Normative data for adiponectin, resistin, interleukin 6, and leptin/receptor ratio in a healthy Spanish pediatric population: relationship with sex steroids

A Higher Adherence to the ALINFA Nutritional Intervention Is Effective for Improving Dietary Patterns in Children

Food patterns are deteriorating and, consequently, not meeting nutritional recommendations. Learning about the adherence to a diet is crucial for understanding children's dietary habits. The objective of the present analysis was to assess the degree of compliance with the ALINFA nutritional intervention and the effectiveness of adherence groups, and to evaluate potential baseline factors predicting a higher adherence to the intervention. A total of 44 children aged 6 to 12 years-old participated in the eight-week intervention. A two-week dietary plan was specifically designed, providing participants with food products, ready-to-eat dishes, and recipes. An intake of 75% of calories of the prescribed diet was defined to divide the participants into high- and low-adherence groups (HA/LA, respectively). From the 44 participants, 24 showed a LA to the intervention, whereas 20 of them were in the HA group. Diet quality improved in both groups (p < 0.001), mainly by increasing cereals and nuts, and reducing pastries. A decrease in BMI z-score was observed (LA: p < 0.001; HA: p = 0.021). Fat mass (p = 0.002), LDL-c (p = 0.036), and CRP (p = 0.023) reductions were only achieved in the HA group, whereas leptin decreased only in the LA group (p = 0.046). All participants ameliorated their dietary habits, but those with better diet quality at baseline experienced greater enhancements in their nutritional status.

Resistin: A Potential Indicator of Aortic Stiffness in Non-Dialysis Chronic Kidney Disease Patients

Background and Objectives: In the progression and development of atherosclerosis, resistin plays a significant role. Chronic kidney disease (CKD), frequently associated with atherosclerosis, exhibits a marked increase in morbidity and mortality rates. This study set out to explore the association between aortic stiffness and serum levels of resistin in non-dialysis-dependent CKD patients ranging from stages 3 to 5. Materials and Methods: We collected fasting blood samples from 240 CKD patients across stages 3 to 5. The concentration of resistin in serum was determined using a commercially available enzyme immunoassay kit. Those patients who exhibited a carotid-femoral pulse wave velocity (cfPWV) greater than 10 m/s were identified as the aortic stiffness group. Results: Out of the 240 CKD patients, 88 (36.7%) were classified within the aortic stiffness group. This group demonstrated higher incidences of diabetes, advanced age, increased body weight, body mass index, body fat mass, systolic and diastolic blood pressure, fasting glucose, and serum resistin levels. Multivariate logistic regression analysis highlighted resistin, diabetes, and body weight as independent predictors of aortic stiffness. Additionally, body fat mass, logarithmically transformed cfPWV (log-cfPWV) values and log-triglyceride levels were independent predictors of log-resistin levels by multivariate stepwise linear regression analysis. Conclusions: In CKD patients from stages 3 to 5, a positive correlation exists between elevated serum resistin levels and cfPWV values, identifying resistin as a potential predictor of aortic stiffness.

A cross-sectional study of the association between circulating sex hormone-binding globulin levels and selected adipokines in women with polycystic ovary syndrome

INTRODUCTION

Changes in the proportion of pro-inflammatory and anti-inflammatory adipokines may reflect the accumulation of lipids in the liver and the development of insulin resistance. Both liver steatosis and insulin resistance result in decreased sex hormone-binding globulin (SHBG) synthesis. This study aimed to analyze associations between circulating SHBG and adipokines levels in women with polycystic ovary syndrome (PCOS).

MATERIAL AND METHODS

A cross-sectional cohort study involved 87 women with phenotype A of PCOS (39 normal weight and 48 obese). Body mass, height, and waist circumference were measured, and BMI was calculated. In addition, body composition was assessed using the bioimpedance method. Serum SHBG levels and plasma apelin-36 and apelin-12, adiponectin, leptin, omentin-1, and RBP-4 were determined by using the ELISA method. The participants were divided into subgroups with SHBG concentrations above and below this lower limit [N = 35 (40.2%) and N = 52 (59.8%), respectively].

RESULTS

The median adiponectin, apelin-12, and apelin-36 levels were significantly lower, and leptin levels were significantly higher in the subgroup with low SHBG levels than that in the subgroup above the lower limit of the reference range, while there were no differences in median omentin-1 and RBP-4 between the study subgroups. There were positive correlations between SHBG and omentin-1, adiponectin, apelin-36, and apelin-12 levels, as well as negative correlation with leptin levels. However, after adjustment by BMI, waist circumference, and body fat percentage, only the association between SHBG and omentin-1 remained significant.

CONCLUSION

Our results show associations between circulating SHBG and adipokine levels in women with PCOS and support the role of hormonal dysfunction of the adipose tissue in the pathogenesis of PCOS.

Impact of puberty, sex determinants and chronic inflammation on cardiovascular risk in young people

Worrying trends of increased cardiovascular disease (CVD) risk in children, adolescents and young people in the Modern Era have channelled research and public health strategies to tackle this growing epidemic. However, there are still controversies related to the dynamic of the impact of sex, age and puberty on this risk and on cardiovascular health outcomes later in life. In this comprehensive review of current literature, we examine the relationship between puberty, sex determinants and various traditional CVD-risk factors, as well as subclinical atherosclerosis in young people in general population. In addition, we evaluate the role of chronic inflammation, sex hormone therapy and health-risk behaviours on augmenting traditional CVD-risk factors and health outcomes, ultimately aiming to determine whether tailored management strategies for this age group are justified.

Association of adipocytokines and adipocytokine ratios with cardiovascular risk factors in Japanese preadolescents

OBJECTIVES

Asians are particularly susceptible to obesity-associated disorders and rapid progression of obesity from childhood to adulthood. Data on the association between adipocytokine parameters, particularly adipocytokine ratios, and cardiovascular risk factors in childhood remain limited. Herein, we assessed the association of resistin, adiponectin, and leptin levels and leptin/adiponectin and resistin/adiponectin ratios with selected cardiovascular risk factors and the influence of unhealthy weight on such associations in children aged 9-10 years.

METHODS

We included 380 children aged 9-10 years from three public elementary schools in Japan.

RESULTS

The body mass index (BMI) was significantly higher in male preadolescents than in female adolescents (median 16.5 kg/m² vs. 16.2 kg/m², p=0.032). No differences in height, weight, waist circumference (WC), waist/height ratio (W/Hr), total cholesterol and high-density lipoprotein cholesterol levels, or atherosclerosis index (AI) were observed between the sexes. Of the adipocytokine levels and ratios analyzed, only the leptin level and leptin/adiponectin ratio (L/Ar) were strongly and significantly positively correlated with the cardiovascular risk factors WC, W/Hr, and BMI (all p<0.05). The AI was not strongly correlated with any adipocytokine levels or ratios. Apart from the strong positive correlation between the L/Ar and W/Hr, no other significant associations were observed between any of the adipocytokine levels or ratios and the selected cardiovascular risk factors.

CONCLUSIONS

Our findings confirmed the value of adipocytokine ratios in risk assessment in pediatric populations, with leptin levels and leptin/adiponectin ratios strongly correlating with risk factors in children aged 9-10 years.

From Metabolic Syndrome to Type 2 Diabetes in Youth

In the frame of metabolic syndrome, type 2 diabetes emerges along a continuum of the risk from the clustering of all its components, namely visceral obesity, high blood pressure and lipids, and impaired glucose homeostasis. Insulin resistance is the hallmark common to all the components and, in theory, is a reversible condition. Nevertheless, the load that this condition can exert on the β-cell function at the pubertal transition is such as to determine its rapid and irreversible deterioration leading to plain diabetes. The aim of this review is to highlight, in the context of metabolic syndrome, age-specific risk factors that lead to type 2 diabetes onset in youth; resume age specific screening and diagnostic criteria; and anticipate potential for treatment. Visceral obesity and altered lipid metabolism are robust grounds for the development of the disease. Genetic differences in susceptibility to hampered β-cell function in the setting of obesity and insulin resistance largely explain why some adolescents with obesity do develop diabetes at a young age and some others do not. Lifestyle intervention with a healthy diet and physical activity remains the pillar of the type 2 diabetes treatment in youth. As to the pharmacological management, metformin and insulin have failed to rescue β-cell function and to ensure long-lasting glycemic control in youth. A new era might start with the approval for use in pediatric age of drugs largely prescribed in adults, such as dipeptidyl peptidase-4 and sodium-dependent glucose transport inhibitors, and of new weight-lowering drugs in the pipeline such as single and multiple agonists of the glucagon-like peptide 1 receptor. The latter drugs can have tremendous impact on the natural history of the disease. By treating diabetes, they will reduce the burden of all the metabolic abnormalities belonging to the syndrome while causing a tremendous weight loss hitherto never seen before.

Effects of childhood obesity and related genetic factors on precocious puberty: protocol for a multi-center prospective cohort study

BACKGROUND

Childhood obesity has important effects on the onset and development of puberty. Although a number of studies have confirmed the relationship between obesity and precocious puberty, little is known about the pleiotropic genes of obesity and precocious puberty and the interaction between genes and environment. There are four objectives: (1) to analyze the incidence of precocious puberty in the general population in China; (2) to verify the direct effect of obesity on children's precocious puberty using a variety of methods; (3) to verify the effect of obesity and its risk gene polymorphism on precocious puberty in a prospective cohort study; and (4) to analyze the interaction effect of genes and environment on pubertal development.

METHODS

We will conduct a multi-center prospective cohort study in three cities, which are selected in southern, central, and northern China, respectively. Primary schools in these cities will be selected by a stratified cluster random sampling method. Primary school students from grade 1 to grade 3 (6 to 10 years old) will be selected for the cohort with extensive baseline data collection, including assessment of pubertal development, family demographic information, early development, sleep pattern, dietary pattern, and physical activity. Participants will be followed up for at least three years, and long-term follow-up will depend on future funding.

DISCUSSION

The findings of this multicenter prospective population-based cohort study may expand previous related puberty development research as well as provide important information on the mechanism of early puberty. Targeted interventions can also be developed to improve adolescent health problems related to puberty development based on the available evidence.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04113070 , prospectively registered on October 2, 2019.

Ontogeny of plasma cytokine and chemokine concentrations across the first week of human life

Introduction/background & aims:

Early life is marked by distinct and rapidly evolving immunity and increased susceptibility to infection. The vulnerability of the newborn reflects development of a complex immune system in the face of rapidly changing demands during the transition to extra-uterine life. Cytokines and chemokines contribute to this dynamic immune signaling network and can be altered by many factors, such as infection. Newborns undergo dynamic changes important to health and disease, yet there is limited information regarding human neonatal plasma cytokine and chemokine concentrations over the first week of life. The few available studies are limited by small sample size, cross-sectional study design, or focus on perturbed host states like severe infection or prematurity. To characterize immune ontogeny among healthy full-term newborns, we assessed plasma cytokine and chemokine concentrations across the first week of life in a robust longitudinal cohort of healthy, full-term African newborns.

Methods:

We analyzed a subgroup of a cohort of healthy newborns at the Medical Research Council Unit in The Gambia (West Africa; N = 608). Peripheral blood plasma was collected from all study participants at birth (day of life (DOL) 0) and at one follow-up time point at DOL 1, 3, or 7. Plasma cytokine and chemokine concentrations were measured by bead-based cytokine multiplex assay. Unsupervised clustering was used to identify patterns in plasma cytokine and chemokine ontogeny during early life.

Results:

We observed an increase across the first week of life in plasma Th1 cytokines such as IFNγ and CXCL10 and a decrease in Th2 and anti-inflammatory cytokines such as IL-6 and IL-10, and chemokines such as CXCL8. In contrast, other cytokines and chemokines (e.g. IL-4 and CCL5, respectively) remained unchanged during the first week of life. This robust ontogenetic pattern did not appear to be affected by gestational age or sex.

Conclusions:

Ontogeny is a strong driver of newborn plasma-based levels of cytokines and chemokines throughout the first week of life with a rising IFNγ axis suggesting post-natal upregulation of host defense pathways. Our study will prove useful to the design and interpretation of future studies aimed at understanding the neonatal immune system during health and disease.

Complex biological patterns of soluble cytokines and CD163 in childhood necessitating age-specific reference intervals for evidence-based clinical interpretation

BACKGROUND

Cytokine measurements to support clinical laboratory and research investigations have become increasingly common in pediatrics. However, there is a paucity of accurate pediatric reference intervals (RIs) essential to the interpretation of cytokine results. To address this gap, here, we establish age- and sex-specific pediatric reference values for clinically relevant inflammatory markers including CD163, and the cytokines IL-1β, IL-6, IL-10, IL-18, TNF-α, IFN-γ, and CXCL-9.

METHODS

Healthy children and adolescents (n = 311, 1-19 years) were recruited as part of the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) study. Multi-analyte measurements in plasma and analytical performance verification were conducted on the ProteinSimple® Ella™ automated immunoassay platform (Bio-Techne, MN, USA). Age- and sex-specific RIs were calculated based on Clinical and Laboratory Standards Institute guidelines. Additionally, 75th and 95th percentile cut-offs were determined.

RESULTS

Three types of reference value distributions were observed: (a) consistent levels throughout age and sex: IL-6, and IFN-γ, (b) gradual decline in concentration with age: CD163, TNF-α, CXCL-9, and IL-10, (c) significantly higher concentrations during ages 4-14 years than earlier and later ages: IL-1β and IL-18. Reference values for CXCL-9, IL-10, and TNF-α under 8 years of age differed significantly from older children. CD163, IL-18 and IL-1β required three age partitions. CD163 demonstrated significant sex differences in ages 8-13 years.

CONCLUSION

The circulating profile of cytokines in children is complex and can vary by age and sex. This necessitates careful interpretation of test results based on age and/or sex specific RIs facilitating more accurate clinical decision making.

Recent Update on the Molecular Mechanisms of Gonadal Steroids Action in Adipose Tissue

The gonadal steroids, including androgens, estrogens and progestogens, are involved in the control of body fat distribution in humans. Nevertheless, not only the size and localization of the fat depots depend on the sex steroids levels, but they can also highly affect the functioning of adipose tissue. Namely, the gonadocorticoids can directly influence insulin signaling, lipid metabolism, fatty acid uptake and adipokine production. They may also alter energy balance and glucose homeostasis in adipocytes in an indirect way, e.g., by changing the expression level of aquaglyceroporins. This work presents the recent advances in understanding the molecular mechanism of how the gonadal steroids influence the functioning of adipose tissue leading to a set of detrimental metabolic consequences. Special attention is given here to highlighting the sexual dimorphism of adipocyte functioning in terms of health and disease. Particularly, we discuss the molecular background of metabolic disturbances occurring in consequence of hormonal imbalance which is characteristic of some common endocrinopathies such as the polycystic ovary syndrome. From this perspective, we highlight the potential drug targets and the active substances which can be used in personalized sex-specific management of metabolic diseases, in accord with the patient's hormonal status.

Salivary concentrations of cytokines and other analytes in healthy children

BACKGROUND

Blood has been the usual biological fluid for measuring analytes, but there is mounting evidence that saliva may be also useful for detecting cytokines in a noninvasive way. Thus, in this study we aimed to determine concentration of cytokines and other analytes in saliva from a population of healthy children.

METHODS

We collected un-stimulated whole saliva samples from clinically healthy children, and concentration of 17 cytokines and 12 other analytes were measured in supernatants. All values were adjusted by albumin content and were log-transformed before multivariate statistical analysis.

RESULTS

We included 114 children (53.5% females) between 6.0 and 11.9 years old. The highest concentrations (medians, pg/µg albumin) were seen for visfatin (183.70) and adiponectin (162.26) and the lowest for IL-13 and IL-2 (~0.003). Albumin concentration was associated with age (r_S = 0.39, p < 0.001). In the multivariate analysis, five analytes (C peptide, ghrelin, GLP-1, glucagon, leptin) inversely correlated with age and positively with height-for-age. Age was also positively associated with PAI-1, while height-for-age was also positively associated with insulin and visfatin. Finally, BMI-for-age had a positive correlation with GM-CSF and insulin.

CONCLUSIONS

Herein, we provided concentration values for 29 analytes in saliva from healthy children that may be useful as preliminary reference framework in the clinical research setting.

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.

High molecular weight adiponectin levels are inversely associated with adiposity in pediatric brain tumor survivors

While children with brain tumors are surviving at record rates, survivors are at risk of cardiovascular disease and type 2 diabetes mellitus; these conditions may be driven by excess body fat. Adiponectin in an adipokine that is inversely associated with the fat mass, and has been linked to cardiometabolic risk stratification in the general population. However, adiponectin’s profile and determinants in SCBT have not been established. We tested the hypothesis that high molecular weight (HMW) adiponectin levels, the more biologically active form of adiponectin, were associated with adiposity in SCBT similarly to non-cancer controls. Seventy-four SCBT (n = 32 female) and 126 controls (n = 59 female) who were 5–17 years old were included. Partial correlations and multivariable regression analyses assessed the relationship between HMW adiponectin and adiposity. HMW adiponectin was inversely associated with total and central adiposity (FM%: β − 0.21, 95% CI − 0.15, − 0.08; p value < 0.0001; WHR: β − 0.14, 95% CI − 0.02, − 0.01; p value < 0.0001 ;WHtR: β − 0.21, 95% CI − 0.05, − 0.03; p value < 0.0001). In conclusion, HMW adiponectin is inversely correlated with adiposity in SCBT. Adiponectin may serve as a biomarker of cardiometabolic risk and response to interventions to prevent and manage obesity and its comorbidities in SCBT.

Leptin: Master Regulator of Biological Functions that Affects Breathing

Obesity is a global epidemic in developed countries accounting for many of the metabolic and cardiorespiratory morbidities that occur in adults. These morbidities include type 2 diabetes, sleep-disordered breathing (SDB), obstructive sleep apnea, chronic intermittent hypoxia, and hypertension. Leptin, produced by adipocytes, is a master regulator of metabolism and of many other biological functions including central and peripheral circuits that control breathing. By binding to receptors on cells and neurons in the brainstem, hypothalamus, and carotid body, leptin links energy and metabolism to breathing. In this comprehensive article, we review the central and peripheral locations of leptin's actions that affect cardiorespiratory responses during health and disease, with a particular focus on obesity, SDB, and its effects during early development. Obesity-induced hyperleptinemia is associated with centrally mediated hypoventilation with decrease CO₂ sensitivity. On the other hand, hyperleptinemia augments peripheral chemoreflexes to hypoxia and induces sympathoexcitation. Thus, "leptin resistance" in obesity is relative. We delineate the circuits responsible for these divergent effects, including signaling pathways. We review the unique effects of leptin during development on organogenesis, feeding behavior, and cardiorespiratory responses, and how undernutrition and overnutrition during critical periods of development can lead to cardiorespiratory comorbidities in adulthood. We conclude with suggestions for future directions to improve our understanding of leptin dysregulation and associated clinical diseases and possible therapeutic targets. Lastly, we briefly discuss the yin and the yang, specifically the contribution of relative adiponectin deficiency in adults with hyperleptinemia to the development of metabolic and cardiovascular disease. © 2020 American Physiological Society. Compr Physiol 10:1047-1083, 2020.

Comparison of plasma adipocytokines & C-reactive protein levels in healthy schoolgoing adolescents from private & government-funded schools of Delhi, India

Background & objectives

Obesity-mediated chronic inflammatory state is primarily governed by lifestyle and food habits in adolescents and marked by alterations in the level of various inflammatory markers. This cross-sectional study was aimed to compare the inflammatory status of healthy Indian adolescents vis-à-vis their obesity profile. The inflammatory state of urban adolescents attending private and government-funded schools, and the relationship between inflammatory marker levels and anthropometric indices in the study participants from both groups were examined.

Methods

A total of 4438 study participants (10-17 yr) were chosen from various schools of Delhi, India, and their anthropometric parameters were measured. Plasma adipocytokines (adiponectin, leptin and resistin) of the study participants were measured by enzyme-linked immunosorbent assay, and plasma C-reactive protein (CRP) levels were assayed by a biochemical analyzer. Metabolic syndrome-related risk factors such as waist circumference, hip circumference (HC), fasting glucose, fasting insulin, Homeostatic Model Assessment of Insulin Resistance, total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol and triglycerides of normal-weight adolescents were also evaluated.

Results

The level of leptin and CRP increased with increasing adiposity, whereas adiponectin levels were found to be negatively related to obesity. All plasma cytokine levels (adiponectin, leptin and resistin) were significantly elevated in female than male adolescents. Age-based classification revealed a distinct trend of variability in the levels of all the inflammatory markers among adolescents of varying age groups. Significant differences were observed between private and government schoolgoing adolescents in terms of anthropometric and inflammatory parameters, with higher adiposity indices in the former group. The relationship of plasma adipokine and CRP levels with various adiposity indices was found to be distinctly different between private and government schoolgoing students.

Interpretation & conclusions

Inflammatory markers were significantly elevated in overweight/obese adolescents. The socio-economic condition of urban Indian schoolgoing adolescents reflecting lifestyle transition has profound effects on their adiposity indices and inflammatory states. Longitudinal studies in different regions of the country need to be done to further confirm the findings.

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.

Inflaming sex differences in mood disorders

Men and women often experience different symptoms or rates of occurrence for a variety of mood disorders. Many of the symptoms of mood disorders overlap with autoimmune disorders, which also have a higher prevalence in women. There is a growing interest in exploring the immune system to provide biomarkers for diagnosis of mood disorders, along with new targets for developing treatments. This review examines known sex differences in the immune system and their relationship to mood disorders. We focus on immune alterations associated with unipolar depression, bipolar depression, and anxiety disorders. We describe work from both basic and clinical research examining potential immune mechanisms thought to contribute to stress susceptibility and associated mood disorders. We propose that sex and age are important, intertwined factors that need to be included in future experimental designs if we are going to harness the power of the immune system to develop a new wave of treatments for mood disorders.

Why monkeys do not get multiple sclerosis (spontaneously): An evolutionary approach

The goal of this review is to apply an evolutionary lens to understanding the origins of multiple sclerosis (MS), integrating three broad observations. First, only humans are known to develop MS spontaneously. Second, humans have evolved large brains, with characteristically large amounts of metabolically costly myelin. This myelin is generated over long periods of neurologic development—and peak MS onset coincides with the end of myelination. Third, over the past century there has been a disproportionate increase in the rate of MS in young women of childbearing age, paralleling increasing westernization and urbanization, indicating sexually specific susceptibility in response to changing exposures. From these three observations about MS, a life history approach leads us to hypothesize that MS arises in humans from disruption of the normal homeostatic mechanisms of myelin production and maintenance, during our uniquely long myelination period. This review will highlight under-explored areas of homeostasis in brain development, that are likely to shed new light on the origins of MS and to raise further questions about the interactions between our ancestral genes and modern environments.

Cardiovascular Adiponectin Resistance: The Critical Role of Adiponectin Receptor Modification

For the past two decades, a great deal of research has been published concerning adiponectin (APN), an abundant protein responsible for regulating numerous biologic functions including antioxidative, antinitrative, anti-inflammatory, and cardioprotective effects. A review of APN and its two major receptors is timely because of new findings concerning the mechanisms by which APN signaling may be altered in pathologic processes such as diabetes and heart failure. In this review we elaborate on currently known information regarding the physiologic role of APN and the known mechanisms underlying pathologic APN resistance - namely, APN receptor downregulation and phosphorylation - and provide insight regarding the future directions of APN research including an assessment of the clinical applicability of preventing pathologic post-translational modification of the APN receptor.

Interrelations among the adipocytokines leptin and adiponectin, oxidative stress and aseptic inflammation markers in pre- and early-pubertal normal-weight and obese boys

PURPOSE

Presumed interrelationships among deleterious aspects of adipose tissue metabolism, inflammation, and cellular oxidative stress could be influenced by pubertal hormonal changes. They were investigated in pre- and early pubertal normal-weight and obese boys before and after an exercise bout employed as an energy demanding stimulator.

METHODS

Cross-sectional study. Seventy-six healthy pre- (mean ± SD, 10.6 ± 0.2 years old, 28 normal-weight, and 11 obese) and early-(11.4 ± 0.2 years old, 25 normal-weight, and 12 obese) pubertal boys, were blood-sampled before and after a bout of exercise at 70% VO₂ max. Leptin, adiponectin, markers of inflammation (high-sensitivity C-reactive protein, high sensitivity IL-6), pro- (thiobarbitouric acid reactive substances, protein carbonyls) and anti- (glutathione, oxidized glutathione, glutathione peroxidase, catalase, total antioxidant capacity) oxidation were measured.

RESULTS

Baseline and post-exercise adiponectin was greater and leptin and high-sensitivity C-reactive protein were lower in normal-weight than in obese pre- and early pubertal boys, while high sensitivity IL-6 was greater in obese than in normal-weight pre-pubertal boys. In pre-pubertal obese boys: at baseline, high-sensitivity C-reactive protein correlated negatively with catalase; high sensitivity IL-6 correlated positively with protein carbonyls; Δ (difference during exercise) adiponectin correlated positively with Δcatalase. In all boys: at baseline, high sensitivity IL-6 correlated positively with leptin and was the best negative and the second best positive predictor for post-exercise glutathione/oxidized glutathione and protein carbonyls, respectively; leptin was the best negative predictor for post-exercise glutathione; waist to height ratio was the best positive predictor for post-exercise thiobarbitouric acid reactive substances; body mass index z-score and adiponectin were, respectively, the best positive predictor for post-exercise protein carbonyls and catalase.

CONCLUSIONS

In all subjects, leptin and adiponectin predict negatively and positively anti-oxidation, respectively, while high sensitivity IL-6 predicts positively and negatively pro- and anti-oxidation, respectively. High-sensitivity C-reactive protein is increased and negatively associated with anti-oxidation in pre-pubertal obese boys, suggesting that childhood obesity is associated with aseptic inflammation and oxidative stress.

The role of sex steroids in white adipose tissue adipocyte function

With the increasing knowledge that gender influences normal physiology, much biomedical research has begun to focus on the differential effects of sex on tissue function. Sexual dimorphism in mammals is due to the combined effects of both genetic and hormonal factors. Hormonal factors are mutable particularly in females in whom the estrous cycle dominates the hormonal milieu. Given the severity of the obesity epidemic and the fact that there are differences in the obesity rates in men and women, the role of sex in white adipose tissue function is being recognized as increasingly important. Although sex differences in white adipose tissue distribution are well established, the mechanisms affecting differential function of adipocytes within white adipose tissue in males and females remain largely understudied and poorly understood. One of the largest differences in the endocrine environment in males and females is the concentration of circulating androgens and estrogens. This review examines the effects of androgens and estrogens on lipolysis/lipogenesis, adipocyte differentiation, insulin sensitivity and adipokine production in adipocytes from white adipose tissue with a specific emphasis on the sexual dimorphism of adipocyte function in white adipose tissue during both health and disease.

Ethnic and Sex Differences in Adiponectin: From Childhood to Adulthood

CONTEXT

Insulin resistance (IR) and type 2 diabetes are increasing, particularly in Hispanic (H) vs non-Hispanic White (NHW) populations. Adiponectin has a known role in IR, and therefore, understanding ethnic and sex-specific behavior of adiponectin across the lifespan is of clinical significance.

OBJECTIVE

To compare ethnic and sex differences in adiponectin, independent of body mass index, across the lifespan and relationship to IR.

DESIGN

Cross-sectional.

SETTING

Primary care, referral center.

PATIENTS

A total of 187 NHW and 117 H participants (8-57 y) without diabetes. Life stage: pre-/early puberty (Tanner 1/2), midpubertal (Tanner 3/4), late pubertal (Tanner 5, <21 years), and adult (Tanner 5, ≥21).

INTERVENTIONS

None.

MAIN OUTCOME MEASURE(S)

Fasting adiponectin, insulin, glucose, and revised homeostatic model assessment of insulin resistance.

RESULTS

Adiponectin was significantly inversely correlated with revised homeostatic model assessment of insulin resistance. Regarding puberty, adiponectin trended downward in late puberty, but only males were significantly lower in adulthood. By sex, adiponectin was lower in adult males vs females of both ethnicities. Regarding ethnicity, H adults of both sexes had lower adiponectin than NHW adults. Of note, in NHW females, adiponectin trended highest in adulthood, whereas in H females, adiponectin fell in late puberty and remained lower in adulthood.

CONCLUSIONS

Adiponectin inversely correlated with IR, trended down in late puberty, and was lowest in adult males. H adults of both sexes had lower adiponectin than NHW adults, and H females followed a more "male pattern," lacking the rebound in adiponectin seen in NHW females after puberty. These data suggest that adiponectin, independent of body mass index, may relate to the greater cardiometabolic risk seen in H populations and in particular H females.

High Prepubertal Leptin Levels Are Associated With Earlier Menarcheal Age

PURPOSE

Given the interplay between metabolic status and the reproductive system, factors governing energy homeostasis could influence the timing of pubertal onset. The aim of this longitudinal study was to determine the influence of metabolic peptides associated to adiposity on menarcheal age.

METHODS

The sample population included 168 girls. Anthropometric and biochemical variables were measured at a prepubertal baseline (6-8 years old) and 7 years later. Leptin and adiponectin levels were determined by Enzyme-Linked ImmunoSorbent Assay, insulin by radioimmunoassay and ghrelin by a multiplexed bead immunoassay.

RESULTS

Adjusted for body mass index, Spearman correlation analysis revealed a significant negative association between prepubertal leptin levels and menarche. The highest prepubertal leptin levels were observed in overweight girls with the earliest menarche. Menarcheal age was significantly associated with variation of adiponectin levels between both baseline and follow-up. Multiple regression analysis showed that prepubertal leptin was the only significant contributing factor, predicting 15.3% of variation in menarcheal age.

CONCLUSIONS

High leptin levels in prepubertal girls are associated with earlier menarcheal age, independent of body mass index. However, the relationship of ghrelin, insulin, or adiponectin levels with menarcheal age is not evident in our population.

Leptin and Adiponectin Serum Levels from Infancy to School Age: Factors Influencing Tracking

BACKGROUND

Early adiponectin and leptin in children correlate with those measured at a later age. Prenatal and early life factors may influence the pattern of leptin and adiponectin longitudinal changes. We aimed to identify subgroups of children with distinct trajectories of leptin and adiponectin over the first eight years of life, and to explore determinants predisposing an individual to be included in a specific trajectory class.

METHODS

The analysis was based on data obtained from the EU Childhood Obesity Project (CHOP) cohort. The current study involved 459 children with adiponectin and leptin measured at 6 months, 5½ and 8 years of age.

RESULTS

Three groups of leptin trajectories were identified: low-decreasing, medium-stable, and high-increasing, and two trajectory groups for adiponectin: lower and higher. The risk to be classified in the high-increasing group was higher than in the low-decreasing group for female gender (OR 10.67; 95% CI 4.94-23.05; p < 0.001); formula feeding (OR 3.34; 95% CI 1.11-10.09; p < 0.05); maternal overweight (OR 4.43; 95% CI 2.20-8.94; p < 0.001); and smoking in pregnancy (OR 4.14; 95% CI 2.07-8.29; p < 0.001). No predictors for being in the higher vs. lower adiponectin group were discovered.

CONCLUSIONS

Mothers' smoking during pregnancy, maternal overweight, and formula feeding distinguished different courses of leptin trajectories; but the effect may be associated with changes in adiposity.

Serotonin transporter gene polymorphism modulates inflammatory cytokine responses during acute stress

Cytokines are important mediators of various stress-related modulations of immune function. A major genetic factor determining inter-individual differences in stress reactivity is polymorphisms of the serotonin (5-hydroxytryptamine, 5HT) transporter (5HTT) gene. A short (S) variant, compared with a long (L) variant, of the promoter region of the 5HTT gene-linked polymorphic region (5HTTLPR) has been related to emotional and stress hyper-reactivity. The present study examined whether the 5HTTLPR can modulate responses of inflammatory cytokines under acute stress. Nine Japanese male participants carrying two copies of the S alleles and nine Japanese males carrying S and L alleles underwent the Trier Social Stress Test (TSST). Inflammatory cytokines, endocrine parameters, heart rate and subjective stress were measured before, during and after the task. The participants carrying the SS alleles, but not those carrying the SL alleles, showed a significant increase of IL-1β immediately after TSST. This hyper-reactivity to acute stress in individuals with the SS alleles was also observed in their heart rate and cortisol levels. These results suggest that the S allele of the 5HTTLPR is consistently associated with stress reactivity in multi-level stress-related biological systems.

The effect of exercise on lipid profiles and inflammatory markers in lean male adolescents: a prospective interventional study

BACKGROUND

Physical activity improves body composition and inflammatory markers in obese individuals, but little is known about the nonobese population.

OBJECTIVE

The aim of this study was to investigate associations between exercise and inflammatory cytokines in lean male adolescents in Taiwan.

METHODS

This interventional study enrolled a total of 79 normal body weight male adolescents [mean age, 16.8 (1.0) years] from the Army Academy of Taiwan. Body composition and inflammatory markers were measured at baseline and upon completion of a 12-week exercise intervention program.

RESULTS

Subjects' postintervention anthropometric measures, including waist circumference [74.6 (5.2)→72.6 (5.2) cm], hip circumference [92.3 (4.1)→89.9 (5.0) cm], body fat mass [10.2 (3.2)→8.2 (3.2) kg], and body fat percentage [15.8% (4.2)→12.6 (4.5)%] declined significantly compared to preintervention (all P<0.001), as did systolic blood pressure (P=0.002) and mean blood pressure (P = 0.020). Postintervention body height and free fat mass increased significantly (both P<0.001). Subjects' postintervention lipids including total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglycerides increased significantly (all P<0.001). Inflammatory markers including adiponectin [14.32 (6.68)→31.31 (30.53) μg/mL, P<0.001], interleukin 6 [2.15 (4.81)→2.86 (6.37) pg/mL, P=0.005], and C-reactive protein [1.00 (2.57)→2.30 (4.17) μg/mL, P<0.001] increased significantly postintervention, but not leptin.

CONCLUSIONS

Exercise training significantly improves body composition and anti-inflammatory adiponectin levels in lean male adolescents.

Reference values for leptin and adiponectin in children below the age of 10 based on the IDEFICS cohort

OBJECTIVE

To establish age- and sex-specific reference values for serum leptin and adiponectin in normal-weight 3.0-8.9-year old European children.

SUBJECTS AND METHODS

Blood samples for hormone analysis were taken from 1338 children of the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health Effects in Children and infantS) study cohort. Only normal-weight children aged 3.0-8.9 years were included (n=539) in our analysis. Using the General Additive Model for Location Scale and Shape, age- and sex-specific percentiles were derived. The influence of under/overweight and obesity on the proposed reference curves based on normal-weight children was investigated in several sensitivity analyses using the sample without obese children (n=1015) and the whole study sample (n=1338).

RESULTS

There was a negative age trend of adiponectin blood levels and a positive trend of leptin levels in boys and girls. Percentiles derived for girls were generally higher than those obtained for boys. The corresponding age-specific differences of the 97th percentile ranged from -2.2 to 4.6 μg ml(-1) and from 2.2 to 4.8 ng ml(-1) for adiponectin and leptin, respectively.

CONCLUSIONS

According to our knowledge, these are the first reference values of leptin and adiponectin in prepubertal, normal-weight children. The presented adiponectin and leptin reference curves may allow for a more differentiated interpretation of children's hormone levels in epidemiological and clinical studies.

Increased leptin/adiponectin ratio and free leptin index are markers of insulin resistance in obese girls during pubertal development

BACKGROUND

Modifications in body fat in obese patients during puberty determine changes in adipokines that affect insulin sensitivity.

AIMS

We hypothesized that the leptin/adiponectin (L/A) ratio and free leptin index (FLI) are good markers of insulin resistance (IR) and total body fat (TBF) during pubertal development.

METHODS

A prospective study of 32 obese girls (OG) and age-matched control girls (CG) was performed. OG were divided into those that maintained a weight loss (WL) of >1 SD of initial body mass index (BMI) (WL group, n = 25) and those without WL (NWL group, n = 7). Oral glucose tolerance tests (OGTT) were performed to evaluate IR. Correlations of adipokines, L/A, and FLI with BMI, waist circumference, percentage of TBF (%TBF) and IR were performed over pubertal development.

RESULTS

The L/A ratio and FLI were increased in OG at baseline. Both indexes decreased in the WL group as puberty progressed, with no change in CG or NWL. In the WL group, a correlation between L/A and FLI with OGTT and %TBF, and L/A and homeostasis model assessment (HOMA) was found throughout the study.

CONCLUSION

The L/A ratio and FLI are good markers to follow changes in IR and %TBF after WL during puberty. Insulin more accurately reflects the changes in IR than HOMA.

Effect of six-month lifestyle intervention on adiponectin, resistin and soluble tumor necrosis factor-α receptors in obese adolescents

The aim of this study was to evaluate the effect of a six-month lifestyle intervention on adiponectin, resistin, and two soluble forms of tumor necrosis factor-α receptor (sTNFR) in obese adolescents. A total of 54 obese adolescents aged 10 to 16 years completed the program. Twenty-four adolescents with normal weight at baseline were used as a control group. Our results demonstrated that obese adolescents had abnormal lipid profile, homeostasis model assessment (HOMA) index, adiponectin level (5.6 ± 2.7 vs. 7.6 ± 2.9 μg/mL, p = 0.005) as well as resistin level (31.0 ± 9.0 vs. 24.3 ± 8.5 ng/mL, p = 0.003), whereas levels of both sTNFRs were similar to those in normal weight subjects. After the six-month lifestyle intervention, obese adolescents had a slight but significant drop in standard deviation score-body mass index (SDS-BMI), a significant decrease in waist circumference, total cholesterol, triglycerides, HOMA index, as well as resistin, and a significant increase in adiponectin and high-density lipoprotein-cholesterol. In adolescents without decreased SDS-BMI, no change was observed in adipokines. Changes in adiponectin correlated negatively with changes in waist circumference (r = -0.275, p = 0.044). Changes in resistin correlated positively with changes in triglycerides (r = 0.302, p = 0.027). The study demonstrated the increase of resistin and the decrease of adiponectin in obese adolescents. Lifestyle intervention improved adipokine abnormalities in obese subjects.

Resistin levels are related to fat mass, but not to body mass index in children

The relationship of resistin levels with obesity remains unclear. The aim of this study was to determine resistin levels in prepubertal children and adolescents and evaluate their association with anthropometric parameters and body composition. The study population included 420 randomly selected 6-8-year-old children and 712 children aged 12-16 years. Anthropometric data were measured and body mass index (BMI) and waist-to-hip and waist-to-height ratios were calculated. Body composition was assessed using an impedance body composition analyzer. Serum resistin levels were determined using a multiplexed bead immunoassay. Resistin levels were not significantly different between sexes. No significant differences in serum resistin concentrations were found between obese, overweight, and normal weight children at any age, and no significant correlations were observed between resistin concentrations and weight or BMI. However, resistin levels showed a significant positive correlation with fat mass in 12-16-year-old children, particularly in girls. In addition to describing serum resistin levels in prepubertal children and adolescents, our study suggests that resistin is related to body fat rather than to BMI in adolescents.

Relationship of adiponectin with sex hormone levels in adolescents

BACKGROUND/AIMS

Adiponectin is an adipose tissue-derived adipocytokine which, starting at puberty, is present in lower levels in males than in females. In adults, a relationship between adiponectin levels and sexual hormones has been suggested, but this association remains unclear in children. Our study aimed to analyze the relationship of adiponectin with dehydroepiandrosterone sulfate, testosterone, estradiol, and sex hormone-binding globulin (SHBG) in adolescents.

METHODS

The population-based sample included 785 healthy 12- to 16-year-old children. Testosterone, estradiol, and dehydroepiandrosterone sulfate levels were assessed by radioimmunoassay. SHBG was measured by immunoradiometric assay. Adiponectin concentrations were measured by ELISA.

RESULTS

Adiponectin levels were positively correlated with SHBG and negatively correlated with the free androgen index independently of body mass index (BMI) and fat mass. No significant correlations were observed between adiponectin and total testosterone or estradiol. Multiple linear regression analysis showed that, after adjustment for BMI, SHBG appears as the primary predictor of adiponectin levels in both sexes, accounting for 5.7% of the variation in adiponectin levels in boys and 7.5% in girls.

CONCLUSION

Adiponectin is related to free androgen index and SHBG levels in adolescents after adjusting for BMI and fat mass, thus suggesting an association between adiponectin levels and androgen bioavailability that would explain the sex-based differences in adiponectin levels through life.

[Adipokines in healthy and obese children]

The worldwide increase in the prevalence of obesity in children and adolescents during the last decades, as well as the mounting evidence indicating that obesity is associated with an increased incidence of comorbidities and the risk of premature death, resulting in a high economic impact, has stimulated obesity focused research. These studies have highlighted the prominent endocrine activity of adipose tissue, which is exerted through the synthesis and secretion of a wide variety of peptides and cytokines, called adipokines. This review presents a summary of the current knowledge and most relevant studies of adipokine dynamics and actions in children, focusing on the control of energy homeostasis, metabolic regulation (particularly carbohydrate metabolism), and inflammation. The particularities of adipose secretion and actions in healthy children, from birth to adolescence, and the modifications induced by early onset obesity are highlighted.

Adipokines in childhood obesity

The worldwide increase in the prevalence of obesity in children and adolescents during the past decades, in addition to mounting evidence indicating that obesity is associated with an increased incidence of comorbidities and the risk of premature death, resulting in a high economical impact, has stimulated obesity-focused research. These studies have highlightened the prominent endocrine activity of adipose tissue, which is exerted through the synthesis and secretion of a wide variety of peptides and cytokines, called adipokines. In the present review, we have summarized the current knowledge and most relevant studies of adipokine dynamics and actions in children, focusing on the control of energy homeostasis, metabolic regulation (particularly, carbohydrate metabolism), and inflammation. The particularities of adipose secretion and actions in healthy children, from birth to adolescence, and the modifications induced by early-onset obesity are highlighted.

Sex hormones and HCV: an unresolved mystery

The biological differences between males and females advocate the ultimate need for gender-specific medicine. The variation in response to viral infection as well as therapy among different genders makes it very intriguing to reveal the responsible factors for causing this discrepancy. HCV is one of the most noxious infectious diseases, however the impact of gender on the response to HCV has received negligible attention in the literature. The controversial studies concerning the effect of gender on the outcome of interferon-based therapy urge a need to judge the gender discrepancy in host factors responsible for both interferon release and action. The main aim of this review is to disentangle the interplay between sex hormones and several viral and host factors responsible for viral clearance in an attempt to clarify the role of gender in modulating the response to HCV as well as interferon-based therapy.

Plasma total adiponectin levels in pediatrics: reference intervals calculated as a continuous variable of age

OBJECTIVE

Plasma total Adiponectin (tAN) is a novel biomarker with interesting potentialities in pediatrics. Age-related intervals are needed for the correct interpretation of results. In this study, we calculated the reference values for tAN using a large number of results derived from pediatric patients.

DESIGN AND METHODS

tAN was determined by ELISA in more than 4000 samples and the results collected in the Laboratory Information System were used for the calculation of reference intervals.

RESULTS

tAN reference values for the different age intervals were obtained and age related tAN reference intervals were calculated. Some differences were observed in males and females. In obese children, no correlation between age and tAN could be observed. On the contrary, significant relations were observed in the total group of patients and in healthy control subjects. For this reason, the parameters of the equations to calculate tAN reference values using age as a continuous variable were defined.

CONCLUSION

The use of continuous tAN reference intervals, calculated on age, should be considered a useful laboratory tool, at least in the pediatric population, for those biomarkers whose reference values have been shown to change from birth to the late adolescence.

Change of Body Composition and Adipokines and Their Relationship with Insulin Resistance across Pubertal Development in Obese and Nonobese Chinese Children: The BCAMS Study

A transient increase in insulin resistance (IR) is a component of puberty. We investigated the impact of body composition and adipokines on IR during puberty in Chinese children. This study included 3223 schoolchildren aged 6-18 years. IR was calculated using homeostasis model assessment (HOMA-IR). We revealed that body mass index (BMI) and waist circumference increased gradually during puberty in both genders, while fat-mass percentage (FAT%) increased steadily only in girls. Change of leptin showed striking sexual dimorphisms: in girls leptin increased steadily during puberty, whereas in boys, after a transient rise at the beginning of puberty, leptin declined by Tanner staging even in those overweight or obese. Inversely, adiponectin level decreased significantly during puberty. In both genders, HOMA-IR started to increase at the beginning of puberty, peaked in the middle, and revised at late puberty in overweight/obesity boys while it stayed high till the end of puberty in girls and normal weight boys. Multivariate regression analysis revealed that leptin presented a stronger indicator of HOMA-IR than anthropometric measures during puberty. Our results demonstrated that gender-specific FAT% and leptin changed with pubertal development. Leptin emerged as a stronger predictor of IR than traditional anthropometric indices, suggesting a prominent role in the development of pubertal IR.

Tracking blood glucose and predicting prediabetes in Chinese children and adolescents: a prospective twin study

We examined the tracking of blood glucose, the development of prediabetes, and estimated their genetic contributions in a prospective, healthy, rural Chinese twin cohort. This report includes 1,766 subjects (998 males, 768 females) aged 6–21 years at baseline who completed a 6-year follow-up study. Oral glucose tolerance test was performed for all subjects at both baseline and follow-up. We found that subjects with low fasting plasma glucose (FPG) or 2 h post-load glucose (PG) levels at baseline tended to remain at the low level at follow-up. Subjects in the top tertile of baseline plasma glucose tended to have a higher risk of developing prediabetes at follow-up compared to the low tertile: in males, 37.6% vs. 27.6% for FPG and 37.2% vs. 25.7% for 2hPG, respectively; in females, 31.0% vs. 15.4% for FPG and 28.9% vs. 15.1% for 2 h PG, respectively. Genetic factors explained 43% and 41% of the variance of FPG, and 72% and 47% for impaired fasting glucose for males and females, respectively; environmental factors substantially contribute to 2hPG status and impaired glucose tolerance. In conclusion, in this cohort of healthy rural Chinese children and adolescents, we demonstrated that both FPG and 2hPG tracked well and was a strong predictor of prediabetes. The high proportion of children with top tertile of blood glucose progressed to prediabetes, and the incidence of prediabetes has a male predominance. Genetic factors play more important role in fasting than postload status, most of which was explained by unique environmental factors.

[Paediatric obesities: from childhood to adolescence]

Obesity, as in every western country, is currently the most prevalent chronic disease in childhood in Spain. This has led to obesity being one of the most common consultations in general paediatrics and, particularly, in paediatric endocrinology. Furthermore, obesity associated comorbidities are increasing in prevalence in children and adolescents. It is widely accepted that this increase in the prevalence of obesity is derived from an imbalance between energy intake and expenditure, associated to the lifestyle in western countries. However, there is increasing evidence of the role of individual and familial genetic background in the risk of developing obesity. The pathophysiological basis of the mechanisms responsible for the control of appetite and energy expenditure are being discovered on the basis of the increasing known cases of human monogenic, syndromic and endocrine obesity. Thus it is no longer appropriate to talk about obesity but rather about «obesities», as their pathophysiological bases differ and they require different diagnostic and management approaches. In 2011, the paediatrician must be aware of this issue and focus the clinical history and physical examination towards these specific clinical sign and symptoms, to better manage the available diagnostic and therapeutic resources when faced with a child with obesity.

Serum concentrations of high-molecular weight adiponectin and their association with sex steroids in premenopausal women

At present, the association between adiponectin and sex hormones in women is controversial. Recent studies suggest that it is high-molecular weight (HMW) adiponectin and the HMW to total adiponectin ratio rather than total adiponectin that are associated with antiatherogenic activities, insulin sensitivity, metabolic syndrome, and prediction of cardiovascular events. The present study aimed to investigate whether measuring HMW adiponectin and the HMW to total adiponectin ratio rather than total adiponectin might be more useful to detect an association between circulating female sex steroids and adipocytokines. In a clinical trial, we investigated the associations of total adiponectin, HMW adiponectin, and the HMW to adiponectin ratio with several androgens and estradiol in 36 healthy premenopausal women with regular cycles. No association between the investigated sex hormones and adiponectin was observed. The HMW adiponectin was negatively correlated with estradiol after adjustment for age and body mass index. The HMW to total adiponectin ratio was significantly negatively associated with testosterone, free testosterone, and androstenedione. The testosterone to estradiol ratio, as a parameter for the estrogen-androgen balance, was not associated with adiponectin or the HMW isoform. In conclusion, there is a negative association between estradiol and HMW adiponectin, and between testosterone, free testosterone, and androstenedione and the HMW to adiponectin ratio. Thus, one mechanism whereby female sex steroids may influence the cardiovascular risk of women could be alteration of the relationship between HMW and total adiponectin concentrations in plasma.

Cord blood adiponectin and infant growth at one year

OBJECTIVE

The aim of this study was to determine the association between cord blood adiponectin and leptin and early infant growth at one year in small for gestational age (SGA) and appropriate for gestational age (AGA) infants.

STUDY DESIGN

In this prospective study adiponectin and leptin concentrations were determined in cord blood of (i) AGA newborns (n = 44) and (ii) SGA newborns (n = 24). At one year of age, height and weight were measured. Linear regression analysis was used to determine which factors were associated with anthropometric measurements at the age of one year.

RESULTS

(i) SGA neonates had a significantly lower median cord blood adiponectin and leptin than AGA neonates; (ii) among SGA neonates, cord blood adiponectin concentrations were negatively correlated with body weight at one year, weight gain after one year and with BMI at one year; and (iii) among AGA neonates cord blood adiponectin concentrations were negatively correlated with body weight at one year, weight gain after one year and with BMI at one year.

CONCLUSION

The disparity in cord blood adiponectin and leptin concentrations between SGA and AGA neonates suggests a role for adipokines in fetal growth.

Childhood obesity: evidence of an association between plasminogen activator inhibitor-1 levels and visceral adiposity

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-1) has been considered as a cardiovascular risk factor, mainly because of its strong association with insulin resistance.

METHODS

To detect independent predictors of circulating PAI-1 levels in obese pediatric patients, we evaluated 86 subjects (mean age 10.7 +/- 2.8 years), 42 of whom were male (49%). Subjects were divided in two groups according to body mass index (BMI): obese subjects (n=61) and healthy non-obese controls (n=25). They were also divided by pubertal status. Besides anthropometric data, levels of PAI-1, leptin and biochemical markers of metabolic syndrome were measured.

RESULTS

The obese group had higher levels of PAI-1, leptin and biochemical markers of metabolic syndrome than nonobese controls (p<0.05). However, multivariate regression analysis showed that only puberty progression (p=0.005) and abdominal circumference/height index (p=0.002) remained independent predictors of PAI-1 levels.

CONCLUSION

In pediatric obesity, fat mass accumulation, mainly of visceral fat, and puberty progression were related to high PAI-1 levels, which might in turn contribute to cardiovascular risk.

Effect of weight loss on high-molecular weight adiponectin in obese children

Our aim was to determine the influence of weight reduction on total (T-) and high-molecular weight (HMW-) adiponectin in obese (OB) prepubertal children. Seventy OB prepubertal white patients were followed for 18 months and studied after reducing their BMI by 1 (n = 51) and 2 standard deviation scores (SDS) (n = 21) under conservative treatment, and 6 months after achieving weight loss (n = 44). Body composition dual-energy X-ray absorptiometry (DXA) and serum levels of T- and HMW-adiponectin, resistin, leptin, leptin soluble receptor (sOB-R), tumoral necrosis factor-α and interleukin-6 were determined. The control group consisted of 61 healthy prepubertal children. At diagnosis T-adiponectin was higher (P < 0.01; confidence interval (+0.04) - (+0.15)) and HMW-adiponectin lower (P < 0.001; confidence interval (-0.45) - (-0.21)) in OB children than in controls. A reduction in body fat increased T- and HMW-adiponectin and sOB-R (all P < 0.001) and decreased leptin (P < 0.001) and interleukin-6 levels (P < 0.05). After 6 months of sustained weight reduction a decrease in tumoral necrosis factor-α (P < 0.01) occurred, whereas weight recovery increased leptin (P < 0.001) and decreased T-adiponectin (P < 0.05). HMW-adiponectin levels negatively correlated with homeostasis model assessment (HOMA) index and BMI in the whole cohort (both P < 0.001), as did T-adiponectin levels and HOMA index in OB patients (P < 0.01), but neither T- nor HMW-adiponectin correlated with body fat content (BFC) in OB children. We conclude that the impairment of T- and HMW-adiponectin levels in childhood obesity is different to that in elder OB patients, showing closer relationship with carbohydrate metabolism parameters than with BFC, but increasing their levels after weight loss and in association with metabolic improvement.

Sex dimorphisms in inflammatory markers and adiposity in African-American youth

OBJECTIVE

There are demonstrated sex differences in the association between adiposity and inflammation in adults. Our aim was to determine sex differences in inflammatory markers and in the association between adiposity and inflammation in a sample of African-American adolescents.

METHODS

Adiposity variables including body mass index (BMI), waist circumference, weight, total fat, trunk fat, and inflammatory markers including interleukin-6 (IL-6), leptin, monocyte chemotactic protein 1 (MCP1), C-reactive Protein (CRP), adiponectin were examined in 166 (53% female) African-American adolescents, aged 14-19 years. Total fat and trunk fat were measured using Dual-Energy X-ray Absorptiometry (DXA).

RESULTS

Results revealed males had higher weight (p=0.01); females had higher BMI, trunk fat, and total fat (p's <0.01). With inflammation, males had higher MCP1 (p=0.024); females had higher leptin (p<0.001), adiponectin (p=0.006), and IL-6 (p=0.026). Partial correlations in males indicated associations of adiposity variables with leptin, adiponectin (all p's <0.01), and CRP (p<0.05); in females, leptin, CRP, and IL-6 were associated with adiposity variables (all p's <0.05). multiple regression analyses revealed female adiposity variables predicted CRP, (R(2)=0.254), IL-6 (R(2)=0.167), and MCP1 (R(2)=0.220). Adiposity variables in males predicted lower adiponectin (R(2)=0245). For both, leptin was predicted by adiposity (males R(2)=0.420 and females R(2)=0.410).

CONCLUSIONS

Data indicate clear sex dimorphisms in the associations between inflammatory markers and adiposity in African-American adolescents, suggesting that preventive measures and treatments for adolescent obesity may need to be sex-specific.