The TyG index cutoff point and its association with body adiposity and lifestyle in children

Triglyceride-glucose index demonstrates reasonable performance as a screening tool but exhibits limited diagnostic utility for insulin resistance: Data from the ELSA-Brasil cohort

Insulin resistance (IR) is a key risk factor for chronic metabolic diseases, but its laboratory diagnosis is still costly; thus, the triglyceride-glucose (TyG) index has been proposed as a surrogate method. Our aim was to provide a detailed analysis of cutoffs and test the hypothesis that the TyG index would present reasonable performance parameters for IR screening. This is a cross-sectional study with baseline data from 12,367 eligible participants of both sexes (aged 35-74 years) from the Brazilian Longitudinal Study of Adult Health. TyG correlation and agreement with the Homeostasis Model Assessment for Insulin Resistance were analyzed. Positive and negative predictive values (PV+, PV-) and likelihood ratio (LR+, LR-) were calculated. A moderate positive correlation between TyG and Homeostasis Model Assessment for Insulin Resistance was observed (Pearson r = 0.419). The area under the receiver operating characteristic curve of TyG for IR diagnosis was 0.742 and the optimal cutoff was 4.665, reaching a kappa agreement value of 0.354. For this cutoff, a PV+ of 59.3% and PV- of 76.0%, as well as an LR+ of 2.07 and LR- of 0.45 were obtained. Alternatively, because high sensitivity is desired for screening tests, selecting a lower cutoff, such as 4.505, increases the PV- to 82.1%, despite decreasing the PV+ to 50.8%. We conclude that TyG has important performance limitations for detecting IR, but that it may still be reasonably useful to help screening for IR in adults because it can be calculated from low-cost routine blood tests.

Body mass index and abdominal waist values are related to increased cardiometabolic risk in schoolchildren aged five to ten years

OBJECTIVE

To evaluate the frequency of obesity and cardiometabolic risk in schoolchildren under ten years old.

METHODS

This is a cross-sectional study with schoolchildren (n=639) aged five to ten years in a municipally of southern of Brazil. The cardiometabolic risk was calculated from values of body mass index (BMI), waist circumference (WC), diastolic (DBP) and systolic blood pressure (SBP), blood glucose levels, triglycerides and total cholesterol (TC). Odds ratio (OR), Spearman correlation and principal component analysis (PCA) were analyzed.

RESULTS

Independent of sex, elevated WC and BMI were related to higher values of SBP, DBP, and TC in schoolchildren. The frequency of cardiometabolic risk was 6.0% in girls and 9.9% in boys. Schoolchildren with elevated values of SBP, triglycerides and TC presented high OR for cardiometabolic risk. PCA indicated that schoolchildren with high WC (p>80) presented more frequently altered glucose levels, triglycerides, and TC.

CONCLUSIONS

Obesity, especially when associated with elevated WC, is related to metabolic dysfunctions and cardiometabolic risk in schoolchildren under ten years of age. These findings indicate the urgency of stablishing metabolic risk for this age group, enabling early diagnosis and adequate treatment, to prevent the development of diabetes and cardiovascular dysfunction throughout life.

The triglyceride-glucose index as an indicator of insulin resistance and cardiometabolic risk in Brazilian adolescents

Objective

To set cutoff points for the triglyceride and glucose index (TyG) as a marker of insulin resistance (IR) for the pediatric population.

Subjects and methods

This was a cross-sectional study with schoolchildren population-based data using data of 377 schoolchildren age 10 to 17 years of both sexes. We studied metabolic variables associated with IR indicators, such as fasting insulin and blood glucose, to calculate the homeostatic model assessment (HOMA-IR), and we studied triglycerides (TG) to determine the TyG index. We obtained TyG cutoff values for IR using the receiver operation characteristic (ROC), with definitions of sensitivity (Sen), specificity (Spe), and area under the ROC curve (AUC), with the HOMA-IR as reference.

Results

The cutoff points of the TyG index for IR in adolescents are 7.94 for both sexes, 7.91 for boys, and 7.94 for girls, indicating moderate discriminatory power. When we also considered anthropometric variables of excess weight [TyG-BMI (body mass index)] and visceral fat [TyG-WC (waist circumference)], these indexes reached AUC values higher than 0.72, enhancing their potential use for a good diagnosis.

Conclusion

TyG has proven to be a useful instrument for identifying IR in adolescent health screening, with high discrimination capacity when added to anthropometric variables, making it a feasible and inexpensive option.

Effects of Endurance Exercise Intensities on Autonomic and Metabolic Controls in Children with Obesity: A Feasibility Study Employing Online Exercise Training

Exercise is one of the major determinants of a healthy lifestyle, which is particularly important in childhood and serves as a powerful preventive tool. On the other hand, obesity and arterial hypertension rates are increasing in children, representing a huge risk for developing major cardiovascular and metabolic diseases in adult life. Of fundamental importance is the modality and volume of exercise required to obtain benefits. In this feasibility study, we considered a group of obese children, studied before and after a 12-week online exercise training program, and subdivided the participants into two groups considering the volume of exercise performed (above or below 1200 MET·min/week). This threshold level was applied in two different ways: subdivision A considered the total weekly physical activity volume (considering both time spent walking for at least 10 min consecutively and time spent performing structured exercise) and subdivision B considered only the weekly volume of structured exercise. We assessed autonomic and metabolic control and auxological and lifestyle parameters. We observed that the improved volume of structured exercise was associated with reduced arterial pressure percentile only in subdivision B and an improvement in markers of vagal and metabolic control was evident. Moreover, the 12-week online exercise training program, defined considering individual fitness level and progressively adapted as the goal was reached, proved to be sustainable from an economical and organizational point of view.

Does Childhood Obesity Trigger Neuroinflammation?

Childhood obesity is constantly increasing around the world, and it has become a major public health issue. Considerable evidence indicates that overweight and obesity are important risk factors for the development of comorbidities such as cognitive decline, neuroinflammation and neurodegenerative diseases. It is known that during obesity, adipose tissue undergoes immune, metabolic and functional changes which could induce a neuroinflammatory response of the central nervous system (CNS). In this context, to inspect if obesity can start to trigger the neuroinflammation from a pediatric age, we surgically collected and analyzed adipose tissue from the periumbilical area of three obese children (AT-OB) and two normal-weight children (AT-Ctrl). We considered the transcriptomic profile of our samples to detect alterations in different biological processes that might be also involved in the inflammatory and neuroinflammatory response. Our results show alterations of lipid and fatty acids metabolism in AT-OB compared to the AT-Ctrl. We also observed an onset of inflammatory response in AT-OB. Interestingly, among the genes involved in neuroinflammation, GRN and SMO were upregulated, while IFNGR1 and SNCA were downregulated. Our study highlights that obesity may trigger inflammation and neuroinflammation from a pediatric age.

Fat Intake and High Triglyceride-Glucose Index in Individuals at Cardiometabolic Risk: An Isocaloric Substitution Analyses

Insulin resistance (IR) is an important risk factor for cardiovascular diseases, and the triglyceride-glucose index (TyG index) is a potential IR biomarker. Evidence also suggests that fat intake may modulate IR status, but this relationship remains unclear. Thus, the present study aimed to analyze the relationship between the TyG index and isocaloric replacement of macronutrients, including the profile of dietary fatty acids in individuals at cardiometabolic risk.

This cross-sectional study enrolled 264 individuals at cardiometabolic risk (age 43.1 ± 16.3 years) who participated in a nutritional intervention study (ReBEC, id: RBR-5n4y2g). The baseline demographic, anthropometric, clinical, dietary, and lifestyle data were used. The TyG index was calculated using the formula ln [fasting triglycerides (mg/dL) × fasting plasma glucose (mg/dL)/2]. Multivariate nutrient density models were used to analyze isocaloric replacement of fatty acids (as 5% of energy). The chance of having a high TyG index (TyG index >8.83, median value) was decreased by 60% after replacing 5% of the energy intake of polyunsaturated fatty acid (PUFA), saturated fatty acid (SFA), and trans fatty acid (TFA) with monounsaturated fatty acid (MUFA) or PUFA and SFA with protein.

Isocaloric replacement of PUFA, SFA, and TFA with MUFA and protein was associated with lower chances of having a high TyG index. These results indicate the importance of macronutrient and dietary fat profiles in the dietary planning of individuals at cardiometabolic risk.

Pentraxin 3 and the TyG Index as Two Novel Markers to Diagnose NAFLD in Children

BACKGROUND

The diagnosis of NAFLD requires a liver biopsy, which is difficult in children. This study explored the diagnostic value of pentraxin 3 (PTX-3) and the triglyceride-glucose (TyG) index for NAFLD in children.

METHODS

Sixty-eight children with NAFLD were selected as study subjects, and 68 healthy children enrolled during the same period served as controls. The TyG index was calculated, serum PTX-3 expression was detected by enzyme-linked immunosorbent assay, and the correlations between PTX-3 or the TyG index and clinical and biochemical indicators were analyzed. A receiver operating characteristics curve analysis and area under the curve (AUC) were used to evaluate diagnostic accuracy.

RESULTS

Serum PTX-3 level and the TyG index of the NAFLD patients were significantly higher than those of the healthy controls (P < 0.001), which was closely related with the BMI, ALT, and insulin resistance. The AUC of PTX-3 for diagnosing NAFLD was 0.731 (95% confidence interval [CI] 0.646-0.806), and the AUC of the TyG index for diagnosing NAFLD was 0.765 (95% CI 0.682-0.835). The AUC of PTX-3, the TyG index, and ALT for the combined diagnosis of NAFLD was 0.964 (95% CI 0.916-0.989).

CONCLUSION

PTX-3 and the TyG index are novel diagnostic biomarkers for NAFLD, as they effectively improved the diagnostic accuracy for NAFLD when combined with ALT.

Six-month multidisciplinary follow-up in multisystem inflammatory syndrome in children: An Italian single-center experience

BACKGROUND

A severe multisystem inflammatory syndrome in children (MIS-C) related to SARS-CoV-2 has been described after infection. A limited number of reports have analyzed the long-term complications related to pro-inflammatory status in MIS-C. We evaluated multiorgan impairment at the 6-month follow-up in MIS-C.

METHODS

We enrolled 33 pediatric patients consecutively hospitalized for MIS-C and monitored for almost 6 months. The inter-relationship of patient's features and disease severity at admission with long term complications was studied by multivariate analysis.

RESULTS

Endo-metabolic derangement, cardiac injury, respiratory, renal and gastrointestinal manifestations and neurological involvement are part of the initial presentation. The most abnormalities appear to resolve within the first few weeks, without significant long term dysfunction at the 6-months follow-up, except for endocrine (non-thyroidal illness syndrome in 12.1%, insulin resistance in 21.2%) and neurological system (27.3% cognitive or psychological, behavioral, adaptive difficulties). Endocrine and heart involvement at admission represent a significant factor on the long term sequelae; however no association between severity score and long-term outcome was noted.

CONCLUSIONS

The severity of initial clinical presentation may be associated to organ domain, however it is not related to long term sequelae. The prevalent organ restoration supports a predominant indirect immune-mediated injury triggered by a systemic inflammatory response; however a direct damage due to the viral entry could be not excluded. Eventhought our preliminary results seem to suggest that MIS-C is not a long-term risk condition for children health, a longer follow-up is mandatory to confirm this hypothesis.

The triglyceride-glucose index as an adiposity marker and a predictor of fat loss induced by a low-calorie diet

BACKGROUND

This study aimed to investigate the putative role of the triglyceride-glucose index (TyG index) computed as ln[TG (mg/dl) × glucose (mg/dl)/2] and derived proxies as predictors of adiposity and weight loss changes after a low-calorie diet (LCD) intervention.

METHODS

A total of 744 adult participants from the multicentre DIOGenes intervention study were prescribed a LCD (800 kcal/day) during 8 weeks. Body composition and fat content at baseline and after 8 weeks were estimated by DEXA/BIA. A multivariate analysis approach was used to estimate the difference in ΔWeight_1-2 (kg), ΔBMI_1-2 (kg/m² ) or ΔFat_1-2 (%) between the basal value (point 1) and after 8 weeks following a LCD (point 2), respectively. The TyG index at baseline (TyG₁ ), after following the LCD for 8 weeks (TyG₂ ) or the TyG index differences between both time points (ΔTyG_1-2 ) were analysed as predictors of weight and fat changes.

RESULTS

TyG₁ was associated with ΔWeight_1-2 (kg) and ΔBMI_1-2 (kg/m² ), with β = 0.812 (p = .017) and β = 0.265 (p = .018), respectively. Also, TyG₂  values were inversely related to ΔFat_1-2 (%), β = -1.473 (p = .015). Moreover, ΔTyG_1-2 was associated with ΔWeight_1-2 (kg) and ΔFat_1-2 (%), β = 0.689 (p = .045) and β = 1.764 (p = .002), respectively. Furthermore, an association between TyG₂ and resistance to fat loss was found (p = .015).

CONCLUSION

TyG₁ index is a good predictor of weight loss induced by LCD. Moreover, TyG₂ was closely related to resistance to fat loss, while ΔTyG_1-2  values were positively associated with body fat changes. Therefore, TyG index and derived estimations could be used as markers of individualized responses to energy restriction and a surrogate of body composition outcomes in clinical/epidemiological settings in obesity conditions.

Blood Fatty Acids Profile in MIS-C Children

MIS-C (multisystem inflammatory syndrome in children) linked to SARS-CoV-2 infection, is a pathological state observed in subjects younger than 21 years old with evidence of either current SARS-CoV-2 infection or exposure within the 4 weeks prior to the onset of symptoms, the presence of documented fever, elevated markers of inflammation, at least two signs of multisystem involvement, and, finally, lack of an alternative diagnosis. They share with adult COVID-19 patients the presence of altered markers of inflammation, but unlike most adults the symptoms are not pulmonary but are affecting several organs. Lipid mediators arising from polyunsaturated fatty acids (PUFA) play an important role in the inflammatory response, with arachidonic acid-derived compounds, such as prostaglandins and leukotrienes, mainly pro-inflammatory and ω3 PUFA metabolites such as resolvins and protectins, showing anti-inflammatory and pro-resolution activities. In order to assess potential alterations of these FA, we evaluated the blood fatty acid profile of MIS-C children at admission to the hospital, together with biochemical, metabolic and clinical assessment. All the patients enrolled showed altered inflammatory parameters with fibrinogen, D-dimer, NT-proBNP, ferritin, aspartate aminotransferase (AST), C-reactive protein (CRP) and TrygIndex levels over the reference values in all the subjects under observation, while albumin and HDL-cholesterol resulted below the normal range. Interestingly, linoleic acid (LA), arachidonic acid (AA) and the ω3 PUFA docosahexaenoic acid (DHA) results were lower in our study when compared to relative amounts reported in the other studies, including from our own laboratory. This significant alteration is pointing out to a potential depletion of these PUFA as a result of the systemic inflammatory condition typical of these patients, suggesting that LA- and AA-derived metabolites may play a critical role in this pathological state, while ω3 PUFA-derived pro-resolution metabolites in these subjects may not be able to provide a timely, physiological counterbalance to the formation of pro-inflammatory lipid mediators. In conclusion, this observational study provides evidence of FA alterations in MIS-C children, suggesting a significant contribution of ω6 FA to the observed inflammatory state, and supporting a potential dietary intervention to restore an appropriate balance among the FAs capable of promoting the resolution of the observed inflammatory condition.

The triglyceride/glucose index as an insulin resistance marker in the pediatric population and its relation to eating habits and physical activity

INTRODUCTION

To examine the triglyceride/glucose index (TyG) as an insulin resistance marker in obese children and adolescents and its relation to clinical and biochemical parameters, body composition and lifestyle.

PATIENTS AND METHOD

Sixty patients aged 7-16 years of age were enrolled. Anthropometric variables were recorded, together with pubertal stage, blood pressure and body composition assessed by bioimpedance. The TyG index was calculated as ln (fasting glucose (mg/dL) × triglycerides (mg/dL))/2 and the HOMA (homeostatic model assessment) index as fasting insulin (μU/mL) × fasting glucose (mmol/L)/22.5. Feeding habits were documented by adherence to the Mediterranean dietary pattern questionnaire, while physical activity was assessed using the International Sedentary Assessment Tool (ISAT), as well as accelerometry (Actigraph wGT3X+).

RESULTS

The mean TyG index was 4.45 ± 0.18, and proved higher in the pubertal group. We found a positive correlation with the HOMA index (r = 0.39; P = 0.03) and TG/HDL-c index (r = 0.53; P < 0.001). The best cut-off point of the TyG index for predicting insulin resistance was 4.21 in prepubertal children (sensitivity 84%, specificity 100%; AUC: 0.84) and 4.33 in pubertal children (sensitivity 89%, specificity 69%; AUC: 0.61). A positive correlation was found with screen time (r = 0.39; P = 0.01), as well as a negative correlation with caloric expenditure (Kcal/day) in the prepubertal group (r = -0.81; P = 0.005).

CONCLUSIONS

The TyG index could be a useful insulin resistance marker in the pediatric population. Moderate to vigorous physical activity should be encouraged, as well as restricting screen time for leisure purposes, mainly in the prepubertal group.

Nutritional Status Influences Oxidative Stress and Insulin Resistance in Preschool Children

Background: Child malnutrition represents a major public health problem with physiological, psychological, and social short- and long-term implications. Objective: To compare the influence of nutritional status on oxidative stress (OS) markers in children aged 3-6 years. Methods: Children were categorized into four groups: underweight, normal weight, overweight, and obesity. Glucose (Glu), cholesterol (Chol), high-density lipoproteins, insulin, triacylglycerols (TG), triacylglycerols/glucose (TyG) index, and the homeostasis model assessment of insulin resistance (HOMA-IR) were analyzed. In addition, OS [malondialdehyde (MDA) and 3-nitrotyrosine (3-NT)] and antioxidant defense markers [superoxide dismutase (SOD), catalase (CAT), and the ratio of reduced/oxidized glutathione (GSH/GSSG)] were quantified. Results: Children with obesity showed significantly higher levels of MDA and 3-NT, and increased SOD activity compared with normal weight children. Glu, Chol, TG levels, TyG indexes, HOMA-IR, MDA, 3-NT, and SOD positively correlated with body mass index (BMI) and Centers for Disease Control and Prevention percentiles (CDC PC). However, CAT concentration and the GSH/GSSG ratio correlated negatively with BMI and CDC PC. In children with underweight, we found a positive correlation of TG levels and TyG indexes with BMI, whereas both markers positively correlated with BMI and CDC PC in children with overweight. MDA negatively correlated with BMI in children with underweight, while a positive association was observed in children with overweight. Finally, SOD, CAT, and GSH/GSSG negatively correlated with both BMI and CDC PC in children with overweight. Conclusions: Malnutrition, especially obesity, is associated with metabolic and OS disturbances in preschool children. It is urgent to design strategies to prevent malnutrition in this age group since this stage of development is crucial to potentially avoid future co-morbidities.

Impaired Glucose-Insulin Metabolism in Multisystem Inflammatory Syndrome Related to SARS-CoV-2 in Children

An interaction between metabolic glucose impairment and coronavirus disease 2019 is reported. The development of a severe multisystem inflammatory syndrome in children (MIS-C) related to SARS-CoV-2 infection has been described. We evaluated the impact of MIS-C on glycemic patterns in pediatric patients. A group of 30 children and adolescents affected by MIS-C were considered; all patients were normal weight. Clinical and biochemical assessments, including surrogate markers of insulin resistance (IR) such as homeostasis model analysis-IR (HOMA-IR) and triglyceride-glucose (TyG) indexes, were recorded. Patients were also invited to undergo an intermittently scanned continuous glucose monitoring (isCGM). HOMA-IR index was calculated in 18 patients (60%), of which 17 (94%) revealed a pathological value. TyG index was computed for all patients and pathological values were detected in all cases. In 15 patients, isCGM data were recorded on average for 9 days (±3 days). Overall, average glucose was 105 mg/dL (±16 mg/dL) and average time spent in the 70-180 mg/dL range (TIR) was 93.76%, with nearly 10% of glucose readings in the 141-180 mg/dL range; glycemic fluctuations over the hyperglycemic threshold were detected in four patients. Regular glucose monitoring may be useful to prevent metabolic imbalance and obtain a better outcome.

Evaluation of Plasma AA/DHA+EPA Ratio in Obese Romanian Children

The aim of the study was to evaluate the plasma profile of arachidonic acid (AA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), as well to analyze the relationship of Omega 6/Omega 3 ratio with anthropo-metric parameters and insulin resistance markers.

Material and methods: Plasma levels of free fatty acids (FFAs) were measured using a high-throughput LC-MS AB Sciex4600 in 202 children (127 obese and 75 non-obese), age and sex-matched. Lipid and glucose profiles were assessed with current laboratory methods, while insulin resistance and beta-cell function were evaluated using HOMA-IR and HOMA-β respectively.

Results: In obese children, AA and AA/(DHA+EPA) ratio were significantly higher regardless of age and gender. In the lowest quartile of DHA, there was a clear trend for insulin resistance, with plasma insulin level, HOMA-IR, and HOMA-β significantly higher compared to the highest quartile of DHA. After adjustment for age and gender DHA remains a negative predictive factor for insulin resistance. Waist-to-height ratio (WHtR), a marker of visceral obesity was higher in children with a higher AA/(DHA+EPA) ratio.

Conclusions: In obese children, the AA is higher in concordance with insulin resistance. Additionally, children with a higher AA/(DHA+EPA) ratio have greater BMI, fat mass, waist circumference, and WHtR, important indicators of central adiposity, and cardio-metabolic disorders. LC/MS is a versatile tool for Omega ratio assessment, especially in children where the sample size is a limiting factor for metabolic and nutrition evaluation.

The triglyceride / glucose index as an insulin resistance marker in the pediatric population and its relation to eating habits and physical activity

INTRODUCTION

To examine the triglyceride/glucose index (TyG) as an insulin resistance marker in obese children and adolescents and its relation to clinical and biochemical parameters, body composition and lifestyle.

PATIENTS AND METHOD

Sixty patients aged 7-16 years of age were enrolled. Anthropometric variables were recorded, together with pubertal stage, blood pressure and body composition assessed by bioimpedance. The TyG index was calculated as ln (fasting glucose (mg/dL)×triglycerides (mg/dL))/2 and the HOMA (homeostatic model assessment) index as fasting insulin (μU/mL)×fasting glucose (mmol/L)/22.5. Feeding habits were documented by adherence to the Mediterranean dietary pattern questionnaire, while physical activity was assessed using the International Sedentary Assessment Tool (ISAT), as well as accelerometry (Actigraph wGT3X+).

RESULTS

The mean TyG index was 4.45±0.18, and proved higher in the pubertal group. We found a positive correlation with the HOMA index (r=0.39; P=.03) and TG/HDL-c index (r=0.53; P<.001). The best cut-off point of the TyG index for predicting insulin resistance was 4.21 in prepubertal children (sensitivity 84%, specificity 100%; AUC: 0.84) and 4.33 in pubertal children (sensitivity 89%, specificity 69%; AUC: 0.61). A positive correlation was found with screen time (r=0.39; P=.01), as well as a negative correlation with caloric expenditure (Kcal/day) in the prepubertal group (r=-0.81; P=.005).

CONCLUSIONS

The TyG index could be a useful insulin resistance marker in the pediatric population. Moderate to vigorous physical activity should be encouraged, as well as restricting screen time for leisure purposes, mainly in the prepubertal group.

Association between triglyceride glucose index and peak growth hormone in children with short stature

Growth hormone (GH) secretion is related to many factors, such as weight and puberty, and the reproducibility of GH provocation tests is very poor. This study aimed to evaluate whether the triglyceride (TyG) index was associated with peak GH in children with short stature. This study included 1095 children with short stature divided into two groups based on peak GH level in GH provocation tests [GH deficiency (GHD) group = 733 children; non-GHD group = 362 children]. We found that the TyG index was significantly higher in the GHD group than in the non-GHD group (P < 0.001). A nonlinear relationship was detected between the TyG index and peak GH, whose point was 7.8. A significant negative association between the TyG index and peak GH was observed when the TyG index was greater than 7.8 (β − 2.61, 95% CI − 3.98, − 1.24; P < 0.001), whereas, the relationship between the TyG index and peak GH was not significant when the TyG index was lower than 7.8 (β 0.25, 95% CI − 1.68, 2.17; P = 0.799). There is a nonlinear relationship between the TyG index and peak GH, and a higher TyG index is associated with decreased peak GH in children with short stature.

Insulin resistance and type 2 diabetes in children

Type 2 diabetes (T2D) is an emerging health risk in obese children and adolescents. Both environmental (lack of physical activity, excess nutritional intake, sedentary lifestyle) and genetic factors contribute to this global epidemic. The growing prevalence of T2D in youth is also associated with a consistently increased incidence of metabolic and cardiovascular complications. Insulin resistance (IR), i.e., whole-body decreased glucose uptake in response to physiological insulin levels, determines impaired glucose homeostasis and it is recognized as cardinal trigger of T2D and cardiovascular disease in both adults and children. In particular, IR and beta-cell dysfunction lead to the persistent hyperglycemia which characterizes T2D. Indeed, both pathological states influence each other and presumably play a crucial, synergistic role in the pathogenesis of T2D, although the precise mechanisms are not completely understood. However, beta-cell dysfunction and IR induce impaired glucose metabolism, thus leading to the progression to T2D. Therefore, understanding the mechanisms correlated with the decline of beta-cell function and IR is crucial in order to control, prevent, and treat T2D in youth. This review focuses on the current knowledge regarding IR and T2D in children and adolescents and showcases interesting opportunities and stimulating challenges for the development of new preventative approaches and therapeutic strategies for young patients with T2D.

Τriglycerides-glucose (TyG) index is a sensitive marker of insulin resistance in Greek children and adolescents

PURPOSE

To investigate the association between Triglyceride-glucose (TyG) index and the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and Matsuda indices in Greek obese children and adolescents, in order to assess whether it could be used as a predictor of insulin resistance.

METHODS

367 children (47.7% boys) with mean age of 9.9 ± 2.3 years, who were investigated for obesity, were included. After overnight fasting, TyG and HOMA-IR indices were calculated in all participants. In a subpopulation of 72 children Matsuda index was also calculated.

RESULTS

48.8% and 36.1% of the participants had insulin resistance according to HOMA-IR and Matsuda index respectively. TyG was significantly and positively correlated with BMI, ΗΟΜΑ-IR, lipid profile and Matsuda index. ROC curve analysis for TyG showed that the optimal cutoff value for the prediction of insulin resistance (HOMA-IR) was 7.96 with sensitivity 65% and specificity 58%. The area under the curve (AUC) was 0.65 which significantly differs from 0.5 (p < 0.001). Similarly, the optimal cutoff value of TyG index for predicting insulin resistance as evidenced by Matsuda was 7.91 with sensitivity 85% and specificity 61%. The AUC was 0.75 (p < 0.001). The odds for insulin resistance (with HOMA-IR) was 2.54 times greater for subjects with TyG higher than 7.96, while the odds for insulin resistance (with Matsuda) was 8.56 times greater for subjects with TyG more than 7.91.

CONCLUSIONS

TyG index shows a positive correlation with insulin resistance among children and adolescents, however further studies are needed to clarify its predictive ability.

TAG-glucose (TyG) index in childhood: an estimate of cut-off points and the relation to cardiometabolic risk in 4- to 9-year-old children

OBJECTIVE

To propose cut-off points for the TAG-glucose (TyG) index in Brazilian children and evaluate the link to cardiometabolic risk.

DESIGN

A cross-sectional study with children from a municipality in Minas Gerais, Brazil. Anthropometric (weight, height, waist circumference and waist:height ratio), biochemical (lipid and glucose profile) and blood pressure (BP) tests were performed. Using the receiver operating characteristic curve, cut-off points for the TyG index were proposed according to sex using homoeostasis model of assessment - insulin resistance (IR) as the reference method.

SETTING

Viçosa, MG, Brazil.

PARTICIPANTS

Children aged 4-9 years (n 515).

RESULTS

The TyG index cut-off points to identify the risk of IR were 7·9 and 8·1 for boys and girls, respectively. We observed that 48·7 % of the children had an increased TyG index. The increased TyG index was associated with overweight, total body and central fat, increased BP and altered lipid profile. Children with an increased TyG index had a higher accumulation of cardiometabolic risk factors.

CONCLUSIONS

According to the cut-off points proposed by the current study, children at risk of IR estimated by the TyG index presented a higher cardiometabolic risk, including isolated risk factors, as to the higher accumulation of these.

Gender-based differences in the clustering of metabolic syndrome factors in children and adolescents

Background We depicted gender-differences in metabolic syndrome (MS) clustering before and after puberty in pediatrics, in order to develop gender specific preventive strategies for childhood obesity. Methods We considered 1079 children and adolescents (529 females and 550 males; mean age 11.5 ± 2.8 year). According to body mass index (BMI) percentiles the subjects were classified as normal weight BMI <75th, overweight BMI 75-95th and with obesity BMI >95th. MS was diagnosed when three of the following criteria for age and sex percentiles were met: BMI >95th, triglycerides (TGs) level >95th, high-density lipoprotein-cholesterol (HDL-c) level <5th, blood pressure (blood pressure) >95th percentile, fasting blood glucose (FBG) >100 mg/dL and/or homeostatic model assessment- insulin resistance (HOMA-IR) >97.5th percentile. Results The prevalence of dismetabolic factors was similar in both genders, except for pathological BP, which was higher in males (p = 0.02). MS was detected only in patients with obesity, with a higher prevalence in pubertal than late/post-pubertal subjects (p < 0.001), without any significant difference between gender. In pre-puberty, the most common MS combination was obesity (HBMI) + hypertension (HBP) + hyperglycemia/insulin resistance (HGLY/IR) followed by HBMI + low HDL-levels (LHDL) + HGLY/IR versus HBMI + HBP + HGLY/IR followed by HBMI + HBP + LHDL, respectively, in females and males. In the early and late/post-pubertal periods, the most prevalent combination remained similar to pre-puberty, additionally in both sexes other combinations, such as HBMI + HTG + HBP + HGLY/IR, HBMI +  HBP + LHDL + HGLY/IR, HBMI + HTG + LHDL + HGLY/IR and HBMI + HTG + LHDL + HBP + HGLY/IR were also detected, differently distributed in males and females. Conclusions We confirm that MS is an important consequence related to obesity, particularly in the post-puberty stage. Some gender-based differences should be considered early in order to identify specific preventive and treatment strategies.

Novel metabolic indices and incident type 2 diabetes among women and men: the Rotterdam Study

AIMS/HYPOTHESIS

Both visceral and truncal fat have been associated with metabolic disturbances. We aimed to investigate the associations of several novel metabolic indices, combining anthropometric and lipid measures, and dual-energy x-ray absorptiometry (DXA) measurements of body fat, with incident type 2 diabetes among women and men from the large population-based Rotterdam Study.

METHODS

Cox proportional hazards models were used to investigate associations of visceral adiposity index (VAI), lipid accumulation product (LAP), the product of triacylglycerol and glucose (TyG), their formula components and DXA measures with incident type 2 diabetes. Associations were adjusted for traditional diabetes risk factors.

RESULTS

Among 5576 women and 3988 men free of diabetes, 511 women and 388 men developed type 2 diabetes during a median follow-up of 6.5 years. In adjusted models, the three metabolic indices VAI (per 1 SD naturally log-transformed HR; 95% CI) (1.49; 1.36, 1.65 in women; 1.37; 1.22, 1.53 in men), LAP (1.35; 1.16, 1.56 in women; 1.19; 1.01, 1.42 in men) and TyG (1.73; 1.52, 1.98 in women; 1.43; 1.26, 1.62 in men), gynoid fat mass (0.63; 0.45, 0.89) and android to gynoid fat ratio (1.51; 1.16, 1.97) in women were associated with incident type 2 diabetes. BMI (1.45; 1.28, 1.65) was the strongest predictor of type 2 diabetes in men.

CONCLUSIONS/INTERPRETATION

Among women, novel combined metabolic indices were stronger risk markers for type 2 diabetes than the traditional anthropometric and laboratory measures and were comparable with DXA measures. Neither combined metabolic indices nor DXA measures were superior to traditional anthropometric and lipid measures in association with type 2 diabetes among men.

Diabetes Type 2 in Neurologically Impaired Children and Adolescents Without Obesity: A New Emerging Entity?

Background: Insulin resistance (IR) plays a key role in the pathogenesis of type 2 diabetes (T2D). In neurologically impaired (NI) children unfavorable cardio-metabolic risk profile with high prevalence of IR has been reported. We evaluated the prevalence of T2D in NI children and adolescents, in order to define if a dedicated glucose monitoring may be recommended in these subjects.

Methods: We retrospectively evaluated 63 patients (11.4 ± 4.0 years) with severe disabilities. Auxological parameters were recorded. Metabolic blood assays included fasting blood glucose (FBG), fasting insulin, triglycerides (TG). IR was detected with the homeostasis model assessment for insulin resistance (HOMA-IR > 97.5th percentile for age and sex) and triglyceride-glucose index (TyG index > 7.88). Elevated FBG was defined with values >100 mg/dl. T2D was defined according to American Diabetes Association criteria.

Results: Impaired insulin sensitivity, pathological TyG index and elevated FBG were observed, respectively, in 41.3, 63.5, and 11.1% patients. T2D was diagnosed in 3.2% asymptomatic patients. The prevalence of diabetes was higher in pre-pubertal compared to pubertal subjects (p = 0.03).

Conclusions: T2D in NI children and adolescents without obesity could represent a new emerging entity. IR and/or surrogate markers of IR index may be useful for the primary screening of this at-risk disabled population so as to prevent diabetes.