Insulin resistance determined by Homeostasis Model Assessment (HOMA) and associations with metabolic syndrome among Chinese children and teenagers

Dietary Intake and Physical Activity in Relation to Insulin Resistance in Young Overweight Saudi Females: An Exploratory Pilot Study

Insulin resistance is a major contributor to the development of several chronic metabolic diseases, including type 2 diabetes mellitus, and is an increasing health concern in Saudi Arabia. Diet and physical activity have been postulated to affect insulin resistance; however, their effects on development of insulin resistance in young overweight Saudi females have not been explored. Therefore, the aim of the study is to investigate whether diet and physical inactivity increases the risk of insulin resistance in young overweight Saudi females. In a cross-sectional study, 42 overweight female Saudi students, aged between 20 and 30 years, were recruited from King Abdul-Aziz University. A questionnaire was used to collect demographics, anthropometric measurements, physical activity, and food frequency data. Blood biomarkers (lipid profile, fasting glucose, and fasting insulin) were measured. Insulin resistance was assessed using homeostasis model assessment 2 (HOMA2)-insulin resistance (IR) scores. A significant difference in median body mass index (BMI) was observed between the HOMA2-IR normal and HOMA2-IR raised index groups (P=0.04). In terms of dietary habits, the insulin resistant group had a higher intake of canned beverages compared with the normal group (P=0.03). No significant differences were found between the groups in terms of waist circumference, hip circumference, waist-to-hip ratio, or body fat percentage. The lipid profile also did not significantly differ between the two groups. This study demonstrates significant differences in HOMA2-IR-defined insulin resistance according to subjects’ BMI and canned beverage intake. A larger study is needed to confirm these associations.

Metabolic Syndrome and Prediabetes Among Yemeni School-Aged Children

PURPOSE

In view of the high rate of obesity and physical inactivity as well as the rising incidence of Type 2 DM among children in the neighboring Gulf countries and Middle East region; the aim of this study was, therefore, to determine the prevalence of metabolic syndrome (MetS) and prediabetes in Yemeni school-aged children.

PATIENTS AND METHODS

In this study, 1402 school children aged 12-13 years old (grade 7) were recruited from public schools in the capital Sana'a during the period April-May 2013. Anthropometric measurements and BP were recorded and BMI was calculated. Fasting venous blood (5 mL) was collected for biochemical analysis including FBG, HbA1c, insulin and lipids profile. Insulin resistance (HOMA-IR) and β-cell function (HOMA-β) were calculated.

RESULTS

The prevalence of prediabetes (as defined by impaired fasting glucose) and MetS (as classified by the IDF 2007) were 0.86% and 0.5%, respectively. Our results also showed 5.21% and 20.26% of the children to have two or one factor(s) of the MetS criteria fulfilled, respectively, with low HDL-c (17%) being the most prevalent MetS component, followed by metabolic glucose (8%), raised TG (5.3%), DBP (1.4%), and high WC (0.5%). Moreover, the prevalence of overweight and obesity was 4.2% and 2.8%, respectively; and about 1.2% of children had abnormal high insulin levels. Children with impaired fasting glucose (IFG) had increased HOMA-IR (p = 0.016) and SBP (p = 0.042) and decreased HDL-c (p = 0.034) and HOMA-β (p < 0.001); whereas obese children had increased WC (p < 0.001) and TG (p = 0.049).

CONCLUSION

The main finding of this study is that Yemeni children are at potential risk of obesity, metabolic syndrome and prediabetes despite their low prevalences. These results highlight the need for early identification and close monitoring of children at risk of later Type 2 DM as an important primary care strategy that can effectively prevent or delay the onset of such condition.

A Multidisciplinary Intervention in Childhood Obesity Acutely Improves Insulin Resistance and Inflammatory Markers Independent From Body Composition

Childhood obesity is an increasing health care problem associated with insulin resistance and low-level systemic inflammation, which can ultimately lead to diabetes. Evidence for efficacy of therapeutic intervention programs on the early development of obesity associated sequelae is moderate. This paper investigates the effect of a multidisciplinary short-term intervention program on insulin resistance and metaflammation in childhood obesity. Two hundred and 36 overweight or obese children and adolescents between the ages of 10 and 14 were included in a prospective 5 months intervention study, which included sports, psychotherapy, and nutritional counseling. Primary endpoints were the effects on body mass index standard deviation score (BMI-SDS) and homeostatic model assessment of insulin resistance (HOMA-IR), key secondary endpoints were the levels of C-reactive protein (CRP), leptin, and adiponectin. At baseline, a substantial proportion of participants showed signs of insulin resistance (mean HOMA-IR 5.5 ± 3.4) despite not meeting the diagnostic criteria for diabetes, and low-level inflammation (mean CRP 3.9 mg/l ± 3.8 mg/l). One hundred and 95 participants (83%) completed the program resulting in a significant reduction in BMI-SDS, HOMA-IR, CRP, and leptin and a significant increase in adiponectin (mean change compared to baseline -0.14, -0.85, -1.0 mg/l, -2.8 ng/ml, and 0.5 μg/ml, respectively; p < 0.001 each). Effects on BMI-SDS, HOMA-IR, CRP, and adiponectin were largely independent whereas leptin was positively correlated with BMI-SDS and total fat mass before and after intervention (r = 0.56 and 0.61, p < 0.001 each). Short-term multidisciplinary intervention successfully improved body composition, insulin sensitivity, low-level systemic inflammation, and the adipokine profile in childhood obesity. Our findings highlight the immediate connection between obesity and the pathophysiology of its sequelae, and emphasize the importance of early intervention. Continued lifestyle modification is likely necessary to consolidate and augment the long-term effects.

Dietary Leucine Supplementation Restores Serum Glucose Levels, and Modifying Hepatic Gene Expression Related to the Insulin Signal Pathway in IUGR Piglets

Simple Summary

Intrauterine malnutrition may compromise the size and structure of fetal organs and tissues, which leads to lower birth weight and a slower rate of growth after weaning. Intrauterine growth restriction/retardation (IUGR) impairs pancreas function, resulting in the decreased glucose levels in serum. Leucine, one of branched chain amino acids, is an essential amino acid and the substrate of protein synthesis. Leucine also acts as a major regulator of hormone signal transduction, like insulin. Dietary branched chain amino acids or leucine have beneficial effects on the glucose metabolism and glycogen synthesis of muscle. Leucine supplementation improves the insulin sensitivity in liver and muscle and then influences the systemic glucose homeostasis. However, it is still unclear whether leucine supplementation would alter insulin sensitivity in IUGR neonatal piglets. Our results showed that dietary leucine supplementation restored serum glucose concentrations, increased insulin and creatinine concentrations, and enhanced protein kinase adenosine monophosphate-activated γ 3-subunit and glucose transporter type 2 expression. These findings suggest that leucine might play a positive role in hepatic lipid metabolism and glucose metabolism in IUGR.

Abstract

This study aimed to investigate the effects of leucine with different levels on the insulin resistance in intrauterine growth restriction/retardation (IUGR) piglets. Thirty-two weaned piglets were arranged in a 2 × 2 factorial design and four treatments (n = 8) were as follow: (1) normal weaned piglets fed a basal diet (CONT), (2) IUGR weaned piglets fed a basal diet (IUGR), (3) normal weaned piglets fed a basal diet with the addition of 0.35% l-leucine (C-LEU), and (4) IUGR fed a basal diet with the addition of 0.35% l-leucine (I-LEU) for a 21-days trial. The results showed that compared to the IUGR group, the I-LEU group had higher final body weight and body weight gain, higher serum glucose concentrations, and higher serum insulin concentrations (p < 0.05). The gene expression of phosphatidylinositol 3-kinase p110 gamma, protein kinase adenosine monophosphate-activated γ 3-subunit, glycogen synthase kinase-3 alpha, and glucose transporter type 2 were increased in the I-LEU group as compared to the IUGR group (p < 0.05). It was concluded that dietary leucine supplementation restored serum glucose concentrations, increased insulin and creatinine concentrations, and enhanced protein kinase adenosine monophosphate-activated γ 3-subunit and glucose transporter type 2 expression, suggesting that leucine might play a positive role in hepatic lipid metabolism and glucose metabolism in IUGR.

Circulating Osteonectin and Adipokine Profiles in Relation to Metabolically Healthy Obesity in Chinese Children: Findings From BCAMS

Background The role of adipokine dysregulation in determining the metabolic fate of obesity is not well studied. We aimed to examine whether the matricellular protein osteonectin and the profiles of certain adipokines could differentiate metabolically healthy obese ( MHO ) versus metabolically unhealthy obese phenotypes in childhood. Methods and Results This study included 1137 obese children and 982 normal-weight healthy ( NWH ) controls recruited from the BCAMS (Beijing Child and Adolescent Metabolic Syndrome) study. MHO was defined by the absence of insulin resistance and/or any metabolic syndrome components. Six adipokines-osteonectin, leptin, adiponectin, resistin, FGF21 (fibroblast growth factor 21), and RBP-4 (retinol binding protein 4)-were assessed. Approximately 20% of obese children displayed the MHO phenotype. MHO children had a more favorable adipokine profile than metabolically unhealthy obese children, with lower osteonectin, leptin, and RBP -4 and higher adiponectin (all P<0.05). Compared with normal-weight healthy controls, MHO children displayed increased leptin, resistin, and RBP -4 levels and reduced adiponectin concentrations (all P<0.05) but similar osteonectin and FGF 21 levels. Among obese subjects, decreased osteonectin (odds ratio [OR]: 0.82; 95% confidence interval [CI] per standard deviation, 0.70-0.97), RBP -4 (OR: 0.77; 95% CI per standard deviation, 0.64-0.93), and leptin/adiponectin ratio (OR: 0.58; 95% CI per standard deviation, 0.43-0.77) were independent predictors of MHO . In addition, compared with children without abnormalities, those with any 3 adipokine abnormalities were 80% less likely to exhibit the MHO phenotype ( OR : 0.20; 95% CI , 0.10-0.43) and 3 times more likely to have metabolic syndrome ( OR : 2.77; 95% CI , 1.52-5.03). Conclusions These findings suggest that dysregulation of adipokines might govern the metabolic consequences of obesity in children. Low osteonectin levels, along with a healthy adipokine profile, might be used as an early marker of the MHO phenotype.

Cutoff values for HOMA-IR associated with metabolic syndrome in the Study of Cardiovascular Risk in Adolescents (ERICA Study)

OBJECTIVE

The aim of this study was to determine the distribution of homeostatic model assessment of insulin resistance (HOMA-IR) values and define its cutoff associated with metabolic syndrome (MetS) in the participants of the Study of Cardiovascular Risk in Adolescents (Estudo de Risco Cardiovascular em Adolescentes).

METHODS

MetS was defined according to the International Diabetes Federation criteria. HOMA-IR values were calculated and tabulated by corresponding percentiles for age and sex. Receiver operating characteristic curves were constructed to identify the optimal cutoff values of HOMA-IR associated with MetS in the total population and by sex.

RESULTS

We evaluated 37 815 adolescents ages 12 to 17 y. The highest HOMA-IR medians were found among girls and boys ages 12 and 14 y, respectively. Thereafter, values tended to decrease with age. The optimal cutoff values of the HOMA-IR associated with MetS in the total population, in female adolescents, and in male adolescents were 2.80, 2.32, and 2.87, respectively. Insulin resistance was prevalent in 19.1% (95% confidence interval, 17.7-20.7) of the total population, and the prevalence was higher among girls and overweight Brazilian adolescents.

CONCLUSIONS

These findings may serve as new reference points for detecting insulin resistance in Brazilian adolescents.

No Associations Between Serum Lipid Levels or HOMA-IR and Asthma in Children and Adolescents: A NHANES Analysis

OBJECTIVE

Studies have reported inconsistent results on the associations between lipids and insulin resistance (IR) and asthma. The purpose of this study was to examine the associations between abnormal serum lipid levels and homeostatic model assessment-IR (HOMA-IR) and the presence of current asthma in children and adolescents.

METHODS

The United States National Health and Nutrition Examination Survey database from 1999 to 2012 was randomly searched for children (aged 3-11 years) and adolescents (aged 12-19 years) with and without asthma and with complete demographic and clinical data of interest. Logistic regression analyses were performed to examine associations between abnormal serum lipids, glucose and HOMA-IR and the current presence of asthma.

RESULTS

The data of 11,662 children (3 to 11 years of age) and 12,179 adolescents (12 to 19 years of age) were included in the analysis. The study group included 3,703 participants with asthma and 20,138 participants without asthma. The prevalence of self-reported current asthma was higher among participants aged between 3-11 years (52.9%) than among those aged between 12-19 years (50.7%). Multivariate analyses, after adjusting for sex, race, income-to-poverty ratio, low birth weight, prenatal maternal smoking, tobacco exposure, C-reactive protein level and body mass index Z-score, revealed no associations between elevated fasting plasma glucose, reduced high-density lipoprotein cholesterol, elevated low-density lipoprotein cholesterol, total cholesterol, triglycerides and HOMA-IR and the presence of current asthma in children or adolescents.

CONCLUSION

In this cross-sectional study, no association was found between abnormal serum lipids or HOMA-IR and the presence of current asthma in children or adolescents.

High TSH Level within Normal Range Is Associated with Obesity, Dyslipidemia, Hypertension, Inflammation, Hypercoagulability, and the Metabolic Syndrome: A Novel Cardiometabolic Marker

(1) Background: Overt and subclinical hypothyroidism has been associated with increased cardiometabolic risks. Here we further explore whether thyroid function within normal range is associated with cardiometabolic risk factors in a large population-based study. (2) Methods: We screened 24,765 adults participating in health examinations in Taiwan. Participants were grouped according to high-sensitive thyroid-stimulating hormone (hsTSH) level as: <50th percentile (0.47–1.48 mIU/L, the reference group), 50–60th percentile (1.49–1.68 mIU/L), 60–70th percentile (1.69–1.94 mIU/L), 70–80th percentile (1.95–2.3 mIU/L), 80–90th percentile (2.31–2.93 mIU/L), and >90th percentile (>2.93 mIU/L). Cardiometabolic traits of each percentile were compared with the reference group. (3) Results: Elevated hsTSH levels within normal range were dose-dependently associated with increased body mass index, body fat percentage, waist circumferences, blood pressure, hemoglobin A1c (HbA1c), fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), high homeostasis model of assessment of beta-cell (HOMA-β), triglycerides, total cholesterols, fibrinogen, and uric acids (p-for-trend <0.001), but not with fasting glucose levels. The association remained significant after adjustment of age, sex, and lifestyle. As compared to the reference group, subjects with the highest hsTSH percentile had significantly increased risk of being overweight (adjusted odds ratio (adjOR): 1.35), increased body fat (adjOR: 1.29), central obesity (adjOR: 1.36), elevated blood pressure (adjOR: 1.26), high HbA1c (adjOR: 1.20), hyperinsulinemia (adjOR: 1.75), increased HOMA-IR (adjOR: 1.45), increased HOMA-β (adjOR: 1.40), hypertriglyceridemia (adjOR: 1.60), hypercholesterolemia (adjOR: 1.25), elevated hsCRP (adjOR: 1.34), increased fibrinogen (adjOR: 1.45), hyperuricemia (adjOR: 1.47), and metabolic syndrome (adjOR: 1.42), but significant risk of low fasting glucose (adjOR: 0.89). Mediation analysis indicates that insulin resistance mediates the majority of the association between thyroid hormone status and the metabolic syndrome. (4) Conclusion: Elevated hsTSH within the normal range is a cardiometabolic risk marker associated with central obesity, insulin resistance, elevated blood pressure, dyslipidemia, hyperuricemia, inflammation, and hypercoagulability.

Insulin Resistance in Children

Insulin resistance (IR) is a pathological condition strongly associated with obesity. However, corticosteroids or growth hormone therapy and genetic diseases may affect insulin sensitivity lifelong. In obese children and adolescents of any age there is an evident association between IR and an increased prevalence of type 2 diabetes (T2D) and other elements contributing to the metabolic syndrome, leading to a higher cardiovascular risk. Therefore, early diagnosis and interventions in the attempt to prevent T2D when glycemia values are still normal is fundamental. The gold standard technique used to evaluate IR is the hyperinsulinemic euglycemic clamp, however it is costly and difficult to perform in clinical and research sets. Therefore, several surrogate markers have been proposed. Although the treatment of insulin resistance in children is firstly targeted to lifestyle interventions, in selected cases the integration of a pharmacological intervention might be taken into consideration. The aim of this review is to present the current knowledge on IR in children, starting with an outline of the recent evidences about the congenital forms of deficiency in insulin functioning and therefore focusing on the physiopathology of IR, its appropriate measurement, consequences, treatment options and prevention strategies.

Adipose Tissue Mediates Associations of Birth Weight with Glucose Metabolism Disorders in Children

OBJECTIVE

This study aimed to examine the associations between low birth weight (LBW) versus high birth weight (HBW) and dysglycemia, including insulin resistance (IR) and impaired fasting glucose (IFG) in children, and aimed to explore the role of adipose tissue in these relationships.

METHODS

A total of 2,935 subjects aged 6 to 18 years were recruited to examine the relationship between birth weight and IR (defined as homeostasis model assessment of IR > 2.3) and IFG. Mediation analyses were conducted to examine the roles of various adipokines and anthropometrics in these relationships.

RESULTS

Children with LBW had a nearly twofold increased risk of IR and IFG compared with children with normal birth weight, even after adjusting for BMI. Decreased circulating adiponectin levels contributed to 21.2% of the LBW-IR relationship, whereas none of the selected adipose markers mediated the LBW-IFG relationship. In contrast, after controlling for current BMI or waist circumference, HBW reduced the risk of IR by 34%, but it was not associated with IFG. The HBW-IR relationship was significantly mediated by reduced leptin levels (21.4%) and fat mass percentage (8.8%), after controlling for BMI.

CONCLUSIONS

These findings suggest the potential role of adipose tissue dysfunction as an underlying mechanism for the birth weight-type 2 diabetes relationship.

Influence of LRP5 (rs556442) polymorphism on insulin resistance in healthy Iranian children and adolescents

Background/aim

Genetic aspects play a role in insulin resistance in children. In this study, for the first time, the association of LRP5 (rs556442) polymorphism and insulin resistance in Iranian children and adolescents was investigated.

Materials and methods

The study population comprises children and adolescents aged 9–18 years. Anthropometric and biochemical parameters were assessed. Insulin resistance/sensitivity was determined by the quantitative insulin sensitivity check index (QUICKI), homeostasis model assessment-insulin resistance (HOMA-IR), insulin-to-glucose ratio, McAuley index, revised McAuley index, fasting insulin resistance index (FIRI), and Bennett’s index. LRP5 (rs566442) single nucleotide polymorphism (SNP) was identified using restriction fragment length polymorphism (RFLP). Linear regression analysis was used to determine the association between the LRP5 polymorphism (rs556442) and insulin sensitivity indexes.

Results

Significant differences were found between GG genotype vs. AG/AA genotypes for McAuley index (P = 0.049) and revised McAuley index (P = 0.044) when adjusted for interaction factors (age, sex, and puberty) in regression models. No significant association was found between LRP5 (rs566442) and other insulin resistance indexes. Also, LRP5 (rs566442) did not show a significant impact on biochemical parameters.

Conclusion

This study showed that LRP5 polymorphism (rs556442) was associated with insulin resistance in Iranian children and adolescents.

Effect of the Interaction between Obstructive Sleep Apnea and Lipoprotein(a) on Insulin Resistance: A Large-Scale Cross-Sectional Study

Both obstructive sleep apnea (OSA) and decreased serum lipoprotein(a) (Lp(a)) concentrations are associated with insulin resistance. However, their interaction effect on insulin resistance has never been investigated. Therefore, we performed a cross-sectional study on OSA-suspected Chinese Han participants. Laboratory-based polysomnographic variables, biochemical indicators, anthropometric measurements, and medical history were collected. Linear regression and binary logistic regression analyses with interaction terms were used to investigate the potential effects of the interaction between the severity of OSA (assessed by the apnea-hypopnea index (AHI)) and Lp(a) concentrations on insulin resistance (assessed by the homeostasis model assessment of insulin resistance (HOMA-IR)), after adjusting for potential confounders including age, gender, body mass index, waist-to-hip circumference ratio, mean arterial pressure, smoking status, drinking status, and lipid profiles. A total of 4,152 participants were enrolled. In the OSA-suspected population, AHI positively correlated with insulin resistance and serum Lp(a) concentrations independently and inversely correlated with insulin resistance. In addition, the interaction analysis showed that the linear association between lgAHI and lgHOMA-IR was much steeper and more significant in subjects with relatively low Lp(a) concentrations, suggesting a significant positive interaction between lgLp(a) and lgAHI on lgHOMA-IR (P = 0.013). Furthermore, the interaction on a multiplicative scale also demonstrated a significant positive interaction (P = 0.044). A stronger association between AHI quartiles and the presence of insulin resistance (defined as HOMA-IR > 3) could be observed for participants within lower Lp(a) quartiles. In conclusion, a significant positive interaction was observed between OSA and decreased Lp(a) with respect to insulin resistance. This association might be relevant to the assessment of metabolic or cardiovascular disease risk in OSA patients.

Metabolic syndrome is a sequela of radiation exposure in hypothalamic obesity among survivors of childhood brain tumors

Survivors of childhood brain tumors may be at risk for early onset of metabolic syndrome, possibly secondary to surgery and/or radiation exposure. This study examines effects of radiation exposure to hypothalamus-pituitary-adrenal axis (HPA) on metabolic risk among survivors of childhood brain tumors. One hundred forty-two met inclusion criteria; 60 had tumor surgery plus radiation exposure (>1 Gray (Gy)) to HPA. The second subgroup of 82 subjects had surgery only and were not exposed to radiation. Both subgroups had survived for approximately 5 years at the time of study. All had clinical evaluation, vital signs, anthropometry, measurement of body composition by dual X-ray absorptiometry and fasting laboratory assays (metabolic panel, insulin, C-peptide, insulin-like growth factor-1, leptin and adiponectin). Body composition data for both subgroups was compared with the National Health and Nutrition Survey (NHANES) subgroup of similar age, gender and body mass index. Cranial surgery was associated with obesity of similar severity in both subgroups. However, survivors exposed to radiation to the HPA also had increased visceral fat mass and high prevalence of growth hormone deficiency and metabolic syndrome. Fat mass alone did not explain the prevalence of the metabolic syndrome in radiation exposure subgroup. Other factors such as growth hormone deficiency may have contributed to metabolic risk. We conclude that prevalence of metabolic syndrome among subjects exposed to hypothalamic radiation was higher than expected from hypothalamic obesity alone. Radiation exposure may exert untoward endocrinopathies due to HPA exposure that worsens metabolic risk. Early screening for metabolic syndrome in this population is indicated.

Advanced glycation end products and their receptors did not show any association with body mass parameters in metabolically healthy adolescents

AIM

We determined the relationship between circulating advanced glycation end products (AGEs), AGE receptors and homeostatic model assessment for insulin resistance (HOMA-IR) in metabolically healthy obese and normal weight adolescents.

METHODS

In 2015, we recruited 80 normal weight adolescents and 80 with obesity from schools Leon city, Mexico, and put them into metabolically healthy (HOMA-IR <3.0) and unhealthy (HOMA-IR >3.0) groups. We measured their body mass index (BMI) and carried out detailed blood analyses.

RESULTS

We found a higher triglycerides, triglycerides/high-density lipoproteins cholesterol (TG/HDL-C) index, HOMA-IR, tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) in the metabolically healthy group and found correlations between HOMA-IR with BMI, the TG/HDL-C index and IL-6 and the TG/HDL-C index and BMI and (TNF-α). There was no correlation between markers of obesity and circulating N-carboxymethyl-lysine (CML) or soluble receptor for advanced glycation end products (sRAGE). Some unhealthy adolescents had higher CML (15.5 ± 2.7 U/mL, p < 0.028) and sRAGE (3123 ± 1364 pg/mL, p < 0.001) than the healthy group.

CONCLUSION

HOMA-IR and the TG/HDL-C index were associated with BMI and inflammation markers. CML and sRAGE were not associated with obesity or inflammation. These parameters were higher in unhealthy obese adolescents.

The Influence of Obesity on Puberty and Insulin Resistance in Mexican Children

Obesity is considered the main risk factor associated with the development of insulin resistance (IR). The aim of this study was to evaluate the influence of obesity on puberty onset and IR in Mexican children. A total of 378 children (189 boys and 189 girls) aged 8-14 years participated in the study. IR was estimated using the homeostasis model assessment for IR (HOMA-IR). The mean fasting glucose (FG) and basal insulin levels were 82 mg/dl and 11.0 μIU/ml in boys and 77.3 mg/dl and 12.3 μIU/ml in girls (P < 0.05). Subjects with obesity at Tanner stages II-V showed increased FG levels (P < 0.05). In boys with obesity, there was a decrease in HOMA-IR in Tanner stage IV and differences in age between boys with normal weight and those with obesity in Tanner V, being older the boys with obesity. Obesity in children and adolescents was associated with higher HOMA-IR values. In boys with obesity, IR increased at the end of pubertal maturation, with a delay in puberty. These findings should be considered on the establishment of IR cutoff values for pubertal population in Mexico and in the establishment of strategies to prevent the health problems related to obesity.

Evaluation of ADA HbA1c criteria in the diagnosis of pre-diabetes and diabetes in a population of Chinese adolescents and young adults at high risk for diabetes: a cross-sectional study

OBJECTIVE

We aimed to assess haemoglobin A1c (HbA1c) for the diagnosis of pre-diabetes and diabetes in a population of Chinese youths at risk of metabolic syndrome.

SETTING

Beijing, China.

PARTICIPANTS

A total of 581 subjects aged 14-28 years underwent evaluation including an oral glucose tolerance test (OGTT). Insulin sensitivity, β-cell function and a number of cardiovascular disease risk factors were evaluated. Receiver operating characteristic (ROC) curves were used to assess the screening efficacy of HbA1c.

RESULTS

Using OGTT data as a standard, the majority (70.0%, 7/10) of subjects with diabetes would have been diagnosed with HbA1c ≥6.5%. In contrast, only 28.1% (16/57) of subjects with pre-diabetes possessed elevated HbA1cs, while the majority (68.4%) had normal HbA1cs. On the contrary, a total of 8.1% (39/479) of youths in the normal HbA1c category (<5.7%) and 21.3% in the pre-diabetes category had pre-diabetes. In the ROC analysis, the area under the curve (AUC) for HbA1c identifying pre-diabetes was 0.680(95% CI 0.640 to 0.719); the optimal threshold was 5.5%, with a sensitivity of 61.4% and specificity of 68.5%. For type 2 diabetes mellitus, the AUC for HbA1c was 0.970 (0.952 to 0.982), and the optimal threshold was 6.1%, with a sensitivity of 90.0% and a specificity of 98.7%. Applying these new cut-offs, pre-diabetic participants (HbA1c 5.5%-6.1%) had lower disposition index and higher risk of dyslipidaemia (OR=1.61,95% CI 1.10 to 2.37) and metabolic syndrome (OR=2.09, 1.27 to 3.45) than those with normal HbA1c (<5.5%).

CONCLUSION

The American Diabetes Association's established HbA1c criteria for pre-diabetes and diabetes (5.7% and 6.5%) may not be appropriately applied to adolescents and young adults in China. Our findings suggest that those with HbA1c of 5.5%-6.1% already exhibit impaired β-cell function and increased cardiometabolic risk factors which may warrant intervention.

TRIAL REGISTRATION NUMBER

NCT03421444.

Evaluation of insulin resistance improvement after laparoscopic sleeve gastrectomy or gastric bypass surgery with HOMA-IR

Our purpose was to explore the remission of insulin resistance after bariatric surgery to discover the mechanism of diabetes remission excluding dietary factors. A retrospective case control study was conducted on patients with type 2 diabetes, who underwent laparoscopic sleeve gastrectomy (LSG) or laparoscopic gastric bypass surgery (LGB) in Beijing Shijitan Hospital from April 1, 2012 to April 1, 2013. The laboratory and anthropometric data was analyzed pre-surgery and during a 2-year follow-up. HOMA-IR was calculated and evaluated. The two surgical procedures were compared. No significant difference in complete remission rate was observed between the two groups (LGB group: 62.1%, LSG group: 60.0%, p = 0.892). HOMA-IR was reduced to a stable level at the 3^rd month after surgery. The cut-off value of HOMA-IR was 2.38 (sensitivity: 0.938, specificity: 0.75) and 2.33 (sensitivity: 0.941, specificity: 0.778) respectively for complete remission after LSG or LGB surgery. Insulin resistance was improved while GLP-1 and Ghrelin was changed significantly in patients with type 2 diabetes prior to weight loss either in the LSG or LGB group. HOMA-IR decreased to less than the cut-off value at the 3^rd month and was closely related to complete remission. The mechanism of bariatric surgery was not due just to simply dietary factors or body weight loss but also the remission of insulin resistance.

Hyperprolactinemia and insulin resistance in drug naive patients with early onset first episode psychosis

BACKGROUND

Hyperprolactinemia and glucose and lipid metabolism abnormalities are often found in patients with schizophrenia and are generally considered secondary to the use of antipsychotic drugs. More recent studies have shown these same neuroendocrine and metabolic abnormalities in antipsychotic naïve patients with first episode psychosis (FEP), rising the hypothesis that schizophrenia itself may be related to an abnormal regulation of prolactin secretion and to impaired glucose tolerance. The aim of this study was to compare prolactin levels, glycometabolism parameters and lipid profile between a sample of 31 drug-naive adolescents in the acute phase of FEP and a control group of 23 subjects at clinical high risk (CHR) of developing psychosis.

METHODS

The assessment involved anthropometric data (weight, height, BMI index, pubertal stage) and blood tests (levels of glucose, glycated hemoglobin, serum insulin, triglycerides, total and fractionated cholesterol, prolactin). Insulin resistance (IR) was calculated through the homeostatic model of assessment (HOMA-IR), assuming a cut-off point of 3.16 for adolescent population. FEP patients and CHR controls were compared by using Student's t-distribution (t-test) for parametric data. P < 0.05 was considered significant.

RESULTS

Significant higher level of prolactin was found in FEP group than in CHR group (mean = 28.93 ± 27.16 vs 14.29 ± 7.86, P = 0.009), suggesting a condition of hyperprolactinemia (HPRL). Patients with FEP were more insulin resistant compared to patients at CHR, as assessed by HOMA-IR (mean = 3.07 ± 1.76 vs 2.11 ± 1.11, P = 0.043). Differences of fasting glucose (FEP = 4.82 ± 0.71, CHR = 4.35 ± 0.62, P = 0.016) and HbA1c (FEP = 25.86 ± 13.31, CHR = 33.00 ± 2.95, P = 0.013), were not clinically significant as the mean values were within normal range for both groups. No significant differences were found for lipid profile. A BMI value within the range of normal weight was found for both groups, with no significant differences.

CONCLUSION

We suggested that HPRL, increase in HOMA-IR, and psychotic symptoms may be considered different manifestations of the acute onset of schizophrenia spectrum psychosis, with a common neurobiological vulnerability emerging since adolescence. The influence of age and gender on clinical manifestations of psychotic onset should be considered for early prevention and treatment of both schizophrenia spectrum psychosis and neuroendocrine-metabolic dysfunctions.

Prevalence and complications of obesity and overweight among Algerian adolescents

OBJECTIVE: To determine the prevalence of overweight and obesity in Algerian adolescents and investigate the associated cardiometabolic complications. METHODS: The study was conducted in the city of Constantine (Algeria). The population included 1100 schooled adolescent, aged 12–18 years, randomly selected. All had anthropometric measurements, and 989 had blood tests. The BMI was calculated and the prevalence of overweight and obesity was determined using the International Obesity Task Force reference values. RESULTS: 179 (16.3%) adolescents were overweight including 74 boys (13.8%) and 105 girls (18.6%), 51 (4.6%) adolescents were obese including 25 (4.6%) boys vs 26 (4.6%) girls (p = 0.09). Overweight and obese adolescents had higher systolic blood pressure/diastolic blood pressure (p = 0.001/p < 0.0001) and abnormal blood lipid levels. Furthermore, the HOMA index was higher in overweight and obese adolescents (p < 0.0001). CONCLUSION: These findings show a high prevalence of overweight and obesity in a population of Algerian adolescents leading to significant cardiometabolic abnormalities.

Metabolic Profiles in Obese Children and Adolescents with Insulin Resistance

BACKGROUND:

In the past several decades, the increasing frequency of overweight and obese children and adolescents in the world has become a public health problem. It has contributed significantly to the already high tide of diabetes, cardiovascular and cerebrovascular diseases.

AIM:

To investigate the frequency of insulin resistance and to evaluate the metabolic profile of insulin resistant and non-insulin resistant obese children and adolescents.

SUBJECTS AND METHODS:

The study included 96 (45 boys, 51 girls) obese children and adolescents aged 4-17 years old (10.50 ± 2.87 years). Only participants with Body Mass Index ≥ 95 percentile were included. We analysed sera for fasting insulin levels (FI), fasting serum triglycerides (TG), total serum cholesterol (TC), fasting plasma glucose (FPG) and plasma glucose 2 hours after the performance of the oral glucose tolerance test (2-h G). Homeostatic model assessment for insulin resistance (HOMA-IR) index was calculated as fasting insulin concentration (microunits per millilitre) x fasting glucose concentration (millimolar)/22.5. The value of HOMA-IR above 3.16 was used as a cut-off value for both genders.

RESULTS:

Insulin resistance was determined in 58.33% of study participants. Insulin resistant participants had significantly higher level of 2-h G (p = 0.02), FI level (p = 0.000) as well as TG levels (p = 0.01), compared to non-insulin resistant group. Strikingly, 70.73% of the pubertal adolescents were insulin resistant in comparison to 49.09% of the preadolescents (p = 0.03). Significantly higher percentage of insulin-resistant participants were girls (p = 0.009). Moreover, a higher percentage of the girls (70.59%) than boys (44.44%) had HOMA-IR above 3.16 and had elevated FI levels (70.59% vs 48.89%). The difference in the frequency of insulin resistance among obese versus severely obese children and adolescents was not significant (p = 0.73, p > 0.05). Our study results also showed positive, but weak, correlation of HOMA-IR with age, FPG, TG and BMI of the participants (p < 0.05).

CONCLUSION:

Higher percentage of insulin-resistant participants was of female gender and was adolescents. In general, insulin resistant obese children and adolescents tend to have a worse metabolic profile in comparison to individuals without insulin resistance. It is of note that the highest insulin resistance was also linked with the highest concentrations of triglycerides.

Cardiovascular Risk Factors After Adolescent Bariatric Surgery

BACKGROUND AND OBJECTIVES

Severely obese adolescents harbor numerous cardiovascular disease risk factors (CVD-RFs), which improve after metabolic and bariatric surgery (MBS). However, predictors of change in CVD-RFs among adolescents have not yet been reported.

METHODS

The Teen-Longitudinal Assessment of Bariatric Surgery study (NCT00474318) prospectively collected anthropometric and health status data on 242 adolescents undergoing MBS at 5 centers. Predictors of change in CVD-RFs (blood pressure, lipids, glucose homeostasis, and inflammation) 3 years after Roux-en-Y gastric bypass and vertical sleeve gastrectomy were examined.

RESULTS

The mean (±SD) age of participants at baseline was 17 ± 1.6 years; 76% were girls, and 72% were white, with a median BMI of 51. Participants underwent Roux-en-Y gastric bypass (n = 161), vertical sleeve gastrectomy (n = 67), or adjustable gastric banding (n = 14). Increasing weight loss was an independent predictor of normalization in dyslipidemia, elevated blood pressure (EBP), hyperinsulinemia, diabetes, and elevated high-sensitivity C-reactive protein. Older participants at time of surgery were less likely to resolve dyslipidemia compared with younger participants, whereas girls were more likely than boys to demonstrate improvements in EBP. Even those participants without frank dyslipidemia or EBP at baseline showed significant improvements in lipid and blood pressure values over time.

CONCLUSIONS

Numerous CVD-RFs improve among adolescents undergoing MBS. Increased weight loss, female sex, and younger age predict a higher probability of resolution of specific CVD-RFs. The elucidation of predictors of change in CVD-RFs may lead to refinements in patient selection and optimal timing of adolescent bariatric surgery designed to improve clinical outcomes.

Metabolic clustering of risk factors: evaluation of Triglyceride-glucose index (TyG index) for evaluation of insulin resistance

BACKGROUND

Metabolic syndrome over the years have structured definitions to classify an individual with the disease. Literature review suggests insulin résistance is hallmark of these metabolic clustering. While measuring insulin resistance directly or indirectly remains technically difficult in general practice, along with multiple stability issues for insulin, various indirect measures have been suggested by authorities. Fasting triglycerides-glucose (TyG) index is one such marker, which is recently been suggested as a useful diagnostic marker to predict metabolic syndrome. However, limited data is available on the subject with almost no literature from our region on the subject.

OBJECTIVE

1. To correlate TyG index with insulin resistance, anthropometric indices, small dense LDLc, HbA1c and nephropathy. 2. To evaluate TyG index as a marker to diagnose metabolic syndrome in comparison to other available markers.

DESIGN-CROSS-SECTIONAL ANALYSIS

Place and duration of study-From Jun-2016 to July-2017 at PSS HAFEEZ hospital Islamabad.

SUBJECTS AND METHODS

From a finally selected sample size of 227 male and female subjects we evaluated their anthropometric data, HbA1c, lipid profile including calculated sdLDLc, urine albumin creatinine raito(UACR) and insulin resistance (HOMAIR). TyG index was calculated using formula of Simental-Mendía LE et al. Aforementioned parameters were correlated with TyG index, differences between subjects with and without metabolic syndrome were calculated using Independent sample t-test. Finally ROC curve analysis was carried out to measure AUC for candidate parameters including TyG Index for comparison.

RESULTS

TyG index in comparison to other markers like fasting triglycerides, HOMAIR, HDLc and non-HDLc demonstrated higher positive linear correlation with BMI, atherogenic dyslipidemia (sdLDLc), nephropathy (UACR), HbA1c and insulin resistance. TyG index showed significant differences between various markers among subjects with and without metabolic syndrome as per IDF criteria. AUC (Area Under Curve) demonstrated highest AUC for TyG as [(0.764, 95% CI 0.700-0.828, p-value ≤ 0.001)] followed by fasting triglycerides [(0.724, 95% CI 0.656-0.791, p-value ≤ 0.001)], sdLDLc [(0.695, 95% CI 0.626-0.763, p-value ≤ 0.001)], fasting plasma glucose [(0.686, 95% CI 0.616-0.756, p-value ≤ 0.001)], Non-HDLc [(0.640, 95% CI 0.626-0.763, p-value ≤ 0.001)] and HOMAIR [(0.619, 95% CI 0.545-0.694, p-value ≤ 0.001)].

CONCLUSION

TyG index, having the highest AUC in comparison to fasting glucose, triglycerides, sdLDLc, non-HDLc and HOMAIR can act as better marker for diagnosing metabolic syndrome.

Serum alanine aminotransferase/aspartate aminotransferase ratio is one of the best markers of insulin resistance in the Chinese population

Background

The alanine aminotransferase (ALT)/aspartate aminotransferase (AST) ratio is reportedly associated with insulin resistance (IR). However, few studies have explored the relationship between the ALT/AST ratio and IR in the Chinese population. Here, we aimed to explore whether the ALT/AST ratio is associated and, if so, to what extent, with IR in the Chinese population as categorized by waist circumference (WC).

Methods

Our data were obtained from the SPECT-China study, a cross-sectional survey on the prevalence of metabolic diseases and risk factors in East China from 2014 to 2015. A total of 8398 participants aged 52.16 ± 13.16 (mean ± standard deviation) years were included in this study. Anthropometric indices, biochemical parameters and clinical characteristics were measured. IR was defined as the top quartile of the homeostasis model assessment of insulin resistance (HOMA-IR > 1.6), and central obesity was defined as a WC ≥90 cm in males or ≥80 cm in females. Linear regression and receiver operating characteristic curve analyses were conducted.

Results

The ALT/AST ratio was significantly correlated and associated with HOMA-IR in both non-centrally obese (r = 0.284, B = 0.509, 95% confidence interval (CI): 0.459–0.559, P < 0.001) and centrally obese subjects (r = 0.372, B = 0.607, 95%CI: 0.532–0.683, P < 0.001) after adjusting for potential confounders. The ALT/AST ratio was one of the best markers of IR, with areas under the curve (AUC) values of 0.66 (0.64–0.68) in non-centrally and 0.68 (0.66–0.70) in centrally obese subjects. In the prediction model for IR, the AUCs were significantly augmented after adding the ALT/AST ratio in both non-centrally obese [AUC 95%CI 0.69(0.67–0.71) vs 0.72(0.70–0.74), P<0.001] and central obese [AUC 95%CI 0.69(0.67–0.71) vs 0.73(0.72–0.75), P<0.001] subjects. The optimal cut-off points of the ALT/AST ratio for identifying IR were 0.80 in non-centrally obese people and 0.78 in centrally obese people, respectively.

Conclusion

The ALT/AST ratio may be one of the best markers for IR in the Chinese population. Whether the ALT/AST ratio should be regarded as an additional metabolic syndrome component in the Chinese population warrants further investigation.

Electronic supplementary material

The online version of this article (10.1186/s12986-017-0219-x) contains supplementary material, which is available to authorized users.

The associations between VDR BsmI polymorphisms and risk of vitamin D deficiency, obesity and insulin resistance in adolescents residing in a tropical country

Background

The vitamin D receptor (VDR) gene is expressed abundantly in different tissues; including adipocytes and pancreatic beta cells. The rs1544410 or BsmI single nucleotide polymorphism (SNP) in the intronic region of the VDR gene has been previously associated with vitamin D levels, obesity and insulin resistance.

Aims

This study was aimed to examine the association between BsmI polymorphism and risk of vitamin D deficiency, obesity and insulin resistance in adolescents living in a tropical country.

Methods

Thirteen-year-old adolescents were recruited via multistage sampling from twenty-three randomly selected schools across the city of Kuala Lumpur, Malaysia (n = 941). Anthropometric measurements were obtained. Obesity was defined as body mass index higher than the 95^th percentile of the WHO chart. Levels of fasting serum vitamin D (25-hydroxyvitamin D (25(OH)D)), glucose and insulin were measured. HOMA-IR was calculated as an indicator for insulin resistance. Genotyping was performed using the Sequenom MassARRAY platform (n = 807). The associations between BsmI and vitamin D, anthropometric parameters and HOMA-IR were examined using analysis of covariance and logistic regression.

Result

Those with AA genotype of BsmI had significantly lower levels of 25(OH)D (p = 0.001) compared to other genotypes. No significant differences was found across genotypes for obesity parameters. The AA genotype was associated with higher risk of vitamin D deficiency (p = 0.03) and insulin resistance (p = 0.03) compared to GG. The A allele was significantly associated with increased risk of vitamin D deficiency compared to G allele (adjusted odds ratio (OR) = 1.63 (95% Confidence Interval (CI) 1.03–2.59, p = 0.04). In those with concurrent vitamin D deficiency, having an A allele significantly increased their risk of having insulin resistance compared to G allele (adjusted OR = 2.66 (95% CI 1.36–5.19, p = 0.004).

Conclusion

VDR BsmI polymorphism was significantly associated with vitamin D deficiency and insulin resistance, but not with obesity in this population.

Risperidone and Cardiometabolic Risk in Children and Adolescents: Clinical and Instrumental Issues

PURPOSE/BACKGROUND

Although second-generation antipsychotics are used to treat and manage symptoms for several psychiatric disorders, data about their adverse effects in developmental age are limited. The aim of this prospective observational study was to verify the cardiovascular and metabolic risk in a sample of antipsychotic-naive children/adolescent patients starting risperidone therapy.

METHODS

Twenty-two patients, younger than 18 years, were recruited. The assessment included anthropometric data, cardiovascular parameters, blood tests, and ultrasonographic abdominal study.

RESULTS

After an average follow-up period of 7.6 months, statistically significant increases in mean values of waist circumference, body mass index (BMI), BMI percentile, BMI z score, total cholesterol, and prolactin were found. Other cardiometabolic parameters showed an upward trend in time. Subjects in pubertal/postpubertal stage and female patients were more susceptible to developing cardiometabolic changes. Moreover, significant correlations between changes in anthropometric and several metabolic parameters were found. A tendency to change in constitution of the liver parenchyma and distribution of the abdominal fat mass with ultrasonographic abdominal study was also evident.

CONCLUSIONS

In our sample, several metabolic parameters showed a sensitivity to risperidone treatment. Because most of these parameters are age dependent, metabolic syndrome criteria used for adults were inappropriate in children and adolescents. Periodic clinical and instrumental evaluations and guidelines for monitoring of any metabolic, laboratory, and instrumental complications are necessary in the perspective of even long-time second-generation antipsychotics treatment in children and adolescents.

Determinants of High Fasting Insulin and Insulin Resistance Among Overweight/Obese Adolescents

Hyperinsulinaemia is the earliest subclinical metabolic abnormality, which precedes insulin resistance in obese children. An investigation was conducted on the potential predictors of fasting insulin and insulin resistance among overweight/obese adolescents in a developing Asian country. A total of 173 overweight/obese (BMI > 85^th percentile) multi-ethnic Malaysian adolescents aged 13 were recruited from 23 randomly selected schools in this cross-sectional study. Waist circumference (WC), body fat percentage (BF%), physical fitness score (PFS), fasting glucose and fasting insulin were measured. Insulin resistance was calculated using homeostasis model assessment of insulin resistance (HOMA-IR). Adjusted stepwise multiple regression analysis was performed to predict fasting insulin and HOMA-IR. Covariates included pubertal stage, socioeconomic status, nutritional and physical activity scores. One-third of our adolescents were insulin resistant, with girls having significantly higher fasting insulin and HOMA-IR than boys. Gender, pubertal stage, BMI, WC and BF% had significant, positive moderate correlations with fasting insulin and HOMA-IR while PFS was inversely correlated (p < 0.05). Fasting insulin was primarily predicted by gender-girls (Beta = 0.305, p < 0.0001), higher BMI (Beta = −0.254, p = 0.02) and greater WC (Beta = 0.242, p = 0.03). This study demonstrated that gender, BMI and WC are simple predictors of fasting insulin and insulin resistance in overweight/obese adolescents.

Association between anti-Mullerian hormone and insulin resistance in non-obese adolescent females with polycystic ovary syndrome

OBJECTIVE

The present study was designed to evaluate the association between anti-Mullerian hormone (AMH) and insulin resistance (IR) in non-obese adolescent females with polycystic ovary syndrome (PCOS) with and without IR.

METHODS

Seventy-seven consecutive non-obese patients were recruited and distributed into three groups according to diagnoses of PCOS and IR. Group I included 27 females diagnosed with PCOS and IR, group II included 18 females diagnosed with PCOS but without IR, and group III included 32 controls without PCOS.

RESULTS

Group I had significantly higher AMH levels compared to group II and group III (p < 0.012 and p < 0.000, respectively). ROC curve analyses demonstrated that the AUC, indicative of the AMH value for discriminating PCOS with IR, was 0.763, with a confidence interval of 0.607-0.920 (p = 0.004). There was a significant positive correlation between serum AMH and HOMA-IR levels in adolescent females with PCOS (p = 0.003).

CONCLUSION

We found that serum AMH levels were higher in non-obese adolescent females with PCOS and IR than in PCOS patients without IR and the healthy controls. There was a significant positive correlation between AMH levels and IR in non-obese adolescent females with PCOS.

Depressive Symptoms Clusters and Insulin Resistance: Race/Ethnicity as a Moderator in 2005-2010 NHANES Data

BACKGROUND

Although depression has been linked to insulin resistance, few studies have examined depressive symptom clusters.

PURPOSE

We examined whether certain depressive symptom clusters are more strongly associated with insulin resistance in a nationally representative sample, and we evaluated potential moderators and mediators.

METHODS

Respondents were 4487 adults from NHANES 2005-2010. Depressive symptoms were measured with the Patient Health Questionnaire-9 (PHQ-9), and insulin resistance was indexed by the homeostatic model assessment (HOMA) score.

RESULTS

Positive relationships between PHQ-9 total, somatic, and cognitive-affective scores and HOMA score were detected (ps <0.001). In a simultaneous model, the somatic (p = 0.017), but not the cognitive-affective (p = 0.071), score remained associated with HOMA score. We observed evidence of (a) moderation by race/ethnicity (relationships stronger in non-Hispanic Whites) and (b) mediation by body mass and inflammation.

CONCLUSIONS

The depressive symptoms-insulin resistance link may be strongest among non-Hispanic Whites and may be driven slightly more by the somatic symptoms.

Disproportionately Elevated Proinsulin Levels as an Early Indicator of β-Cell Dysfunction in Nondiabetic Offspring of Chinese Diabetic Patients

Objective. To study the characteristics of β-cell dysfunction and insulin resistance (IR) in the first-degree relatives (FDRs) of T2DM in Chinese population and to examine the usefulness of proinsulin (PI) for evaluating β-cell dysfunction. Methods. 229 subjects of nondiabetic FDRs, 71 newly diagnosed T2DM, and 114 with normal glucose tolerance (NGT) but not FDRs (NGT-non-FDRs) were verified by a 2-hour oral glucose tolerance test. Specific insulin (SI) and PI were measured by highly sensitive ELISA. Results. Compared to NGT-non-FDRs, NGT-FDRs showed higher levels of fasting and 2-hour PI, fasting PI-to-SI ratio (FPI/SI), and HOMA-IR (p < 0.01). Meanwhile, fasting PI, FPI/SI, and HOMA-IR were increased steadily from NGT-FDRs to prediabetes-FDRs and were highest in T2DM group (p < 0.001), whereas a significant decrease in HOMA-B could be observed only in T2DM group. Moreover, a progressive deterioration of β-cell function in NGT-FDRs, prediabetes-FDRs, and T2DM could be identified by FPI/SI even after adjusting for HOMA-IR: relative to non-FDRs controls, mean FPI/SI levels were increased 1.5, 2.0, and 4.7-fold, respectively (all p < 0.01). Conclusions.  β-cell dysfunction as assessed by disproportionate secretion of proinsulin and IR by HOMA (using specific insulin assay) already exist in FDRs of T2DM even with normal glucose status. Compared with HOMA-B, FPI/SI could detect β-cell failure in earlier stage of diabetes development.

Identification of cutoff points for Homeostatic Model Assessment for Insulin Resistance index in adolescents: systematic review

Objective:

To identify cutoff points of the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index established for adolescents and discuss their applicability for the diagnosis of insulin resistance in Brazilian adolescents.

Data source:

A systematic review was performed in the PubMed, Lilacs and SciELO databases, using the following descriptors: "adolescents", "insulin resistance" and "Receiver Operating Characteristics Curve". Original articles carried out with adolescents published between 2005 and 2015 in Portuguese, English or Spanish languages, which included the statistical analysis using Receiver Operating Characteristics Curve to determine the index cutoff (HOMA-IR) were included.

Data synthesis:

A total of 184 articles were identified and after the study phases were applied, seven articles were selected for the review. All selected studies established their cutoffs using a Receiver Operating Characteristics Curve, with the lowest observed cutoff of 1.65 for girls and 1.95 for boys and the highest of 3.82 for girls and 5.22 for boys. Of the studies analyzed, one proposed external validity, recommending the use of the HOMA-IR cutoff>2.5 for both genders.

Conclusions:

The HOMA-IR index constitutes a reliable method for the detection of insulin resistance in adolescents, as long as it uses cutoffs that are more adequate for the reality of the study population, allowing early diagnosis of insulin resistance and enabling multidisciplinary interventions aiming at health promotion of this population.

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.

Effects of n-3 polyunsaturated fatty acids high fat diet intervention on the synthesis of hepatic high-density lipoprotein cholesterol in obesity-insulin resistance rats

Background

n-3 polyunsaturated fatty acids (PUFA) have previously been demonstrated in association with a reduced risk of chronic diseases, including insulin resistance, cancer and cardiovascular disease. In the present study, we analyzed the effects of n-3 PUFA-rich perilla oil (PO) and fish oil (FO) high fat diet intervention against the synthesis of hepatic high-density lipoprotein cholesterol (HDL-c) in obesity-insulin resistance model rats.

Methods

In the modeling period, the male SD rats were randomly divided into 2 groups. The rats in the high fat (HF) group were given a high fat pure diet containing 20.62 % lard. In the intervention period, the model rats were intervened with purified high-fat diets rich in PO or FO, containing same energy content with high fat pure diet in HF. After the intervention, the protein and mRNA expressions status of the key genes involved in synthesis of hepatic HDL-c were measured for further analytic comparison.

Results

The obesity-insulin resistance model rats were characterized by surprisingly high levels of serum triglyceride (TG) and increased body weight (P < 0.05, each). After the intervention, there were no apparent changes in the serum HDL-c and total cholesterol (TCH). In addition, the FO could up-regulate the hepatic adenosine triphosphate (ATP) binding cassette transporter A1 (ABCA1) mRNA (P < 0.01) and protein expressions, as well as increase the level of serum apolipoprotein A-1 (apoA-1) (P < 0.0001), and elevate the hepatic apoA-1mRNA expression (P < 0.01). Different from FO, the PO specifically elevated the hepatic ABCA1mRNA expression (P < 0.01).

Conclusions

The FO high fat diets promoted the synthesis of HDL-c in the obesity-insulin resistance rats.

Reference ranges of HOMA-IR in normal-weight and obese young Caucasians

AIMS

Insulin resistance (IR) may develop very early in life being associated with occurrence of cardiometabolic risk factors (CMRFs). Aim of the present study was to identify in young Caucasians normative values of IR as estimated by the homeostasis model assessment (HOMA-IR) and cutoffs diagnostic of CMRFs.

METHODS

Anthropometrics and biochemical parameters were assessed in 2753 Caucasians (age 2-17.8 years; 1204 F). Reference ranges of HOMA-IR were defined for the whole population and for samples of normal-weight and overweight/obese individuals. The receiver operator characteristic analysis was used to find cutoffs of HOMA-IR accurately identifying individuals with any CMRF among total cholesterol and/or triglycerides higher than the 95th percentile and/or HDL cholesterol lower than the 5th for age and sex, impaired glucose tolerance, and alanine aminotransferase levels ≥40 U/l.

RESULTS

Overweight/obese individuals had higher HOMA-IR levels compared with normal-weight peers (p < 0.0001) at any age. HOMA-IR index rose progressively with age, plateaued between age 13 and 15 years and started decreasing afterward. HOMA-IR peaked at age 13 years in girls and at 15 years in boys. The 75th percentile of HOMA-IR in the whole population (3.02; AUROC = 0.73, 95 % CI = 0.70-0.75), in normal-weight (1.68; AUROC = 0.76, 95 % CI = 0.74-0.79), and obese (3.42; AUROC = 0.71, 95 % CI = 0.69-0.72) individuals identified the cutoffs best classifying individuals with any CMRF.

CONCLUSIONS

Percentiles of HOMA-IR varied significantly in young Caucasians depending on sex, age, and BMI category. The 75th percentile may represent an accurate cutoff point to suspect the occurrence of one or more CMRFs among high total cholesterol and triglycerides, low HDL cholesterol, and ALT ≥ 40 UI/l.

Cardiometabolic risk markers of normal weight and excess body weight in Brazilian adolescents

Excess body weight leads to a variety of metabolic changes and increases the risk for cardiovascular diseases (CVD) in adulthood. The objective of this study was to investigate the presence of risk markers for CVD among Brazilian adolescents of normal weight and with excess body weight. The markers included blood pressure, C-reactive protein, homocysteine, tumor necrosis factor alpha, fibrinogen, fasting insulin and glucose, homeostasis model assessment of insulin resistance (HOMA-IR), leptin, total cholesterol, low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), and triglycerides. We calculated odds ratios (OR) using logistic regression and adjusted for potential confounders such as age, sex, physical activity, and socioeconomic background. Compared with normal weight subjects, overweight/obese adolescents were more likely to have higher systolic blood pressure (OR = 3.49, p < 0.001), fasting insulin (OR = 8.03, p < 0.001), HOMA-IR (OR = 8.03, p < 0.001), leptin (OR = 5.55, p < 0.001), and LDL-c (OR = 5.50, p < 0.001) and lower serum HDL-c concentrations (OR = 2.76, p = 0.004). After adjustment for confounders, the estimates did not change substantially, except for leptin for which the risk associated with overweight increased to 11.09 (95% CI: 4.05-30.35). In conclusion, excess body weight in adolescents exhibits strong associations with several markers that are established as causes of CVD in adults. This observation stresses the importance of primary prevention and of maintaining a healthy body weight throughout adolescence to reduce the global burden of CVD.

Profile of Free Fatty Acids and Fractions of Phospholipids, Cholesterol Esters and Triglycerides in Serum of Obese Youth with and without Metabolic Syndrome

The study evaluated the profile of circulating fatty acids (FA) in obese youth with and without metabolic syndrome (MetS) to determine its association with nutritional status, lifestyle and metabolic variables. A cross-sectional study was conducted in 96 young people, divided into three groups: obese with MetS (OBMS), obese (OB) and appropriate weight (AW). FA profiles were quantified by gas chromatography; waist circumference (WC), fat folds, lipid profile, high-sensitivity C-reactive protein, glucose, insulin, the homeostasis model assessment (HOMA index), food intake and physical activity (PA) were assessed. The OBMS group had significantly greater total free fatty acids (FFAs), palmitic-16:0 in triglyceride (TG), palmitoleic-16:1n-7 in TG and phospholipid (PL); in the OB group, these FAs were higher than in the AW group. Dihomo-gamma-linolenic (DHGL-20:3n-6) was higher in the OBMS than the AW in PL and FFAs. Linoleic-18:2n-6 in TG and PL had the lowest proportion in the OBMS group. WC, PA, total FFA, linoleic-18:2n-6 in TG and DHGL-20:3n-6 in FFAs explained 62% of the HOMA value. The OB group presented some higher proportions of FA and biochemical values than the AW group. The OBMS had proportions of some FA in the TG, PL and FFA fractions that correlated with disturbances of MetS.

Use of the triglyceride to HDL cholesterol ratio for assessing insulin sensitivity in overweight and obese children in rural Appalachia

BACKGROUND

Studies have suggested that triglyceride to HDL-cholesterol ratio (TRG/HDL) is a surrogate marker of insulin resistance (IR), but information regarding its use in pediatric patients is limited. This study investigated the ability of TRG/HDL ratio to assess IR in obese and overweight children.

METHODS

The sample consisted of de-identified electronic medical records of patients aged 10-17 years (n=223). Logistic regression was performed using TRG/HDL ratio as a predictor of hyperinsulinemia or IR defined using homeostasis model assessment score.

RESULTS

TRG/HDL ratio had limited ability to predict hyperinsulinemia (AUROC 0.71) or IR (AUROC 0.72). Although females had higher insulin levels, male patients were significantly more likely to have hypertriglyceridemia and impaired fasting glucose.

CONCLUSIONS

TRG/HDL ratio was not adequate for predicting IR in this population. Gender differences in the development of obesity-related metabolic abnormalities may impact the choice of screening studies in pediatric patients.

Biomarkers of Metabolic Syndrome: Biochemical Background and Clinical Significance

Biomarkers of the metabolic syndrome are divided into four subgroups. Although dividing them in groups has some limitations, it can be used to draw some conclusions. In a first part, the dyslipidemias and markers of oxidative stress are discussed, while inflammatory markers and cardiometabolic biomarkers are reviewed in a second part. For most of them, the biochemical background and clinical significance are discussed, although here also a well-cut separation cannot always be made. Altered levels cannot always be claimed as the cause, risk, or consequence of the syndrome. Several factors are interrelated to each other and act in a concerted, antagonistic, synergistic, or modulating way. Most important conclusions are summarized at the end of every reviewed subgroup. Genetic biomarkers or influences of various food components on concentration levels are not included in this review article.

Metabolic Syndrome in Children and Adolescents: a Critical Approach Considering the Interaction between Pubertal Stage and Insulin Resistance

Pediatricians increasingly diagnose the metabolic syndrome (MetS) in recent years to describe cardiovascular risk and to guide management of the obese child. However, there is an ongoing discussion about how to define the MetS in childhood and adolescence. Since insulin resistance-the major driver of MetS-is influenced by pubertal stage, it is questionable to use definitions for MetS in children and adolescents that do not take into account pubertal status. A metabolic healthy status in prepubertal stage does not predict a metabolic healthy status during puberty. Furthermore, cardiovascular risk factors improve at the end of puberty without treatment. However, having a uniform internationally accepted definition of the MetS for children and adolescents would be very helpful for the description of populations in different studies. Therefore, the concept of MetS has to be revisited under the influence of puberty stage.

The Prevalence of Metabolic Syndrome and Cardiovascular Risk Factors in Obese Children and Adolescents in Dalmatia: A Hospital Based Study

Obesity and metabolic syndrome (MS) are one of the biggest public health issues in child and adolescent population. To the best of the authors' knowledge, this hospital based study is the first report on the prevalence of MS in obese children and adolescents in Dalmatia, the Mediterranean part of Croatia. The objectives of this study were to determine the prevalence of individual cardiovascular risk factors and MS. Between January 2009 and June 2014, 201 obese subjects aged 6 to 18 were analyzed retrospectively from our Pediatric Endocrine Unit database. The subjects were then classified in two groups of obesity; subjects with BMI z score 2.0-3.0 were classified as moderately obese and subjects with BMI z score > 3.0 were classified as severely obese. The overall prevalence of MS using the modified IDF criteria was 30.3%. The most common component of MS in both groups was arterial hypertension, while impaired fasting glucose was the least common component of MS. Our finding of high prevalence of MS underlines the importance of early childhood obesity treatment.

[Identification of cutoff points for Homeostatic Model Assessment for Insulin Resistance index in adolescents: systematic review]

OBJECTIVE

To identify cutoff points of the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index established for adolescents and discuss their applicability for the diagnosis of insulin resistance in Brazilian adolescents.

DATA SOURCE

A systematic review was performed in the PubMed, Lilacs and SciELO databases, using the following descriptors: "Adolescents", "insulin resistance" and "ROC curve". Original articles carried out with adolescents published between 2005 and 2015 in Portuguese, English or Spanish languages, which included the statistical analysis using ROC curve to determine the index cutoff (HOMA-IR) were included.

DATA SYNTHESIS

A total of 184 articles were identified and after the study phases were applied, seven articles were selected for the review. All selected studies established their cutoffs using a ROC curve, with the lowest observed cutoff of 1.65 for girls and 1.95 for boys and the highest of 3.82 for girls and 5.22 for boys. Of the studies analyzed, one proposed external validity, recommending the use of the HOMA-IR cutoff >2.5 for both genders.

CONCLUSIONS

The HOMA-IR index constitutes a reliable method for the detection of insulin resistance in adolescents, as long as it uses cutoffs that are more adequate for the reality of the study population, allowing early diagnosis of insulin resistance and enabling multidisciplinary interventions aiming at health promotion of this population.

Cardiovascular Risk Factors in Severely Obese Adolescents: The Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS) Study

IMPORTANCE

Severe obesity is increasingly common in the adolescent population but, as of yet, very little information exists regarding cardiovascular disease (CVD) risks in this group.

OBJECTIVE

To assess the baseline prevalence and predictors of CVD risks among severely obese adolescents undergoing weight-loss surgery.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study was conducted from February 28, 2007, to December 30, 2011, at the following 5 adolescent weight-loss surgery centers in the United States: Nationwide Children's Hospital in Columbus, Ohio; Cincinnati Children's Hospital Medical Center in Cincinnati, Ohio; Texas Children's Hospital in Houston; University of Pittsburgh Medical Center in Pittsburgh, Pennsylvania; and Children's Hospital of Alabama in Birmingham. Consecutive patients aged 19 years or younger were offered enrollment in a long-term outcome study; the final analysis cohort consisted of 242 participants.

MAIN OUTCOMES AND MEASURES

This report examined the preoperative prevalence of CVD risk factors (ie, fasting hyperinsulinemia, elevated high-sensitivity C-reactive protein levels, impaired fasting glucose levels, dyslipidemia, elevated blood pressure, and diabetes mellitus) and associations between risk factors and body mass index (calculated as weight in kilograms divided by height in meters squared), age, sex, and race/ethnicity. Preoperative data were collected within 30 days preceding bariatric surgery.

RESULTS

The mean (SD) age was 17 (1.6) years and median body mass index was 50.5. Cardiovascular disease risk factor prevalence was fasting hyperinsulinemia (74%), elevated high-sensitivity C-reactive protein levels (75%), dyslipidemia (50%), elevated blood pressure (49%), impaired fasting glucose levels (26%), and diabetes mellitus (14%). The risk of impaired fasting glucose levels, elevated blood pressure, and elevated high-sensitivity C-reactive protein levels increased by 15%, 10%, and 6%, respectively, per 5-unit increase in body mass index (P < .01). Dyslipidemia (adjusted relative risk = 1.60 [95% CI, 1.26-2.03]; P < .01) and elevated blood pressure (adjusted relative risk = 1.48 [95% CI, 1.16-1.89]; P < .01) were more likely in adolescent boys compared with adolescent girls. White individuals were at greater risk of having elevated triglyceride levels (adjusted relative risk = 1.76 [95% CI, 1.14-2.72]; P = .01) but were less likely to have impaired fasting glucose levels (adjusted relative risk = 0.58 [95% CI, 0.38-0.89]; P = .01).

CONCLUSIONS AND RELEVANCE

Numerous CVD risk factors are apparent in adolescents undergoing weight-loss surgery. Increasing body mass index and male sex increase the relative risk of specific CVD risk factors. These data suggest that even among severely obese adolescents, recognition and treatment of CVD risk factors is important to help limit further progression of disease.

Hypertension outcomes in metabolically unhealthy normal-weight and metabolically healthy obese children and adolescents

Metabolically healthy obesity (MHO) begins in childhood and continues into adulthood. However, the association between MHO and the risk of developing hypertension remains controversial. A prospective cohort study was conducted to investigate the risk of hypertension in MHO and metabolically unhealthy normal-weight (MUNW) Chinese children and adolescents. A total of 1183 participants, 6-18 years old at baseline with normal blood pressure values, were studied using follow-up data from the cohort of the Beijing Child and Adolescent Metabolic Syndrome (BCAMS) study. The participants were classified according to the body mass index and the presence/absence of metabolic abnormality, which was defined by metabolic syndrome (MetS) or insulin resistance (IR). During the 6-year follow-up period, 239 (20.2%) participants developed incident hypertension. After adjusting for age, sex, physical activity, pubertal stage, dietary habits and family history of hypertension, an increased risk for hypertension was observed in the MHO individuals (risk ratio, RRMetS 5.42; 95% confidence interval (CI) 3.19-9.22 and RRIR 7.59; 95% CI 1.64-35.20) compared with their metabolically healthy normal-weight counterparts. Independent of the definition of metabolic abnormality, the MUNW subjects did not have an elevated incidence of hypertension. These results suggest that the risk of developing hypertension is increased in the MHO but not in the MUNW individuals.

Anthropometric parameters and their associations with cardio-metabolic risk in Chinese working population

BACKGROUND

There remains controversy regarding which of the anthropometric indicators best defines obesity. In this study, we compared the efficacy of using body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) in the diagnosis of obesity and assessed their associations with diabetes, hypertension, and dyslipidemia in an urban working population in China.

METHODS

Anthropometric measurements, blood pressure, plasma lipids, fasting and 2-hour plasma glucose (PG) levels by a 75 gram oral glucose tolerance test (OGTT) were obtained from 2603 working Chinese who had no history of cardiovascular diseases or diabetes. Cardio-metabolic risk factors including high blood pressure, dyslipidemia, and glucose intolerance were evaluated. The diagnoses of overweight and obesity were based on the WHO definitions with BMI for general obesity and WC and WHR for central obesity.

RESULTS

Based on BMI, WC and WHR, there were 31.3%, 16.6%, 35.2% of the studied subjects, respectively, being overweight and 2.0%, 5.6%, 9.2% being obese. Among women but not men, more overweight and obese subjects were diagnosed using WHR and WC. The number of cardio-metabolic risks was higher by WC criterion than BMI and WHR in the whole group (p <0.05) and female subjects (p <0.01). Comparing the three anthropometric indexes predicting hypertension, hyperglycemia, dyslipidemia and multiple cardio-metabolic risks, for women, it was WC having the largest areas under ROC curves (0.759, 0.746, 0.701 and 0.773 respectively); while in men, it was WC for hypertension, WHR for hyperglycemia, BMI for dyslipidemia and WC for multiple cardio-metabolic risks (areas under ROC curves were 0.658, 0.686, 0.618 and 0.695 respectively).

CONCLUSIONS

Among Chinese working population, the need of lower cutoff values to define overweight and obesity were observed. Central obesity indicator (WC) is the preferred measure to predict the presence of cardio-metabolic risk in Chinese female subjects.

Healthy Chilean Adolescents with HOMA-IR ≥ 2.6 Have Increased Cardiometabolic Risk: Association with Genetic, Biological, and Environmental Factors

OBJECTIVE

To determine the optimal cutoff of the homeostasis model assessment-insulin resistance (HOMA-IR) for diagnosis of the metabolic syndrome (MetS) in adolescents and examine whether insulin resistance (IR), determined by this method, was related to genetic, biological, and environmental factors.

METHODS

In 667 adolescents (16.8 ± 0.3 y), BMI, waist circumference, glucose, insulin, adiponectin, diet, and physical activity were measured. Fat and fat-free mass were assessed by dual-energy X-ray absorptiometry. Family history of type 2 diabetes (FHDM) was reported. We determined the optimal cutoff of HOMA-IR to diagnose MetS (IDF criteria) using ROC analysis. IR was defined as HOMA-IR values above the cutoff. We tested the influence of genetic, biological, and environmental factors on IR using logistic regression analyses.

RESULTS

Of the participants, 16% were obese and 9.4 % met criteria for MetS. The optimal cutoff for MetS diagnosis was a HOMA-IR value of 2.6. Based on this value, 16.3% of participants had IR. Adolescents with IR had a significantly higher prevalence of obesity, abdominal obesity, fasting hyperglycemia, and MetS compared to those who were not IR. FHDM, sarcopenia, obesity, and low adiponectin significantly increased the risk of IR.

CONCLUSIONS

In adolescents, HOMA-IR ≥ 2.6 was associated with greater cardiometabolic risk.