Association of the urinary sodium to urinary specific gravity ratio with metabolic syndrome in Korean children and adolescents: The Korea National Health and Nutrition Examination Survey 2010-2013

Association between urinary sodium and circulating lipid levels: a Mendelian randomization study

Background

Urinary sodium was indicated to be associated with dyslipidemia, but inconsistent conclusions for this association exist across the present observational studies.

Objectives

This study aimed to evaluate the causal association between urinary sodium and circulating lipid levels [low-density lipoprotein cholesterol (LDL-C), triglycerides, and high-density lipoprotein cholesterol (HDL-C)] through Mendelian randomization.

Methods

Univariable Mendelian randomization (UVMR) and multivariable Mendelian randomization (MVMR) with pleiotropy-resistant methods were performed. Data for urinary sodium were obtained from the genome-wide association study (GWAS) from 446,237 European individuals. Data for lipid profiles were extracted from GWAS based on the UK Biobank (for the discovery analysis) and the Global Lipids Genetics Consortium (for the replication analysis).

Results

In the discovery analysis, UVMR provided evidence that per 1-unit log-transformed genetically increased urinary sodium was associated with a lower level of HDL-C level (beta = -0.32; 95% CI: -0.43, -0.20; p = 7.25E-08), but not with LDL-C and triglycerides. This effect was still significant in the further MVMR when considering the effect of BMI or the other two lipid contents. In contrast, higher genetically predicted triglycerides could increase urinary sodium in both UVMR (beta = 0.030; 95% CI: 0.020, -0.039; p = 2.12E-10) and MVMR analyses (beta = 0.029; 95% CI: 0.019, 0.037; p = 8.13E-10). Similar results between triglycerides and urinary sodium were found in the replication analysis.

Conclusion

Increased urinary sodium may have weak causal effects on decreased circulating HDL-C levels. Furthermore, genetically higher triglyceride levels may have independent causal effects on increased urinary sodium excretion.

Prevalence of metabolic syndrome and its association with oral health: First results from the Kurdish cohort study

Aims

Investigate the association between oral and dental health (ODH) and metabolic syndrome (MetS) in adults aged 35-70 years.

Methods

The study utilized data from the enrollment phase of Dehgolan prospective cohort study in the west of Iran. A cross-sectional assessment was conducted on a total of 3996 participants, involving a comprehensive oral examination and the assessment of their oral hygiene behavior (ODH). MetS was defined according to the updated National Cholesterol Education Program Adult Treatment Panel III. Logistic regression used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for sociodemographic characteristics.

Results

MetS was more prevalent among those who not daily brushing and flossing. Participants with missing teeth (MT) show higher prevalent of MetS. Being female, lower age, illiteracy, family history of diabetes, low physical activity, and salt at table were independently associated with increase odds of MetS (p < 0.05). Odds of MetS were significantly decreased with use flossing (OR = 0.75; CI = 0.60-0.93), decayed (OR = 0.83; CI = 0.72-0.97), filled (OR = 0.84; CI = 0.71-0.99), and increased with MT (OR = 1.45; CI = 1.16-1.81) as long as adjusted for ODH factors. When other potential confounder such as sociodemographic, personal and nutritional habits were adjusted, daily flossing was the only factor that still statistically decreased (OR = 0.79; CI = 0.62-0.99) the odds of MetS.

Conclusion

Daily flossing was the only factor that independently associated with MetS. Relationship of other ODH factors with Mets were confounded by sociodemographic characteristics of the participants.

Urinary sodium, iodine, and volume in relation to metabolic syndrome in Mesoamerican children and their parents

BACKGROUND AND AIMS

The roles of sodium or iodine intake on the metabolic syndrome (MetS) etiology remain controversial. We evaluated the associations of 24 h urinary sodium and iodine with MetS among Mesoamerican children and their adult parents.

METHODS AND RESULTS

We conducted a cross-sectional study among 217 school-age children and 478 parents from 9 Mesoamerican cities. Exposures were high 24 h urinary sodium excretion and concentration (>2000 mg/d or mg/L, respectively) and high 24 h urinary iodine excretion and concentration (≥300 μg/d or μg/L, respectively). In children, the outcome was a standardized metabolic score from five criteria analogous to the Adult Treatment Panel (ATP) III criteria. In adults, MetS was defined according to the ATP III criteria. We estimated adjusted mean differences in the metabolic risk score and adjusted prevalence ratios of MetS between exposure categories using multivariable regression. In children, high sodium concentration was associated with a 0.10 units (43% of a SD) higher score (P = 0.001) and high iodine concentration was related to a 0.09 units (39% of a SD) higher score (P = 0.009). Unexpectedly, high 24 h urinary volume was associated with a lower metabolic score. In adults, high 24 h sodium excretion was related to hypertension and high iodine concentration was related to increased MetS prevalence.

CONCLUSION

High sodium and iodine concentrations, but not 24 h iodine excretion, are significantly associated with MetS in children, whereas high 24 h urinary volume is related to a decreased metabolic score. In adults, high iodine concentration tends to be related to increased MetS prevalence, but not 24 h iodine excretion.

Analysis of spot urine biomarkers and association with body weight in Japanese elementary schoolchildren

Childhood obesity is rapidly increasing worldwide and is largely the consequence of adoption of unhealthy diets excessive in calories and salt (NaCl) as well as devoid in pivotal micronutrients such as potassium (K) and magnesium (Mg). Education-based programs aiming to encourage healthy food knowledge and behaviors are crucial at a young age, and for this purpose, convenient ways to assess daily dietary intake are warranted. We therefore attempted to evaluate the dietary intake of Okinawan schoolchildren in Japan by analyzing a series of biomarkers in morning spot urine samples and explore whether these biomarkers correlate with body weight and a series of metabolic parameters. We enrolled 98 third-grade elementary schoolchildren in Okinawa, Japan. Morning spot urine samples were collected and analyzed using high-performance liquid chromatography (HPLC) to assess dietary intake. We found that estimated daily NaCl intake was higher in obese/overweight children as compared to healthy-weight children (p = 0.0001). There was also a significant positive correlation between body mass index (BMI) and NaCl intake (Spearman) (ρ = 0.45, p < 0.0001) and a negative correlation between BMI and Mg/Cr (ρ =  -0.27, p = 0.01). Furthermore, Na/K ratio was higher in samples collected on Monday (weekend) as compared to samples collected on Thursday or Friday (weekday) (p < 0.0001).

CONCLUSION

Via the use of morning spot urine analyses, our results show that NaCl intake was associated with obesity, and Mg excretion negatively correlated with BMI in Japanese schoolchildren, highlighting the potential role of these micronutrients in maintaining a healthy body weight.

WHAT IS KNOWN

•Overweight and obesity are largely due to excessive consumption of calories and positively correlated with salt (NaCl) intake. •Spot urine methods are convenient for assessing the nutritional needs and targeting prevention programs in children.

WHAT IS NEW

•Utilizing morning spot urine analyses, estimated NaCl intake is positively correlated and Mg/Cr negatively correlated with BMI in Okinawan schoolchildren. •As estimated via morning spot urine samples, a greater proportion of children likely exceeds the recommended NaCl intake on the weekend as compared to weekday.

Association between childhood obesity and familial salt intake: analysis of data from Korean National Health and Nutrition Examination Survey, 2014-2017

High salt intake is known as a risk factor of childhood obesity. As family members share not only genes but also their diet habit, parents' salt intake may affect to their children's obesity. In this study, we investigated correlations between childhood obesity and parents' or children's sodium intakes based on a nationwide survey data. From the Korean National Health and Nutrition Examination Survey data from 2014 to 2017, 802 boys and 657 girls aged 10-18 years, and their parents were included. BMI z-score and 24-hour urinary sodium excretion, which is estimated through Tanaka's equation, were used to examine associations between obesity and sodium intakes. The BMI status and the prevalence of obesity between children and their parents showed strong positive correlations in both sexes (all p < 0.001). The urinary sodium excretion between children and their parents showed positive correlations in both sexes (all p < 0.05). Children with higher urinary sodium excretion showed higher BMI (in both sexes, p < 0.001) and higher parental obesity compared to those with lower urinary sodium excretion, however, statistical significances of the latter relationship were varied by sex. In conclusion, our study suggests close relationship between childhood obesity and their sodium intakes, which also correlate well with parental BMIs and diet behavior. Therefore, parental education and active participation could be crucial in regulating childhood obesity.

Dietary intake and nutritional status of Korean children and adolescents: a review of national survey data

In Korea, several national cross-sectional surveys monitor the diet, nutritional status, and health status of children. This continual dedicated national surveillance system contributes to the identification of nutritional and health issues, establishment of public health policies, and development of nutrition recommendations. This paper provides recent information about the Korea National Health and Nutrition Examination Survey and the Korean Youth Risk Behavior Web-based Survey and describes key nationwide survey findings published in the last 5 years on infant feeding practices and the dietary intake and nutritional status of Korean infants, children, and adolescents. There have been increasing trends in children, and teenagers who skip breakfast, eat fast food, consume sugary drinks, have vitamin D deficiency, and are obese. This review will inform pediatricians, nutritionists, and other health care practitioners who track children's growth and development. It may also help researchers and policymakers identify diet-related policies and strategies for chronic disease prevention in Korean infants, children, and adolescents.

Handgrip Strength and Current Smoking Are Associated with Cardiometabolic Risk in Korean Adolescents: A Population-Based Study

This study aimed to identify the independent association of handgrip strength and current smoking with cardiometabolic risk in adolescents. Data of 1806 adolescents (12–18 years) from the Korea National Health and Nutrition Examination Surveys were analyzed by complex samples logistic regression analyses. Handgrip strength was normalized by body weight into relative handgrip strength. A cardiometabolic risk index score was calculated from the z-scores of the following components: waist circumference, triglycerides, high-density lipoprotein cholesterol, glucose, and blood pressure. Relative handgrip strength showed an inverse association with high cardiometabolic risk, with an adjusted odds ratio of 8.5 (95% confidence interval [CI], 3.7–19.3) for boys and 5.7 (95% CI, 2.9–11.2) for girls on comparing the lowest and the highest age-and sex-specific quartiles of relative handgrip strength. The adjusted odds ratios for high cardiometabolic risk on comparing the second quartile and the highest quartile of relative handgrip strength were 3.9 (95% CI, 1.7–8.9) in boys and 2.6 (95% CI, 1.3–5.3) in girls. Current smoking was independently associated with high cardiometabolic risk in boys aged 15–18 years. These findings suggest the need to increase muscle strength in adolescents and reduce smoking in older boys to promote cardiometabolic health.

Association between Sleep Duration and Body Composition in Girls Ten to Eighteen Years of Age: A Population-Based Study

Background: This study aimed to evaluate the relationship between sleep duration and body composition as measured by dual-energy X-ray absorptiometry (DXA). Methods: Based on data obtained from the Korea National Health and Nutrition Examination Survey (2010), 303 girls were divided into three groups by sleep duration: very short, short, and recommended. Results: By analysis of covariance, compared with the "very short" group, the "recommended" group had reduced adjusted mean DXA-assessed total mass (TM, 46.46 kg vs. 51.36 kg, p = 0.012), fat mass (FM, 14.38 kg vs. 17.55 kg, p = 0.002), and fat mass percentage (FMP, 30.66% vs. 33.15%, p = 0.017) in the whole body; TM (20.85 kg vs. 23.63 kg, p = 0.007), FM (5.82 kg vs. 7.64 kg, p = 0.001), and FMP (27.48% vs. 30.70%, p = 0.009) in the trunk; TM (4.59 kg vs. 5.15 kg, p = 0.006), FM (1.62 kg vs. 2.05 kg, p = 0.001), and FMP (27.48% vs. 30.70%, p = 0.019) in the arms; and TM (16.75 kg vs. 18.23 kg, p = 0.042) and FM (6.09 kg vs. 6.97 kg, p = 0.018) in the legs. By multiple linear regression analysis, sleep duration in hours had a significant negative association with DXA-assessed TM (β = -1.221, p = 0.016) and FM (β = -0.760, p = 0.006) in the whole body; FM (β = -0.014, p = 0.026) in the head; TM (β = -0.699, p = 0.010), FM (β = -0.454, p = 0.003), and FMP (β = -0.714, p = 0.030) in the trunk; TM (β = -0.152, p = 0.005) and FM (β = -0.101, p = 0.004) in the arms; and FM (β = -0.191, p = 0.045) in the legs. Conclusions: Our results suggest that shorter sleep duration is related to higher FM, but not lean mass, especially in the trunk.

Analysis of the dietary factors associated with suspected pediatric nonalcoholic fatty liver disease and potential liver fibrosis: Korean National Health and Nutrition Examination Survey 2014-2017

Background

The prevalence of nonalcoholic fatty liver disease (NAFLD) has increased as the obese pediatric population has increased. NAFLD causes progressive liver injury and the only effective treatment is lifestyle modifications. However, few studies have examined the dietary risk factors for pediatric NAFLD or liver fibrosis. Here, we evaluated the dietary factors associated with suspected NAFLD and potential liver fibrosis in Korean children.

Methods

Data collected from 1674 children and adolescents aged 10–18 years during the 2014–2017 Korean National Health and Nutrition Examination Surveys analyzed. The 24-h recall method measured the food consumed 1 day before the survey. The “suspected NAFLD” group included excessive body mass index (BMI) subjects ≥ 85th percentile) with alanine aminotransferase (ALT) levels exceeding the upper normal limit (24.1 U/L for boys and 17.7 U/L for girls); the “healthy control” group included subjects with a BMI and ALT level below these thresholds. Sodium intake was assessed by the urinary sodium-to-urinary specific gravity unit ratio (U-Na-to-SGU ratio). A pediatric NAFLD index (PNFI) higher than 3 indicated potential liver fibrosis.

Results

The overall prevalence of suspected NAFLD and potential liver fibrosis was 8.2 and 4.5%, respectively. The suspected NAFLD group had a larger proportion of males and subject with a greater height, BMI standard deviation score (BMI-SDS), systolic and diastolic blood pressure SDS, waist circumference, hemoglobin A1c, and levels of total cholesterol, triglycerides, aspartate aminotransferase (AST) and ALT than the control group. The suspected NAFLD group presented significantly higher U-Na-to-SGU ratios and cholesterol intake. The PNFI > 3 subgroup included a significantly larger proportion of males and subjects with higher BMI-SDS, AST and ALT values, and intake of water, carbohydrate, protein, calcium, phosphorus, iron and vitamin B2. After adjusting for confounders, male, BMI-SDS, AST, and protein and carbohydrate intake were independent risk factors for potential liver fibrosis. Niacin intake was an independent protective factor for potential liver fibrosis.

Conclusions

Children with suspected NAFLD had higher urinary sodium level and cholesterol intake than healthy controls. Protein and carbohydrate intake were independent risk factors for potential liver fibrosis; niacin was an independent protective factor.

The association of dietary patterns and adherence to WHO healthy diet with metabolic syndrome in children and adolescents: Tehran lipid and glucose study

BACKGROUND

The optimal dietary pattern for reducing the extent of metabolic syndrome (MetS) has not been well established yet. The aim of this study was to evaluate dietary patterns and adherence to WHO healthy diet in children and adolescents and their associations with MetS.

METHODS

Subjects of this cohort study were selected from among children and adolescents of the Tehran Lipid and Glucose Study participants, aged 6-18 years (n = 424). Dietary measurements were collected using a valid and reliable food frequency questionnaire. MetS was defined as the existence of at least 3 risk factors according to the Cook criteria. Diet was assessed based on dietary components of the WHO healthy diet. Dietary patterns were defined by principal component analysis.

RESULTS

The mean ± SD age of participants (42% boys and 57% girls) was 13.5 ± 3.7 years. The most consistency with the WHO healthy diet was observed for cholesterol, free sugar and protein consumption in both genders, and the least was for n-3 poly-unsaturated fatty acid, trans-fatty acid and salt. Intake of SFA up to 12% of energy intake (third quartile) reduced the risk of MetS, compared to the first quartile. Subjects in the third quartile of n-6 poly-unsaturated fatty acid intake (6.2% of energy) showed the lowest odds ratio of MetS compared to the first quartile (OR: 0.18, CI: 0.04-0.66). In the adjusted model, the risk of MetS reduced across quartiles of MUFA intake by 60% (OR: 1, 0.40, 0.40, 0.42; P trend = 0.05). No significant trends were observed in the risk of MetS components across quartiles of the WHO healthy diet components. Three major dietary patterns were identified, the healthy, unhealthy and cereal/meat. An increased risk of MetS was observed in the highest quartile of unhealthy dietary pattern score compared to the lowest quartile (OR: 1, 0.81, 0.93, 2.49; P trend = 0.03).

CONCLUSIONS

Our results demonstrated that the majority of our population did not meet some components of WHO healthy diet recommendations. The quality and quantity of fatty acid intakes were associated with risk of MetS. Adherence to unhealthy dietary pattern was associated with two-fold increase in MetS risk.

The Relationship Between Tri-ponderal Mass Index and Metabolic Syndrome and Its Components in Youth Aged 10-20 Years

The current study aimed to evaluate the distribution of the tri-ponderal mass index (TMI) according to sex and age and the relationship of obesity groups according to sex- and age-specific TMI with metabolic syndrome (MetS) and its components. A total of 8,464 subjects aged 10-20 years were classified into 4 groups according to sex- and age-specific TMI: (i) underweight, (ii) normal weight, (iii) overweight, and (iv) obese. The range of the 50th percentiles of TMI was from 13.24 kg/m3 at 10 years to 12.94 kg/m3 at 20 years among males and from 12.19 kg/m3 to 12.84 kg/m3 among females. In the analysis of covariance, obesity groups according to sex- and age-specific TMI were positively correlated with waist circumference (WC) standard deviation score; systolic blood pressure (BP); diastolic BP; and levels of glucose, total cholesterol, triglycerides (TGs), and low-density lipoprotein cholesterol, but for both sexes, the obesity groups were negatively related to high-density lipoprotein cholesterol (HDL-C). In the multiple logistic regression, subjects in the overweight group had higher odds ratios (ORs) for elevated WC (29.18), elevated BP (1.33), elevated TGs (2.55), reduced HDL-C (2.31), and MetS (8.93) than those with normal weight. Participants in the obesity group had increased ORs for elevated WC (154.67), elevated BP (2.22), elevated glucose (3.54), elevated TGs (4.12), reduced HDL-C (3.69), and MetS (25.57) compared to participants with normal weight after adjustment for confounders. Our results suggest that sex- and age-specific TMI may be applicable in the clinical setting as a useful screening tool.

Paucity of high-quality studies reporting on salt and health outcomes from the science of salt: A regularly updated systematic review of salt and health outcomes (April 2017 to March 2018)

The purpose of this review is to identify, summarize, and critically appraise studies on dietary salt and health outcomes that were published from April 2017 to March 2018. The search strategy was adapted from a previous systematic review on dietary salt and health. Identified studies were screened based on a priori defined criteria to identify publications eligible for detailed critical appraisals. Overall, 6747 citations were identified by the search strategy, and 42 health outcome studies were identified. Three of the 42 studies met the criteria for methodological quality and health outcomes and underwent detailed critical appraisals and commentary. In addition, a systematic review and meta-analysis was critically appraised, although it did not strictly meet our methodological criteria. All four of the studies critically appraised found that sodium reduction improved blood pressure, especially in individuals with hypertension. In addition, sodium reduction reduced albuminuria in patients with stage 1-3 chronic kidney disease. Examination of the time course of blood pressure responses to sodium reduction revealed lowering sodium in the context of an average American diet may not produce maximal blood pressure reductions within a 4-week intervention period. This review provides further evidence of the benefit of sodium reduction for blood pressure lowering and gives insights into the subgroups of the population that may derive the greatest benefit from sodium reduction and the time course required to see benefit. Only three high-quality studies were identified during this 12-month review period, highlighting the critical need for more well-conducted rigorous studies in this area.