of recent studies on sodium intake and health, examine the risk of bias (ROB) of selected studies, and provide direction for future research. Seven online databases were searched monthly from January 2015 to December 2019. We selected human studies that met specified population, intervention, comparison, outcome, time, setting/study design (PICOTS) criteria and abstracted attributes related to the study population, design, intervention, exposure, and outcomes, and evaluated ROB for the subset of studies on sodium intake and cardiovascular disease risks or indicators. Of 41,601 abstracts reviewed, 231 studies were identified that met the PICOTS criteria and ROB was assessed for 54 studies. One hundred and fifty-seven (68%) studies were observational and 161 (70%) focused on the general population. Five types of sodium interventions and a variety of urinary and dietary measurement methods were used to establish and quantify sodium intake. Five observational studies used multiple 24-h urine collections to assess sodium intake. Evidence mainly focused on cardiovascular-related indicators (48%) but encompassed an assortment of outcomes. Studies varied in ROB domains and 87% of studies evaluated were missing information on ≥1 domains. Two or more studies on each of 12 outcomes (e.g., cognition) not previously included in systematic reviews and 9 new studies at low ROB suggest the need for ongoing or updated systematic reviews of evidence on sodium intake and health. Summarizing evidence from assessments on sodium and health outcomes was limited by the various methods used to measure sodium intake and outcomes, as well as lack of details related to study design and conduct. In line with research recommendations identified by the National Academies of Science, future research is needed to identify and standardize methods for measuring sodium intake.

Nineteen-year trends in fermented food consumption and sodium intake from fermented foods for Korean adults from 1998 to 2016

Objective:

Fermented foods such as kimchi are traditional foods in Korea and could provide beneficial health effects. However, fermented foods also contribute to increased Na intake since salt is added during the fermentation process. The present research aimed to examine trends in the consumption of fermented foods and Na intake over time by Korean adults, using data from the Korea National Health and Nutrition Examination Survey (KNHANES).

Design:

KNHANES is a cross-sectional survey; data from 1998 to 2016 were divided into seven groups from KNHANES I to VII.

Setting:

Demographic information on sex, age, education and income were collected. Assessment of fermented food and Na consumption was conducted via analysis of 24 h dietary recall data. Multivariate linear regressions and logistic regressions were performed to calculate the P for trends by applying strata, cluster and sampling weights by SAS PROC SURVEY.

Participants:

The target population was Korean adults, aged ≥19 years, who participated in a 24 h dietary recall. The total number was 76 199, with 32 324 men and 43 875 women.

Results:

A significant decline in fermented food consumption was observed from 1998 to 2016 in both men and women (P < 0·0001). Among fermented foods, kimchi consumption was greatly reduced while pickled vegetables consumption showed a marked increase. Similarly, Na intake from fermented foods declined significantly over time in both men and women (P < 0·0001).

Conclusions:

The consumption of fermented foods and Na intake from fermented foods by Korean adults decreased significantly over time from 1998 to 2016.

Lower Leg Fat Depots Are Associated with Albuminuria Independently of Obesity, Insulin Resistance, and Metabolic Syndrome (Korea National Health and Nutrition Examination Surveys 2008 to 2011)

BACKGROUND

Although the involvement of obesity in metabolic disorders is well known, leg fat depot influences on albuminuria have not been determined.

METHODS

This population-based, cross-sectional study used a nationally representative sample of 2,076 subjects aged ≥20 years from the Korea National Health and Nutrition Examination Surveys of 2008 to 2011. The ratio of leg fat to total fat (LF/TF ratio) was assessed by dual X-ray absorptiometry, and albuminuria was defined as more than one positive dipstick test or an albumin-to-creatinine ratio of ≥30 mg/g.

RESULTS

Individuals whose LF/TF ratio was in the lowest tertile showed a higher proportion of albuminuria than those in the highest tertile (odds ratio [OR], 2.82; 95% confidence interval [CI], 2.01 to 3.96; P<0.001). This association was observed in both sexes, all age groups, and all subgroups stratified by body mass index, waist circumference, homeostasis model assessments of insulin resistance, and the presence of metabolic syndrome (all, P<0.05). Multiple logistic regression analyses also demonstrated that the lowest LF/TF ratio was independently associated with albuminuria risk (OR, 1.55 to 2.16; all, P<0.05). In addition, the risk of albuminuria was higher in sarcopenic individuals with lower LF/TF ratios than in the highest LF/TF ratio subjects without sarcopenia (OR, 3.73; 95% CI, 2.26 to 6.13).

CONCLUSION

A lower LF/TF ratio was associated with an increased risk of albuminuria independent of obesity, insulin resistance, and metabolic syndrome, and when combined with sarcopenia, the albuminuria risk synergistically increased. Hence, our findings may have implications to improve risk stratification and recommendations on body fat distribution in the general population.

Factors Predicting Sodium Intake of Korean Americans with Type 2 Diabetes

The increasing prevalence of type 2 diabetes mellitus (T2DM) and its complications including cardiovascular disease and chronic kidney disease threaten Korean Americans (KAs). High dietary sodium intake contributes to both conditions. The purpose of the study was to assess dietary sodium consumption and to examine the predictors of sodium intake among KA with T2DM. A total 232 KA who had uncontrolled diabetes participated in this study. The majority of the sample (69%) consumed more sodium than current national guidelines. A high level of energy intake was the strongest predictor for sodium intake with gender and marital status also related. Our findings identified predictive factors to excessive sodium intake and these data support the need for culturally-tailored education about appropriate dietary sodium and energy intake are needed for patients about T2DM.

Evaluation of the association between the number of natural teeth and anemia among Korean adults using nationally representative data

BACKGROUND

Anemia as a chronic disease is defined as anemia occurring in chronic infections with inflammatory conditions. The purpose of this study is to assess the association between the number of natural teeth and anemia using nationally representative data.

METHODS

This study involved a cross-sectional analysis using data from the Korean National Health and Nutrition Examination Survey from 2010 to 2012. A total of 16,875 respondents aged > 19 years without missing values were included in this study. The association between the number of natural teeth and anemia was evaluated by multivariable logistic regression analyses after adjusting for age, sex, body mass index, smoking habits, drinking habits, exercise levels, income levels, education levels, vitamin D levels, diabetes, toothbrushing frequency, energy intake, and percentage of fat in total energy intake among Korean adults.

RESULTS

There was a significant decrease in prevalence of anemia and a significant increase in hemoglobin levels in participants with more natural teeth (P < 0.05). Adjusted odds ratios and their 95% confidence intervals for anemia in participants with numbers of natural teeth of < 15, 15 to 19, 20 to 24, or 24 to 28 were 1 (reference), 0.856(0.591 to 1.24), 0.659(0.5 to 0.868), and 0.607(0.463 to 0.797), respectively, with adjustment for confounding factors (P < 0.05).

CONCLUSION

The number of natural teeth is negatively associated with anemia in Korean adults, and the number of natural teeth may be considered an independent risk indicator of anemia.

Clinical implications of age and sex in the prevalence of periodontitis in Korean adults with diabetes

The present study was performed to assess the risk factors for periodontitis in Korean adults with diabetes. Data from the Korean National Health and Nutrition Examination Survey of the Korean population, conducted between January 2012 and December 2014 were used in the investigation. The presence of periodontitis in participants with diabetes in association with demographic variables and the anthropometric characteristics of the participants was investigated. Multiple logistic regression analyses were used to assess the associations between periodontitis and age, sex, diabetic control and duration of diabetes, following adjustment for confounding factors. The odds ratio of periodontitis was higher in individuals ≥65 years old compared with individuals <65 years old (1.152). The odds ratio of periodontitis was significantly higher in males compared with females (1.774). The number of patients with moderate and severe periodontitis differed significantly between different age groups. The present study revealed that age, sex and oral health behavior are risk indicators for periodontitis in patients with diabetes. The present study suggests that that an increased age, being male and engaging in poor oral health behavior increases the risk of periodontitis in participants with diabetes.

The Science of Salt: A regularly updated systematic review of the implementation of salt reduction interventions (March-August 2016)

This review aims to identify, summarize, and appraise studies reporting on the implementation of salt reduction interventions that were published between March and August 2016. Overall, 40 studies were included: four studies evaluated the impact of salt reduction interventions, while 36 studies were identified as relevant to the design, assessment, and implementation of salt reduction strategies. Detailed appraisal and commentary were undertaken on the four studies that measured the impact of the interventions. Among them, different evaluation approaches were adopted; however, all demonstrated positive health outcomes relating to dietary salt reduction. Three of the four studies measured sodium in breads and provided consistent evidence that sodium reduction in breads is feasible and different intervention options are available. None of the studies were conducted in low- or lower middle-income countries, which stresses the need for more resources and research support for the implementation of salt reduction interventions in these countries.

Association between underweight and tooth loss among Korean adults

There is growing interest in the relationship between body mass index and oral health. Previous study showed that being underweight was significantly associated with having lower masticatory performance. This study was performed to assess the relationship between an underweight body mass index lower than 18.5 and the number of natural teeth using nationally representative data. Initially, a total of 25,534 individuals were candidates in the Korean National Health and Nutrition Examination Survey. The analysis in this study was confined to 17,870 subjects who were 19 years or older and without missing values for outcome variables. Body mass index and number of natural teeth were evaluated. Multiple regression analysis was used to evaluate the risk of tooth loss in relation to body mass index. Adjusted odds ratios and their 95% confidence intervals for chewing discomfort in individuals who were underweight, normal, overweight, obese, and extremely obese were 1.712(1.156–2.535), 1.111(0.939–1.315), 1(reference), 0.949(0.798–1.128), and 1.172(0.807–1.700), respectively, after adjustment. The association between underweight and tooth loss was proven by multiple logistic regression analyses after adjusting for confounding factors. Underweight may be considered a potential risk indicator for tooth loss in Korean adults.