Analysis of the association of leptin and adiponectin concentrations with metabolic syndrome in children: Results from the IDEFICS study

The role of adipokines and ghrelin in interactions and clinical implications in childhood obesity

BACKGROUND

Childhood obesity is a growing global health concern, especially prevalent in the Arabian Peninsula, and is known to contribute to metabolic syndrome and insulin resistance. This study aimed to investigate the interplay between adipokines (leptin and adiponectin), ghrelin, and insulin homeostasis in childhood obesity.

MATERIAL AND METHODS

A case-control study was conducted in Babylon involving 120 children/adolescents (7-17 years). The participants were divided into two groups: 60 obese and 60 healthy controls. Anthropometric and biochemical measures were examined, applying World Health Organization (WHO) growth standards to categorize weight status. Data on blood lipids, glucose, adipokines, and ghrelin were collected in Babylon (Merjan Medical City), ensuring accuracy and providing insights into pediatric obesity's metabolic and hormonal status.

RESULT

Clinical, anthropometric, and laboratory attributes of children were evaluated, with classification as normal-weight or obese based on BMI/Z-score and Waist Circumference. The obese group exhibited elevated triglycerides and insulin levels, as well as reduced adiponectin levels (P ≤ 0.001). Leptin levels showed a positive correlation with BMI/Z-score (r = 0.352, P = 0.006). A diagnostic model demonstrated the significant diagnostic capacity of leptin (AUC > 99%) and its importance in predicting childhood obesity. Each unit increase in leptin elevated the probability of obesity by a factor of 1.197 (95% CI: 1.0507-1.3632, P = 0.0068).

CONCLUSION

The study revealed significant differences in clinical, biochemical, and biological markers of obesity between the research groups and the control group. Leptin emerged as a significant predictor of obesity, demonstrating high diagnostic accuracy. The complex interactions among these adipokines underscore the necessity for comprehensive obesity management strategies.

Comparison of Diagnostic Models to Estimate the Risk of Metabolic Syndrome in a Chilean Pediatric Population: A Cross-Sectional Study

The pediatric population has various criteria for measuring metabolic syndrome (MetS). The diversity of consensus for diagnosis has led to different non-comparable reported prevalence. Given the increase in its prevalence in pediatric ages, it is necessary to develop efficient methods to encourage early detection. Consequently, early screening for the risk of MetS could favor timely action in preventing associated comorbidities in adulthood. This study aimed to establish the diagnostic capacity of models that use non-invasive (anthropometric) and invasive (serum biomarkers) variables for the early detection of MetS in Chilean children. A cross-sectional study was carried out on 220 children aged 6 to 11. Multivariate logistic regressions and discriminant analyses were applied to determine the diagnostic capacity of invasive and non-invasive variables. Based on these results, four diagnostic models were created and compared: (i) anthropometric, (ii) hormonal (insulin, leptin, and adiponectin), (iii) Lipid A (high-density cholesterol lipoprotein [HDL-c] and triglycerides [TG]) and (iv) Lipid B (TG/HDL-c). The prevalence of MetS was 26.8%. Lipid biomarkers (HDL-c and TG) and their ratio (TG/HDL-c) presented higher diagnostic capacity, above 80%, followed by body mass index (BMI, 0.71-0.88) and waist-to-height ratio (WHtR, 0.70-0.87). The lipid model A was the most accurate (sensitivity [S] = 62.7%, specificity [E] = 96.9%, validity index 87.7%), followed by the anthropometric model (S = 69.5%, E = 88.8% and validity index = 83.6%). In conclusion, detecting MetS was possible through invasive and non-invasive methods tested in overweight and obese children. The proposed models based on anthropometric variables, or serum biomarkers of the lipid model A, presented acceptable validity indices. Moreover, they were higher than those that measured adipokines, leptin, and adiponectin. The anthropometric model was the most cost-effective and easy to apply in different environments.

Neonatal Birthweight, Infant Feeding, and Childhood Metabolic Markers

OBJECTIVE

Antenatal and early neonatal nutritional environment may influence later metabolic health. Infants of mothers with gestational diabetes mellitus (GDM) have higher risk for childhood obesity and metabolic syndrome (MetS). Leptin and adiponectin are known biomarkers for MetS and may guide interventions to reduce later obesity. We sought to examine the relationship between birthweight, early infancy feeding practices, and biomarkers for MetS in offspring of women with mild GDM.

STUDY DESIGN

Secondary analysis of a prospective observational follow-up study on the offspring of women who participated in a multicenter randomized treatment trial on mild GDM. Children were evaluated by research coordinators and biospecimens collected at the age of 5 to 10. Plasma concentrations of leptin and adiponectin were compared between large for gestational age (LGA) and average birthweight (AGA) infants, and according to whether solid foods were introduced early (<6 months of age) or at the recommended age (≥6 months of age). Multivariable analysis adjusted for fetal sex, race/ethnicity, and maternal body mass index.

RESULTS

Leptin and adiponectin were measured in 336 plasma samples. In bivariate analysis, compared with AGA children, LGA children had lower leptin (5.0 ng/mL [3.6-6.0] vs. 5.8 ng/mL [4.5 = 6.6], p = 0.01) and similar adiponectin (6.3 µg/mL [5.1-7.9] vs. 6.4 µg/mL [5.3-8.6], p = 0.49) concentrations. Maternal/child characteristics were similar between the early/delayed solid feeding groups. Leptin and adiponectin concentrations were similar in the early fed and delayed feeding groups (5.8 ng/mL [4.6-6.7] vs. 5.6 ng/mL [4.2-6.6], p = 0.50 and 6.4 µg/mL [5.4-8.1] vs. 6.4 µg/mL [5.1-8.8], p = 0.85, respectively). After controlling for covariates, children who were LGA and AGA at birth had similar leptin concentrations.

CONCLUSION

Birthweight and early infancy feeding practice are not associated with alterations in leptin and adiponectin in children of women with mild GDM.

KEY POINTS

· Adipocytokines are markers of metabolic status.. · Children of women with mild GDM may be at risk for MetS.. · Biomarkers similar in LGA and AGA groups.. · Biomarkers similar in early and delayed solid-fed groups.. · Nonhuman milk does not modify effect of feeding practice..

Vascular Function and Distribution of Adiponectin Isomers during Puberty in Children and Adolescents with Obesity

INTRODUCTION

Youth with obesity have abnormal vascular function that relates to the anti-atherogenic adipose-derived hormone, adiponectin. The distribution of adiponectin isomers changes during normal puberty, but there are no data in relation to vascular function. We aimed to evaluate vascular function, adiponectin, and its isomers longitudinally in peri-pubertal youth with obesity and controls.

METHODS

The study is a cohort longitudinal study involving 30 children and adolescents with obesity (body mass index [BMI] z-score 2.31 ± 0.24; age 12.8 ± 3 years, 17 male participants) and 28 age-/sex-matched healthy controls (12.8 ± 3 years, 14 male participants). Vascular function (flow-mediated dilatation [FMD], glyceryl trinitrate-mediated dilatation [GTN]), total adiponectin and isomers, and laboratory and clinical variables were assessed at 0, 18, and 36 months.

RESULTS

FMD and GTN were stable during puberty in both groups, remaining consistently lower in obese children (p = 0.02, p < 0.001). The change in total (p = 0.02) and high-molecular weight (HMW) (p = 0.02) adiponectin differed between the groups: falling in controls by the end of puberty but not falling further during puberty in obesity. In obesity, impaired GTN was associated longitudinally with lower total (B = 7.85, p = 0.006) and HMW (B = 3.72, p = 0.03) adiponectin. In controls, more favourable GTN was longitudinally associated with a lower BMI z-score (B = -3.04, p = 0.027) and lower waist circumference (B = -0.35, p = 0.009).

CONCLUSIONS

Vascular dysfunction and lower levels of adiponectin are associated in children and adolescents with obesity during puberty and do not deteriorate further. Healthy children's better vascular function, within the normal range, is associated with a lower BMI z-score and waist circumference.

Sedentary Time and Fast-Food Consumption Associated With Weight Gain During COVID-19 Lockdown in Children and Adolescents With Overweight or Obesity

BACKGROUND

The coronavirus disease pandemic is predicted to have adverse health effects on children and adolescents who are overweight or obese due to restricted school activity and stay-at-home orders. The purpose of this observational study was to determine the factors associated with weight gain in children and adolescents with overweight and obesity during coronavirus disease 2019 (COVID-19) lockdown.

METHODS

Ninety-seven participants (sex- and age-specific body mass index (BMI) ≥ 85th percentile) were included. A baseline examination was conducted pre-COVID-19 (August 2019 to January 2020), and re-examination was performed post-lockdown (June to September 2020) and the results were compared. Correlation and regression analyses were conducted to investigate the association among changes in cardiometabolic markers and lifestyle behaviors with changes in BMI z-score.

RESULTS

During the COVID-19 pandemic, an increase in BMI z-score (2.56 [2.01-2.94] to 2.62 [2.03-3.18]) was noticed in children and adolescents with obesity. Changes in cardiometabolic markers including liver enzymes, triglycerides (r = 0.398), leptin (r = 0.578), and adiponectin (r = -0.326), as well as muscular strength (r = -0.212), were correlated with the increase in BMI z-score. According to a multivariate regression analysis, changes in sedentary time (B = 0.016; 95% confidence interval [CI], 0.001-0.032) and fast-food consumption (B = 0.067; 95% CI, 0.013-0.122) were the lifestyle variables associated with BMI z-score increase.

CONCLUSION

Changes in lifestyle behaviors including fast-food consumption and sedentary time during the COVID-19 pandemic may be associated with weight gain. In order to prevent health-related risks in children and adolescents with obesity during the pandemic, it is important to maintain the level of physical activity and healthy dietary habits.

Exercise training modulates adipokine dysregulations in metabolic syndrome

Metabolic syndrome (MetS) is a cluster of risk factors for various metabolic diseases, and it is characterized by central obesity, dyslipidemia, hypertension, and insulin resistance. The core component for MetS is adipose tissue, which releases adipokines and influences physical health. Adipokines consist of pro and anti-inflammatory cytokines and contribute to various physiological functions. Generally, a sedentary lifestyle promotes fat accumulation and secretion of pro-inflammatory adipokines. However, regular exercise has been known to exert various beneficial effects on metabolic and cognitive disorders. Although the mechanisms underlying exercise beneficial effects in MetS are not fully understood, changes in energy expenditure, fat accumulation, circulatory level of myokines, and adipokines might be involved. This review article focuses on some of the selected adipokines in MetS, and their responses to exercise training considering possible mechanisms.

Association of fibroblast growth factor 21 with metabolic syndrome and endothelial function in children: a prospective cross-sectional study on novel biomarkers

PURPOSE

Metabolic and cardiovascular disease prevention starting in childhood is critical for reducing morbidity later in life. In the present study, the association of novel biomarkers with metabolic syndrome (MS) and vascular function/structure indices of early atherosclerosis in children was investigated.

METHODS

This was a prospective study of 78 children (8-16 years of age) grouped based on the presence or absence of MS. The serum biomarkers investigated included fibroblast growth factor 21 (FGF21), leptin, adiponectin, and insulinlike growth factor binding protein-1 (IGFBP1). Endothelial function and carotid atherosclerosis were assessed based on brachial artery flow-mediated dilation (FMD) and carotid intima-media thickness, respectively.

RESULTS

Children with MS (n=12) had higher levels of FGF21 (median [interquartile range]: 128 [76-189] pg/mL vs. 60 [20-98] pg/mL, P=0.003) and leptin (18.1 [11-34.8] pg/mL vs. 7.5 [1.9-16.5] ng/mL, P=0.003), and lower levels of IGFBP1 (1.5 [1.2-2.1] ng/mL vs. 2.3 [1.5-6] ng/mL, P=0.028) compared with children without MS. FMD inversely correlated with FGF21 (Spearman rho= -0.24, P=0.035) and leptin (rho= -0.24, P=0.002) in all children. The best cutoff value of FGF21 levels for MS diagnosis was above 121.3 pg/mL (sensitivity/specificity, 58/86%). Only FGF21 was significantly associated with the presence of MS after adjustment for body mass index, age, and sex (odds ratio per 10 pg/mL increase: 1.10 [95% confidence interval, 1.01-1.22]; P=0.043).

CONCLUSION

Increased FGF21 levels were associated with the presence of MS and worse endothelial function in children. Larger studies are needed to evaluate the potential value of FGF21 as a biomarker that could predict future metabolic/cardiovascular disease at an early stage.

Appetitive behaviors and body composition in school-age years: Bi-directional analyses in a population-based birth cohort

Cross-sectional studies have consistently associated appetitive behaviors with child body mass index. However, few prospective studies have investigated the association between appetite and other measures of body composition and its directionality. We aimed to investigate the bi-directional relationship between appetitive behaviors and body composition in school-aged children. Data from 3668 children of the Generation XXI birth cohort were analyzed. Appetitive behaviors were assessed at 7 and 10 years through the Children's Eating Behavior Questionnaire. Higher fat mass and fat-free mass were measured through tetrapolar bioelectric impedance and waist-to-weight and waist-to-height ratios were calculated. Fat and fat-free mass indexes, waist-to-weight and waist-to-height age- and sex-specific z-scores were then calculated. Cross-lagged analyses were performed (body composition at 7 to appetitive behaviors at 10 and the reverse) to measure the magnitude and direction of associations. Fat mass and waist-to-height ratio at 7y predicted greater food approach behaviors at 10y (Enjoyment of Food, Food Responsiveness, Desire to Drink and Emotional Overeating), but not waist-to-weight, which seems to be consequence of child's avid appetite (e.g. Enjoyment of Food at 7y: β_standardized = 0.085, 95%CI = 0.041; 0.128, p < 0.001). Child scores on food avoidant behaviors, such as Satiety Responsiveness (β_standardized = -0.073, 95%CI = -0.110;-0.034, p < 0.001) and Slowness in Eating (β_standardized = -0.080, 95% CI = -0.120;-0.041, p < 0.001) at 7y predicted lower fat-free mass at 10. Appetitive behaviors may not solely predict weight status, but the path of association between body composition and later appetitive behavior may also be true, especially for food approaching behaviors and adipose tissue. Interventions aiming to prevent excess weight should focus on appetitive behaviors. Moreover, in children with higher adiposity, other pathways also seem to regulate appetite and need to be considered in interventions.

Adipokines and C-reactive protein as indicators of MetS presence in obese Greek children: The Healthy Growth Study

BACKGROUND

Metabolic syndrome (MetS) occurs in a proportion of overweight and obese children and increases their future risk of serious health complications, even in adolescence and young adulthood. We aimed to explore the role of certain adipokines and inflammatory markers in identifying children with MetS.

METHODS

This study is a secondary analysis of data coming from the Healthy Growth Study, a cross-sectional study conducted with schoolchildren in Greece. The present study included data from a representative sample of 1376 schoolchildren (mean age: 11.19 ± 0.66 years), recruited from 77 primary schools in four large regions in Greece. Anthropometric, clinical and biochemical data were recorded. Children's body weight status and the presence of MetS were determined and their correlation with the serum levels of leptin, adiponectin and C-reactive protein (CRP) was explored.

RESULTS

The prevalence of the MetS was 21.7 % and 3.7 % in obese and overweight children, respectively. The balance of adipokines was disturbed in obesity, as the serum level of adiponectin decreased as body weight increased, while the serum level of leptin increased. The serum level of the inflammatory marker CRP increased significantly as body weight increased. Discriminant analysis showed that these factors could distinguish the children with MetS as compared to children with no MetS.

CONCLUSIONS

In the under study Mediterranean childhood population, monitoring of the levels of adipokines and CRP could identify the overweight and obese children with MetS. Appropriate individualized dietary and lifestyle interventions can be applied in these children to prevent health complications associated with MetS.

Neonatal and Adolescent Adipocytokines as Predictors of Adiposity and Cardiometabolic Risk in Adolescence

OBJECTIVE

This study aimed to examine associations of changes in leptin and adiponectin concentrations from birth to age 12 years with adolescent adiposity and cardiometabolic risk in the Health Outcomes and Measures of Environment (HOME) Study, a prospective birth cohort (Cincinnati, Ohio; N = 166).

METHODS

Adiposity and cardiometabolic risk factors were assessed at age 12 years using anthropometry, dual-energy x-ray absorptiometry, and fasting serum biomarkers. Cardiometabolic risk scores were calculated by summing age- and sex- standardized z scores for individual cardiometabolic risk factors.

RESULTS

Most serum adipocytokine concentrations at birth were not associated with adiposity or cardiometabolic risk outcomes. Leptin and adiponectin concentrations at age 12 years were associated with all outcomes in the expected direction. Adolescents with increasing (β: 4.2; 95% CI: 3.2 to 5.2) and stable (β: 2.2; 95% CI: 1.2 to 3.2) leptin concentrations from birth to age 12 years had higher cardiometabolic risk scores than adolescents with decreasing concentrations (reference group). Adolescents with increasing (e.g., fat mass index = β: -1.04; 95% CI: -1.27 to -0.80) and stable (β: 0.66; 95% CI: -0.92 to -0.40) adiponectin/leptin ratios had more favorable adiposity outcomes than adolescents with decreasing ratios.

CONCLUSIONS

In this cohort, changes in leptin concentrations and adiponectin/leptin ratios over childhood were associated with adiposity and cardiometabolic risk scores, indicating that adipocytokine concentrations are potential biomarkers for predicting excess adiposity and cardiometabolic risk in adolescence.

CXCL8 expression and methylation are correlated with anthropometric and metabolic parameters in childhood obesity

Childhood obesity is a global and increasing health issue. Inflammation and dysregulated adipose tissue secretion are common findings in obesity and have been related to poor metabolic function. Given that DNA methylation impacts gene expression and is responsive to environmental changes, we aimed, in addition to characterize the patients in anthropometric and biochemical terms, to determine the expression of cytokines and adipokines, assess the methylation on regulatory regions of the genes that code for these molecules, and investigate the association of the expression and gene methylation with anthropometric and biochemical parameters in childhood obesity. Obese children present dyslipidemia, dysregulated serum levels of adipokines and their ratios, altered leukocytic expression of cytokines, and higher methylation at the CXCL8 promoter as compared to the control group. However, no significant results were observed in the fasting plasma glucose levels or the methylation of TGFB1, LEP, and the enhancer region of ADIPOQ. We also found negative correlations of CXCL8 expression with anthropometric and biochemical parameters, and positive correlation of CXCL8 promoter methylation and the serum levels of hepatic enzymes. Our results indicate that changes in metabolic parameters observed in childhood obesity are associated with the expression of adipokines and cytokines, and the methylation status at the CXCL8 promoter. CXCL8 may be a key factor for these alterations, as it correlates with many of the parameters assessed in the present study.

Liver Enzymes Correlate With Metabolic Syndrome, Inflammation, and Endothelial Dysfunction in Prepubertal Children With Obesity

Background: Metabolic syndrome (MetS) can start in children with obesity at very young ages. Non-alcoholic fatty liver disease (NAFLD) is considered to be the hepatic component of metabolic syndrome. If left untreated, the clinical course of NAFLD can be progressive and can become chronic if not detected at an early stage. Objective: We aimed to quantify the differences in liver enzymes between prepubertal children with obesity and children with normal weight to determine any associations between them and parameters related to MetS, adipokines, or markers of endothelial dysfunction and inflammation. Methods: This cross-sectional study included 54 prepuberal children with obesity (aged 6-9 years) and 54 children with normal weight, matched by age and sex. Liver enzymes, C-reactive protein (CRP), interleukin-6, soluble intercellular adhesion molecule-1 (sICAM-1), adipokines, and parameters related to metabolic syndrome (MetS) were all measured. Results: Alanine aminotransferase (ALT) levels, serum butyryl cholinesterase (BChE), leptin, CRP, sICAM-1, triglycerides, blood pressure, and homeostasis model assessment for insulin resistance were significantly higher in children with obesity, while Apolipoprotein A-1, HDL-cholesterol, and adiponectin were significantly lower. In the children with obesity group, ALT and BChE levels correlated with anthropometric measurements, insulin resistance, and lipid parameters, leptin, interleukin-6, CRP, and sICAM-1 while BChE levels negatively correlated with adiponectin. Conclusions: Compared to children with normal weight, prepubertal children with obesity had elevated values for liver enzymes, leptin, markers of insulin resistance, inflammation, and endothelial dysfunction, and variables associated with MetS. There was also a correlation between these disorders and liver enzyme levels.

Leptin at birth and at age 7 in relation to appetitive behaviors at age 7 and age 10

Leptin contributes to the control of food intake and energy balance. However, its association with appetitive behaviors during childhood is not well understood. We aimed to investigate the association between leptin, assessed at birth and at 7 years of age (y), and appetitive behaviors assessed at 7 and 10 y. Children from a Portuguese cohort with assessment of leptin levels at birth from umbilical cord blood (n = 645) and at 7 y from venous blood samples (n = 587), were included. The Children's Eating Behavior Questionnaire assessed appetitive behaviors at 7 and 10 y. Weight and height were measured at 7 and 10 y to derive BMI z-scores (BMIz). A series of Generalized Linear Models tested relationships between leptin and appetitive behaviors, adjusting for potential confounders (maternal age, education, pre-pregnancy BMI, smoking during pregnancy, child physical activity and child BMIz), and interaction terms for child sex and child BMIz. At 7 y, 116 boys and 118 girls were classified as having overweight/obesity, and these children had higher leptin levels. Cross-sectional analyses using the 7 y data produced the strongest results. Higher leptin at 7 y was significantly associated with lower scores on Satiety Responsiveness, Food Fussiness and Slowness in Eating, and higher scores on Food Responsiveness, Enjoyment of Food and Emotional Overeating at 7 y. Only the association with Emotional Overeating remained when adjusting for child BMIz. Significant interaction effects between child sex and leptin were found for appetite at 7 y, such that higher leptin was associated with higher Food Responsiveness (p < 0.001) and lower Slowness in Eating (p < 0.001) to a greater extent among boys. Umbilical cord blood leptin was not associated with appetitive behaviors at 7 or 10 y. Our results show that leptin levels are positively associated with food approach and negatively with food avoidant behaviors. Associations were more consistent in cross-sectional analyses (at 7 y), were largely dependent on child weight, and tended to be stronger among boys. Our findings support a role for leptin in affecting appetite, with potential consequences for current weight status and future weight gain.

Clinical Outcomes in Critically Ill Children With Excess Weight: A Retrospective Cohort Study

BACKGROUND

Because of its high prevalence and negative impact on quality of life and longevity, overweight in childhood and adolescence is a major public health concern. The objective of the present study was to determine whether excess weight is associated with clinical outcomes in critically ill children and adolescents admitted to the pediatric intensive care unit (PICU).

METHOD

This retrospective cohort study was performed with children and adolescents admitted to a PICU over 3 years. Nutrition status was classified based on the body mass index z-score for age, following World Health Organization (WHO) criteria. The following outcomes were assessed: mortality, need for mechanical ventilation, length of admission, and multiple organ dysfunction syndrome.

RESULTS

Of 1468 patients admitted during the study period, 1407 were included in the study: 956 (68.0%) had adequate weight, 228 (16.2%) were overweight, and 223 (15.8%) were underweight. Associations were detected between most variables and all nutrition categories (underweight, adequate weight, and overweight). In the descriptive analysis, mortality was more prevalent in nutrition status extremes (extremely underweight or overweight). An independent association between nutrition status and mortality was not detected in any category.

CONCLUSION

Nutrition status was not independently associated with poor outcomes. However, overweight should be considered a potential risk factor for adverse clinical outcomes in PICU admissions.

Prospective Associations of Serum Adiponectin, Leptin, and Leptin-Adiponectin Ratio with Incidence of Metabolic Syndrome: The Korean Genome and Epidemiology Study

Although the role of adiponectin and leptin in the etiology of metabolic syndrome (MetS) has been explored in various populations, limited knowledge is available on the prospective association of adiponectin and leptin with the risk of MetS development. The present study aimed to evaluate the associations of adiponectin, leptin, and the leptin-adiponectin (LA) ratio with the future risk of MetS in middle-aged and older Korean adults. Using a prospective, population-based Ansan-Ansung cohort of the Korean Genome and Epidemiology Study (KoGES), 2691 Korean adults (1317 men and 1374 women) were included in the present study. Serum adiponectin and leptin concentrations were measured using commonly available enzyme-linked immunosorbent assay kits. Multivariable Cox proportional hazard models were used to investigate the relationships of the different adiponectin and leptin concentrations and LA ratio with the incident MetS. During a mean follow-up of 6.75 years, a total of 359 (27.26%) men and 385 (28.02%) women were identified as developing new-onset MetS. After controlling for covariates, higher adiponectin levels were associated with lower incidence of MetS (hazard ratio (HR) for third vs. first tertile: 0.53, 95% confidence interval (CI): 0.40–0.70 for men and HR: 0.54, 95% CI: 0.42–0.71 for women), while higher leptin levels (HR for third vs. first tertile: 2.88, 95% CI: 2.01–4.13 for men and HR: 1.55, 95% CI: 1.13–2.13 for women) and LA ratio (HR for third vs. first tertile: 3.07, 95% CI: 2.13–4.44 for men and HR: 1.94, 95% CI: 1.41–2.66 for women) were associated with an increased incidence of MetS. Among men, in the fully adjusted models an increase by one standard deviation (SD) in adiponectin levels was associated with a 10% decrease in MetS risk (HR per SD: 0.90, 95% CI: 0.85–0.95) while leptin and LA ratio was associated with a 5% (HR per SD: 1.05, 95% CI: 1.01–1.08) and 40% (HR per SD: 1.40, 95% CI: 1.22–1.62) increase in MetS risk, respectively. Among women, a significant association with MetS risk was observed only in adiponectin levels (HR per SD: 0.91, 95% CI: 0.88–0.95). We found that higher adiponectin level was associated with a lower risk of MetS, while higher leptin level and LA ratio were associated with elevated MetS incidence, irrespective of body mass index at baseline in both Korean men and women. Adiponectin and leptin levels and LA ratio could play a role as a useful biomarker in the prediction of future MetS development among middle-aged and older Koreans.

Leptin, adiponectin, and their ratio as markers of insulin resistance and cardiometabolic risk in childhood obesity

BACKGROUND

It is imperative to develop markers for risk stratification and detection of cardiometabolic comorbidities in children with obesity. The adipokines leptin and adiponectin are both involved in fat mass regulation and the development of obesity-related disorders; furthermore, their ratio (leptin/adiponectin ratio) is suggested to be associated with insulin resistance and cardiometabolic risk.

OBJECTIVE

To evaluate associations between fasting serum concentrations of the adipokines (total leptin and adiponectin as well as the L/A ratio) and cardiometabolic comorbidities in children with overweight/obesity.

METHODS

A total of 2258 children with overweight/obesity or normal weight aged 6 to 18 years were studied. Differences in anthropometrics and adipokine concentrations were tested using Wilcoxon rank-sum test. Associations between the adipokines and cardiometabolic risk were tested using Spearman's correlation and logistic regression, adjusted for age and body mass index SD score (BMI-SDS).

RESULTS

Compared to normal weight children; children with overweight/obesity exhibited higher leptin concentrations, lower adiponectin concentrations, and higher L/A ratios. After adjusting for age and degree of obesity, girls with overweight/obesity in the upper quartile range for the L/A ratio, when compared with girls in the lower quartile range, were more likely to have insulin resistance (odds ratio [OR]: 7.78 [95% confidence interval [CI], 3.78-16.65]), dysglycemia (OR: 3.08 [95% CI, 1.35-7.31]), and dyslipidemia (OR: 2.53 [95% CI, 1.18-5.59]); while boys were more likely to have insulin resistance (OR: 4.45 [95% CI, 2.03-10.10]).

CONCLUSIONS

Independent of the degree of obesity, leptin, adiponectin, and the L/A ratio were associated with insulin resistance and other cardiometabolic comorbidities in children with overweight/obesity, but the L/A ratio exhibited stronger associations than the respective adipokines.

An update on metabolic syndrome: Metabolic risk markers and adipokines in the development of metabolic syndrome

Metabolic syndrome is a collection of physiological and biochemical abnormalities about 20-25% of adult population in developing countries is suffering from metabolic syndrome. Previous research demonstrated that adipose tissue plays an important role in energy regulation via endocrine, paracrine and autocrine signals as results of obesity due to accumulation of adipose tissue to excess that by time affects negatively both physical and psychological health and well being, it has been found that adipose tissues produces a variety of factors known as "adipokines" which play a key role in the development and progression of the disease and also hypothesized that adipokines are a possible link between obesity and the other risk components of the Metabolic syndrome. Many of the adipokines exert multiple actions in a variety of cellular processes leading to a complex array of abnormal characteristic of Metabolic syndrome. Abnormal production of these adipokines by expanded visceral fat during Adiposity contributes to a pro-inflammatory state. Increasing evidence suggests that aberrant production/release of adipokine from adipocyte i.e. adiponectin, leptin and resistin etc, may contribute to the health problems associated with Adiposity such as dyslipidemia, insulin resistance and atherosclerosis. This study conclusively have shown a significant role of adipokines secreted by adipose tissue and various metabolic risk markers play a important role in the development of Metabolic syndrome.

Adiponectin and Cardiovascular Risk. From Pathophysiology to Clinic: Focus on Children and Adolescents

Adiponectin (Ad) is a cytokine produced by adipocytes that acts on specific receptors of several tissues through autocrine, paracrine, and endocrine signaling mechanisms. Ad is involved in the regulation of cell survival, cell growth, and apoptosis. Furthermore, Ad plays an important pathophysiological role in metabolic activities by acting on peripheral tissues involved in glucose and lipid metabolism such as skeletal muscle, and the liver. Adiponectin has anti-inflammatory, anti-atherogenic, and insulin-sensitizing effects. For this reason, low levels of Ad are associated with the development of cardiovascular complications of obesity in adulthood. Numerous studies have shown that, even in children and adolescents, Ad is associated with risk factors for cardiovascular diseases. In obese children, reduced levels of Ad have been reported and Ad plasma levels are inversely related with abdominal obesity. Moreover, lower Ad concentrations are associated with the development of metabolic syndrome, insulin resistance and hypertension in pediatric subjects. In addition to a higher prevalence of cardiovascular risk factors, plasma values of Ad are also inversely associated with early organ damage, such as an increase in carotid intima-media thickness. It has been suggested that low Ad levels in childhood might predict the development of atherosclerosis in adulthood, suggesting the possibility of using Ad to stratify cardiovascular risk in obese children. Some evidence suggests that lifestyle modification may increase Ad plasma levels. The aim of this review is to summarize the evidence on the relationship between Ad, obesity, metabolic alterations and hypertension in children and adolescents, and to address the possibility that Ad represents an early marker of cardiovascular risk in pediatric subjects. Furthermore, the effects of non-pharmacological treatment (weight loss and physical activity) on Ad levels are considered.

Higher adiponectin concentrations are associated with reduced metabolic syndrome risk independently of weight status in Brazilian adolescents

OBJECTIVE

To evaluate the association between adiponectin concentrations and metabolic syndrome (MetS) risk and to investigate if this association is independent of weight status in adolescents.

METHODS

Adiponectin concentrations and MetS risk were assessed in 4546 Brazilian adolescents (12-17 years old) enrolled in The Study of Cardiovascular Risks in Adolescents ("ERICA"), a cross-sectional multicenter study in Brazil. For analyses, adiponectin was categorized in sex and age-specific quartiles and MetS risk was expressed as a continuous score, calculated as the average of the standardized values (z-score) of the five MetS components. Multiple linear regression models were used to investigate the association between the quartiles of adiponectin and MetS risk.

RESULTS

Adiponectin was inversely associated with waist circumference and log-transformed triglycerides, and positively associated with HDL-c. We also observed an inverse association between adiponectin concentrations and MetS risk. After adjustment for sociodemographic variables, physical activity, skipping breakfast and body mass index (BMI), higher quartiles of adiponectin remained inversely associated with waist circumference and MetS risk. A direct association between adiponectin and HDL-c was also observed. In further analysis, the sample was stratified by weight status and an inverse association between quartiles of adiponectin and MetS risk was observed in both normal weight and overweight/obese adolescents.

CONCLUSION

Higher adiponectin concentrations were independently and inverse associated with MetS risk in Brazilian adolescents, even after adjusting for BMI. These results were similar in normal weight and overweight/obese adolescents, suggesting that adiponectin may play a role in early development of MetS.

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.

Update on endocrine aspects of childhood obesity

PURPOSE OF REVIEW

Although childhood obesity has leveled off in the last decade, 'severe obesity' continues to be on the rise. Various genetic, environmental and hormonal factors contribute to obesity. This article reviews the most current understanding of obesity's multifactorial origin and recent recommendations for its management in childhood and adolescence.

RECENT FINDINGS

Epigenetics plays a key role in transmitting obesity risk to offspring. Single-nucleotide polymorphisms at genetic loci for adipokines and their receptors are associated with obesity. Gut microbiota is an important regulator of weight status, and Bifidobacterium species improves metabolic status. The incidence of comorbidities including prediabetes and type 2 diabetes has increased. Novel biomarkers such as alpha-hydroxybutyrate and branched-chain amino acids correlate with insulin sensitivity and predict glycemic control in adolescents. Lifestyle modifications and pharmacotherapy can produce small BMI changes. Bariatric surgery induces substantial weight loss and remission of comorbidities.

SUMMARY

Alterations in genetics, epigenetics and microbiota influence childhood obesity. Lifestyle modification remains the mainstay of management and pharmacotherapy with Food and Drug Administration approved medications is recommended only for patients resistant to lifestyle changes and for comorbidities. Bariatric surgery produces sustained weight loss and cardiovascular benefits and is an effective option for adolescents with severe obesity.

Postpartum maternal adipokines and infant weight for length at 1 year in women with gestational diabetes

BACKGROUND

Maternal, cord blood and childhood adipokines have been associated with childhood obesity. We investigated whether postpartum maternal adipokines are associated with increased weight at 1 year of age in children of women with gestational diabetes (GDM).

METHODS

Plasma leptin and adiponectin concentrations were measured in 160 women at approximately 12 weeks following pregnancy with GDM and compared with infant weight for length z-score at 1 year of age after adjustment for maternal and infant demographic variables.

RESULTS

No association was demonstrated between maternal postpartum leptin and adiponectin concentrations and infant weight for length z-score at 1 year of age.

Leptin-adiponectin imbalance as a marker of metabolic syndrome among Chinese children and adolescents: The BCAMS study

Purpose

Leptin and adiponectin have opposite effects on subclinical inflammation and insulin resistance, both involved in the development of metabolic syndrome (MS). We aimed to investigate whether leptin/adiponectin ratio (L/A), as a marker of these two adipokines imbalance, may improve diagnosis of MS in children and adolescents, and determined its cut-off value in the diagnosis of MS.

Methods

A total of 3,428 subjects aged 6–18 years were selected from Beijing Child and Adolescent Metabolic Syndrome study. Adipokine leptin and adiponectin were measured using enzyme-linked immunosorbent assay. Odds ratio of MS per 1 z-score of adipokine was examined using logistic regression. Diagnosis accuracy was assessed using c-statistics (AUC) and net reclassification index.

Results

The levels of leptin and L/A increased with number of positive MS components, while the levels of adiponectin declined in both boys and girls (all P <0.001). AUCs for diagnosis of MS in girls were 0.793, 0.773, and 0.689 using L/A, leptin and adiponectin, respectively; and AUCs in boys were 0.822, 0.798, and 0.697 for L/A, leptin and adiponectin, respectively. Notably, L/A outperformed individual leptin or adiponectin in discriminating a diagnosis of MS (all P < 0.02 in AUC comparisons). In addition, the optimal cut-offs of L/A by ROC curve differed by genders and pubertal stages, which were 1.63, 1.28, 1.95 and 1.53 ng/ug for total, pre-, mid- and postpubertal boys, respectively and 2.19, 0.87,1.48 and 2.27 ng/ug for total, pre-, mid- and postpubertal girls, respectively, yielding high sensitivity and moderate specificity for a screening test.

Conclusions

In this pediatric population, leptin-adiponectin imbalance, as reflected by an increase in L/A level, was found to be a better diagnostic biomarker for MS than leptin or adiponectin alone. Future longitudinal studies are needed to further validate the gender-specific cutoff values.