Sex, puberty, and ethnicity have a strong influence on growth and metabolic comorbidities in children and adolescents with obesity: Report on 1300 patients (the Madrid Cohort)

Prepubertal Children With Obesity Have High Free IGF-1 Levels and Accelerated Growth Despite Reduced Pappalysin Levels

BACKGROUND

Prepubertal children with obesity frequently have enhanced growth, accelerated skeletal maturation, and changes in the growth hormone-insulin-like growth factor (GH-IGF) axis. However, the involvement of pappalysins (PAPP-A, PAPP-A2) and stanniocalcins (STC1, STC2) as regulators of IGF bioavailability has not been studied in obesity.

OBJECTIVE

We aimed to determine the effects of childhood obesity and weight reduction on serum levels of PAPP-A, PAPP-A2, STC1, and STC2 and their relationship with IGF bioavailability, growth, and other components of the GH-IGF system.

METHODS

Prepubertal children with severe obesity (150, 50% males/females, age: 7.72 ± 2.05 years, BMI z-score: 4.95 ± 1.70, height z-score: 1.28 ± 1.04) were studied at diagnosis and after a minimum of 0.5 BMI z-score reduction. Two hundred and six healthy age- and sex-matched children were used as controls.

RESULTS

Children with obesity had decreased serum concentrations of PAPP-A, PAPP-A2 and STC2, but increased total and free IGF-I, intact IGFBP-3, acid-labile subunit (ALS), IGF-II, and insulin levels, with no difference in the free IGF-I/total IGF-I ratio. Neither the standardized body mass index (BMI) nor height correlated with any biochemical parameter analyzed. A decrease in IGF-II, insulin, and ALS with an increase in IGFBP-2 and -5, STC2, and PAPP-A were observed after weight loss.

CONCLUSION

Increased circulating total and free IGF-I, insulin, and IGF-II may all contribute to the increased rate of prepubertal growth and bone maturation observed in children with obesity, with STC2 possibly being involved.

Reversibility of Hyperglycemic States in Children with Obesity - Diagnostic Pitfalls in the Assessment of Glucose Metabolism in Children and Adolescents with Obesity

Objective

Disorders of glucose metabolism in children with obesity are less common than in adults. There is also evidence that they may be transient. The aims of this study were to determine the prevalences of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and type 2 diabetes mellitus (DM2) and its reversibility in pediatric patients with obesity and to define the factors determining the reversibility of prediabetes or progression to diabetes.

Methods

Retrospective analysis included of young patients with obesity. Patients presented and were treated between 2000-2022 at a single center.

Results

The study included 573 (316 girls; 55.15%) Caucasian patients with median body mass index (BMI) Z-score of 3.95 (range 2.0-9.9) and median age 13.9 (2.9-17.1) years old. OGTT results were normal in 90.8% (n=520) and signs of prediabetes occurred in 9.2% (n=53); IFG 17%, IGT 88.7%, DM 0%. Among those who underwent OGTT twice (n=53), impaired glucose regulation was present in 9.3% (n=5) (IFG 40%, IGT 80%, DM 0%) at baseline and in 14.8% subject (n=8) (IFG 25%, IGT 50%, DM 25%) at follow-up after lifestyle modification only. After 12-36 months of follow up, in those with a history of IGT, 60% reverted to normal glucose tolerance, while IFG and IGT persisted in 20% and 20%, respectively, and none progressed to DM. The risk factors for progression of glucose metabolism disorders were increase of BMI Z-score, higher insulin levels and elevated homeostatic model assessment-insulin resistance.

Conclusion

IFG and IGT are common in pediatric patients with obesity, while the progression to DM2 is rare. Disorders of glucose metabolism have reversible character.

Identifying metabotypes of insulin resistance severity in children with metabolic syndrome

BACKGROUND

Insulin resistance is a frequent precursor of typical obesity and metabolic syndrome complications. However, accurate diagnosis remains elusive because of its pathophysiological complexity and heterogeneity. Herein, we have explored the utility of insulin secretion dynamics in response to an oral glucose tolerance test as a surrogate marker to identify distinct metabotypes of disease severity.

METHODS

The study population consisted of children with obesity and insulin resistance, stratified according to the post-challenge insulin peak timing (i.e., early, middle, and late peak), from whom fasting and postprandial plasma and erythrocytes were collected for metabolomics analysis.

RESULTS

Children with late insulin peak manifested worse cardiometabolic health (i.e., higher blood pressure, glycemia, and HOMA-IR scores) than early responders. These subjects also showed more pronounced changes in metabolites mirroring failures in energy homeostasis, oxidative stress, metabolism of cholesterol and phospholipids, and adherence to unhealthy dietary habits. Furthermore, delayed insulin peak was associated with impaired metabolic flexibility, as reflected in compromised capacity to regulate mitochondrial energy pathways and the antioxidant defense in response to glucose overload.

CONCLUSIONS

Altogether, these findings suggest that insulin resistance could encompass several phenotypic subtypes characterized by graded disturbances in distinctive metabolic derangements occurring in childhood obesity, which serve as severity predictive markers.

Predictors of adherence to follow-up and treatment success in childhood obesity

INTRODUCTION

Management of childhood obesity, based upon behavioural, physical activity and dietary guidance, usually achieves limited success and is hindered by a high attrition rate. The identification of potential predictors of either weight loss or early weight management attrition could help develop personalised management plans in order to improve patient outcomes.

PATIENTS AND METHODS

We conducted a retrospective study in a cohort of 1300 patients with obesity managed in speciality clinics for up to 5 years with outpatient conservative treatment. We studied the family background and personal characteristics (demographic, behavioural, psychosocial, anthropometric and metabolic) of patients who dropped out before completing the first year of the programme and patients who achieved significant weight loss, with a separate analysis of patients who achieved substantial reductions in weight compared to the rest of the cohort.

RESULTS

The mean age of the patients in the cohort was 10.46 years (SD, 3.48) the mean BMI z-score 4.01 (SD, 1.49); 52.8% of the patients were male, 53.3% were prepubertal, 75.8% were Caucasian and 19% Latin. We found a higher proportion of Latinla ethnicity and compulsive eating in the group of patients with early attrition from the weight management follow-up. In the group of patients with substantial weight loss, a greater proportion were male, there was a higher frequency of dietary intake control at home and obesity was more severe, and the latter factor was consistently observed in patients who achieved substantial weight loss at any point of the follow-up.

CONCLUSIONS

Some family and personal characteristics in childhood obesity are associated with an increased risk of early withdrawal from follow-up or a greater probability of successful outcomes; however, the predictive value of these variables is limited.

Sex differences in cardiometabolic risk factors and in response to lifestyle intervention in prepubertal and pubertal subjects with obesity

Objectives

Childhood obesity is a growing health problem and requires a tailored treatment. This study explored the sex differences in cardiovascular risk factors in children/adolescents with obesity and in response to a weight loss intervention.

Methods

Five hundred and thirty-three children/adolescents with obesity and their parents underwent to a 3-months lifestyle intervention program. Tanner criteria were used to assess the pubertal stage. Before and after 3 months, anthropometric measurements, blood pressure (BP), and biochemical measurements were assessed.

Results

Four hundred and forty five participants completed the treatment (age 12.4 ± 2.7 years, males 45.8%, prepubertal 29.2%, BMI z score 2.3 ± 0.2). In comparison to boys, prepubertal girls had higher values of BMI z score (2.4 ± 02 vs. 2.3 ± 0.2, p < 0.05), waist circumference z score (2.2 ± 0.3 vs. 2.0 ± 0.3, p < 0.05), HOMA-IR [2.9 (2.1-4.9) vs. 2.3(1.5-3.6), p < 0.01], prevalence of hypertransaminasemia (41.3% vs. 17.7%, p < 0.05) and lower levels of HDL cholesterol (46.2 ± 9.8 vs. 51.2 ± 10.5 mg/dl, p < 0.05). In the pubertal stage, boys had worse cardiometabolic risk profile than girls, including unfavourable measure of systolic BP (z score: 0.6 ± 1.0 vs. 0.3 ± 1.0, p < 0.01), fasting glucose (87.2 ± 6.1 vs. 84.8 ± 7.7 mg/dl, p < 0.01), ALT (26.9 ± 21.5 vs. 20.2 ± 10.6 U/L, p < 0.001) and uric acid (6.1 ± 1.9 vs. 5.0 ± 1.0 mg/dl, p < 0.001). After the lifestyle intervention, changes in BMI z score (p < 0.05) were higher in pubertal boys than pubertal girls. The systolic blood pressure decrease was greater in pubertal boys than in their female counterpart (Δ systolic BP: -7.2 mmHg in boys vs. -3.6 mmHg in girls, p < 0.05; Δ systolic BP z score: -0.6 in boys vs. -0.3 in girls, p < 0.05). LDL cholesterol showed an improvement only in boys, and ALT in the whole group.

Conclusion

Our study showed that a short-term lifestyle intervention is more effective in reducing BMI z score and cardiovascular risk factors in pubertal boys than in their female counterparts. Further investigation is needed to deepen this gender difference, especially to develop a tailor-made intervention.

Identifying subgroups of childhood obesity by using multiplatform metabotyping

Introduction: Obesity results from an interplay between genetic predisposition and environmental factors such as diet, physical activity, culture, and socioeconomic status. Personalized treatments for obesity would be optimal, thus necessitating the identification of individual characteristics to improve the effectiveness of therapies. For example, genetic impairment of the leptin-melanocortin pathway can result in rare cases of severe early-onset obesity. Metabolomics has the potential to distinguish between a healthy and obese status; however, differentiating subsets of individuals within the obesity spectrum remains challenging. Factor analysis can integrate patient features from diverse sources, allowing an accurate subclassification of individuals. Methods: This study presents a workflow to identify metabotypes, particularly when routine clinical studies fail in patient categorization. 110 children with obesity (BMI > +2 SDS) genotyped for nine genes involved in the leptin-melanocortin pathway (CPE, MC3R, MC4R, MRAP2, NCOA1, PCSK1, POMC, SH2B1, and SIM1) and two glutamate receptor genes (GRM7 and GRIK1) were studied; 55 harboring heterozygous rare sequence variants and 55 with no variants. Anthropometric and routine clinical laboratory data were collected, and serum samples processed for untargeted metabolomic analysis using GC-q-MS and CE-TOF-MS and reversed-phase U(H)PLC-QTOF-MS/MS in positive and negative ionization modes. Following signal processing and multialignment, multivariate and univariate statistical analyses were applied to evaluate the genetic trait association with metabolomics data and clinical and routine laboratory features. Results and Discussion: Neither the presence of a heterozygous rare sequence variant nor clinical/routine laboratory features determined subgroups in the metabolomics data. To identify metabolomic subtypes, we applied Factor Analysis, by constructing a composite matrix from the five analytical platforms. Six factors were discovered and three different metabotypes. Subtle but neat differences in the circulating lipids, as well as in insulin sensitivity could be established, which opens the possibility to personalize the treatment according to the patients categorization into such obesity subtypes. Metabotyping in clinical contexts poses challenges due to the influence of various uncontrolled variables on metabolic phenotypes. However, this strategy reveals the potential to identify subsets of patients with similar clinical diagnoses but different metabolic conditions. This approach underscores the broader applicability of Factor Analysis in metabotyping across diverse clinical scenarios.

The N221D variant in PCSK1 is highly prevalent in childhood obesity and can influence the metabolic profile

OBJECTIVES

To study the prevalence and influence on metabolic profile of the prohormone-convertase-1 (PCSK1) N221D variant in childhood obesity, proven its role in the leptin-melanocortin signaling pathway as in proinsulin and other prohormone cleavage.

METHODS

Transversal study of 1066 children with obesity (mean age and BMI Z-score 10.38 ± 3.44 years and +4.38 ± 1.77, respectively), 51.4 % males, 54.4 % prepubertal, 71.5 % Caucasians and 20.8 % Latinos. Anthropometric and metabolic features were compared between patients carrying the N221D variant in PCSK1 and patients with no variants found after next generation sequencing analysis of 17 genes (CREBBP, CPE, HTR2C, KSR2, LEP, LEPR, MAGEL2, MC3R, MC4R, MRAP2, NCOA1, PCSK1, POMC, SH2B1, SIM1, TBX3 and TUB) involved in the leptin-melanocortin pathway.

RESULTS

No variants were found in 531 patients (49.8 %), while 68 patients carried the PCSK1 N221D variant (42 isolately, and 26 with at least one additional gene variant). Its prevalence was higher in Caucasians vs. Latinos (χ2 7.81; p<0.01). Patients carrying exclusively the PCSK1 N221D variant (n=42) showed lower insulinemia (p<0.05), HOMA index (p<0.05) and area under the curve for insulin in the oral glucose tolerance test (p<0.001) and higher WBISI (p<0.05) than patients with no variants, despite similar obesity severity, age, sex and ethnic distribution.

CONCLUSIONS

The N221D variant in PCSK1 is highly prevalent in childhood obesity, influenced by ethnicity. Indirect estimation of insulin resistance, based on insulinemia could be byassed in these patients and underestimate their type 2 diabetes mellitus risk.

Altered insulin secretion dynamics relate to oxidative stress and inflammasome activation in children with obesity and insulin resistance

BACKGROUND

Insulin resistance (IR) is considered the main driver of obesity related metabolic complications, and is related to oxidative stress and inflammation, which in turn promote each other. There is currently no specific definition of IR in children, rather, that for adult population is used by pediatric endocrinologists instead. Altered insulin secretion dynamics are associated with worse metabolic profiles and type 2 diabetes mellitus development, thus we aimed to test whether insulin response relates to oxidative stress and inflammation in children.

METHODS

We conducted a case-control study, including 132 children classified as follows: 33 children without obesity (Lean); 42 with obesity but no IR according to the American Diabetes Association criteria for adults (OBIR-); 25 with obesity and IR and an early insulin response to an oral glucose tolerance test (OGTT) (EP-OBIR +); 32 with obesity, IR, and a late insulin peak (LP-OBIR +); and studied variables associated with lipid and carbohydrate metabolism, oxidative stress, inflammation and inflammasome activation.

RESULTS

The measured parameters of children with obesity, IR, and an early insulin response were similar to those of children with obesity but without IR. It was late responders who presented an impaired antioxidant system and elevated oxidative damage in erythrocytes and plasma, and inflammasome activation at their white blood cells, despite lower classical inflammation markers. Increased uric acid levels seems to be one of the underlying mechanisms for inflammasome activation.

CONCLUSIONS

It is insulin response to an OGTT that identifies children with obesity suffering oxidative stress and inflammasome activation more specifically. Uric acid could be mediating this pathological inflammatory response by activating NLRP3 in peripheral blood mononuclear cells.

The Congenital and Acquired Mechanisms Implicated in the Etiology of Central Precocious Puberty

The etiology of central precocious puberty (CPP) is multiple and heterogeneous, including congenital and acquired causes that can be associated with structural or functional brain alterations. All causes of CPP culminate in the premature pulsatile secretion of hypothalamic GnRH and, consequently, in the premature reactivation of hypothalamic-pituitary-gonadal axis. The activation of excitatory factors or suppression of inhibitory factors during childhood represent the 2 major mechanisms of CPP, revealing a delicate balance of these opposing neuronal pathways. Hypothalamic hamartoma (HH) is the most well-known congenital cause of CPP with central nervous system abnormalities. Several mechanisms by which hamartoma causes CPP have been proposed, including an anatomical connection to the anterior hypothalamus, autonomous neuroendocrine activity in GnRH neurons, trophic factors secreted by HH, and mechanical pressure applied to the hypothalamus. The importance of genetic and/or epigenetic factors in the underlying mechanisms of CPP has grown significantly in the last decade, as demonstrated by the evidence of genetic abnormalities in hypothalamic structural lesions (eg, hamartomas, gliomas), syndromic disorders associated with CPP (Temple, Prader-Willi, Silver-Russell, and Rett syndromes), and isolated CPP from monogenic defects (MKRN3 and DLK1 loss-of-function mutations). Genetic and epigenetic discoveries involving the etiology of CPP have had influence on the diagnosis and familial counseling providing bases for potential prevention of premature sexual development and new treatment targets in the future. Global preventive actions inducing healthy lifestyle habits and less exposure to endocrine-disrupting chemicals during the lifespan are desirable because they are potentially associated with CPP.

Carbohydrate metabolism impairment in children and adolescents with cystic fibrosis

INTRODUCTION

Development of cystic fibrosis-related diabetes (CFRD) is associated with worsening of nutritional status and lung function, as well as increased mortality. The relevance of diagnosing the «pre-diabetic» status in these patients has not been addressed and the utility of HbA1c measurement in these patients is under discussion.

AIM

To study and characterise the different categories of carbohydrate metabolism impairment in paediatric patients with cystic fibrosis.

PATIENTS AND METHODS

A transversal study for characterisation of carbohydrate metabolism impairment according to clinical and anthropometric status and genetic background in 50 paediatric patients with cystic fibrosis (CF) was undertaken. Oral glucose tolerance tests (OGTT) for determination of glucose and insulin levels measurement and continuous subcutaneous glucose monitoring (CSGM) were performed.

RESULTS

6% of patients presented with CFRD, 26% impaired glucose tolerance, 10% an indeterminate glucose alteration and 2% impaired fasting glucose. The severity of glycaemic impairment correlated positively with age and negatively with standardised height (p < 0.05) with intergroup differences in HbA1c levels (p < 0.01), with the latter correlating with the duration of hyperglycaemia throughout CSGM. No intergroup differences in mutation prevalence, pulmonary function test, nutritional status or disease exacerbations in the previous year were found. The daily enzyme replacement dose correlated with the glucose area under the curve (AUC, p < 0.05) but not with insulin-AUC.

CONCLUSIONS

An older age and greater enzyme replacement need are correlated with more severe carbohydrate metabolism impairment and lower standardized height in paediatric CF patients, with HbA1c correlating with the duration of hyperglycaemia. The study of the full glucose/insulin AUCs throughout the OGTT affords no additional information compared to glucose determination at 120 min in these patients.

Prevalence and risk factors associated with different comorbidities in obese children and adolescents

INTRODUCTION

Different obesity-related comorbidities already present in childhood, such as: vitamin D deficiency, impaired carbohydrate metabolism, dyslipidaemia, arterial hypertension and non-alcoholic steatohepatitis. In this study, we aim to analyse the prevalence of comorbidities and to determine the predictive factors that affect these comorbidities.

MATERIAL AND METHODS

Anthropometric, demographic and biochemical variables were collected from obese patients between six and 18 years of age. Subsequently, a statistical analysis was performed to describe the characteristics of the patients and the prevalence of comorbidities, as well as their predictive factors.

RESULTS

A total of 158 obese children (76 boys and 82 girls) with a mean age at diagnosis of 12.48 years and a BMI Z-score of +3.24 SDS were included. The most prevalent comorbidities were vitamin D deficiency (64.2%), insulin resistance (45.1%), dyslipidaemia (32.2%), hyperuricaemia (18.5%) and arterial hypertension (15%). Age, BMI Z-score, percentage of fat mass and male sex have been found to be predictors of these comorbidities.

CONCLUSION

Obese children and adolescents have a high prevalence of comorbidities. Once the diagnosis of obesity has been established, it would be very useful to identify early those patients with a higher risk of comorbidities, knowing their relationship with sex, age, BMI Z-score, percentage of fat mass and pubertal stage.

Single Point Insulin Sensitivity Estimator in Pediatric Non-Alcoholic Fatty Liver Disease

BACKGROUND

Attenuated insulin-sensitivity (IS) is a central feature of pediatric non-alcoholic fatty liver disease (NAFLD). We recently developed a new index, single point insulin sensitivity estimator (SPISE), based on triglycerides, high-density-lipoprotein and body-mass-index (BMI), and validated by euglycemic-hyperinsulinemic clamp-test (EHCT) in adolescents. This study aims to assess the performance of SPISE as an estimation of hepatic insulin (in-)sensitivity. Our results introduce SPISE as a novel and inexpensive index of hepatic insulin resistance, superior to established indices in children and adolescents with obesity.

MATERIALS AND METHODS

Ninety-nine pubertal subjects with obesity (13.5 ± 2.0 years, 59.6% males, overall mean BMI-SDS + 2.8 ± 0.6) were stratified by MRI (magnetic resonance imaging) into a NAFLD (>5% liver-fat-content; male n=41, female n=16) and non-NAFLD (≤5%; male n=18, female n=24) group. Obesity was defined according to WHO criteria (> 2 BMI-SDS). EHCT were used to determine IS in a subgroup (n=17). Receiver-operating-characteristic (ROC)-curve was performed for diagnostic ability of SPISE, HOMA-IR (homeostatic model assessment for insulin resistance), and HIRI (hepatic insulin resistance index), assuming null hypothesis of no difference in area-under-the-curve (AUC) at 0.5.

RESULTS

SPISE was lower in NAFLD (male: 4.8 ± 1.2, female: 4.5 ± 1.1) than in non-NAFLD group (male 6.0 ± 1.6, female 5.6 ± 1.5; P< 0.05 {95% confidence interval [CI]: male NAFLD 4.5, 5.2; male non-NAFLD 5.2, 6.8; female NAFLD 4.0, 5.1, female non-NAFLD 5.0, 6.2}). In males, ROC-AUC was 0.71 for SPISE (P=0.006, 95% CI: 0.54, 0.87), 0.68 for HOMA-IR (P=0.038, 95% CI: 0.48, 0.88), and 0.50 for HIRI (P=0.543, 95% CI: 0.27, 0.74). In females, ROC-AUC was 0.74 for SPISE (P=0.006), 0.59 for HOMA-IR (P=0.214), and 0.68 for HIRI (P=0.072). The optimal cutoff-level for SPISE between NAFLD and non-NAFLD patients was 5.18 overall (Youden-index: 0.35; sensitivity 0.68%, specificity 0.67%).

CONCLUSION

SPISE is significantly lower in juvenile patients with obesity-associated NAFLD. Our results suggest that SPISE indicates hepatic IR in pediatric NAFLD patients with sensitivity and specificity superior to established indices of hepatic IR.

Conservative Treatment for Childhood and Adolescent Obesity: Real World Follow-Up Profiling and Clinical Evolution in 1300 Patients

Background: Limited therapeutic tools and an overwhelming clinical demand are the major limiting factors in pediatric obesity management. The optimal protocol, environment, body mass index (BMI) change targets and duration of obesity-oriented interventions remain to be elucidated. Aims: We aimed to characterize the singularities of follow-up, anthropometric and metabolic evolution of a large cohort of pediatric patients with obesity in a specialized university hospital outpatient obesity unit. Patients and methods: Follow-up duration (up to seven years), attrition rate and anthropometric and metabolic evolution of 1300 children and adolescents with obesity were studied. An individualized analysis was conducted in patients attaining a high level of weight loss (over 1.5 BMI-SDS (standard deviation score) and/or 10% of initial weight; n = 252; 19.4%) as well as in "metabolically healthy" patients (n = 505; 38.8%). Results: Attrition rate was high during the early stages (11.2% prior to and 32.5% right after their initial metabolic evaluation). Mean follow-up time was 1.59 ± 1.60 years (7% of patients fulfilled 7 years). The highest BMI reduction occurred in the first year (-1.11 ± 0.89 SDS, p < 0.001 in 72.5% of patients). At the end of the follow-up, improvements in glucose and lipid metabolism parameters were observed (both p < 0.05), that were highest in patients with the greatest weight reduction (all p < 0.01), independent of the time spent to achieve weight loss. The pubertal growth spurt negatively correlated with obesity severity (r = -0.38; p < 0.01) but patients attaining adult height exceeded their predicted adult height (n = 308, +1.6 ± 5.4 cm; p < 0.001). "Metabolically healthy" patients, but with insulin resistance, had higher blood pressure, glucose, uric acid and triglyceride levels than those without insulin resistance (all p < 0.05). Preservation of the "metabolically healthy" status was associated with BMI improvement. Conclusions: Behavioral management of children with obesity can be effective and does not impair growth but is highly conditioned by high attrition. The best results regarding BMI reduction and metabolic improvement are achieved in the first year of intervention and can be preserved if follow-up is retained.

The pubertal growth spurt is diminished in children with severe obesity

BACKGROUND

At the population level, there is a negative linear correlation between childhood body mass index (BMI) and pubertal height gain. However, in children with obesity, there are no studies showing whether the severity of obesity affects pubertal height gain. Moreover, how obesity in childhood affects pubertal timing is controversial, especially in boys. We aimed to investigate the impact of severe obesity in childhood on the pubertal growth spurt in both sexes.

METHODS

The study group consisted of 68 patients (32 boys) with childhood onset obesity followed in a Spanish university hospital. The QEPS growth model was used to calculate pubertal growth function estimates for each individual. The highest individual prepubertal BMI SDS value was related to the age at onset of pubertal growth and pubertal height gain. Results were compared to analyses from individuals in a community-based setting (n = 1901) with different weight status.

RESULTS

A higher peak BMI in childhood was associated with less specific pubertal height gain in children with moderate-to-extreme obesity. For boys, the higher the BMI, the earlier the onset of pubertal growth. For girls with obesity, this correlation was not linear.

CONCLUSIONS

Obesity in childhood impairs the pubertal growth spurt in a severity-related fashion.

IMPACT

The higher the BMI in childhood, the lower the pubertal height gain in children with moderate-to-extreme obesity. For boys with obesity, the higher the BMI, the earlier the onset of pubertal growth. The results contribute to the research field of how weight status in childhood is related to pubertal timing and pubertal growth. The results have implications for understanding how childhood obesity is related to further growth.

A combination of circulating chemokines as biomarkers of obesity-induced insulin resistance at puberty

BACKGROUND

In obesity adipose tissue undergoes structural re-modelling leading to a chronic low-grade inflammatory state linked to insulin resistance (IR).

OBJECTIVE

We aimed to develop a clinically relevant biomarker model for stratifying IR in adolescents with obesity.

METHODS

Cytokines [tumour cell derived factor 1α, monocyte chemoattract protein (MCP) 1, eotaxin and fractalkine], growth factors [brain-derived neurotrophic factor, pro-fibrotic platelet-derived growth factor (PDGF-BB) and insulin-like growth factor 1] and biochemical/metabolic factors were analysed in serum of 143 pubertal patients with obesity (50% IR; 50% non-IR) and 33 controls. Factor analysis, correlation, binary logistic regression and receiver operating characteristic analysis were used to evaluate combinations of these biomarkers as possible diagnostic tools for IR.

RESULTS

Two biomarker IR models combining levels of triglycerides (TG)/HDL, eotaxin, MCP-1 and PDGF-BB in pubertal patients with obesity of both sexes were defined. Altered levels of MCP-1, eotaxin, and PDGF-BB constitute a main component that determines 27.7% of the variance explaining IR. Growth and inflammatory factors comprise two other components linked to the first, together accounting for 59.2% of the variance determining IR.

CONCLUSIONS

PDGF-BB, MCP-1, eotaxin, TG and cholesterol concentrations constitute a solid panel of biomarkers associated with IR in pubertal children with obesity that could be useful in their stratification in a clinical setting for stratification.

Association of uric acid with cardiovascular risk in Brazilian children and adolescents

BACKGROUND AND AIM

Hyperuricemia in adults is associated with cardiovascular risk factors. However, there is less data regarding this association in children and adolescents. Our purpose was to determine association between serum uric acid (SUA) and cardiovascular risk.

METHODS AND RESULTS

A fasting blood sample was collected from 1750 participants aged 6-17 years enrolled in a social project and public schools in Espírito Santo, Brazil. Internal cut-offs were generated to define high SUA (≥90th percentile of SUA concentration for sex and age group). Body mass index percentile (pBMI), body fat percentage (BFP) and muscle mass were determined by bioimpedance. Data are given as mean ± standard deviation. High SUA was associated with overweight/obesity (OR 3.7 CI 95% 2.7-5.0), high waist circumference (WC) (OR 3.9 CI 95% 2.9-5.4), low HDL (OR 2.0 CI 95% 1.5-2.8), high blood pressure (BP) (OR 1.8 CI 95% 1.1-3.2), high BFP (OR 4.1 CI 95% 2.7-6.4), metabolic syndrome (MetS) (OR 3.6 CI 95% 1.8-7.1) and insulin resistance (OR 1.7 CI 95% 1.1-2.7). Individuals in the fourth quartile of SUA, compared to those in the first quartile, showed higher age, pBMI, WC, BFP and muscle mass. Using a reference value of 5.5 mg/dL, the prevalence of hyperuricemia in the sample was 10.3% (CI 95% 8.9-11.7%).

CONCLUSION

Higher SUA values are associated with higher cardiovascular risk in childhood and adolescence. The main cardiovascular risk factors associated with hyperuricemia were overweight/obesity, high WC, dyslipidemia, high BFP, high BP, insulin resistance and MetS.

Insulin Resistance in Obese Children: What Can Metabolomics and Adipokine Modelling Contribute?

The evolution of obesity and its resulting comorbidities differs depending upon the age of the subject. The dramatic rise in childhood obesity has resulted in specific needs in defining obesity-associated entities with this disease. Indeed, even the definition of obesity differs for pediatric patients from that employed in adults. Regardless of age, one of the earliest metabolic complications observed in obesity involves perturbations in glucose metabolism that can eventually lead to type 2 diabetes. In children, the incidence of type 2 diabetes is infrequent compared to that observed in adults, even with the same degree of obesity. In contrast, insulin resistance is reported to be frequently observed in children and adolescents with obesity. As this condition can be prerequisite to further metabolic complications, identification of biological markers as predictive risk factors would be of tremendous clinical utility. Analysis of obesity-induced modifications of the adipokine profile has been one classic approach in the identification of biomarkers. Recent studies emphasize the utility of metabolomics in the analysis of metabolic characteristics in children with obesity with or without insulin resistance. These studies have been performed with targeted or untargeted approaches, employing different methodologies. This review summarizes some of the advances in this field while emphasizing the importance of the different techniques employed.

Validity assessment of the single-point insulin sensitivity estimator (spise) for diagnosis of cardiometabolic risk in post-pubertal hispanic adolescents

Insulin measurements are not advised for cardiometabolic risk screening in large groups. Here we assessed the accuracy of the single-point insulin sensitivity estimator (SPISE) to diagnose cardiometabolic risk in Chilean adolescents. In 678 post-pubertal adolescents (52% males, M(SD) age = 16.8 (0.2) years), height, weight, waist circumference, blood lipids, glucose, insulin, and blood pressure were measured. BMI, HOMA-IR, and SPISE were estimated; HOMA-IR values ≥ 2.6 were considered insulin resistance (IR). Metabolic syndrome (MetS) was defined with the joint IDF/AHA/NHBLI standard. Using receiver operating characteristic curves, we obtained optimal SPISE cutpoints for IR and MetS diagnosis. The prevalence of MetS and IR was 8.2% and 17.1%, respectively. In males, the optimal cutoff for MetS diagnosis was 5.0 (sensitivity: 97%; specificity: 82%), and the optimal cutoff for IR diagnosis was 5.9 (sensitivity: 71%; specificity: 83%). In females, a SPISE of 6.0 had the highest sensitivity (90%) and specificity (74%) for MetS diagnosis. A SPISE of 6.4 was the optimal cutoff for IR diagnosis; however, sensitivity and specificity were 61% and 75%. In males and female post-pubertal adolescents, SPISE had a very good and good diagnostic performance, respectively, in predicting MetS. It was an accurate diagnostic tool for IR prediction in males, but not necessarily in females.

Short-Term Diet Induced Changes in the Central and Circulating IGF Systems Are Sex Specific

Insulin-like growth factor (IGF) 1 exerts a wide range of functions in mammalians participating not only in the control of growth and metabolism, but also in other actions such as neuroprotection. Nutritional status modifies the IGF system, although little is known regarding how diet affects the newest members of this system including pregnancy-associated plasma protein-A (PAPP-A) and PAPP-A2, proteases that liberate IGF from the IGF-binding proteins (IGFBPs), and stanniocalcins (STCs) that inhibit PAPP-A and PAPP-A2 activity. Here we explored if a 1-week dietary change to either a high-fat diet (HFD) or a low-fat diet (LFD) modifies the central and peripheral IGF systems in both male and female Wistar rats. The circulating IGF system showed sex differences in most of its members at baseline. Males had higher levels of both free (p < 0.001) and total IGF1 (p < 0.001), as well as IGFBP3 (p < 0.001), IGFBP5 (p < 0.001), and insulin (p < 0.01). In contrast, females had higher serum levels of PAPP-A2 (p < 0.05) and IGFBP2 (p < 0.001). The responses to a short-term dietary change were both diet and sex specific. Circulating levels of IGF2 increased in response to LFD intake in females (p < 0.001) and decreased in response to HFD intake in males (p < 0.001). In females, LFD intake also decreased circulating IGFBP2 levels (p < 0.001). In the hypothalamus LFD intake increased IGF2 (p < 0.01) and IGFBP2 mRNA (p < 0.001) levels, as well as the expression of NPY (p < 0.001) and AgRP (p < 0.01), but only in males. In conclusion, short-term LFD intake induced more changes in the peripheral and central IGF system than did short-term HFD intake. Moreover, these changes were sex-specific, with IGF2 and IGFBP2 being more highly affected than the other members of the IGF system. One of the main differences between the commercial LFD employed and the HFD or normal rodent chow is that the LFD has a significantly higher sucrose content, suggesting that this nutrient could be involved in the observed responses.

Ethnicity Strongly Influences Body Fat Distribution Determining Serum Adipokine Profile and Metabolic Derangement in Childhood Obesity

Background: Body fat content and distribution in childhood is influenced by sex and puberty, but interethnic differences in the percentage and distribution of body fat also exist. The abdominal visceral/subcutaneous fat ratio has been the main feature of body fat distribution found to associate with the serum adipokine profile and metabolic derangement in adulthood obesity. This has also been assumed for childhood obesity despite the known singularities of this disease in the pediatric age in comparison to adults. Objective: We aimed to investigate the effect of ethnicity, together with sex and pubertal status, on body fat content and distribution, serum adipokine profile, metabolic impairment and liver steatosis in children and adolescents with obesity. Patients and Methods: One hundred and fifty children with obesity (50% Caucasians/50% Latinos; 50% males/50% females) were studied. Body fat content and distribution were studied by whole body DXA-scan and abdominal magnetic resonance, and their relationships with liver steatosis (as determined by ultrasonography), glycemia, insulinemia, lipid metabolism, uric acid, total and HMW-adiponectin, leptin, leptin-receptor, and sex steroid levels were explored. Results: Latino patients had more severe truncal obesity (higher trunk/lower limb fat ratio, odds ratio 10.00; p < 0.05) and higher prevalence of liver steatosis than Caucasians regardless of sex or pubertal status, but there were no difference in the visceral/subcutaneous abdominal fat ratio, except for pubertal females. A higher trunk/lower limb fat ratio, but not the visceral/subcutaneous abdominal fat ratio, was associated with adipokine profile impairment (higher free leptin index and lower adiponectin levels), insulin resistance and dyslipidemia, and was further enhanced when liver steatosis was present (p < 0.05). A higher abdominal visceral/subcutaneous fat ratio was observed in prepubertal children (p < 0.01), except for Latino females, whereas predominant subcutaneous fat deposition was observed in adolescents. Conclusion: Ethnicity is one of the main determinants of increased trunk body fat accumulation in Latino children with obesity, which is best estimated by the trunk/lower limb fat ratio and related to the development of metabolic derangement and liver steatosis.