Adiponectin and insulin resistance in childhood obesity

Obesity, bone marrow adiposity, and leukemia: Time to act

Obesity has taken the face of a pandemic with less direct concern among the general population and scientific community. However, obesity is considered a low-grade systemic inflammation that impacts multiple organs. Chronic inflammation is also associated with different solid and blood cancers. In addition, emerging evidence demonstrates that individuals with obesity are at higher risk of developing blood cancers and have poorer clinical outcomes than individuals in a normal weight range. The bone marrow is critical for hematopoiesis, lymphopoiesis, and myelopoiesis. Therefore, it is vital to understand the mechanisms by which obesity-associated changes in BM adiposity impact leukemia development. BM adipocytes are critical to maintain homeostasis via different means, including immune regulation. However, obesity increases BM adiposity and creates a pro-inflammatory environment to upregulate clonal hematopoiesis and a leukemia-supportive environment. Obesity further alters lymphopoiesis and myelopoiesis via different mechanisms, which dysregulate myeloid and lymphoid immune cell functions mentioned in the text under different sequentially discussed sections. The altered immune cell function during obesity alters hematological malignancies and leukemia susceptibility. Therefore, obesity-induced altered BM adiposity, immune cell generation, and function impact an individual's predisposition and severity of leukemia, which should be considered a critical factor in leukemia patients.

Salivary and gingival crevicular fluid biomarkers of periodontal health and/or obesity among children and adolescents: A systematic review and meta-analysis

Objectives

To investigate the association of salivary and gingival crevicular fluid (GCF) biomarkers with periodontal status and obesity in children and adolescents.

Data/sources

A literature search up to July 2023 was conducted through PubMed, Web of Science, Embase, ProQuest Medical Database, ProQuest SciTech Premium Collection, and the Cochrane Library. Observational studies comparing salivary and GCF biomarkers in children and adolescents with compromised periodontal status and/or obesity were included for data extraction. A meta-analysis was performed to estimate the overall standardised mean difference.

Study selection

Fifteen observational studies met the inclusion criteria and were included in this systematic review. Meta-analysis was only applicable in synthesising the dyadic relationship between GCF biomarkers and obesity. The results demonstrated that children and adolescents with obesity had significantly higher GCF levels of tumour necrosis factor-alpha (SMD:0.56; 95% CI:0.07, 1.04), adiponectin (SMD:0.33; 95% CI:0.06, 0.60), leptin (SMD:0.52; 95% CI:0.15, 0.90), and interleukin-1 beta (SMD:0.71; 95% CI:0.44, 0.99) than those with normal weight.

Conclusion

To date, no study has well addressed the triadic association between salivary or GCF biomarkers, periodontal status, and obesity among children and adolescents. Further in-depth, high-quality studies are required to investigate these associations.

Clinical significance

Periodontal disease and obesity are growing public health crises worldwide. Their relationship has been intensively studied. Investigating the salivary or GCF biomarkers alterations could help better understand the relationship between periodontal disease and obesity, which would assist in tailoring future oral health promotion programs.

Effect of Sprint Interval Training on Cardiometabolic Biomarkers and Adipokine Levels in Adolescent Boys with Obesity

This study investigated the effect of supervised sprint interval training (SIT) on different cardiometabolic risk factors and adipokines in adolescent boys with obesity. Thirty-seven boys were allocated to either a SIT group (13.1 ± 0.3 years; body mass index [BMI]: 30.3 ± 0.9 kg·m^-2) or a control group (CONT) (13.7 ± 0.4 years; BMI: 32.6 ± 1.6 kg·m^-2). The SIT group performed 4-6 × 30 s all-out cycling sprints, interspersed with 4 min rest, for 3 sessions/week, during a 12-week period, while the non-exercising CONT group maintained a habitual lifestyle. Anthropometric measurements, triglycerides, fasting insulin and glucose, total cholesterol (TC), high- (HDLc) and low-density (LDLc) cholesterol, leptin and adiponectin in blood, cardiorespiratory fitness (CRF), and a metabolic syndrome severity risk score (MSSS) were calculated before and after the 12-week period. Compared to baseline values, a significant reduction in MSSS was seen in the SIT group after intervention. LDLc showed favorable changes in SIT compared to CONT (-0.06 ± 0.1 vs. 0.19 ± 0.01 mmol·L^-1; p = 0.025). Additionally, CRF increased in the SIT group compared to the CONT group (5.2 ± 1.1 vs. -2.1 ± 1.1 mL·min^-1·kg^-1, p < 0.001). Moreover, a 12-week all-out SIT training effectively improves cardiometabolic health in adolescent boys with obesity.

Metabolic Derangement in Pediatric Patient with Obesity: The Role of Ketogenic Diet as Therapeutic Tool

Obesity is defined as a condition characterized by an excessive fat accumulation that has negative health consequences. Pediatric obesity is associated with an increased risk for many diseases, including impaired glycemic and lipidic control that may lead to the development of chronic, and potentially disabling, pathologies, such as type 2 diabetes mellitus (T2DM) and cardiovascular events, in adult life. The therapeutic strategy initially starts with interventions that are aimed at changing lifestyle and eating behavior, to prevent, manage, and potentially reverse metabolic disorders. Recently, the ketogenic diet (KD) has been proposed as a promising dietary intervention for the treatment of metabolic and cardiovascular risk factors related to obesity in adults, and a possible beneficial role has also been proposed in children. KD is very low in carbohydrate, high in fat, and moderate to high in protein that may have the potential to promote weight loss and improve lipidic derangement, glycemic control, and insulin sensitivity. In this review, we present metabolic disorders on glycemic and lipidic control in children and adolescents with obesity and indication of KD in pediatrics, discussing the role of KD as a therapeutic tool for metabolic derangement. The results of this review may suggest the validity of KD and the need to further research its potential to address metabolic risk factors in pediatric obesity.

Polycystic Ovary Syndrome in Insulin-Resistant Adolescents with Obesity: The Role of Nutrition Therapy and Food Supplements as a Strategy to Protect Fertility

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in young reproductive-aged women. PCOS is often associated with obesity and impairs reproductive health. Even though several theories have been proposed to explain the pathogenic mechanism of PCOS, the role of insulin resistance (IR) as a key etiological component, independently of (but amplified by) obesity, is well recognized. The consequent hyperinsulinemia activates excessive ovarian androgen production, leading to PCOS. Additionally, the state of chronic inflammation related to obesity impacts ovarian physiology due to insulin sensitivity impairment. The first-line treatment for adolescents with obesity and PCOS includes lifestyle changes; personalized dietary interventions; and, when needed, weight loss. Medical nutrition therapy (MNT) and the use of specific food supplements in these patients aim at improving symptoms and signs, including insulin resistance and metabolic and reproductive functions. The purpose of this narrative review is to present and discuss PCOS in adolescents with obesity, its relationship with IR and the role of MNT and food supplements in treatment. Appropriate early dietary intervention for the management of adolescents with obesity and PCOS should be considered as the recommended approach to restore ovulation and to protect fertility.

Adiponectin signalling in bone homeostasis, with age and in disease

Adiponectin is the most abundant circulating adipokine and is primarily involved in glucose metabolism and insulin resistance. Within the bone, osteoblasts and osteoclasts express the adiponectin receptors, however, there are conflicting reports on the effects of adiponectin on bone formation and turnover. Many studies have shown a pro-osteogenic role for adiponectin in in vivo murine models and in vitro: with increased osteoblast differentiation and activity, alongside lower levels of osteoclastogenesis. However, human studies often demonstrate an inverse relationship between adiponectin concentration and bone activity. Moreover, the presence of multiple isoforms of adiponectin and multiple receptor subtypes has the potential to lead to more complex signalling and functional consequences. As such, we still do not fully understand the importance of the adiponectin signalling pathway in regulating bone homeostasis and repair in health, with age and in disease. In this review, we explore our current understanding of adiponectin bioactivity in the bone; the significance of its different isoforms; and how adiponectin biology is altered in disease. Ultimately, furthering our understanding of adiponectin regulation of bone biology is key to developing pharmacological and non-pharmacological (lifestyle) interventions that target adiponectin signalling to boost bone growth and repair in healthy ageing, following injury or in disease.

Relationship between insulin resistance and adipocytokines: the mediator role of adiposity in children

Background: Leptin and adiponectin interact with each other in the modulation of obesity and insulin resistance (IR) and it is also important to consider the role of cardiorespiratory and muscular fitness in these relationships.Aim: To analyse the relationship between IR with adipocytokines in children, and to test the mediation effect of %BF (percentage of body fat) in the association of IR with leptin, adiponectin, and L/A ratio.Subjects and methods: This cross-sectional study comprised a sample of 150 schoolchildren, aged 6-11 years, from school in Porto Alegre, Brazil. The following variables were evaluated: cardiorespiratory fitness (CRF), muscular fitness (MF), percentage of body fat (%BF), and biochemical variables (leptin, adiponectin, glucose, and insulin).Results: IR was associated with leptin and L/A ratio, after adjustments for age, sex, sexual maturation, and CRF. When adjusted for age, sex, sexual maturation, and MF, an association was found between IR with leptin and L/A ratio. Moreover, %BF was a mediator in the association between IR and leptin, as well as IR and L/A ratio, explaining 54% and 57% of these associations, respectively.Conclusion: Leptin and L/A ratio are positively associated with IR after adjustments. Also, %BF is a mediator in the associations between IR and leptin and L/A ratio.

Adiponectin is associated with cardio-metabolic traits in Mexican children

The adipocyte-derived adiponectin hormone bridges obesity and its cardio-metabolic complications. Genetic variants at the ADIPOQ locus, in ADIPOR1, and ADIPOR2 have been associated with adiponectin concentrations and cardio-metabolic complications in diverse ethnicities. However, no studies have examined these associations in Mexican children. We recruited 1 457 Mexican children from Mexico City. Six genetic variants in or near ADIPOQ (rs182052, rs2241766, rs266729, rs822393), ADIPOR1 (rs10920533), and ADIPOR2 (rs11061971) were genotyped. Associations between serum adiponectin, genetic variants, and cardio-metabolic traits were assessed using linear and logistic regressions adjusted for age, sex, and recruitment center. Serum adiponectin concentration was negatively associated with body mass index, waist to hip ratio, low-density lipoprotein cholesterol, total cholesterol, triglycerides, fasting glucose, fasting insulin, homeostatic model assessment of insulin resistance, dyslipidemia and overweight/obesity status (7.76 × 10⁻⁴⁰ ≤ p ≤ 3.00 × 10⁻³). No significant associations between genetic variants in ADIPOQ, ADIPOR1, and ADIPOR2 and serum adiponectin concentration were identified (all p ≥ 0.30). No significant associations between the six genetic variants and cardio-metabolic traits were observed after Bonferroni correction (all p < 6.9 × 10⁻⁴). Our study suggests strong associations between circulating adiponectin concentration and cardio-metabolic traits in Mexican children.

The Relationship Between Glycemic Variability and Inflammatory Markers in Obese Children with Insulin Resistance and Metabolic Syndrome

OBJECTIVE

Increased glycemic variability (GV) is associated with increased oxidative stress, vascular complications, and mortality in metabolic syndrome (MS) and diabetes mellitus patients. To investigate the relationship between GV and inflammatory parameters in obese children with insulin resistance (IR) and to elucidate their effects on the development of MS.

METHODS

Fifty obese adolescents with IR were included in the study. All patients underwent anthropometric measurements, body fat analysis, and continuous glucose monitoring system (CGMS) for 24 hours. Serum lipids, adiponectin, and interleukin-6 (IL-6) levels were measured. GV coefficient (GVC) was calculated using the standard deviation and the average glucose value obtained by CGMS. IR was diagnosed according to the results of oral glucose tolerance test (OGTT). MS was diagnosed according to the modified World Health Organization and the International Diabetes Federation criteria.

RESULTS

Twenty-seven of the patients had MS and the remaining had only IR. Body fat mass, HbA1c, IL-6 levels, and peak insulin levels in the OGTT were significantly higher in the group with MS, but there was no difference in adiponectin levels. GVC was not different between the groups, but GVC significantly positively correlated with homeostasis model of assessment for IR, as well as with fasting, peak, and total insulin levels when all the patients were analyzed, while no significant relation was detected with adiponectin and IL-6 levels.

CONCLUSION

This study suggests that GV is not different among obese adolescents with IR and MS. There seems to be a significant association between GV and IR parameters. However, other diagnostic criteria of MS (hypertension and/or dyslipidemia) or elevated IL-6 levels does not cause further increase in GV.

Clustered Cardiovascular Risk Factors Are Associated with Inflammatory Markers in Adolescents

BACKGROUND

Clusters of cardiovascular risk (CVR) factors are associated with an increased risk of developing cardiovascular diseases (CVDs). This cross-sectional study assessed the associations between classic CVR factor clusters and inflammatory markers in Brazilian adolescents.

METHODS

Measurements included anthropometric, clinical and biochemical parameters and selected inflammatory markers in 487 adolescents (236 boys/251 girls; 12.06 ± 1.41 years).

RESULTS

After stratifying the population by gender and adjusting for potential confounding variables, principal component analysis was performed and it produced 5 independent components in both genders: adiposity, glucose metabolism, blood pressure, high-density lipoprotein (HDL)/triacylglycerols (TG), and cholesterol/low-density lipoprotein. Glucose metabolism was inversely associated with interleukin-1β (IL-1β) in both genders (r = -0.026; r = -0.021); blood pressure was inversely associated with tumor necrosis factor alpha (TNF-α) in girls (r = -0.046); HDL/TG was positively associated with interleukin-6 in girls (r = 0.012), with IL-1β (r = 0.010) TNF-α (r = 0.045) in boys, and inversely associated with adiponectin in both genders (r = -0.015; r = -0.013).

CONCLUSION

The results suggest that lipid metabolism alterations, as potential early events in the development of CVDs, have a strong link to the inflammatory process, in contrast to other clusters of risk factors.

Enhanced nutrition improves growth and increases blood adiponectin concentrations in very low birth weight infants

Background

Adequate nutrient supply is essential for optimal postnatal growth in very low birth weight (VLBW, birth weight<1,500 g) infants. Early growth may influence the risk of metabolic syndrome later in life.

Objective

To evaluate growth and blood metabolic markers (adiponectin, leptin, and insulin-like growth factor-1 (IGF-1)) in VLBW infants participating in a randomized nutritional intervention study.

Design

Fifty VLBW infants were randomized to an enhanced nutrient supply or a standard nutrient supply. Thirty-seven infants were evaluated with growth measurements until 2 years corrected age (CA). Metabolic markers were measured at birth and 5 months CA.

Results

Weight gain and head growth were different in the two groups from birth to 2 years CA (weight gain: p_interaction=0.006; head growth: p_interaction=0.002). The intervention group improved their growth z-scores after birth, whereas the control group had a pronounced decline, followed by an increase and caught up with the intervention group after discharge. At 5 months CA, adiponectin concentrations were higher in the intervention group and correlated with weight gain before term (r=0.35) and nutrient supply (0.35≤r≤0.45). Leptin concentrations correlated with weight gain after term and IGF-1 concentrations with length growth before and after term and head growth after term (0.36≤r≤0.53).

Conclusion

Enhanced nutrient supply improved early postnatal growth and may have prevented rapid catch-up growth later in infancy. Adiponectin concentration at 5 months CA was higher in the intervention group and correlated positively with early weight gain and nutrient supply. Early nutrition and growth may affect metabolic markers in infancy.

Clinical Trial Registration (ClinicalTrials.gov) no.: NCT01103219

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.

The comparison of chemerin, adiponectin and lipid profile indices in obese and non-obese adolescents

AIMS

The growing prevalence of obesity and its related metabolic disorders in adolescents shows the necessity of urgent focus on the related factors. Adipocytes secretions and their pro- or anti-inflammatory roles play effective roles in adipocytes metabolism. We assessed the relation between adiponectin, chemerin and lipid profile in hit phase of life.

METHODS

This case-control study conducted on 78 adolescent girls, divided based on BMI percentile. Serum chemerin, adiponectin, lipid profile and body fat mass were measured. Data were analyzed using Pearson correlation test. The interactive relation between these variables was assessed using Structural Equation Modeling (SEM). Data were analyzed using SPSS software and AMOS software.

RESULTS

Chemerin were correlated significantly with triglyceride (r=0.584 versus r=0.319), HDL-cholestrol (r=-0.323 versus r=-0.335), LDL-cholestrol (r=0.368 versus r=0.327) and fat mass (r=0.372 versus r=0.357) in obese versus non-obese girls; while the mentioned correlation were non-significant with total cholesterol in obese group (r=0.233 versus r=0.336). Furthermore, there were significant association between adiponectin and triglyceride (r=-0.404 versus r=-0.317), HDL-cholesterol (r=0.332 versus r=0.316) and fat mass (r=-0.529 versus r=-0.346) in obese versus non-obese girls, respectively.

CONCLUSION

There were positive associations between lipid profile components and serum chemerin levels. Adiponectin levels were in positive correlation with HDL-cholesterol concentrations. Chemerin showed positive correlations with potent health threatening components of lipid profile including triglyceride and cholesterol levels in adolescents.

Evidence in obese children: contribution of hyperlipidemia, obesity-inflammation, and insulin sensitivity

Background

Evidence shows a high incidence of insulin resistance, inflammation and dyslipidemia in adult obesity. The aim of this study was to assess the relevance of inflammatory markers, circulating lipids, and insulin sensitivity in overweight/obese children.

Methods

We enrolled 45 male children (aged 6 to 13 years, lean control = 16, obese = 19, overweight = 10) in this study. The plasma total cholesterol, HDL cholesterol, triglyceride, glucose and insulin levels, the circulating levels of inflammatory factors, such as TNF-α, IL-6, and MCP-1, and the high-sensitive CRP level were determined using quantitative colorimetric sandwich ELISA kits.

Results

Compared with the lean control subjects, the obese subjects had obvious insulin resistance, abnormal lipid profiles, and low-grade inflammation. The overweight subjects only exhibited significant insulin resistance and low-grade inflammation. Both TNF-α and leptin levels were higher in the overweight/obese subjects. A concurrent correlation analysis showed that body mass index (BMI) percentile and fasting insulin were positively correlated with insulin resistance, lipid profiles, and inflammatory markers but negatively correlated with adiponectin. A factor analysis identified three domains that explained 74.08% of the total variance among the obese children (factor 1: lipid, 46.05%; factor 2: obesity-inflammation, 15.38%; factor 3: insulin sensitivity domains, 12.65%).

Conclusions

Our findings suggest that lipid, obesity-inflammation, and insulin sensitivity domains predominantly exist among obese children. These factors might be applied to predict the outcomes of cardiovascular diseases in the future.

Endocrine and Metabolic Effects of Adipose Tissue in Children and Adolescents

Adipose tissue is implicated in many endocrine and metabolic processes. Leptin was among the first identified adipose-secreted factors, which act in an auto-, para- and endocrine manner. Since leptin, many other adipose tissue factors were determined, some primarily secreted from the adipocytes, some from other cells of the adipose tissue.

So-called adipokines are not only involved in obesity and its complications, as are insulin resistance, type 2 diabetes and other components of the metabolic syndrome, but also in growth, reproduction, bone metabolism, immune response, cancer development and many other important biological processes. Research in the field of adipokines has revealed new insights into the physiological and pathophysiologal processes and opened new therapeutic possibilities. In the present article, a special emphasis is devoted to research in children and adolescents.

Adiponectin/resistin levels and insulin resistance in children: a four country comparison study

Background

There are few reports on the effects of ethnicity or gender in the association between adipocytokines and insulin resistance in children of different ages. This study assessed associations between serum concentrations of adiponectin/resistin and parameters of insulin resistance in children from 4 different countries.

Methods

A total of 2,290 children were analyzed in this study; each was from one of 4 different countries (Japan, Thailand, Italy and USA), and grouped according to age (8–11 years old in Group 1 and 12–15 years old in Group 2).

Results

Adioponectin was higher in female than in male children, and in Group 1 than in Group 2. Generally, adiponectin was lower in Asian as compared to Italian and American children. These tendencies remained even after adjustment for body mass index (BMI) or waist circumstance (WC). Among older children (Group 2), resistin was higher in female than in male children. Significant correlations by non-parametric univariate correlation coefficients and Spearman’s rank correlation coefficients were found between adiponectin and homeostasis model assessment of insulin resistance (HOMA-IR), and fasting serum insulin levels in young Japanese, Italian, and American female children(p < 0.01, p < 0.05, p < 0.05, respectively). Correlations between serum adiponectin and HOMA-IR were also found among older male Italian, American, and Thai children (p < 0.05, p < 0.001, p < 0.001, respectively). In multiple regression analysis by forced entry method, adiponectin correlated with HOMA-IR in Italian and American male children, and in all older female children regardless of country of origin. There was no correlation between resistin and markers of insulin resistance in children from any of the countries.

Conclusions

We conclude that serum adiponectin concentrations are lower in Asian as compared to Italian and American children, and that adiponectin but not resistin contributes to differences in markers for insulin resistance in children from different populations.

Metabolic Setup and Risks in Obese Children

BACKGROUND

In the past decades, the obesity epidemic in children of all ages has been an important research field for detecting the metabolic causes and consequences of obesity, the major focus being on insulin and adipocytokine levels. Metabolic work-up in obese children is recommended in the age group as young as 2-6 years. There is evidence that birth weight can be a factor causing obesity later in life accompanied by metabolic complications.

METHODS

Insulin, leptin, and adiponectin levels were analyzed in 269 obese children and 60 controls, as well as 110 newborn children with different birth weight and different length of gestation, using standard methods.

RESULTS

In 53.6% of the obese children, complications of obesity such as diabetes mellitus, obesity, hyperlipidemia, heart attack or stroke were found in family members. The peak insulinemia on OGTT was significantly higher in the pubertal compared to the prepubertal group (110.5± 75.9 μU/mL versus 72.2±62.7 μU/mL) (p<0.005). Glucose intolerance was confirmed in 24%. The leptin level was significantly higher and the adiponectin level was lower in pubertal obese children compared to the prepubertal children and controls (p<0.05). In newborns the leptin and adiponectin levels were in correlation with anthropometric parameters: body weight (BW), body length (BL), BW/BL, BMI, and the pondered index (p<0.05).

CONCLUSION

Obese children have high insulinemia in all ages, reaching its peak towards puberty. The leptin and adiponectin levels might be indicators of the metabolic syndrome. Our findings in newborns might influence the nutritional approach in the future in order to prevent complications of obesity.

Abdominal obesity and serum adiponectin complexes among population-based elementary school children in Japan: a cross-sectional study

Background

There are a limited number of studies regarding the association between abdominal obesity and serum adiponectin complexes (high, medium, and low molecular weight adiponectins) among population-based elementary school children, especially in Japan, where blood collection is not usually performed during annual health examinations of school children. The aim of the present study was to investigate the relationship between abdominal obesity and serum adiponectin complexes among population-based elementary school children in Japan.

Methods

Subjects were all the fourth-grade school children (9 or 10 years of age) in the town of Ina during 2005–2008 (N = 1675). The height, weight, percent body fat, and waist circumference (WC) of each subject were measured. Blood samples were drawn from subjects to measure adiponectin isoform values. Childhood abdominal obesity was defined as “a waist-to-height ratio greater than or equal to 0.5” or “a WC greater than or equal to 75 cm”. The Wilcoxon rank-sum test and the logistic regression model were used to analyze the association between abdominal obesity and each adiponectin isoform value.

Results

Data from 1654 subjects (846 boys and 808 girls) were analyzed. Adiponectin complexes were lower in the abdominal obesity group than in the non-abdominal obesity group regardless of sex. Abdominal obesity significantly increased the odds ratio (OR) for each adiponectin isoform level less than or equal to the median value in boys; the OR (95% confidence interval [CI]) was 2.50 (1.59-3.92) for high molecular weight adiponectin (HMW-adn), 2.47 (1.57-3.88) for medium molecular weight adiponectin (MMW-adn), and 1.75 (1.13-2.70) for low molecular weight adiponectin (LMW-adn). In girls, the OR (95% CI) was 1.95 (1.18-3.21) for HMW-adn, 1.40 (0.86-2.28) for MMW-adn, and 1.06 (0.65-1.70) for LMW-adn.

Conclusions

Abdominal obesity was associated with lower adiponectin complexes and the influence of abdominal obesity varied by adiponectin isoform. Furthermore, the impact of abdominal obesity was larger in boys than in girls. The present study results suggest that prevention of abdominal obesity could contribute to the prevention of lower adiponectin levels, especially in boys.

The combined effects of physical exercise training and detraining on adiponectin in overweight and obese children

Background

The purpose of this study is to assess the combined exercise programs (12 weeks' physical exercise training, resistance and aerobic) and 6 weeks' detraining on the correlation of metabolic syndrome (MS) markers and plasma adiponectin level in two groups.

Methods

Participants were divided into two groups [physical exercise training group (EG, n = 8) and control group (CG, n = 7)]. The EG performed a 12-week training program (aerobic and resistance training twice/wk, more than 40 min/d). After 12 weeks' exercise training and 6 weeks' detraining, we also evaluated MS markers and plasma adiponectin at three time periods (baseline, EBP; 12 weeks' exercise program, 12 EP; 12 weeks' and 6 weeks' detraining, 12 + 6 EDP) in overweight and obese children.

Results

Compared with the CG, After the 12 weeks' exercise treatment, weight, body mass index (BMI), waist girth, percent body fat, lean body mass (LBM), percentage lean body, systolic blood pressure, and insulin and homeostatic model assessment (HOMA) indices were lowered in the EG, and plasma adiponectin levels were not altered in the EG. After 6 weeks' detraining, insulin, insulin resistance, and plasma adiponectin levels were significantly increased in the EG. In the adiponectin level, there were positive correlations with LBM and percent lean body and negative correlations with percent body fat, insulin, and insulin resistance after 12 weeks' physical exercise intervention and 6 weeks' detraining.

Conclusion

These findings suggest that combined physical training is a useful tool in the management of MS markers in the training periods. Moreover, there was an additive effect even after the 6-weeks detraining period.

Association of cardiac changes with serum adiponectin and resistin levels in obese and overweight children

OBJECTIVES

To investigate serum adiponectin and resistin levels in childhood obesity and their relationship with cardiac changes and insulin resistance.

METHODS

Seventy-one obese and 24 overweight children and 40 healthy children and adolescents were selected for the study. Height and weight measurements, BMI values and BMI SD score values were obtained for each individual. After blood pressure measurement, left ventricular wall thickness, left ventricular mass, stroke volume, cardiac output, systolic and diastolic functions of the left ventricle were measured using an M-mode, two dimensional color-coded echocardiography device. Blood samples of the individuals were obtained for fasting blood sugar, total blood cholesterol, triglyceride, low-density lipoprotein (LDL) cholesterol, very low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, insulin, C-peptide, adiponectin and resistin values.

RESULTS

Cholesterol and LDL values, homeostasis model assessment of insulin resistance, fasting insulin and fasting C-peptide values of the obese and overweight groups were higher (P<0.01). Adiponectin level (P<0.001) and resistin level (P<0.05) of the obese and overweight groups were lower than those of the control group (P<0.05). Echocardiographic evaluation showed diastolic dysfunction in addition to increased left ventricular wall thickness and left ventricle mass values in the obese and overweight children. We also detected a significant positive correlation among left ventricular mass, interventricular septum systolic diameter and resistin in obese children. Among the factors, resistin level was determined as an independent predictor of left ventricular mass in obese children.

CONCLUSION

In this study, even in asymptomatic obese and overweight children, cardiac structural and functional changes, such as increased left ventricular mass and diastolic dysfunction, were demonstrated. Although decreased adiponectin level was not related to cardiac changes, it was shown that decreased serum resistin levels in the obese cases lead to left ventricle hypertrophy.

Association of adiponectin gene G276T polymorphism with atherogenic indicators in obese children

Adiponectin plays a protective role against atherosclerosis. Genetic investigation has revealed that G276T adiponectin gene polymorphism is related to adiponectin concentration and metabolic disturbances. The aim of the present study was to investigate the association of adiponectin gene G276T polymorphism with indices of atherosclerosis in obese children. We examined 159 children (125 obese and 34 non-obese). G276T of adiponectin gene polymorphism was identified using a PCR-RFLP method. The intima media thickness (IMT) was evaluated in 82 patients. In all children, the anthropometric indices, fasting plasma total cholesterol (TC), HDL and LDL cholesterol, triglycerydes (TG), C-reactive protein (CRP), and adiponectin were measured. Oral glucose tolerance test (OGTT) also was performed. We found that the obese patients presented with higher values of atherogenic indicators than the non-obese patients. The indicators positively correlated with CRP and lipid concentrations. Ninety one percent of obese children presented with elevated IMT which correlated with CRP. The children with GG genotype (GG + GT allele) had lower values of BMI, TC, and TG but higher adiponectin concentrations. The mean level of adiponectin was statistically decreased in the compared with the homozygous TT children. The other anthropometric and atherogenic indicators did not differ between these two sets of obese children. We conclude that adiponectin concentrations were decreased in children with polymorphism G276T in adiponectin gene. The study, however, failed to show significant associations between carotid IMT, lipid markers, blood pressure, or HOMA-IR in obese children.

The role of PAI-1 and adiponectin on the inflammatory state and energy balance in obese adolescents with metabolic syndrome

Obesity is a chronic inflammatory disease and is considered a risk factor for metabolic syndrome. In this study, 57 obese adolescents with and without metabolic syndrome underwent 1 year of weight loss therapy. At baseline, the metabolic syndrome (MS) patients presented higher values of PAI-1 than the non-metabolic syndrome patients (n-MS). After therapy, significant improvements in anthropometrics and biochemical, inflammatory, and neuroendocrine variables were observed in both groups. However, the n-MS group presented better results than the MS group. Indeed, we found positive correlations in both groups between PAI-1 and neuropeptide Y (NPY) and between PAI-1 and NPY/AgRP. Inflammatory biomarkers may thus play a role in energy balance. The clinical trial registration number is NCT01358773.

Development of youth percent body fat standards using receiver operating characteristic curves

BACKGROUND

Few studies have identified health-related criterion standards of percent body fat (%BF) in U.S. youth. Further, existing standards are static thresholds (e.g., 25%, 30%) and do not account for normal growth and maturation.

PURPOSE

The purpose of this study was to identify thresholds of %BF in youth linked to metabolic syndrome in a large sample of U.S. children and adolescents.

METHODS

Percent fat was derived from the skinfold thicknesses of those aged 12-18 years, from the National Health and Nutrition Examination Survey (NHANES [1999-2004, N=1966]). Metabolic syndrome was classified using previously published standards based on the National Cholesterol Education Program/Adult Treatment Panel III adult values at age 20 years. Using %BF z-scores as the test and metabolic syndrome as the criterion, receiver operating characteristic (ROC) curve analysis was used to identify %BF thresholds.

RESULTS

ROC analysis indicated that %BF can be used with moderate accuracy to identify metabolic syndrome in adolescents. %BF thresholds of 22.3% and 35.1% in boys and 31.4% and 38.6% in girls (at age 18 years) were found to be indicative of "low" and "high" metabolic syndrome risk.

CONCLUSIONS

Age- and gender-specific %BF thresholds for creating separate risk groups were identified in relation to metabolic syndrome status. The selected thresholds identify adolescents with unfavorable metabolic profiles. These values could be extrapolated to younger children using previously created %BF centiles, which potentially allows for earlier identification and intervention of at-risk youth if tracking of current %BF was maintained.

Paracrine-acting adiponectin promotes mammary epithelial differentiation and synergizes with genistein to enhance transcriptional response to estrogen receptor β signaling

Mammary stromal adipocytes constitute an active site for the synthesis of the adipokine, adiponectin (APN) that may influence the mammary epithelial microenvironment. The relationship between "local," mammary tissue-derived APN and breast cancer risk is poorly understood. Here, we identify a novel mechanism of APN-mediated signaling that influences mammary epithelial cell proliferation, differentiation, and apoptosis to modify breast cancer risk. We demonstrate that early dietary exposure to soy protein isolate induced mammary tissue APN production without corresponding effects on systemic APN levels. In estrogen receptor (ER)-negative MCF-10A cells, recombinant APN promoted lobuloalveolar differentiation by inhibiting oncogenic signal transducer and activator of transcription 3 activity. In ER-positive HC11 cells, recombinant APN increased ERβ expression, inhibited cell proliferation, and induced apoptosis. Using the estrogen-responsive 4X-estrogen response element promoter-reporter construct to assess ER transactivation and small interfering RNA targeting of ERα and ERβ, we show that APN synergized with the soy phytoestrogen genistein to promote ERβ signaling in the presence of estrogen (17β-estradiol) and ERβ-specific agonist 2,3-bis(4-hydroxyphenyl)-propionitrile and to oppose ERα signaling in the presence of the ERα-specific agonist 4,4',4'-(4-propyl-(1H)-pyrazole-1,3,5-triyl)trisphenol. The enhancement of ERβ signaling with APN + genistein cotreatments was associated with induction of apoptosis, increased expression of proapoptotic/prodifferentiation genes (Bad, p53, and Pten), and decreased antiapoptotic (Bcl2 and survivin) transcript levels. Our results suggest that mammary-derived APN can influence adjacent epithelial function by ER-dependent and ER-independent mechanisms that are consistent with reduction of breast cancer risk and suggest local APN induction by dietary factors as a targeted approach for promotion of breast health.

Adiponectin as a biomarker of the metabolic syndrome in children and adolescents

The prevalence of obesity in children and adolescents has been increasing worldwide. As in adults, childhood obesity is closely related to hypertension, dyslipidemia, type 2 diabetes, and insulin resistance (IR) syndrome. Moreover, obese children have been found to be at increased risk of becoming obese adults. Obese children and adolescents tend to develop serious medical and psychosocial complications and also are at greater risk morbidity and mortality in adulthood. The molecular basis of the pathogenesis of obesity-linked disorders has not been fully elucidated. Adipose tissue serves not only as an energy storage organ, but also as an endocrine organ. It releases many factors with autocrine, paracrine and endocrine functions. Adipokines such as leptin, resistin, tumor necrosis factor-α, interleukin-6, adipsin, visfatin, and adiponectin are biologically active molecules produced by adipose tissue. They play a role in energy homeostasis, and in glucose and lipid metabolism. Adiponectin level, unlike that of other adipocytokines, is decreased in obesity and increased after weight reduction. Adiponectin has been associated with both central obesity and increased visceral adipose tissue and it has anti-inflammatory, anti-atherogenic, and potent insulin-sensitizing (anti-diabetic) effects.

Hormones and cytokines in childhood obesity

OBJECTIVE

Obesity is a growing worldwide health problem affecting both adults and children. Effective prevention and treatment modalities can be achieved by understanding the pathogenesis of obesity better. This review addresses some of the issues related to the hormones and cytokines taking part in the pathogenesis of obesity, energy balance and inflammation.

DESIGN

We reviewed current literature on this broad subject especially concentrating on the functions of the hormones and cytokines taking part in the pathogenesis of the childhood obesity. Using the key words obesity, children, hormones, cytokines publications and cross references were evaluated from PubMed database between 1957 and 2009.

RESULTS

In children, leptin and ghrelin are two hormones which have major influence on energy balance. Leptin is responsible from long term regulation of energy balance and ghrelin functions as an appetite stimulatory signal. In contrast to ghrelin, obestatin acts as an anorexigenic hormone by suppressing food intake. Adipokines secreted from adipose tissue are the key regulators of inflammation in obesity. Increased TNF-alpha and IL-6 levels but decreased levels of adiponectin and IL-10 are associated with increased inflammation, tissue injury and complications of obesity.

CONCLUSIONS

Development, pathogenesis and complications of childhood obesity consist of complex mechanisms including numerous cytokines and hormones. New treatment modalities depend on understanding these complex mechanisms.

Metabolic predictors for early identification of fatty liver using doppler and B-mode ultrasonography in overweight and obese adolescents

(1) to evaluate the frequency of asymptomatic fatty liver disease (FLD) using both Doppler and B-mode ultrasound (US) in overweight and obese adolescents; (2) to compare metabolic findings of fatty liver (FL) assessed by two methods; and (3) to evaluate metabolic predictors of FL shown by these methods. Fifty-nine overweight and obese adolescents aged between 9.0 and 17.0 years and 41 non-obese healthy adolescents were included in this study. B-mode and right hepatic vein Doppler ultrasonography (US) were performed and anthropometric indices, lipid profiles, and adiponectin levels were evaluated in all adolescents. HDL-C levels were significantly lower in patients with FL detected by Doppler US compared to patients without FL (p < 0.05). HDL-C levels were inversely correlated with presence of FL assessed by two methods (r = -0.285, p = 0.004; r = -0.328, p = 0.001, respectively) and adiponectin levels were correlated with presence of FL only detected by B-mode US (r = -0.263, p = 0.008). Adiponectin levels were significantly lower in patients with FL than those without FL assessed by B-Mode US (p = 0.049). Multiple regression analysis revealed that HDL-C levels was the most important predictor of FL assessed by Doppler US (p = 0.027), while body mass index was the determinant of FL assessed by two methods (p < 0.001) in asymptomatic overweight and obese adolescents. It was found that FLD, identified by both B-mode and Doppler US, is seen frequently in asymptomatic overweight and obese adolescents. Elevated BMI is associated with increased risk of FL assessed by two ultrasonographic methods. When using Doppler US, low HDL-C levels can be used as a good predictor for presence of FLD in overweight and obese adolescents.