Prevalence of insulin resistance and cardiometabolic risk in Korean children and adolescents: a population-based study

Association between metabolically healthy obesity and carotid intima-media thickness in Korean adolescents with overweight and obesity

PURPOSE

Data regarding the association between metabolically healthy obesity (MHO) and preclinical atherosclerosis in childhood are lacking. Carotid intima-media thickness (cIMT) is a noninvasive method used to assess cardiovascular risk. This study examined the relationships among cIMT, metabolic phenotypes, and cardiometabolic risk factors (CMRFs) in overweight and obese adolescents.

METHODS

Anthropometric, biochemical, and cIMT data were collected. The study participants were categorized as MHO or metabolically unhealthy obesity (MUO) based on insulin resistance. CMRFs were assessed using blood pressure (BP); levels of triglycerides, high-density lipoprotein cholesterol (HDL-C), and fasting plasma glucose; or a diagnosis of diabetes mellitus. Differences in cIMT values were evaluated according to the metabolic phenotype and factors associated with cIMT.

RESULTS

Among the 111 participants (80 boys, 72.1%), 23 (20.7%) were classified as MHO and 88 (79.3%) as MUO. The MHO group exhibited lower glycated hemoglobin and triglyceride levels and higher HDL-C levels compared to those exhibited by the MUO group (all P<0.01). The cIMT values did not differ significantly between the MHO and MUO groups. The high cIMT tertile group revealed higher systolic BP compared to that exhibited by the low cIMT tertile group (123.7±2.1 mmHg vs. 116.9±1.6 mmHg, P=0.028). Mean cIMT was positively correlated with age (β=0.009) and body mass index (BMI) (β=0.033) after adjusting for covariates (both P<0.05).

CONCLUSION

In overweight and obese Korean adolescents, cIMT was associated with age and BMI but not with metabolic phenotype or CMRFs. Further research is warranted to determine the relationship between cIMT during adolescence and cardiovascular outcomes during adulthood.

Prediction of insulin resistance and elevated liver transaminases using serum uric acid and derived markers in children and adolescents

OBJECTIVE

To investigate the relationship of serum uric acid (Uacid) and derived parameters as predictors of insulin resistance (IR) and elevated liver transaminases in children and adolescents METHODS: Data of 1648 participants aged 10-18 years was analyzed using nationwide survey. Logistic regression analysis was performed with IR and elevated liver transaminases as dependent variables, and odds ratios (ORs) and 95% confidence intervals (CIs) for tertiles 2 and 3 of each parameter in comparison to tertile 1, which served as the reference. Receiver operating characteristic (ROC) curves were generated to assess predictability of the parameters for IR and elevated liver transaminases.

RESULTS

Hyperuricemia, IR, and elevated liver transaminases were significantly associated with each other. All Uacid and derived markers showed continuous increase in ORs and 95% CIs for IR and elevated liver transaminases across the tertiles of several biochemical and metabolic variables of interest (all p < 0.001), and were also significantly predictive in ROC curve. Overall, Uacid combined with obesity indices showed higher ORs and area under the curve (AUC) compared to Uacid alone. Uacid-body mass index (BMI) standard deviation score presented the largest AUC for IR. For elevated liver transaminases, Uacid-BMI and Uacid-waist-to-height ratio showed the largest AUC.

CONCLUSIONS

Uacid combined with obesity indices are robust markers for prediction of IR and elevated liver transaminases in children and adolescents. Uacid and derived markers have potential as simple markers which do not require fasting for screening of IR and elevated liver transaminases in children and adolescents.

Establishing reference values for percentage of appendicular skeletal muscle mass and their association with metabolic syndrome in Korean adolescents

PURPOSE

The association between appendicular skeletal muscle mass (ASM) and cardiometabolic risk has been emphasized. We estimated reference values of the percentage of ASM (PASM) and investigated their association with metabolic syndrome (MS) in Korean adolescents.

METHODS

Data from the Korea National Health and Nutrition Examination Survey performed between 2009 and 2011 were used. Tables and graphs of reference PASM were generated using 1,522 subjects, 807 of whom were boys aged 10 to 18. The relationship between PASM and each component of MS in adolescents was further analyzed in 1,174 subjects, 613 of whom were boys. Moreover, the pediatric simple MS score (PsiMS), the homeostasis model assessment of insulin resistance (HOMA-IR), and the triglyceride-glucose (TyG) index were analyzed. Multivariate linear and logistic regressions adjusting for age, sex, household income, and daily energy intake were performed.

RESULTS

In boys, PASM increased with age; the trend was different in girls, in whom PASM declined with age. PsiMS, HOMA-IR, and TyG index showed inverse associations with PASM (PsiMS, β=-0.105, P<0.001; HOMA-IR, β=-0.104, P<0.001; and TyG index, β=-0.013, P<0.001). PASM z-score was negatively associated with obesity (adjusted odds ratio [aOR], 0.22; 95% CI, 0.17-0.30), abdominal obesity (aOR, 0.27; 95% CI, 0.20-0.36), hypertension (aOR, 0.65; 95% CI, 0.52-0.80), and elevated triglycerides (aOR, 0.67; 95% CI, 0.56-0.79).

CONCLUSION

The probability of acquiring MS and insulin resistance decreased as PASM values increased. The reference range may offer clinicians information to aid in the effective management of patients. We urge clinicians to monitor body composition using standard reference databases.

Naringenin alleviates the excessive lipid deposition of polycystic ovary syndrome rats and insulin-resistant adipocytes by promoting PKGIα

BACKGROUND

Naringenin (NGEN) has anti-inflammatory and anti-diabetic effects. On this basis, this study aims to determine whether NGEN affects insulin resistance (IR) in polycystic ovary syndrome (PCOS).

METHODS

CCK-8 assay and oil red O staining were used to detect the cytotoxicity of NGEN and lipid production in cells or tissues, respectively. The differentiated mature SW872 cells were treated with palmitic acid (PA) to mimic IR cell model. Through detecting glucose consumption, the changes of inflammation and glycolipid metabolism can be observed with the assessment on expression levels of the inflammatory factors as well as lipid synthesis- (ACC, SREBP1c, PPARγ), glucose metabolism- and thermogenesis (ATGL, GLUT4, UCP1)-related genes. Insulin sensitivity was determined by changes in glucose consumption and PKGIα pathway. PKGIα was silenced to verify the protective mechanism of NGEN. PCOS rat model was constructed to confirm the results of cell experiments in vivo.

RESULTS

NGEN generated no effect on SW872 cell viability. SW872 cells were differentiated and mature, as evidenced by lipid droplet formation, lipid synthesis gene activation, sugar metabolism and inhibition of thermogenesis-related genes. PA induction promoted lipid synthesis in mature adipocytes, and inhibited glucose metabolism and cell insulin sensitivity. NGEN pretreatment effectively alleviated the above-mentioned abnormalities. The protective mechanism of NGEN was achieved through promoting PKGIα activation. NGEN also mitigated the abnormal glucose and lipid metabolism in PCOS rats.

CONCLUSION

NGEN inhibits the expression of PKGIα to alleviate IR that occurs in PCOS.

Tuina (Chinese massage) for insulin resistance and sensitivity: A protocol for systematic review and meta-analysis of animal and human studies

INTRODUCTION

Insulin resistance (IR) could be regarded as a therapeutic target for metabolic diseases. Therefore, multiple therapeutic strategies that target IR should be applied to provide a more effective means of treatment. It aims to determine Tuina's efficacy and safety for IR through this systematic review and meta-analysis.

METHODS

From the inception to July 31, 2023, we will search four English databases (Pubmed, Embase, Cochrane Central Register of Controlled Trials, Web of Science) and two Chinese databases (China National Knowledge Infrastructure and the Chinese Science and Technology Periodical Database). We will search and include studies of both human and animal models that evaluate Tuina's effects on insulin sensitivity or resistance. Data selection, data extraction, and risk of bias assessment will be made by two independent reviewers. We will evaluate the methodological quality of all included studies and conduct meta-analyses using Review Manager Software 5.4.1.

DISCUSSION

In both animal and human studies, the effects and safety of Tuina for IR will be evaluated. The evidence generated bythis study will validate effects and safety of Tuinain treating IR and inform future research and clinical decision-making.

TRAIL REGISTRATION

PROSPERO Registration ID: CRD42022360128.

Handgrip Strength Is Associated with Metabolic Syndrome and Insulin Resistance in Children and Adolescents: Analysis of Korea National Health and Nutrition Examination Survey 2014-2018

Background

Reduced handgrip strength (HGS) is associated with adverse cardiometabolic health outcomes. We examined HGS, metabolic syndrome (MetS), and insulin resistance (IR) in children and adolescents.

Methods

The following population-based data from 2,797 participants (aged 10-18 years) of the Korea National Health and Nutrition Examination Survey 2014-2018 were analyzed: complete anthropometric measures, HGS, MetS, and IR (subgroup with fasting insulin, n=555). HGS was analyzed as the combined HGS (CHGS) and the normalized CHGS (nCHGS=CHGS divided by body weight).

Results

At a mean age of 14.4 years, 276 participants (9.9%) had abdominal obesity, 56 (2.0%) had MetS, and 118 (20.9%) had IR. Individual components of MetS and IR were inversely associated with the nCHGS. The odds ratios (ORs) for MetS and IR decreased significantly with higher nCHGS after adjustment for sex, age, physical activity, and sedentary times. The optimal cut-off values that predicted MetS were 0.80 kg/kg (males) and 0.71 kg/kg (females), with significant associations with MetS (OR: 7.4 in males; 5.7 in females) and IR (OR: 3.3 in males; 3.2 in females) observed when nCHGS values were lower than those cut-offs.

Conclusion

HGS is associated with MetS and IR and might be a useful indicator of cardiometabolic risk factors in children and adolescents.

The association between C-reactive protein, metabolic syndrome, and prediabetes in Korean children and adolescents

PURPOSE

Metabolic syndrome (MetS) is a state of chronic inflammation, and high-sensitivity C-reactive protein (hsCRP) indicates inflammation. This paper evaluates the associations between hsCRP and MetS and its components in Korean children and adolescents.

METHODS

We analyzed the data of 1,247 subjects (633 males, 14.2±2.7 years) from the Korea National Health and Nutrition Examination Survey 2016-2017. This study defined MetS and its components using the modified National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) criteria.

RESULTS

The mean hsCRP level was 0.86±1.57 mg/dL (median and interquartile range: 0.37 and 0.43 mg/dL). Subjects with MetS had higher hsCRP level than subjects without MetS (geometric mean: 1.08 mg/dL vs. 0.46 mg/dL, p<0.001). With a higher quartile value of hsCRP, the prevalence of MetS increased. Compared to the lowest quartile, the odds ratio (OR) for MetS in the highest quartile was 7.34 (3.07-17.55) after adjusting for age and sex. In the top quartile of hsCRP, the risk of abdominal obesity and low HDL was high after adjusting for age, sex, and other components of MetS. Additionally, the OR for prediabetes (HbA1c ≥5.7%) in the highest quartile was 2.70.

CONCLUSION

Serum hsCRP level was positively associated with MetS and prediabetes using NCEP-ATP III criteria. Among the MetS components, abdominal obesity and low HDL were highly correlated with hsCRP in Korean children and adolescents.

Increasing prevalence of fasting hyperglycemia in adolescents aged 10-18 years and its relationship with metabolic indicators: the Korea National Health and Nutrition Examination Study (KNHANES), 2007-2018

PURPOSE

Pediatric diabetes is a common health burden worldwide. This study aimed to investigate the prevalence of fasting hyperglycemia in Korean youth aged 10-18 years and to evaluate its association with metabolic indicators.

METHODS

To assess the risk of diabetes in domestic children and adolescents, the prevalence of fasting hyperglycemia was calculated, a trend was evaluated using multi-year Korea National Health and Nutrition Examination Survey (KNHANES) data, and multivariate analysis was performed to evaluate the relationships between hyperglycemia and metabolic factors.

RESULTS

The prevalence of fasting hyperglycemia, defined as impaired fasting glucose (fasting glucose level > 100 mg/dL and < 125 mg/dL), or diabetes mellitus (fasting glucose ≥ 126 mg/dL) was estimated in Korean teenagers. The prevalence increased from the fourth (2007-2009) to the fifth (2010-2012), sixth (2013-2015), and seventh (2016-2018) KNHANES surveys, from 5.39 to 4.79, 10.03, and 11.66 per 100 persons, respectively. In multivariate analysis, systolic blood pressure and serum triglycerides were higher in the fasting hyperglycemia group; systolic blood pressures were 109.83 mmHg and 112.64 mmHg and serum triglycerides were 81.59 mg/dL and 89.60 mg/dL in the normal blood glucose and fasting hyperglycemia groups, respectively.

CONCLUSION

The prevalence of fasting hyperglycemia among children and adolescents has increased over the past decade, and this increase is potentially associated with metabolic abnormalities such as hypertension and hypertriglyceridemia. Effort is urgently required to reduce this chronic medical burden in adolescence.

Comparison of the Triglyceride Glucose Index and Modified Triglyceride Glucose Indices to Predict Nonalcoholic Fatty Liver Disease in Youths

OBJECTIVE

To assess the associations between the triglyceride glucose (TyG) index and modified TyG indices with nonalcoholic fatty liver disease (NAFLD) and evaluate their ability as predictors of NAFLD in youths.

STUDY DESIGN

We analyzed the cross-sectional data of 3728 individuals aged 10-19 years using the Korea National Health and Nutrition Examination Survey, a nationally representative survey. Logistic regression analysis was performed, and ORs and 95% CIs of tertiles 2 and 3 for each variable for predicting NAFLD were calculated and compared with those of tertile 1 as the reference. Receiver operating characteristic (ROC) curves were plotted to evaluate the ability of each variable for NAFLD prediction.

RESULTS

All TyG and modified TyG indices exhibited progressively increased ORs and 95% CIs for NAFLD across all tertiles (all P < .001). In addition, all TyG and modified TyG indices significantly predicted NAFLD through ROC curves. All modified TyG indices were superior to the TyG index for predicting NAFLD in all subjects and in males. Among females, the TyG-waist-to-height ratio was superior to the TyG index, TyG-body mass index (BMI), and TyG-waist circumference (WC), and the TyG-BMI SDS and TyG-WC were superior to the TyG index.

CONCLUSIONS

The TyG and modified TyG indices are markers for NAFLD prediction in youths, and the modified TyG indices are superior to the TyG index. Modified TyG indices have the potential to be simple and cost-effective markers in screening for NAFLD in youths.

Impact of Insulin Resistance on Cardiometabolic Risk Factors and an Anthropometry-Based Predictive Nomogram for Insulin Resistance Among Adolescents in China

OBJECTIVE

We aimed to investigate the impact of insulin resistance (IR), as determined by the homeostasis model assessment of insulin resistance (HOMA-IR), on cardiometabolic risk factors (CMRFs), and develop an anthropometry-based predictive nomogram for IR among adolescents in China.

DESIGN

Data were acquired from a cross-sectional study with a stratified cluster sampling method, conducted among adolescents in Northeast China.

PARTICIPANTS

A total of 882 adolescents (aged 12-16 years, 468 boys) were included.

MEASUREMENTS

All participants underwent anthropometric and biochemical examinations. The thresholds of IR included the 90th percentile of the HOMA-IR for adolescents with a normal body mass index (BMI) and fasting plasma glucose (FPG) level within each sex group (Cutoff A), and the 75th percentile for all participants of the same sex (Cutoff B).

RESULTS

The HOMA-IR was associated with CMRFs. IR, as defined by both cutoffs A and B, was significantly associated with most CMRFs, except decreased HDL-C levels. Excellent concordance (κ = 0.825) was found between these two criteria in diagnosing IR. However, IR using cutoff A, was more closely associated with cardiometabolic risk. The incidence of IR, as defined by cutoff A, was 18.93% and increased from 10.99% to 43.87% based on the different BMI categories. Further, an anthropometry-based predictive model for IR, incorporating sex, age, waist-to-hip ratio, weight and BMI, was developed and presented as a nomogram.

CONCLUSIONS

IR among adolescents is strongly related to cardiometabolic risk. We developed an anthropometry-based predictive nomogram for IR among adolescents, which may facilitate health counselling and self-risk assessments.

The Determinants of Adolescent Glycolipid Metabolism Disorder: A Cohort Study

BACKGROUND

The increased prevalence of glycolipid metabolism disorders (GLMD) in childhood and adolescents has a well-established association with adult type 2 diabetes and cardiovascular diseases; therefore, determinants of GLMD need to be evaluated during this period.

OBJECTIVES

To explore the prevalence of and risk factors for GLMD from the prenatal period through childhood and adolescence.

METHODS

A bidirectional cohort study which was established in 2014 and followed between March 1 and July 20, 2019, was used to illustrate the impact factors for GLMD. Stratified cluster sampling in urban-rural areas was used to include subjects from four communities in Chongqing. 2808 healthy children aged between 6 and 9 years in 2014 entered the cohort in 2014 and followed in 2019 with a follow-up rate of 70%. 2,136 samples (aged 11.68 ± 0.60 years) were included.

RESULTS

The prevalence rates of insulin resistance (IR), prediabetes/diabetes, and dyslipidemia were 21.02%, 7.19%, and 21.61%, respectively. Subjects with an urban residence, no pubertal development, dyslipidemia in 2014, higher family income, and higher parental education had significantly elevated fasting insulin (FI) or homeostasis model assessment of insulin resistance (HOMA-IR) levels; subjects with female sex, no pubertal development, dyslipidemia in 2014, obesity, gestational hypertension, maternal weight gain above Institute of Medicine guidelines, and single parents had increased triglyceride or triglyceride/high-density lipoprotein (HDL). Adolescents with rural residence had higher HbA1c level.

CONCLUSION

We observed that the prevalence of GLMD was high in childhood and adolescents, and rural-urban areas, sex, pubertal development, dyslipidemia in a younger age, maternal obesity, and hypertension were associated with increased GLMD risk, suggesting that implementing the community-family intervention to improve the GLMD of children is essential.

A population-based study of TyG index distribution and its relationship to cardiometabolic risk factors in children and adolescents

The purpose of this study was to present age- and sex-specific distributions of the triglyceride-glucose (TyG) index and to evaluate their relationship with cardiometabolic risk factors in children and adolescents. A total of 7404 participants aged 10-18 years from the Korean National Health and Nutrition Survey were included as the reference population. The TyG index was calculated as ln(fasting triglyceride [mg/dL] × fasting glucose [mg/dL]/2). The percentile of the TyG index exhibited a steady linear relationship with age for both sexes. TyG index significantly correlated with waist circumference (WC) standard deviation score (SDS; r = 0.110, p < 0.001), systolic blood pressure (SBP; r = 0.104, p < 0.001), diastolic blood pressure (DBP; r = 0.083, p < 0.001), glucose (r = 0.220, p < 0.001), high-density lipoprotein cholesterol (HDL-C; r = - 0.325, p < 0.001), and triglycerides (TG; r = 0.926, p < 0.001). Multiple linear regression analysis revealed that the TyG index was significantly associated with WC SDS (β = 0.116, p < 0.001), SBP (β = 2.009, p < 0.001), DBP (β = 1.464, p < 0.001), glucose (β = 3.376, p < 0.001), HDL-C (β =  - 6.431, p < 0.001), and TG (β = 85.518, p < 0.001). Our results suggest that the TyG index has a steady linear distribution for sex and age in children and adolescents and constitutes an indicator for predicting metabolic disorders that could lead to cardiovascular disease later in life.

Association of Diabetes Mellitus and Alcohol Abuse with Cancer: Molecular Mechanisms and Clinical Significance

Diabetes mellitus (DM), one of the metabolic diseases which is characterized by sustained hyperglycemia, is a life-threatening disease. The global prevalence of DM is on the rise, mainly in low- and middle-income countries. Diabetes is a major cause of blindness, heart attacks, kidney failure, stroke, and lower limb amputation. Type 2 diabetes mellitus (T2DM) is a form of diabetes that is characterized by high blood sugar and insulin resistance. T2DM can be prevented or delayed by a healthy diet, regular physical activity, maintaining normal body weight, and avoiding alcohol and tobacco use. Ethanol and its metabolites can cause differentiation defects in stem cells and promote inflammatory injury and carcinogenesis in several tissues. Recent studies have suggested that diabetes can be treated, and its consequences can be avoided or delayed with proper management. DM has a greater risk for several cancers, such as breast, colorectal, endometrial, pancreatic, gallbladder, renal, and liver cancer. The incidence of cancer is significantly higher in patients with DM than in those without DM. In addition to DM, alcohol abuse is also a risk factor for many cancers. We present a review of the recent studies investigating the association of both DM and alcohol abuse with cancer incidence.

HOMA indices as screening tests for cystic fibrosis-related diabetes

BACKGROUND

We assessed the diagnostic performances of homeostasis model assessment indices (HOMA) of β-cell function (HOMA-%β) and of insulin resistance (HOMA-IR) for cystic fibrosis related diabetes (CFRD) screening.

METHODS

Data were collected from a prospective cohort of 228 patients with CF (117 adults and 111 children). Fasting insulin and glucose levels were measured to calculate HOMA-%β and HOMA-IR. HOMA-%β <100 indicated insulin secretion deficiency and HOMA-IR >1 insulin resistance. Both were used to calculate sensitivity, specificity, and positive and negative predictive values (PPV and NPV). Two-hour oral glucose tolerance tests (2h-OGTT) defined CFRD. Analyses were conducted separately for children and adults. Performances of HOMA-%β and HOMA-IR were calculated at inclusion, for each year of follow-up and for pooled data over the follow-up period.

RESULTS

Sensitivity, specificity, NPV and PPV were respectively: 88%, 45%, 98% and 11% for HOMA-%β and 42%, 48%, 91% and 6% for HOMA-IR in the pooled data of children; and 83%, 18%, 90% and 10% for HOMA-%β, and 39%, 80%, 92% and 18% for HOMA-IR in the pooled data of adults. Combining HOMA-%β and HOMA-IR did not improve performances.

CONCLUSION

Within both age groups, HOMA-%β <100 provided good sensitivity and NPV. HOMA-IR >1 had low sensitivity. Calculation of the HOMA-%β could be an interesting first-line screening approach to exclude CFRD and thus avoid unnecessary OGTT in patients for whom value is ≥100. However, HOMA-%β<100 does not support the diagnosis of CFRD and should be complemented by OGTT.

Prediction of Insulin Resistance by Modified Triglyceride Glucose Indices in Youth

The triglyceride glucose (TyG) index, derived from a combination of fasting glucose and triglycerides, has been suggested as a useful marker for insulin resistance (IR), in addition to modified TyG indices that combine obesity parameters. This study investigated the association and utility of TyG and modified TyG indices for IR prediction in youth. Based on the Korea National Health and Nutritional Examination Survey, the data of 3728 youth aged 10–19 years were analyzed. Odds ratios (ORs) and 95% confidence intervals (CIs) of tertiles 2 and 3 for each parameter were calculated and compared with tertile 1 as a reference. To compare the parameters for identifying IR, receiver operating characteristic curves were plotted and the area under the curve (AUC) was calculated. The ORs and 95% CIs for insulin resistance (IR) progressively increased across tertiles of each parameter. Overall, all modified TyG indices presented higher ORs and AUC than the TyG index. The TyG-body mass index standard deviation score showed the largest AUC for IR detection in all subjects. In conclusion, TyG and modified TyG indices could be used as valuable markers for the prediction of IR in youth. Moreover, modified TyG indices had better diagnostic accuracy than the TyG index.

Comparison of different criteria for the definition of insulin resistance and its relationship to metabolic risk in children and adolescents

PURPOSE

Childhood obesity frequently persists into adulthood and is associated with insulin resistance (IR) and increased long-term morbidity and mortality. We compared IR criteria concerning 'age-specific cutoff point' (ACOP) and 'fixed cutoff point' (FCOP) for the identification of IR and investigated their correlation with metabolic syndrome (MS).

METHODS

Data were acquired from the 5th Korea National Health and Nutrition Examination Survey (2010-2011). Participants ranged from 10 to 17 years of age and underwent fasting plasma glucose, insulin concentration, and lipid panel measurements. High fasting plasma insulin levels or increased homeostatic model assessment insulin resistance (HOMA-IR) were defined as IR. We analyzed MS and IR frequencies according to FCOP or ACOP.

RESULTS

Among 719 participants, 165 (22.9%) were overweight or obese based on their body mass index. We found no prevalence of MS in underweight/normal weight participants and 12.7% prevalence rate in overweight or obese participants. IR according to ACOP was more closely associated with MS than IR according to FCOP. No differences were found in predicting the frequency of MS using FCOP or ACOP in both fasting plasma insulin and HOMA-IR.

CONCLUSION

The frequency of MS in participants with IR defined using ACOP and FCOP was similar. However, IR using ACOP was more closely associated with MS than IR using FCOP.

Serum uric acid in Korean children and adolescents: reference percentiles and association with metabolic syndrome

PURPOSE

To establish age/sex-specific reference intervals for serum uric acid and to examine the associations between serum uric acid level and metabolic syndrome (MetS) and its components in Korean children and adolescents.

METHODS

We analyzed data for 1,349 subjects aged 10 to 19 years from the Korea National Health and Nutrition Examination Survey 2016-2017.

RESULTS

The mean uric acid levels were 5.9±1.3 mg/dL (interquartile range, 5.0-6.8 mg/dL) in males and 4.6±0.9 mg/dL (interquartile range, 3.9-5.2 mg/dL) in females. The mean uric acid level increased significantly from 10-13 years of age in males, but not in females. The overall prevalence of MetS was 5.9% (7.3% in males and 4.3% in females; P=0.022). The prevalences of MetS in the lowest, second, third, and highest quartiles of uric acid level were 4.4%, 3.3%, 6.1%, and 15.2%, respectively, in males (P for trend &lt;0.001) and 1.9%, 0.0%, 4.1%, and 10.9%, respectively, in females (P for trend &lt;0.001). Compared with the lowest quartile of uric acid level, the odds ratio (with 95% confidence interval) for MetS in the highest quartile was 2.897 (1.140-7.361) in males and 5.173 (1.459-18.342) in females. Subjects in the highest quartile exhibited increased risk for abdominal obesity and low high-density lipoprotein cholesterol in both sexes.

CONCLUSION

Serum uric acid level is positively associated with MetS and its components abdominal obesity and low high-density lipoprotein cholesterol.

PREVALENCE OF INSULIN RESISTANCE AND ASSOCIATION WITH METABOLIC RISK FACTORS AND FOOD CONSUMPTION IN ADOLESCENTS - RECIFE/BRAZIL

OBJECTIVE

To identify the prevalence of insulin resistance in adolescents and its associations with metabolic factors and food intake.

METHODS

Cross-sectional study conducted with a stratified, complex, school-based sample. The subjects were adolescents (n=1,081) who participated in the Study of Cardiovascular Risk in Adolescents in the city of Recife (Pernambuco, Brazil). We analyzed demographic, socioeconomic, behavioral, anthropometric, biochemical, and dietary variables. Insulin resistance was defined as HOMA-IR>75th percentile. A Poisson multivariate regression model with robust variance adjustment was used, and variables with p≤0.05 in the final model were considered statistically associated with insulin resistance.

RESULTS

Median age was 14 years (interquartile range: 13-16 years), and 25.3% of the sample showed insulin resistance. The variables associated with insulin resistance in the final model were age, body mass index-for-age (BMI/A), biochemical markers (triglycerides and high-density lipoprotein cholesterol) and saturated fat intake, with insulin resistance being more prevalent in individuals whose consumption of this type of fat was below the median of the sample distribution.

CONCLUSIONS

Insulin resistance was prevalent in the adolescents analyzed and was significantly associated with metabolic variables and saturated fat intake.

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.

Association of Thyroid-Stimulating Hormone and Thyroid Hormones with Cardiometabolic Risk Factors in Euthyroid Children and Adolescents Aged 10-18 Years: A Population-Based Study

Recent evidence indicates that low-normal thyroid function test results within the reference ranges may be related to increased cardiometabolic risk factors. The current study aimed to evaluate the relationship between thyroid function using thyroid-stimulating hormone (TSH) and free thyroxine (FT4) and cardiometabolic risk factors and the clustering of these risk factors (metabolic syndrome) in euthyroid children and adolescents. A total of 250 euthyroid children and adolescents aged 10-18 years were included using data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2015. In the unadjusted correlation analyses, TSH was positively correlated with glucose (r = 0.172, P = 0.006), hemoglobin A1c (HbA1c) (r = 0.149, P = 0.018), insulin (r = 0.144, P = 0.023), homeostatic model assessment for insulin resistance (HOMA-IR) (r = 0.163, P = 0.010), and triglyceride (TG) (r = 0.155, P = 0.014), whereas FT4 was negatively associated with the waist circumference (WC) standard deviation score (SDS) (r = -0.134, P = 0.035), body mass index (BMI) SDS (r = -0.126, P = 0.046), insulin (r = -0.219, P < 0.001), and HOMA-IR (r = -0.211, P < 0.001). In the multiple linear regression analysis, TSH was positively associated with glucose (β = 1.179, P = 0.021), HbA1c (β = 0.044, P = 0.039), and TG (β = 8.158, P = 0.041) after adjustment for possible confounders. FT4 was negatively associated with serum fasting insulin (β = -5.884, P = 0.017) and HOMA-IR (β = -1.364, P = 0.023) in the multiple linear regression analysis. Boys and girls with elevated glucose levels had a higher adjusted mean TSH level compared to those without elevated glucose levels after controlling for confounding factors in the analysis of covariance (2.16 mIU/L vs 3.88 mIU/L, P = 0.004). Our results suggest that higher TSH and/or lower FT4 levels, even within the reference ranges, may be related to increased cardiometabolic risk factors.

Association of Sleep Duration with Obesity and Cardiometabolic Risk Factors in Children and Adolescents: A Population-Based Study

This study aimed to evaluate the relationships between sleep duration and overweight/obesity, obesity, and metabolic syndrome (MetS) and its components in children and adolescents. A total of 6,048 participants aged 10–18 years were divided into the following four sleep-duration groups based on age-specific sleep duration: i) very short; ii) short; iii) recommended; and iv) long. The participants in the very short sleep-duration group had an increased odds ratio (OR) of 1.76 for overweight/obesity, 1.69 for obesity, and 1.49 for elevated waist circumference (WC) compared with the recommended sleep-duration group. The subjects in the long sleep-duration group had an increased OR of 2.71 for elevated triglyceride (TG) compared with those in the recommended sleep-duration group. In subgroup analyses, boys in the very short sleep-duration group exhibited an increased OR of 1.78 for overweight/obesity compared with those in the recommended sleep-duration group. Compared with girls in the recommended sleep-duration group, those in the very short sleep-duration group exhibited an increased OR of 1.69 for overweight/obesity, 2.28 for obesity, and 1.57 for elevated WC; in contrast, girls in the very short sleep-duration group exhibited a decreased OR of 0.58 for elevated TG. The girls in the long sleep-duration group had an increased OR of 3.86 for elevated TG compared with those with recommended sleep-duration. Our results suggest that shorter sleep durations may be related to overweight/obesity, obesity, and central obesity, and longer sleep durations may be associated with elevated TG. However, the nature of these relationships may be dependent on sex.

The Influence of Sleep and Reading on Overweight of the Children

The active leisure, in particular reading, and hours of sleep play an important role in health and body mass index (BMI) in children. The aim of this study is to analyze, by means of path analysis, how these variables interact in influencing children's weight. Two hundred and ninety-one children took part in the study. Their BMI was calculated and they were interviewed. A path analysis indicates that spending more time on leisure-time reading facilitates the control of BMI in two ways. Firstly, it is associated a greater number of active leisure activities (r = .35 p &lt; .001) and predicts more hours of sleep (β = .13 p &lt; .05), which in turn predicts a lower BMI (β = -.15 p &lt; .001). Furthermore, it has been observed that spending more time reading is associated with less time spent on sedentary leisure activities (r = -.17 p &lt; .001). It would appear that in order to control overweight in children, it is necessary to foster a well-ordered lifestyle. Reading as the last activity of the day can make a significant contribution to this process.

Association between Changes in Anthropometric Indices and in Fasting Insulin Levels among Healthy Korean Adolescents: The JS High School Study

BACKGROUND

This study investigated the association between changes in anthropometric indices and fasting insulin levels among healthy adolescents and whether the association differed by baseline obesity status.

METHODS

This analysis was based on data collected for the JS High School study; 884 healthy adolescents aged 15 to 16 years followed up for 24 to 30 months were included. Changes in anthropometric indices and fasting insulin levels were computed as the difference between baseline and follow-up values. Multivariate linear regression models were used to determine the association between changes in anthropometric indices and fasting insulin levels. Based on body mass index (BMI)-for-age and waist circumference (WC)-for-age percentiles, participants were classified as normal weight (<85th percentile), overweight (85th percentile to <95th percentile), or obese (≥95th percentile).

RESULTS

Changes in BMI, WC, waist-hip ratio, and waist-height ratio were significantly associated with changes in fasting insulin levels in both sexes (P<0.05). In analyses stratified by baseline obesity status, the association between change in BMI and change in fasting insulin was significantly stronger in overweight (males: standardized β=1.136; females: standardized β=1.262) and obese (males: standardized β=1.817; females: standardized β=2.290) participants than in those with normal weight (males: standardized β=0.957; females: standardized β=0.976) at baseline. Results were similar for changes in WC.

CONCLUSION

Changes in anthropometric indices were positively associated with fasting insulin level increases. Moreover, those who were overweight or obese at baseline had a higher absolute increase in fasting insulin levels per one standard deviation unit increase in anthropometric indices than adolescents with normal weight.

Psychological Factors and Cardiovascular Disease Risk Factors as Mediators of the Relationship between Overweight/Obesity and Cognitive Function among School Children in Kuala Lumpur, Malaysia

BACKGROUND

Recent research suggests that a negative relationship exists between adiposity and cognitive function in children. However, limited information is known on how they are related. This study aimed to examine the mediators of the relationship between overweight/obesity and cognitive function among school children in Kuala Lumpur, Malaysia.

METHODS

This is a cross-sectional comparison study whereby 225 overweight/obese children matched for age, sex, and ethnicity with 225 normal weight children participated in this study. Body image dissatisfaction, disordered eating, and depressive symptoms were assessed through a self-administered questionnaire. Blood pressure was measured, whereas blood was drawn to determine insulin, high-sensitivity C-reactive protein (hs-CRP), glucose, and lipid profiles. Homeostasis model assessment-estimated insulin resistance (HOMA-IR) was calculated using glucose and insulin levels. Wechsler's Intelligence Scale for Children-Fourth Edition (WISC-IV) was used to assess cognitive function in children. Ordinary least square regression analysis was conducted to determine the direct and indirect relationships between weight status and cognitive function.

RESULTS

A negative relationship was found between overweight/obesity with cognitive function. Overweight/obese children were on average 4.075 units lower in cognitive function scores compared to normal weight children. Such difference was found through mediators, such as body image dissatisfaction, disordered eating, depression, systolic blood pressure, triglycerides, HOMA-IR, and hs-CRP, contributing 22.2% of the variances in cognitive function in children.

CONCLUSION

Results highlight the important mediators of the relationship between overweight/obesity and cognitive function. Consequently, future interventions should target to improve psychological well-being and reduce cardiovascular disease risk for the prevention of poorer cognitive performance in overweight/obese children.

Changes in insulin sensitivity over time and associated factors in HIV-infected adolescents

OBJECTIVE

To compare prevalence of insulin resistance between perinatally HIV-infected (PHIV+) and perinatally HIV-exposed, but uninfected adolescents (PHEU), determine incidence of and contributory factors to new and resolved cases of insulin resistance in PHIV+, and evaluate glucose metabolism.

DESIGN

Cross-sectional design for comparison of prevalence among PHIV+ and PHEU. Longitudinal design for incidence and resolution of insulin resistance among PHIV+ at risk for these outcomes.

METHODS

The source population was adolescents from pediatric HIV clinics in the United States and Puerto Rico participating in the Pediatric HIV/AIDS Cohort Study, an ongoing prospective cohort study designed to evaluate impact of HIV infection and its treatment on multiple domains in preadolescents and adolescents. Insulin resistance was assessed by homeostatic model assessment of insulin resistance. Those with incident insulin resistance underwent 2-h oral glucose tolerance test and HbA1c. Baseline demographic, metabolic, and HIV-specific variables were evaluated for association with incident or resolved insulin resistance.

RESULTS

Unadjusted prevalence of insulin resistance in PHIV+ was 27.3 versus 34.1% in PHEU. After adjustment for Tanner stage, age, sex, and race/ethnicity, there was no significant difference between groups. Factors positively associated with developing insulin resistance included female sex, higher BMI z score, and higher waist circumference; those associated with resolving insulin resistance included male sex and lower BMI z score.

CONCLUSION

Prevalence of insulin resistance in PHIV+ and PHEU was substantially higher than that reported in HIV-uninfected nonoverweight youth, but similar to that in HIV-uninfected obese youth. Factors associated with incident or resolved insulin resistance among PHIV+ were similar to those reported in HIV-negative obese youth. However, a contributory role of HIV infection and/or its treatment to the incident risk of insulin resistance cannot be excluded.

Insulinaemia and insulin resistance in Caucasian general paediatric population aged 2 to 10 years: Associated risk factors

BACKGROUND

The aim of this study is to determine values of insulinaemia, homeostasis model assessment (HOMA) index and quantitative insulin sensitivity check index (QUICKI) among a population of prepubertal Caucasian children, to analyse factors associated with insulin resistance (IR), and to study its association with cardiovascular risk factors.

MATERIALS AND METHODS

Population-based study conducted on a randomly selected sample of prepubescent Caucasian subjects aged 2.00 to 9.99 years old. Anthropometric measurements, blood pressure, and fasting blood samples were obtained, including fasting glucose, triglycerides, High Density Lipoprotein (HDL)-cholesterol, and insulin. In addition, QUICKI and HOMA indices were calculated. Generalised additive models for location, scale and shape (GAMLSS) was used to calculate centiles curves and multivariate logistic regression analysis to assess factors associated with IR.

RESULTS

A total of 654 subjects were included. Mean values obtained for insulinaemia, HOMA index, and QUICKI were 3.74 μIU/mL, 0.73, and 0.44, respectively, in the overall population and 3.32 μIU/mL, 0.64 and 0.46, respectively, in normal weight subjects. The main factor associated with IR was abdominal obesity (odds ratio [OR] 3.38 [95% CI 1.44-7.94] in the subgroup aged 2.00-5.99 years and OR 9.14 [3.42-24.41] for those aged 6.00-9.99 years). An increased risk of hyperglycaemia (P = 0.043), hypertriglyceridaemia (P < .001), and HDL < p10 (P = 0.021) was described among children aged 2.00 to 5.99 years with IR, and among those aged 6.00 to 9.99 years, IR was associated with an increased risk of hypertriglyceridaemia (P < .001).

CONCLUSION

Abdominal obesity was the main factor associated with IR. Metabolic changes associated with IR seem to be present from early stages of life, which highlights the importance of the prevention, early diagnosis and treatment of obesity.

Asymmetric dimethylarginine (ADMA) is identified as a potential biomarker of insulin resistance in skeletal muscle

To unravel metabolic determinats of insulin resistance, we performed a targeted metabolomics analysis in Korean Children-Adolescent Cohort Study (KoCAS, n = 430). Sixty-seven metabolites were associated with insulin resistance in adolescents and the association also found in an adult population (KoGES, n = 2,485). Functional interactions of metabolites with gene/proteins using biological pathway with insulin resistance were not identified biological significance and regulatory effects of asymmetric dimethylarginine (ADMA). However, ADMA showed a higher association with adolescent obesity (P < 0.001) and adult diabetes (P = 0.007) and decreased after obesity intervention program. Functional studies in cellular and mouse models demonstrated that an accumulation of ADMA is associated with the regulation of obesity-induced insulin resistance in skeletal muscle. ADMA treatment inhibited dimethylarginine-dimethylaminohydrolase (DDAH) activity and mRNA expression in insulin resistance muscle cell. Moreover, the treatment led to decrease of phosphorylation of insulin receptor (IR), AKT, and GLUT4 but increase of protein-tyrosine phosphatase 1B (PTP1B). Accordingly, increased ADMA significantly inhibited glucose uptake in myotube cell. We suggest that accumulation of ADMA is associated with modulation of insulin signaling and insulin resistance. ADMA might expand the possibilities of new therapeutic target for functional and clinical implications in the control of energy and metabolic homeostasis in humans.

Association of sodium intake with insulin resistance in Korean children and adolescents: the Korea National Health and Nutrition Examination Survey 2010

BACKGROUND

This study aimed to evaluate the relationship between sodium intake and insulin resistance indices.

METHODS

A total of 718 Korean children and adolescents (411 boys) aged 10-18 years who participated in the Korea National Health and Nutrition Examination Survey (KNHANES) were included in the study. The urinary sodium to urinary creatinine ratio was used as a surrogate for sodium intake. The homeostatic model assessment of insulin resistance (HOMA-IR) and the quantitative insulin sensitivity check index (QUICKI) were used as indices of insulin resistance.

RESULTS

The mean urinary sodium to urinary creatinine ratio was 11.34 in males and 10.17 in females. The urinary sodium to urinary creatinine ratio was significantly positively correlated with HOMA-IR (r=0.165, p<0.001) and inversely correlated with QUICKI (r=-0.181, p<0.001) in Pearson's correlation analyses. In a multivariate linear regression analysis, the urinary sodium to urinary creatinine ratio was independently and significantly positively associated with HOMA-IR (β=0.073, p=0.018) and significantly inversely associated with QUICKI (β=-0.080, p=0.007) after adjustment for possible confounders. HOMA-IR was independently and significantly positively associated with the urinary sodium to urinary creatinine ratio (β=0.087, p=0.018), whereas QUICKI was independently and significantly negatively associated with the urinary sodium to urinary creatinine ratio (β=-0.097, p=0.009) after controlling for confounders.

CONCLUSIONS

Our results suggest that sodium intake, as estimated by the urinary sodium to urinary creatinine ratio, may be independently associated with insulin resistance in children and adolescents.

Insulin Resistance and Its Association with Metabolic Syndrome in Korean Children

Background

This study investigated the association between insulin resistance (IR) and metabolic syndrome (MetS) in children.

Methods

A cross-sectional study involving 1036 healthy children aged between 7 and 13 years was conducted. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated as an index of IR. Participants were classified according to the HOMA-IR quartiles.

Results

Incremental, linear trends were found in age (p < 0.001), body mass index (BMI) (p < 0.001), body fat (p < 0.001), waist circumference (p < 0.001), resting blood pressures (BP) (p < 0.001), triglycerides (TG) (p < 0.001), total cholesterol (TC) (p < 0.001), high density lipoprotein-cholesterol (HDL-C) (p < 0.001), FBG (p < 0.001), and insulin (<0.001) according to incremental HOMA-IR categories (from the 1st to 4th quartile). Compared with children in the 1st HOMA-IR quartile, children in the 4th HOMA-IR quartile had significantly higher odd ratios (ORs) of abnormalities in systolic (p = 0.051) and diastolic BP (p = 0.005), FBG (p < 0.001), TG (p < 0.001), TC (p = 0.016), and HDL-C (p = 0.006) even after adjustments for age, gender, BMI, and body fat percentage. Children in the 3rd HOMA-IR quartile had significant abnormalities in FBG (p < 0.001), TG (p = 0.001), and HDL-C (p = 0.010) even after adjustments for the covariates.

Conclusion

The current findings suggest that IR is significantly associated with the clustering of MetS risk factors in children in Korea.

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

Objectives

This study aimed to evaluate the association between sodium intake and metabolic syndrome (MetS) in Korean boys.

Methods

A total of 1,738 boys aged 10–18 years were included in this study from the Korea National Health and Nutrition Examination Survey (KNHANES) during the years 2010–2013. Sodium intake was assessed using the urinary sodium excretion to urinary specific gravity ratio (U-Na to U-SG ratio).

Results

The median U-Na to U-SG ratio was 133.27 mmol/L (interquartile range: 95.66–178.50 mmol/L). Significant positive associations were found between the U-Na to U-SG ratio and the TG (P = 0.001 for trend) and TG concentrations, and these concentrations were significantly higher in boys with a U-Na to U-SG ratio in the highest quartile compared with those with a ratio in the lowest (P = 0.001) and second (P = 0.033) quartiles, as demonstrated through analysis of covariance (ANCOVA) after adjustment for possible confounders, including age, BMI standard deviation score, ferritin, vitamin D, house income, smoking, alcohol intake, physical activity, season, total intake, total energy intake, protein intake, fat intake, carbohydrate intake, and water intake. Significant inverse associations were found for the U-Na to U-SG ratio with the HDL-C (P = 0.033 for trend) and HDL-C levels, and these values were significantly lower in boys with a ratio in the highest quartile compared with those with a ratio in the second quartile (P = 0.020), as demonstrated through an ANCOVA. Although the trends did not reach statistical significance, a higher U-Na to U-SG ratio tended to be associated with higher SBP (P = 0.086 for trend), DBP (P = 0.063 for trend), and glucose levels (P = 0.099 for trend), as illustrated through ANCOVA. Boys with a ratio in the highest quartile exhibited a 1.73-fold increased risk for elevated TG (95% CI, 1.19–2.51) and a 2.66-fold increased risk for MetS (95% CI, 1.11–6.35) compared with those with a ratio in the lowest quartile, as demonstrated through multivariate logistic regression analyses after adjusting for confounders.

Conclusions

Our results suggest that high sodium intake may be significantly independently associated with MetS in Korean boys aged 10–18 years.

Early menarche is associated with non-alcoholic fatty liver disease in adulthood

BACKGROUND

The aim of this study was to examine the association between early menarche (<12 years) and non-alcoholic fatty liver disease (NAFLD) in premenopausal women and to explore whether it is mediated by adult obesity and insulin resistance.

METHODS

We analyzed data of premenopausal women, aged ≥15 years, from the Korea National Health and Nutrition Examination Survey (2007-2009). We divided the women into three groups: early menarche, reference (12.00-15.99 years), and late menarche. The presence of NAFLD was determined using hepatic steatosis index >36.0.

RESULTS

Of the 4,387 women evaluated, 673 (15.4%) met the criteria for NAFLD. The prevalence of NAFLD was higher in both women with early and late menarche compared with the reference (early, 23.4%; reference, 14.0%; late, 19.9%, P < 0.001). After adjustment of confounders including age, the OR for NAFLD in early menarche compared with the reference was 3.04 (95%CI: 1.99-4.65). Further adjustment of mediators, such as central obesity or insulin resistance, attenuated the association to 1.91-2.17. There was no association, however, between late menarche and NAFLD after adjustment of confounders.

CONCLUSIONS

Early menarche was associated with an increased risk of NAFLD in young and middle-aged premenopausal Korean women.

Prevalence and Clinical Characteristics of Metabolically Healthy Obesity in Korean Children and Adolescents: Data from the Korea National Health and Nutrition Examination Survey

Metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO) are differentiated by the presence of cardiometabolic risk factors (CMRFs) and insulin resistance (IR). This study aimed to evaluate the prevalence and clinical characteristics of MHO in Korean children and adolescents and to investigate the anthropometric, laboratory, and lifestyle predictors of MHO. This study included data from 530 obese subjects, aged 10-19 years, obtained from the Fourth Korea National Health and Nutrition Examination Survey. Subjects were classified into MHO and MUO groups according to the presence of CMRF (MHO(CMRF)/MUO(CMRF)) and degree of IR (MHO(IR)/MUO(IR)). Demographic, anthropometric, cardiometabolic, and lifestyle factors were compared between the groups. Logistic regression analysis and receiver operating characteristic curve analysis were performed to identify factors that predicted MHO. The prevalence of MHO(CMRF) and MHO(IR) in obese Korean youth was 36.8% (n = 197) and 68.8% (n = 356), respectively. CMRF profiles were significantly less favorable in MUO children. Longer and more vigorous physical activity and less protein intake were associated with MHO(CMRF) phenotype. The best predictors of MHO(CMRF) and MHO(IR) were waist circumference (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.77-0.88; P < 0.001) and body mass index (BMI) standard deviation score (OR, 0.24; 95% CI, 0.15-0.39; P < 0.001), respectively. The prevalence of MHO differed depending on how it was defined. To adequately manage obesity in youth, the approach to individuals with MHO and MUO should be personalized due to variation in clinical characteristics. Longitudinal studies are needed to evaluate long-term consequences of MHO.

Validation of surrogate markers for metabolic syndrome and cardiometabolic risk factor clustering in children and adolescents: A nationwide population-based study

Prevalence of metabolic syndrome (MetS) in children is increasing and identifying the risk factors for MetS during childhood is an important first step to prevent chronic diseases later in life. The aim of the present study was to evaluate the prevalence of MetS and cardiometabolic risk factor (CMRF) clustering among Korean children and adolescents and to validate the associated anthropometric and laboratory surrogate markers. We used data from the 2011–2014 Korean National Health and Nutrition Examination Survey. In total, data for 2,935 subjects (1539 boys, 52.6%) aged 10–19 years were assessed. MetS was defined by central obesity plus any two or more of CMRFs such as abdominal obesity, hypertension, hyperglycemia, hypertriglyceridemia, and decreased high density lipoprotein cholesterol (HDL-C) using the International Diabetes Federation criteria for children and adolescents. The presence of two or more CMRFs was classified as CMRF clustering. The prevalence of MetS and CMRF clustering in this group was found to be 1.8% and 8.9%, respectively. The receiver operating characteristic analysis of MetS and CMRF clustering, and the area under the curve (95% confidence interval) of surrogate markers revealed that the waist circumference to height ratio [0.960 (95% CI 0.959–0.960), cut-off 0.491] showed the highest predictability for MetS whereas triglyceride to HDL-C ratio [0.891 (95% CI 0.891–0.892), cut-off 2.63] showed the highest predictability for CMRF clustering. Long-term follow-up is needed for further validation.

Association of insulin resistance with near peak bone mass in the femur and lumbar spine of Korean adults aged 25-35: The Korean National Health and Nutrition Examination Survey 2008-2010

Objective

This study aimed to evaluate the relationship between insulin resistance and the bone mineral density (BMD) of femur and lumbar spine in Korean adults who are expected to exhibit near peak bone mass.

Methods

Data from the Korean National Health and Nutrition Examination Survey 2008–2010 were analyzed. A total of 2,750 participants aged 25−35 years were included. Insulin resistance was assessed using a homeostatic model assessment of insulin resistance (HOMA-IR) and serum fasting insulin.

Results

In a multivariate linear regression analysis, the HOMA-IR was significantly inversely associated with the BMD of the total hip (TH, β = −0.052, P = 0.002), femoral neck (FN, β = −0.072, P<0.001), femoral trochanter (FTr, β = −0.055, P = 0.003), femoral intertrochanter (FITr, β = −0.041, P = 0.015), and lumbar spine (LS, β = −0.063, P = 0.001) among all study subjects after adjustment for gender, age, height, weight, whole body fat mass percentage, systolic blood pressure, diastolic blood pressure, total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, vitamin D, smoking, alcohol intake, physical activity, education level, and household income in both genders as well as labor, the use of oral contraceptives, and age at menarche in females. The serum fasting insulin was significantly inversely associated with the BMD of the TH (β = −0.055, P = 0.001), FN (β = −0.072, P<0.001), FTr (β = −0.055, P = 0.003), FITr (β = −0.045, P = 0.009), and LS (β = −0.064, P = 0.001) among all subjects in a multivariate linear regression analysis.

Conclusion

Our results suggest that insulin resistance may be independently and inversely associated with the near peak bone mass of the femur and lumbar spine.

Pathologic Impact of Insulin Resistance and Sensitivity on the Severity of Liver Histopathology in Pediatric Non-Alcoholic Steatohepatitis

PURPOSE

Insulin resistance (IR) has an important role in the development of non-alcoholic steatohepatitis (NASH). We aimed to analyze the association between liver histopathology and IR in pediatric patients with NASH.

MATERIALS AND METHODS

In 24 children with non-alcoholic fatty liver disease (NAFLD), we investigated whether the hepatic pathologic characteristics have relations with following three biochemical indices; IR index including homeostasis model assessment of IR (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), and insulin sensitivity indices-free fatty acid (ISI-FFA).

RESULTS

Among 24 patients, 16 (66.6%) had a high NAFLD activity score (NAS), which is diagnostic of NASH. Higher serum triglyceride level was significantly correlated with a high NAS. Higher steatosis grades were significantly associated with low insulin sensitivity (p=0.023). In addition, severe lobular inflammation was associated with higher IR: HOMA-IR (p=0.014) and QUICKI (p=0.023). Severe fibrosis correlated with low insulin sensitivity and high IR indexes: ISI-FFA (p=0.049), HOMA-IR (p=0.028), and QUICKI (p=0.007).

CONCLUSION

Patients with high IR had more severe lobular inflammation and hepatic fibrosis. Analyses of biochemical and endocrine parameters can be applied to determine the severity of the hepatic pathologic status in patients with NASH, especially in children who cannot undergo a liver biopsy.

Population-based cross-sectional study on insulin resistance and insulin-secretory capacity in Japanese school children

AIMS/INTRODUCTION

Little information is available regarding the status of insulin resistance (IR) and insulin deficiency (ID), as well as their relationship with obesity in children using the homeostasis model assessment (HOMA) in a population-based setting.

MATERIALS AND METHODS

The study included a total of 445 ninth-grade children participating in health check-up programs implemented in Tsunan Town, Niigata, Japan (boys/girls, 252/193 [participation rates: 98.1/95.5%]). HOMA of insulin resistance ≥2.5 was defined as IR, and HOMA of β-cell function <40 defined as ID.

RESULTS

The medians (25-75th percentiles) of HOMA of insulin resistance, HOMA of β-cell function, Disposition Index and body mass index in boys were 1.2 (0.8-1.7), 64 (44-93), 52 (43-64) and 19.2 (18.0-20.7) kg/m² , respectively, vs 1.5 (1.0-2.0), 86 (63-120), 60 (50-74) and 20.4 (18.9-22.0) kg/m² , respectively, in girls. The HOMA of insulin resistance, HOMA of β-cell function and Disposition Index values were significantly higher in the girls (P = 0.002, P < 0.001 and P < 0.001, respectively). Those with IR accounted for a significantly higher proportion of girls than boys (15.5/8.7%; P = 0.027); those with obesity accounted for 9.9/10.7% (boys/girls); and those with IR and obesity accounted for 2.4/4.7%. Those with ID accounted for a significantly higher proportion of boys than girls (20.6/8.8%; P = 0.001), whereas those with ID and obesity accounted for a very small proportion of either group (0.4/0.5%).

CONCLUSIONS

The presence of IR was higher among the girls. In contrast, ID was more frequent among the boys. The infrequent presence of ID among children might support the presence of non-obese type 2 diabetes adults in Japan.

Association of serum ferritin with insulin resistance, abdominal obesity, and metabolic syndrome in Korean adolescent and adults: The Korean National Health and Nutrition Examination Survey, 2008 to 2011

This study aimed to evaluate the associations of serum ferritin with insulin resistance indices, body fat mass/percentage, and all the components of metabolic syndrome (MetS), as well as the risk for MetS according to serum ferritin levels in Korean adolescents and adults.A total of 15,963 Korean males and females aged 16 to 80 years were analyzed using data from the Korean National Health and Nutrition Examination Survey, 2005 to 2011.The median serum ferritin concentration was 98.82 ng/mL for males and 38.60 ng/mL for females (P < 0.001). Increased risks of greater waist circumference and elevated glucose levels, elevated triglyceride levels, and reduced high-density lipoprotein cholesterol levels were noted across the serum ferritin quartiles after adjustment for confounders in both genders (P ≤ 0.012 for trend). Insulin resistance indices and abdominal obesity (trunk fat mass/percent) increased across the ferritin concentration quartiles after adjustment for confounders in males and females (P ≤ 0.011 for trend), and the risk of MetS increased across the ferritin quartiles in males (P < 0.001 for trend) and females (P = 0.001 for trend). The highest serum ferritin quartile exhibited a 1.62-fold increased risk of MetS (95% CI, 1.28-2.12) in males and a 1.36-fold increased risk of MetS (95% CI, 1.09-1.69) in females compared with the lowest quartile after adjustment for confounders.Our results suggest that ferritin is associated with insulin resistance and abdominal obesity.

The changes of subtypes in pediatric diabetes and their clinical and laboratory characteristics over the last 20 years

PURPOSE

We studied the changes in subtypes of diabetes mellitus (DM) in children and evaluated the characteristics of each group over the past 20 years. In addition, we also examined the correlation between the glycated hemoglobin (HbA1c) values at the time of diagnosis and lipid profiles.

METHODS

The patients were divided into 2 groups: there were a total of 190 patients under 20 years of age firstly diagnosed with DM in Ajou University Hospital. The patients in groups I and II were diagnosed from September 1995 to December 2004 and from January 2005 to April 2014, respectively.

RESULTS

The characteristics were compared between the 2 groups of patients. The result showed an increase in percentage of type 2 diabetes and maturity onset diabetes of the young (MODY) patients between the 2 groups. HbA1c and total cholesterol level had statistical significances to explain increasing the low-density lipoprotein cholesterol level among age, HbA1c, total cholesterol level, and z-scores of weight and body mass index (BMI) in type 2 diabetes. R-square was 0.074. However, z-score of BMI and total cholesterol level, not HbA1c, had statistical significances in type 1 diabetic patients. R-square was 0.323.

CONCLUSION

The increase in the proportions of both type 2 diabetes and MODY in the last 10 years needed to be reminded when diagnosing the subtypes of DM, and the dyslipidemia should be attended more as a common problem of pediatric diabetic patients.

Optimal cut-off values for the homeostasis model assessment of insulin resistance (HOMA-IR) and pre-diabetes screening: Developments in research and prospects for the future

Diabetes mellitus (DM) appears to be increasing rapidly, threatening to reduce life expectancy for humans around the globe. The International Diabetes Federation (IDF) has estimated that there will be 642 million people living with the disease by 2040 and half as many again who will be not diagnosed. This means that pre-DM screening is a critical issue. Insulin resistance (IR) has emerged as a major pathophysiological factor in the development and progression of DM since it is evident in susceptible individuals at the early stages of DM, and particularly type 2 DM (T2DM). Therefore, assessment of IR via the homeostasis model assessment of IR (HOMA-IR) is a key index for the primary prevention of DM and is thus found in guidelines for screening of high-risk groups. However, the cut-off values of HOMA-IR differ for different races, ages, genders, diseases, complications, etc. due to the complexity of IR. This hampers the determination of specific cut-off values of HOMA-IR in different places and in different situations. China has not published an official index to gauge IR for primary prevention of T2DM in the diabetic and non-diabetic population except for children and adolescents ages 6-12 years. Hence, this article summarizes developments in research on IR, HOMA-IR, and pre-DM screening in order to provide a reference for optimal cut-off values of HOMA-IR for the diagnosis of DM in the Chinese population.

Early menarche is associated with metabolic syndrome and insulin resistance in premenopausal Korean women

In pediatrics, identifying risk factors is important in planning the prevention of cardiovascular disease. The aim of this study was to determine whether there is an independent association between early menarche (<12 years) and metabolic syndrome (MetS) in Korean women. We analyzed data from 4463 premenopausal women from the Fourth Korea National Health and Nutrition Examination Survey-IV (2007-2009). MetS was defined by the International Diabetes Federation for Asians and insulin resistance (IR) was defined as HOMA-IR more than 3.05. The prevalence of MetS and IR was 7.9 and 15.0%. Women (55.6%) with MetS also showed IR. The prevalence of MetS was higher in both women with early menarche and late menarche (≥16 years) compared with the reference group (early, 12.8%; reference, 7.0%; late, 11.0%, both P = 0.002). However, the odds ratio for MetS was 3.54 (95% confidence interval (CI), 2.14-5.87) and for IR was 2.98 (95% CI, 1.99-4.47) after adjusting for age and other confounders such as lifestyle variables, reproductive variables and sociodemographic variables only in women with early menarche

CONCLUSION

Early menarche was associated with an increased risk of MetS and IR in premenopausal Korean women.

WHAT IS KNOWN

Early menarche is associated with higher risk of CVD-related death and all-cause mortality in Western studies. Early menarche is associated with higher risk of diabetes in Korean premenopausal women.

WHAT IS NEW

Early menarche (<12 years) is associated with metabolic syndrome and insulin resistance in nationally representative Korean premenopausal women. However, late menarche (>16 years) is not associated with metabolic syndrome after controlling for age and other confounders.

Triglyceride is a useful surrogate marker for insulin resistance in Korean women with polycystic ovary syndrome

PURPOSE

To evaluate lipid profiles and liver enzymes as surrogate markers used for recognizing insulin resistance in Korean women with polycystic ovary syndrome (PCOS).

MATERIALS AND METHODS

458 women with PCOS were divided into two groups: non-obese with a body mass index (BMI)<25.0 kg/m² and obese with a BMI≥25.0 kg/m². Anthropometric measures and blood sampling for hormone assay, liver enzymes, lipid profiles and 75 g oral glucose tolerance test were performed. Insulin resistance was defined as homeostasis model assessment of insulin resistance (HOMA-IR)≥2.5. Areas under the receiver operating characteristic (ROC) curves were used to compare the power of serum markers. Multiple linear regression analysis was used to evaluate the contribution of each confounding factor for HOMA-IR.

RESULTS

In non-obese and obese groups, the ROC curve analyses demonstrated that the best marker for insulin resistance was triglyceride (TG), with the areas under the ROC curve of 0.617 and 0.837, respectively. Low-density lipoprotein cholesterol (LDL-C) was the significant marker for insulin resistance with areas under the ROC curve of 0.698 in obese group, but not significant in non-obese group. TG and LDL-C were significantly associated with HOMA-IR in both non-obese and obese PCOS women by multiple linear regression analysis. The optimal cut-off points of TG≥68.5 was a marker for predicting insulin resistance in non-obese PCOS patients and TG≥100.5 in obese group.

CONCLUSION

TG can be used as a useful marker for insulin resistance in Korean women with PCOS, especially for obese patients.

Early menarche increases the risk of Type 2 diabetes in young and middle-aged Korean women

AIMS

To investigate the association between early menarche (menarche age < 12 years) and Type 2 diabetes mellitus in young and middle-aged Korean women.

METHODS

We analysed data for 4657 women aged 20-50 years from the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV) (2007-2009).

RESULTS

The prevalence of Type 2 diabetes was 2.8%. Women with early menarche had a higher prevalence of impaired fasting glucose than did women with later menarche (age ≥ 12 years) in the 20-30 age group (7.4% vs. 3.0%), and a higher prevalence of diabetes in the 30-40 (6.3% vs. 1.7%) and 40-50 (18.5% vs. 4.4%) age groups. The odds ratio (OR) of Type 2 diabetes in women with early menarche was 3.61 [95% confidence interval (CI), 1.90-6.88] after adjusting for age. In multivariate regression, the OR of Type 2 diabetes decreased to 2.52 (95% CI, 1.29-4.94) after further adjusting for BMI. However, the OR decreased to 2.04 (95% CI, 0.95-4.39) without significance after adjusting for HOMA-IR.

CONCLUSIONS

Early menarche increased the risk of Type 2 diabetes in young and middle-aged Korean women although adulthood adiposity attenuated the relationship. Knowledge of age at menarche is important in identifying women at risk for diabetes.

The hemoglobin values of Korean adolescents show distinctive characteristics in comparison to those of Caucasians and African Americans

BACKGROUND

Hematologic reference values vary by ethnicity. We aimed to determine reference values of hemoglobin (Hb) for Korean adolescents.

METHODS

Using data from the 5th Korean National Health and Nutrition Examination Survey (KNHANES), we obtained reference values for Hb in adolescents aged 10-20 years.

RESULTS

Among 2,526 subjects recruited, 330 were excluded due to chronic diseases (9 congenital heart disease, 6 epilepsy, and 1 thyroid disease) or abnormal laboratory values (253 subjects with Fe/TIBC <16%, 103 subjects with MCV <80 fl). Accordingly, data from 2,196 subjects (male = 1,196 and female = 1,000) were analyzed and age- and gender-stratified means and percentile values of Hb were obtained. Pertinent findings observed in the current study were: (i) Hb levels in Korean male were similar to those of non-Hispanic Caucasians; (ii) Hb values in females were similar to those of non-Hispanic Caucasians until age of 15, and thereafter were slightly lower. Prevalence of anemia according to WHO criteria and our own criteria (Hb levels <2 standard deviations of age- and gender-specific values) in total sample was 3.5% (88/2,526) and 3.8% (97/2,526), respectively. Anemia was more prevalent in female in comparison with male (6.5% vs. 1.0%, P < 0.001).

CONCLUSIONS

Our results could be used as a national reference standard to correctly classify a large population sample. Further studies are necessary to determine reference Hb values for children younger than 10 years and identify genetic variations associated with distinctive characteristics observed in this study.