Recently discovered adipokines and cardio-metabolic comorbidities in childhood obesity

Nutritional Status and Selected Adipokines in Children with Irritable Bowel Syndrome

BACKGROUND

The aim of this study was to assess the nutritional status and serum concentrations of adipokines in children with irritable bowel syndrome (IBS) and healthy controls. We also sought to evaluate their relation to metabolic parameters.

METHODS

We studied 33 IBS patients (11 girls, 22 boys) aged 5-17 years and 30 healthy age-matched controls (11 girls, 19 boys). The analysis included anthropometric measurements, body composition parameter measurements using bioimpedance, and biochemical tests and measurements of serum concentrations of leptin, adiponectin, chemerin, and omentin-1.

RESULTS

The results of the anthropometric measurements were comparable between the patients and the controls. The patients had higher triglycerides, HOMA-IRs, and chemerin concentrations than the healthy subjects. The HDL cholesterol and omentin-1 levels were lower than in the controls. Leptin and adiponectin did not differ significantly between the groups. An analysis of the receiver operator curves (ROCs) showed that serum concentrations of chemerin ≥ 232.8 ng/mL had 30% sensitivity and 87% specificity when they were used to differentiate between children with IBS and healthy subjects. In the case of serum omentin-1 concentrations ≤ 279.4 ng/mL, the sensitivity and specificity were 60% and 80%, respectively.

CONCLUSIONS

The nutritional status of children with IBS did not differ from that of the healthy controls. We found significant differences in serum chemerin and omentin-1 concentrations between IBS patients and healthy children. These adipokines could be used as IBS biomarkers as they demonstrate good specificity and moderate sensitivity. The serum concentrations of chemerin and omentin-1 in IBS patients were related to nutritional status and insulin resistance.

The effect of high-intensity interval training on serum and adipose tissues vaspin levels in rats fed a high-fat high-sucrose diet

BACKGROUND

Vaspin is an adipocytokine with insulin-sensitizing and anti-inflammatory traits.

OBJECTIVES

The purpose of this study was to evaluate the effect of high-intensity interval training (HIIT) on serum, visceral and subcutaneous adipose tissue vaspin levels in rats exposed to a diet high in fat and sugar (HFS).

MATERIALS AND METHODS

Thirty-two male Wistar rats were randomly divided into HFS and standard diet (SD) groups. After 12 weeks, each group was divided into sedentary and HIIT groups. HIIT program was performed 3 times/week for 8 weeks. Retroperitoneal adipose tissue, inguinal adipose tissue and serum were collected to analyze vaspin levels. Also, serum glucose and insulin levels, insulin resistance index (HOMA-IR) and retroperitoneal and inguinal fat weights were measured.

RESULTS

HFS significantly increased weight gain, weight of inguinal (p=0.001) and retroperitoneal fat depots (p<0.001), serum glucose levels (p<0.001) and HOMA-IR (p<0.001). The HIIT was able to decline weight gain and fat mass (p<0.05) but did not affect inguinal and retroperitoneal fat depots' vaspin levels. Eight weeks' HIIT significantly increased serum vaspin (p=0.002) and decreased insulin (p=0.001) levels only in rats fed with SD.

CONCLUSIONS

Although the HIIT program can cause significantly reducing effects on weight gain and fat depots' weights, it does not effect on circulating and fat depots' vaspin levels in rats fed an HFS.

Changes of omentin-1 and chemerin during 4 weeks of lifestyle intervention and 1 year follow-up in children with obesity

AIMS

Data about the influence of short-term lifestyle intervention in children with obesity on long-term follow-up body weight, adipokines and cardiometabolic risk parameters is scarce.

METHODS

In a subgroup of the LOGIC-trial (Long-term Effects of Lifestyle Intervention in Obesity and Genetic Influence in Children), we assessed anthropometry (BMI, BMI-SDS (Standard Deviation Score), adipokines (omentin-1, chemerin, leptin, adiponectin) and cardiometabolic risk parameters, (e.g. hsCRP) in children with overweight/obesity after 4 weeks of lifestyle intervention (n = 156, 14.0 ± 1.8 yrs) and after one year follow-up (n = 50). Data were compared to normal weight children (JuvenTUM school cohort; n = 152, 13.3 ± 0.7 yrs).

RESULTS

Short-term lifestyle intervention was associated with a significant reduction in BMI and BMI-SDS (p < 0.001), with significant reductions in hsCRP, leptin, and chemerin levels, and an increase in adiponectin and omentin-1 levels (p < 0.001 for all). After one year follow-up a significant reduction in BMI and BMI-SDS was observed in children from the LOGIC-trial (p < 0.001). Improvements in adiponectin (p = 0.025) and chemerin levels (p = 0.027) were seen in children with clear weight loss success (BMI-SDS reduction ≥ 0.2), whereas children with no or only mild weight loss success showed an increase in leptin levels (p < 0.001). An increase in omentin-1 levels was observed after 1 year independent of weight change (p < 0.001).

CONCLUSION

Effects of short-term weight reduction on mean BMI and BMI-SDS persist over one year. Improvements in omentin-1 levels were independent of short-term or long-term weight loss.

TRIAL REGISTRATION

ClinicalTrials.gov: LOGIC-trial: NCT01067157, JuvenTUM-trial: NCT00988754.

The "Adipo-Cerebral" Dialogue in Childhood Obesity: Focus on Growth and Puberty. Physiopathological and Nutritional Aspects

Overweight and obesity in children and adolescents are overwhelming problems in western countries. Adipocytes, far from being only fat deposits, are capable of endocrine functions, and the endocrine activity of adipose tissue, resumable in adipokines production, seems to be a key modulator of central nervous system function, suggesting the existence of an “adipo-cerebral axis.” This connection exerts a key role in children growth and puberty development, and it is exemplified by the leptin–kisspeptin interaction. The aim of this review was to describe recent advances in the knowledge of adipose tissue endocrine functions and their relations with nutrition and growth. The peculiarities of major adipokines are briefly summarized in the first paragraph; leptin and its interaction with kisspeptin are focused on in the second paragraph; the third paragraph deals with the regulation of the GH-IGF axis, with a special focus on the model represented by growth hormone deficiency (GHD); finally, old and new nutritional aspects are described in the last paragraph.

Body image perception and body composition in early adolescents: a longitudinal study of an Italian cohort

BACKGROUND

Adolescence is a sensitive period of life in which everyone faces physical and psychological changes. No longitudinal studies considering changes in body image perception and body composition in Italian adolescents have been carried out. The aims of this study were to evaluate the longitudinal change in body composition and weight status in a sample of Italian students of both sexes over the 3 years of middle school and to analyse the influence of these parameters on the perception and satisfaction of one's own body image.

METHODS

Sixty-four males and seventy females were followed longitudinally from 11 to 14. Age at first measurement was 11.8 ± 0.3 yrs. in males and 11.9 ± 0.3 yrs. in females, then the students were measured again after 1 year and 2 years. Anthropometric measurements were collected and body composition was assessed by skinfolds. Maturity status was detected by age at menarche in females and by estimated age at peak height velocity in males; sports practice was assessed by a questionnaire. Body Silhouette Charts were used to assess body image perception. The degree of body image dissatisfaction and improper perception of weight status were evaluated. Univariate and multivariate analyses were applied.

RESULTS

Height, sitting height, leg length, and weight increments were higher in males than in females, and in both sexes the sitting height increment was higher than that of leg length. Skinfold thicknesses and percentage of body fat, showed a decrease in males and an increase in females over the 3 years. About 90% of the sample practiced sport during the 3 years. No significant variations in body image perception were observed among repeated measures but significantly differences were observed between sexes. Although the girls showed a lower incidence of overweight and obesity than boys, girls had a higher dissatisfaction than males. Males were less accurate in one's perception of one's own weight status.

CONCLUSIONS

The changes in body composition observed in the sample of the present study were in accordance with their maturity stage. An increase in parameters connected with adiposity is observed in females and a decrease in males. Body image perception did not seem to change with growth, but associations were found between body image perception and BMI and sex. Monitoring body image perception in young adolescents, especially in females and in overweight/obese subjects, is a priority to prevent nutritional disorders.

Association of chemerin gene promoter methylation in maternal blood and breast milk during gestational diabetes

The intrauterine environment and early-life nutrition are regulated by maternal biomarkers in the blood and breast milk. We aimed to explore epigenetic modifications that may contribute to differential chemerin expression in maternal plasma, colostrum, and breast milk and find its association with fetal cord blood and infant weight at 6 weeks postpartum. Thirty-three gestational diabetes mellitus (GDM) mothers and 33 normoglycemic mothers (NGT) were recruited. Two maternal blood samples (28th week of gestation and 6 weeks postpartum), cord blood, colostrum, and mature milk were collected. Methylation-specific polymerase chain reaction and enzyme-linked immunosorbent assay were conducted. The weight of the babies was measured at birth and 6 weeks postpartum. Serum chemerin levels at the 28th gestational week and 6 weeks postpartum were significantly lower for the NGT group as compared to the GDM group; (P < 0.05). Higher colostrum chemerin concentrations were observed in the GDM group and remained elevated in mature milk as compared to NGT (P < 0.05). Colostrum and breast milk chemerin levels showed an independent association with infant weight at 6 weeks postpartum (r = 0.270; P = 0.034) (r = 0.464; P < 0.001). Forty percent GDM mothers expressed unmethylated chemerin reflecting increased chemerin concentration in the maternal blood. This pattern was also observed in newborn cord blood where 52% of samples showed unmethylated chemerin in contrast to none in babies born to normoglycemic mothers. The results of this study highlight the critical importance of altered chemerin regulation in gestational diabetic mothers and its effect during early life period and suggest a possible role in contributing to childhood obesity.

High-Intensity Interval Training Does Not Change Vaspin and Omentin and Does Not Reduce Visceral Adipose Tissue in Obese Rats

This study aimed to determine the expression of omentin and vaspin, inflammatory markers, body composition, and lipid profile in diet-induced obese rats and high-intensity interval training (HIIT). Forty Wistar rats were divided into four groups: untrained normal diet, trained normal diet (T-ND), untrained high-fat diet (Unt-HFD), and trained high-fat diet (T-HFD). For the animals of the Unt-HFD and T-HFD groups, a high-fat diet was offered for 4 weeks. After that, all the animals in the T-ND and T-HFD groups were submitted to HITT, three times per week, for 10 weeks (2 weeks of adaptation and 8 weeks of HIIT). Muscle (gastrocnemius), liver, epididymal adipose tissue, retroperitoneal adipose tissue, visceral adipose tissue (VAT), and serum were collected to analyze TNF-α, IL-6, PCR, IL-8, IL-10, IL-4, vaspin, and omentin. A body composition analysis was performed before adaptation to HIIT protocol and after the last exercise session using dual-energy X-ray absorptiometry. Omentin and vaspin in the VAT were quantified using Western blotting. The results showed that, when fed a high-fat diet, the animals obtained significant gains in body fat and elevated serum concentrations of vaspin and blood triglycerides. The HIIT was able to minimize body fat gain but did not reduce visceral fat despite the increase in maximum exercise capacity. Moreover, there was a reduction in the serum levels of adiponectin, IL-6, and IL-10. Finally, we concluded that, although the training protocol was able to slow down the weight gain of the animals, there was no reduction in visceral fat or an improvement in the inflammatory profile, including no changes in omentin and vaspin.

Adipocyte Fatty Acid-Binding Protein 4 is Altered in Growth Discordant Dichorionic, but not in Monochorionic Twins

Context

The fetal period has a critical and long-lasting impact on the regulation of metabolic processes and a life-long predisposition for obesity and metabolic syndrome. The exact mechanisms are unknown, but epigenetic regulation likely plays a major role. Twins represent an excellent model to study these mechanisms, as they share the same intrauterine environment and similar or even the same genetic information. We examined cord blood levels of adipocyte fatty-acid binding protein 4 (A-FABP or FABP4), a novel adipokine correlated with obesity and metabolic disease in children and adults.

Objective

To examine A-FABP levels in the cord blood of twins with concordant and discordant growth and in singletons with intrauterine growth restriction (IUGR).

Design

Cohort study of 36 twin pairs (25 growth concordant and 11 growth discordant), and 42 singleton pregnancies (28 IUGR and 13 normally grown controls, 1 HELLP).

Outcome Measures

Cord blood A-FABP levels measured by enzyme-linked immunosorbent assay (ELISA).

Results

A-FABP levels were higher in the smaller of growth discordant dichorionic (DC) twins versus their co-twins (109.46 ± 62.80 ng/mL vs. 72.93 ± 36.66 ng/mL, P = 0.028). A-FABP was negatively correlated with birth weight and gestational age (P < 0.001), but not with birth weight z-score (P = 0.37).

Conclusions

Increased A-FABP levels might be associated with an increased metabolic risk in growth-restricted (twins) and prematurely born infants.

Metabolic Syndrome in Children and Adolescents: Diagnostic Criteria, Therapeutic Options and Perspectives

PURPOSE OF REVIEW

This review summarizes our current understanding of the metabolic syndrome (MetS) in children and adolescents. Special emphasis is given towards diagnostic criteria and therapeutic options.

RECENT FINDINGS

Consistent diagnostic criteria to define MetS in childhood and adolescence are not available to date. There is common agreement that the main features defining MetS include (1) disturbed glucose metabolism, (2) arterial hypertension, (3) dyslipidemia, and (4) abdominal obesity. However, settings of cut-off values are still heterogeneous in the pediatric population. Additional features that may define cardiometabolic risk, such as non-alcoholic fatty liver disease (NAFDL) or hyperuricemia, are not considered to date. Prevalence of childhood obesity has more than doubled since 1980, and 6-39% of obese children and adolescents already present with MetS, depending on the definition applied. There is common agreement that a consistent definition of MetS is urgently needed for children to identify those at risk as early as possible. Such definition criteria should consider age, gender, pubertal stage, or ethnicity. Additional features such as NAFDL or hyperuricemia should also be included in MetS criteria. Lifestyle modification is still the main basis to prevent or treat childhood obesity and MetS, as other therapeutic options (pharmacotherapy, bariatric surgery) are not available or not recommended for the majority of affected youngster.

Serum omentin-1 levels in obese children

Background Obesity is an important cause of morbidity, and it has an increasing frequency in childhood. Studies have reported that 33% of adults and 20-27% of children and adolescents are obese. Recently, it has been shown that the prevalence of obesity in the childhood group is higher than the past years. Omentin-1 is an adipokine which is synthesized from the visceral fat tissue but not synthesized in the subcutaneous fat tissue. Omentin-1 has been shown to increase insulin-mediated glucose uptake, especially in the adipose tissue. Studies have shown that plasma omentin-1 levels, which play an important role in the pathogenesis of insulin resistance, are significantly lowered in obese, polycystic ovary syndrome (PCOS) and diabetic patients. The aim of this study was to investigate the relationship between obesity and omentin-1 levels in children. Methods The study included obese children with a body mass index (BMI) greater than the 95th percentile and healthy children with a BMI lower than the 85th percentile. Obese and healthy individuals had similar age and sex distributions. Glucose, insulin, lipid profiles, thyroid panels and metabolic markers were evaluated. Results The levels of omentin-1 in obese children were significantly lower than in the control group (p<0.05). Results of Spearman's correlation analysis for all participants showed that omentin-1 levels were negatively related with triglycerides, total cholesterol, serum free thyroxine (FT4), insulin, homeostatic model assessment of insulin resistance (HOMA-IR), body weight, waist circumference (WC) and BMI percentile values. Conclusions Our findings indicate that serum omentin-1 levels are lower in obese children than in non-obese individuals. Omentin-1 can be used as a metabolic biomarker in children and adolescents.

Aerobic exercise decreases chemerin/CMKLR1 in the serum and peripheral metabolic organs of obesity and diabetes rats by increasing PPARγ

Objective

To investigate the influences of exercise on the levels of chemerin and its receptor chemokine-like receptor (CMKLR1) in the peripheral metabolic organs of obesity and diabetes rats, and whether the mechanism is related to peroxisome proliferator activated receptor γ (PPARγ), a key modulator of glycolipid metabolism.

Methods

Obesity rats induced by 8-week high fat diet (HFD) were randomly divided into obesity group (OB) and exercised obesity group (EOB) with 8 rats each group, and 40 diabetes rats established by 8-week HFD plus low dose of streptozotocin were randomly divided into 4 groups: diabetes group (DM), exercised diabetes group (EDM), exercised diabetes plus PPARγ agonist pioglitazone group (EDP), and exercised diabetes plus PPARγ antagonist GW9662 group (EDG). The rats in EOB, EDM, EDG and EDP groups participated in a 4-week moderate-intensity aerobic exercise on a treadmill with gradually increasing intensity, once a day and 6 days/week, and 30 min before each exercise EDP and EDG were administrated to the rats in EDP and EDG groups, respectively. Before and after 4-week exercise, glycolipid metabolism indexes, serum chemerin and the levels of chemerin and CMKLR1 in metabolic organs such as liver and gastrocnemius were investigated (not detecting adipose for no available perirenal adipose from DM rats).

Results

(1) In addition to serum chemerin, the levels of chemerin and CMKLR1 in the liver and gastrocnemius of EOB and EDM rats were declined, accompanied with the improved glycolipid metabolism. (2) The decreased chemerin/CMKLR1 in the EDM rats were reversed by PPARγ antagonist GW9662 and further strengthened by PPARγ agonist pioglitazones.

Conclusions

Besides serum chemerin, the levels of chemerin/CMKLR1 in the metabolic organs of obesity and diabetes rats were alleviated by exercise, which were likely to be associated with the improvement of glycolipid metabolism. Exercise-induced decrements of chemerin/CMKLR1 in the diabetes rats were mediated by PPARγ.

Electronic supplementary material

The online version of this article (10.1186/s12986-019-0344-9) contains supplementary material, which is available to authorized users.

Glucose Metabolism in Turner Syndrome

Turner syndrome (TS) is one of the most common female chromosomal disorders. The condition is caused by complete or partial loss of a single X chromosome. Adult patients with TS have a high prevalence of diabetes mellitus (DM). Deranged glucose metabolism in this population seems to be genetically triggered. The traditional risk factors for DM in the general population may not play a major role in the pathogenesis of DM in patients with TS. This review focuses on the latest research studies pertaining to abnormalities of glucose metabolism in TS. We extensively review the available evidence pertaining to the influence of insulin secretion and sensitivity, obesity, autoimmunity, lifestyle, growth hormone, and sex hormone replacement therapy on the occurrence of DM in these patients.

The correlation between serum adipokines levels and metabolic indicators in girls with Turner syndrome

OBJECTIVE

The following study investigated the serum adiponectin, chemerin and vaspin levels and their relationship with body mass index (BMI), glucose and lipid metabolism in girls with Turner Syndrome (TS).

METHODS

A total of 64 girls with TS (mean age, 12.22 ± 3.98 years; mean BMI, 18.90 ± 3.45 kg/m²) were ascertained by chromosome analysis. Height, weight, waist circumference, hip circumference and blood pressure were measured, as well as the levels of fasting plasma glucose (FPG), fasting plasma insulin, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG). The BMI, BMI standard deviation score (SDS), waist to hip ratio, waist to height ratio and insulin resistance index (HOMA-IR) were calculated. The TS group and the control group were subdivided into non-puberty or puberty subgroup.

RESULTS

The TS group had higher waist to hip ratio and waist to height ratio compared to the control group. There was no significant difference in FPG, fasting plasma insulin, HOMA-IR, blood lipid and blood pressure between the two groups. Significantly higher serum levels of adioponectin (12.51 ± 4.58 μg/ml) and chemerin (173.71 ± 37.88 ng/ml) and significantly lower levels of vaspin (0.67 ± 0.47 ng/ml) were found in the TS group compared to the control group (9.30 ± 3.17 μg/ml, 159.43 ± 23.19 ng/ml and 1.06 ± 0.49 ng/ml, respectively) (all P < 0.05). In the TS group, adiponectin levels were negatively correlated with age, BMI and TG (r = -0.251, -0.247, -0.294, P < 0.05 for all). In the control group, adiponectin levels were negatively correlated with BMI and BMI SDS (r = -0.416 and -0.315, P < 0.05 for both), while vaspin levels were positively correlated with age, fasting plasma insulin and HOMA-IR (r = 0.257, 0.273 and 0.282, P < 0.05 for all). In addition, significantly higher levels of adiponectin were found in the non-puberty subgroup (13.88 ± 4.49) μg/ml compared to puberty subgroup (9.72 ± 3.39) μg/ml (P < 0.05), while no significant differences in chemerin and vaspin were found between the two TS subgroups.

CONCLUSIONS

Elevated adiponectin and chemerin levels and significantly reduced vaspin were found in girls with TS. Puberty or estrogen replacement therapy may reduce adiponectin in girls with TS.

Novel Insights in the Metabolic Syndrome in Childhood and Adolescence

Metabolic syndrome (MetS) is recognized as an escalating major health risk in adults as well as in children and adolescents. Its prevalence ranges from 6 to 39% depending on the applied definition criteria. To date, there is no consensus on a MetS definition for children and adolescents. However, most authors agree on essential components such as glucose intolerance, central obesity, hypertension, and dyslipidemia; each representing a risk for cardiovascular disease. Recently, associations between MetS and non-alcoholic fatty liver disease, hyperuricemia, and sleep disturbances have emerged. Biomarkers like adipocytokines are a subject of current research as they are implicated in the pathogenesis of the MetS. Epigenetics and gestational programming, especially the role of microRNA, comprise a novel, rapidly developing and promising research focus on the topic of MetS. MicroRNAs are increasingly valued for potential roles in the diagnosis, stratification, and therapeutics of MetS. Early detection of risk factors, screening for metabolic disturbances, and the identification of new therapies are major aims to reduce morbidity and mortality related to MetS. Dietary modification and physical activity are currently the only adopted treatment approaches. Pharmacological therapies and bariatric surgery are still contradictory and, therefore, are only recommended in selected high-risk cases.

CHEMERIN AND FACTORS RELATED TO CARDIOVASCULAR RISK IN CHILDREN AND ADOLESCENTS: A SYSTEMATIC REVIEW

OBJECTIVE

To review findings on chemerin and factors related to cardiovascular risk in children and adolescents.

DATA SOURCE

A systematic review was performed, according to the standards proposed by the PRISMA guideline, on PubMed, Science Direct, and Lilacs databases. The descriptor "chemerin" was used in combination with "children" and "adolescent", no time limit applied. The research encompassed only original articles written in English, conducted with human subjects - the adult and elderly populations excluded -, as well as literature reviews, brief communications, letters, and editorials.

DATA SYNTHESIS

After independent analyses of the studies by two reviewers, seven articles meeting the eligibility criteria, published between 2012 and 2016, remained for the review. Cross-sectional, prospective, cohort, and case-control studies were included. The importance of chemerin adipokines on the risk factors for cardiovascular disease is demonstrated by its association with obesity and diabetes mellitus, as well as clinical, anthropometric, and biochemical parameters. However, the strength of evidence from these studies is relatively low, due to their heterogeneity, with several limitations such as small samples and consequent lack of representativeness, lack of standardization in dosage methods, cross-sectional design of most studies, and impossibility of extrapolating results.

CONCLUSIONS

The deregulation of chemerin caused by increased adipose tissue may contribute to the development of cardiovascular diseases, suggesting that this adipokine may play a significant role in early identification of individuals at risk.

Decrease in serum chemerin through aerobic exercise plus dieting and its association with mitigation of cardio-metabolic risk in obese female adolescents

BACKGROUND

The objective of this study was to determine the effects of a 4-week aerobic exercise plus dieting intervention on serum chemerin in obese female adolescents and its possible role in mitigating cardio-metabolic risk including glucose and lipid metabolism, central fat and inflammation.

METHODS

Fifty obese female adolescents were randomly divided into two groups: exercise plus dieting group (n=30) and dieting group (n=20). The participants in the exercise plus dieting group completed 4 weeks of moderate aerobic exercise combined with dieting, while the subjects in the dieting group undertook only dieting. Before and after the experiments, anthropometric index, parameters of glucose and lipid metabolism, serum chemerin and classic inflammatory indicators (C-reactive protein [CRP], tumor necrosis factor-α [TNF-α], interleukin-1β [IL-1β], IL-6, leptin and adiponectin) were measured.

RESULTS

Compared with the dieting group, a decrease in serum chemerin was found in the exercise plus dieting group, accompanied by significant improvements in anthropometric index, glucose and lipid metabolism and inflammatory factors. In addition, a higher serum chemerin level was found in obese adolescents with metabolic syndrome (MetS), and the disappearance of MetS induced by exercise plus dieting might be related to the decrease in chemerin. Correlation analysis showed the correlations of the decrease in chemerin with the changes in body fat, glucose and lipid metabolic index, leptin and adiponectin/leptin ratio.

CONCLUSIONS

This is the first report that as short a duration as 4-week aerobic exercise plus dieting decreased serum chemerin in obese female adolescents, which might be associated with the improvement in glucose and lipid metabolism, mitigation of inflammation and decrease in MetS incidence, thus lowering cardio-metabolic risk, while no health benefit resulted from slight dieting.

Association of Childhood Obesity and the Immune System: A Systematic Review of Reviews

The growing prevalence of childhood obesity has become a serious health problem over the past decades. As the immune system is greatly affected by excess weight, in this review of reviews, we discuss the findings of review articles about the relationship between childhood/maternal obesity and children's immune system. We searched English-language articles in PubMed, Scopus, ISI Thomson Reuters, and Google Scholar databases. All relevant reviews, either systematic or narrative, were retrieved. Then their quality was assessed by using the Assessment of Multiple Systematic Reviews and International Narrative Systematic Assessment tools, respectively. In the final step, 26 reviews were included. Our review suggests that childhood obesity is associated with extensive changes in the serum levels of inflammatory and anti-inflammatory cytokines and proteins, as well as the number of immune cells and their behavior. Therefore, it might cause or exacerbate diseases such as asthma, allergy, atopic dermatitis (AD), and obstructive sleep apnea syndrome. Moreover, childhood obesity may reduce the immune system responsiveness to vaccines and microorganisms. Furthermore, studies suggest that maternal obesity increases the risk of asthma in offspring. Future studies are needed to determine different associations of childhood obesity with allergy, atophic dermatitis, and autoimmune diseases.

Adipose Tissue-Derived Omentin-1 Function and Regulation

Omentin-1, also known as intelectin-1, is a recently identified novel adipocytokine of 313 amino acids, which is expressed in visceral (omental and epicardial) fat as well as mesothelial cells, vascular cells, airway goblet cells, small intestine, colon, ovary, and plasma. The level of omentin-1 expression in (pre)adipocytes is decreased by glucose/insulin and stimulated by fibroblast growth factor-21 and dexamethasone. Several lines of experimental evidence have shown that omentin-1 plays crucial roles in the maintenance of body metabolism and insulin sensitivity, and has anti-inflammatory, anti-atherosclerotic, and cardiovascular protective effects via AMP-activated protein kinase/Akt/nuclear factor-κB/mitogen-activated protein kinase (ERK, JNK, and p38) signaling. Clinical studies have indicated the usage of circulating omentin-1 as a biomarker of obesity, metabolic disorders including insulin resistance, diabetes, and metabolic syndrome, and atherosclerotic cardiovascular diseases. It is also possible to use circulating omentin-1 as a biomarker of bone metabolism, inflammatory diseases, cancers, sleep apnea syndrome, preeclampsia, and polycystic ovary syndrome. Decreased omentin-1 levels are generally associated with these diseases. However, omentin-1 increases to counteract the acute phase after onset of these diseases. These findings indicate that omentin-1 may be a negative risk factor for these diseases, and also act as an acute-phase reactant by its anti-inflammatory and atheroprotective effects. Therapeutic strategies to restore omentin-1 levels may be valuable for the prevention or treatment of these diseases. Weight loss, olive oil-rich diet, aerobic training, and treatment with atorvastatin and antidiabetic drugs (metformin, pioglitazone, and exenatide) are effective means of increasing circulating omentin-1 levels. This review provides insights into the potential use of omentin-1 as a biomarker and therapeutic target for these diseases. © 2017 American Physiological Society. Compr Physiol 7:765-781, 2017.

Cord Blood Adipocyte Fatty Acid-Binding Protein Levels Correlate With Gestational Age and Birth Weight in Neonates

CONTEXT

Infants born small for gestational age (SGA) have increased risk for obesity and metabolic syndrome, but the underlying mechanisms are not fully elucidated. Adipocyte fatty acid-binding protein (AFABP) is an adipokine that has been implicated in modulation of insulin sensitivity and lipid metabolism. Higher plasma AFABP levels are associated with increased risk of metabolic syndrome and cardiovascular morbidity in adults. Alterations in AFABP levels during fetal growth have not been characterized.

OBJECTIVE

To examine AFABP levels in neonatal cord blood in relation to gestational age and birth weight.

DESIGN

A cross-sectional study of 361 neonates born at a tertiary academic center.

OUTCOME MEASURES

Plasma AFABP levels were measured by enzyme-linked immunosorbent assay. For comparison, venous samples from 26 adults were analyzed.

RESULTS

AFABP levels were higher in neonates compared with adults (P < 0.01). Preterm infants had higher AFABP levels [48.2 (31.2 to 73.3) ng/mL] compared with full-term infants [35.8 (25.1 to 51.5)] ng/mL, P < 0.01). There was a negative correlation between AFABP and gestational age (r = 0.28, P = 0.02). Among full-term infants, AFABP levels in SGA infants were lower [28.6 (24.2 to 37.3) ng/mL], compared with appropriate for gestational age [36.1 (25.5 to 50.4) ng/mL] and large for gestational age infants [45.0 (24.6 to 62.4) ng/mL, P < 0.05].

CONCLUSIONS

These associations may reflect the higher metabolic activity during fetal development. AFABP may also be involved in fetal growth and the association between SGA status and obesity and metabolic syndrome in later life.

Association between dietary pattern and cardiometabolic risk in children and adolescents: a systematic review

OBJECTIVE

To evaluate the association between dietary patterns and cardiometabolic risk factors in children and adolescents.

DATA SOURCE

This article followed the recommendations of PRISMA, which aims to guide review publications in the health area. The article search strategy included searches in the electronic databases MEDLINE via PubMed, Scopus, and LILACS. There was no date limitation for publications. The descriptors were used in English according to MeSH and in Portuguese according to DeCS. Only articles on dietary patterns extracted by the a posteriori methodology were included. The question to be answered was: how much can an "unhealthy" dietary pattern influence biochemical and inflammatory markers in this population?

DATA SYNTHESIS

The studies showed an association between dietary patterns and cardiometabolic alterations. The patterns were characterized as unhealthy when associated to the consumption of ultraprocessed products, poor in fiber and rich in sodium, fat, and refined carbohydrates. Despite the associations, in several studies, the strength of this association for some risk markers was reduced or lost after adjusting for confounding variables.

CONCLUSION

There was a positive association between "unhealthy" dietary patterns and cardiometabolic alterations in children and adolescents. Some unconfirmed associations may be related to the difficulty of assessing food consumption. Nevertheless, studies involving dietary patterns and their association with risk factors should be performed in children and adolescents, aiming at interventions and early changes in dietary habits considered to be inadequate.

Metallothioneins regulate the adipogenic differentiation of 3T3-L1 cells via the insulin signaling pathway

Knockout of metallothionein (MT) genes contributes to a heavier body weight in early life and the potential to become obese through the intake of a high fat diet (HFD) in mice. It has thus been suggested that MT genes regulate the formation of adipose tissue, which would become the base for later HFD-induced obesity. We evaluated the fat pads of mice during the lactation stage. The fat mass and adipocyte size of MT1 and MT2 knockout mice were greater than those of wild type mice. Next, we assayed the ability of small interfering RNA (siRNA) to silence MT genes in the 3T3-L1 cell line. The expressions of MT1 and MT2 genes were transiently upregulated during adipocyte differentiation, and the siRNA pretreatment led to the suppression of the expression of both MT mRNAs and proteins. The MT siRNA promoted lipid accumulation in adipocytes and caused proliferation of post-confluent preadipocytes; these effects were suppressed by an inhibitor of phosphatidylinositol 3-kinase (LY294002). In addition, MT siRNA promoted insulin-stimulated phosphorylation of Akt, a downstream kinase of the insulin signaling pathway. Enhanced lipid accumulation in 3T3-L1 cells resulting from MT-gene silencing was inhibited by pretreatment with an antioxidant, N-acetylcysteine, used as a substitute for antioxidant protein MTs. These results suggest that interference in MT expression enhanced the activation of the insulin signaling pathway, resulting in higher lipid accumulation in 3T3-L1 adipocytes.

Role of circulating adipocytokines vaspin, apelin, and visfatin in the loss of appetite in underweight children: a pilot trial

OBJECTIVES

To investigate serum concentrations of vaspin, apelin, and visfatin in underweight children and their association with anthropometric and nutritional markers of malnutrition.

SUBJECTS AND METHODS

We recruited 44 underweight prepubertal children (youngest age = 2 years) with thinness grades of 1, 2, and 3, and body weights < 90% of ideal body weight due to loss of appetite and less frequent hunger episodes. Forty-one healthy age- and gender-matched controls were also included in the study. Serum fasting vaspin, apelin, and visfatin concentrations were measured by enzyme immunoassay technique.

RESULTS

Mean vaspin and apelin levels were significantly lower in underweight children compared to controls (vaspin: 0.44 ± 0.18 vs. 0.58 ± 0.35 pg/mL, p = 0.024; apelin: 483.37 ± 333.26 vs. 711.71 ± 616.50 pg/mL, p = 0.041). Visfatin levels were lower in underweight children compared to controls, but the values were not statistically significant (177.81 ± 158.01 vs. 221.15 ± 212.94 pg/mL, p = 0.119).

CONCLUSIONS

In underweight children, decreased vaspin and apelin levels should be considered in the etiology of anorexia.