Relationship between Plasma Adiponectin Levels and Metabolic Risk Profiles in Taiwanese Children

Serum adiponectin, body adiposity and metabolic parameters in obese Egyptian children with Down syndrome

OBJECTIVES

Children with Down syndrome (DS) have a higher risk for obesity. Adiponectin plays a crucial role in obesity-related cardiometabolic comorbidities. The study aimed to explore whether body adiposity indicators, the frequency of metabolic syndrome (MetS) and its components, serum adiponectin and insulin resistance indices as well as the validity of serum adiponectin as a biomarker for MetS are different in prepubertal obese-DS children compared to matched obese-controls.

METHODS

Cross-sectional study included 150 prepubertal children classfied into three groups; obese-DS (n=50), obese-control (n=50) and normal-weight-control (n=50). Participants were evaluated for waist-circumference (WC), body adiposity, serum triglycerides, HDL-C, adiponectin and Homeostasis-Model-Assessment of Insulin-Resistance (HOMA-IR). MetS was defined using modified Adult Treatment Panel III-criteria.

RESULTS

Obese-DS had significantly higher WC, %body fat, total-fat mass, trunk-fat mass, trunk/appendicular-fat mass ratio, triglycerides, insulin and HOMA-IR and significantly lower HDL-C values compared to obese-control. Higher prevalence of MetS and its components were observed in obese-DS that was evident at younger age. Adiponectin was significantly lower in obese-DS compared with obese-control and in obese-DS children with MetS compared to obesecontrol with MetS. The decrease in adiponectin with increasing grades of obesity was pronounced in obese-DS. Adiponectin exhibited strong correlations with body adiposity, several MetS components and HOMA-IR in obese-DS. Adiponectin performed better as a biomarker for MetS among obese-DS (AUC=0.808) than obese-control (AUC=0.674).

CONCLUSIONS

Prepubertal obese-DS displayed excess body adiposity with pronounced central fat distribution, atherogenic lipid profile and higher insulin resistance compared to matched obese-control. Adiponectin performed better as potential biomarker of MetS in obese-DS than obese-control.

Association of adiponectin and metabolic syndrome in adolescents: the caspian- III study

Background

This study aimed to investigate the associations between metabolic syndrome (Mets) and adiponectin concentrations in Iranian adolescents.

Methods

This study was conducted as a sub-study of a national school- based surveillance program in 10–18 year- old students from 27 provinces in Iran. Plasma adiponectin was measured in 180 randomly selected participants. Metabolic syndrome (Mets) was defined based on the Adult Treatment Panel III (ATP- III) criteria modified for the pediatric age group. Multiple logistic regression analyses were used to evaluate the association between adiponectin and cardiometabolic risk factors.

Results

The median of adiponectin concentrations was significantly lower among participants with Mets [2.95 μg/ml (interquartile range 2.72–3.30)] compared with subjects without Mets [4.55 μg/ml (interquartile range 3.02–5.75)]. Adiponectin showed significant negative association with higher number of Mets components (P- trend < 0.05). Significant correlations were observed between adiponectin concentrations and metabolic parameters, except blood pressure.

Significant inverse association existed between adiponectin levels and presence of Mets (OR, 0.21; 95%CI: 0.10–0.45; p < 0.001). In multivariate models, this association remained significant after adjustment for other risk factors (OR, 0.18; 95%CI: 0.07–0.47; p < 0.001.

Conclusions

Adiponectinhas inverse association with cardiometabolic parameters in Iranian adolescents, and it is a determinant of Mets independent of other risk factors. These findings can be used in comparison with other ethnic groups. Further longitudinal studies are necessary to assess the clinical impact of such inverse association.

Interleukin 10 and clustering of metabolic syndrome components in pediatrics

BACKGROUND

Interleukin 10 (IL-10) has multifaceted anti-inflammatory properties that are known to regulate insulin sensitivity and atherosclerotic development. However, studies in children are limited and have yielded conflicting results. The aim of this study was to evaluate whether changes in this circulating anti-inflammatory cytokine is a marker for metabolic syndrome.

MATERIALS AND METHODS

This cross-sectional study involved children and young adolescents from eight elementary schools and two junior high schools located in Taipei and New Taipei City. A total of 553 children ages 8, 11 and 13 years old were included in the analysis. Parameters for obesity, anti- and pro-inflammatory cytokines, and metabolic risk profiles were evaluated.

RESULTS

Overweight/obese children had lower serum IL-10 concentrations compared with normal weight children in the same age group (all P < 0·001). IL-10 quartiles were negatively associated with body mass index (BMI) and percentage (%) body fat (all P < 0·05). Multivariate regression analysis showed significant inverse relationship between IL-10 concentrations and % body fat (β = -0·009, P < 0·0001), and total cholesterol (β = -0·726, P = 0·003), and a small positive correlation between IL-10 and systolic blood pressure (β = 0·980, P = 0·027). In normal weight children, IL-10 concentrations were independently associated with fasting plasma insulin (β = 0·2912, P = 0·001) and waist circumference (β = 0·0069, P = 0·022). By contrast, % body fat (β = -0·016, P = 0·0009) was independently associated with IL-10 concentrations in overweight and obese children. Association between IL-10 and fasting plasma insulin concentrations was weaker in overweight/obese children compared with normal weight (β = 0·283, P = 0·011 vs. β = 0·2912, P = 0·001).

CONCLUSION

Our data indicate that changes in circulating IL-10 concentrations are marker of metabolic risk in children.

Association of adipokines with blood pressure in rural Chinese adolescents

Previous research has demonstrated that adipokines influence blood pressure (BP). Limited data exist in healthy adolescents, who are in a critical period for preventing the development of high BP. This study investigated the association of leptin, adiponectin and the leptin-to-adiponectin ratio (LAR) with BP in rural Chinese adolescents. This report included 1245 adolescents (average body mass index: 19.3 kg m(-2)) aged 13-21 years from an established twin cohort. We examined gender-specific associations between plasma adipokines and BP, with adjustment for measures of adiposity and insulin resistance (IR). We estimated the genetic contribution to adipokines using the twin design and Cholesky decomposition models. There was no correlation between leptin and adiponectin levels. Leptin was positively associated with systolic blood pressure (SBP) in males and diastolic blood pressure in females, but the association disappeared after adjusting for adiposity and IR. LAR was positively associated with SBP (β(s.e.): 1.94(0.45)), P<0.01), adiponectin was negatively associated with SBP (β(s.e.): -2.18(0.63)), P<0.001) only in males, and such associations were independent of adiposity and IR. A test of gender × adiponectin interaction was significant (P=0.01). Heritability estimation showed that both environmental and genetic factors contribute to variance in adipokines. In these relatively lean Chinese adolescents, leptin was positively associated with BP in both genders, but was adiposity/IR dependent. Adiponectin was negatively associated with SBP in males, independent of adiposity/IR.

Relationship between cardiovascular risk factors and adipokines in adolescents

This study evaluated the associations of adipokines with cardiovascular risk factors.

SUBJECTS/METHODS

60 normal weight (BMI ≤75th percentile) and 60 overweight (BMI ≥95th percentile) adolescents aged 10-14 years. Resting systolic and diastolic blood pressures (SBP, DBP) and waist circumference were obtained in duplicate. Circulating adiponectin, resistin, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), total cholesterol (TC), high-density lipoprotein (HDL), and triglycerides (TG) were measured from fasting plasma samples.

RESULTS

Simple correlations showed that SBP was significantly related (p < 0.05) to adiponectin (r = -0.185), resistin (r = 0.207), and IL-6 (r = 0.238); HDL was significantly related to adiponectin (r = 0.398) and TNF-α (r = -0.227). TG was only related to adiponectin (r = -0.292, p < 0.05). Multiple regression models controlling for puberty and ethnicity indicated that adiponectin (R(2) = 0.152, p < 0.05), resistin (R(2) = 0.152, p < 0.05), and IL-6 (R(2) = 0.170, p < 0.05) were associated with SBP. The association between adiponectin and HDL was stronger in normal weight versus overweight adolescents (R(2) = 0.336, p < 0.05). None of the other models showed differences in the associations by weight status.

CONCLUSIONS

In adolescents, SBP but not DBP was associated with most adipokines. HDL, but not TC, was also associated with some adipokines. TG were only associated with adiponectin. Associations were mostly related to adiposity.

Gender differences exist in the association of leptin and adiponectin levels with insulin resistance parameters in prepubertal Arab children

AIM

Differences in correlations between leptin, adiponectin and insulin resistance in children exist in different ethnic populations. No such information is available in Arab children. This study aims to fill this gap.

METHODS

Three hundred and twenty-five prepubertal children were recruited in this cross-sectional study. Body mass index (BMI), waist and hip circumferences and fasting glucose were measured by standard procedures. Serum insulin, leptin and adiponectin were assayed by ELISA.

RESULTS

Leptin and adiponectin levels were significantly correlated with anthropometric parameters, HOMA-IR and insulin in all subjects and with fasting glucose in girls only. Correlations of adiponectin with HOMA-IR and insulin in boys and of leptin with insulin in girls were independent of BMI, waist and hip circumferences.

CONCLUSION

Gender differences exist in the distribution of adipocytokines in prepubertal children. The associations of adipocytokines with obesity biomarkers in prepubertal children suggest a causal link between childhood obesity and the risk of an early diabetes onset.

Impact of child obesity on adipose tissue physiology: assessment of adipocytokines and inflammatory cytokines as biomarkers of obesity

Obesity could be interpreted as a low grade inflammatory state. The role of cytokines for innate and acquired immune response and adipocytokines in pathogenesis of obesity is not completely understood. The aim of the study was to evaluate anthropometric parameters, adipocytokines and inflammatory cytokine levels as biomarkers of childhood obesity. This investigation was designed as a longitudinal observational study. Forty-seven obese children (19 males and 28 females) were enrolled by Pediatric Clinic of the Foundation IRCCS Policlinico San Matteo, Pavia, Italy. For each patients a blood sample, used for other biochemical evaluations, was collected. Cytokines and adipocytokines plasmatic levels were determined using an ELISA method. Plasma leptin levels are in correlation with age (r=0.5; P<0.001) and BMI-z score (r=0.36; P<0.001), particularly in girls; plasma resistin levels are in inverse correlation with age, particularly in boys (r=-0.67; P<0.001) and in correlation with BMI-z score (r=0.52; P=0.002). Plasma leptin and resistin levels show a good correlation with antrophometric parameters of child obesity (sex and BMI z score). This study suggests that leptin and resistin can be considered as biomarker of childhood obesity and its comorbility. We observed a statistically significant correlation between plasma leptin and resistin levels and antrophometric parameters of child obesity (sex and BMI z score). This study suggests that adipocytokines, such as leptin and resistin, can be considered as biomarkers of childhood obesity.

Plasma adiponectin level and sleep structures in children with Prader-Willi syndrome

Adiponectin, an adipose tissue-derived hormone, has been negatively related to obstructive sleep apnea syndrome. Besides sleep apnea, children with Prader-Willi syndrome (PWS) may have excessive daytime sleepiness and rapid eye movement (REM) sleep abnormality. The aim of this study is to determine whether changes in sleep structures are related to plasma adiponectin levels in PWS. Correlations between adiponectin level and sleep variables were analyzed in 28 children with PWS and 18 controls. Overnight polysomnography was performed. The fasting plasma adiponectin levels were higher in the children with PWS than in the controls (P = 0.0006). In the PWS, Epworth sleepiness scale was significantly higher (P = 0.002); sleep latency (P = 0.003) and REM latency (P = 0.001) were significantly shortened; the apnea-hypopnea index (AHI) was significantly increased (P = 0.0001); and the duration of non-rapid eye movement (NREM) sleep stages 3 and 4 was decreased (P = 0.005). Multiple regression analysis revealed correlations between the adiponectin level and the total sleep time (beta = 0.688, P = 0.009), AHI (beta = 1.274, P = 0.010), REM latency (beta = -0.637, P = 0.021) and the percentage of NREM sleep (beta = -7.648, P = 0.002) in PWS. In children with PWS, higher plasma adiponectin levels were independently associated with several sleep variables, which was not observed in the control group. These results suggest a potential influence of elevated adiponectin level on the sleep structures in PWS.

Association between insulin, leptin, adiponectin and blood pressure in youth

OBJECTIVE

To examine whether insulin, leptin and adiponectin are independent correlates of blood pressure (BP) in a large population-based sample of children and adolescents.

METHODS

We studied 655 boys and 667 girls aged 9, 13 and 16 years who participated in the Quebec Child and Adolescent Health and Social Survey, a province-wide school-based survey conducted in 1999.

RESULTS

Strong, positive univariate associations between BMI, insulin and leptin Z-scores, and both systolic and diastolic BP were found in both sexes. Adiponectin Z-scores were negatively associated with systolic BP in girls only. In multivariate analyses only BMI and insulin Z-scores were significantly associated with systolic BP. In boys, each 1 SD increase in BMI was associated with a 4 mmHg increase in mean systolic BP; each 1 SD increase in insulin was associated with a 1 mmHg increase in mean systolic BP. Only insulin Z-scores were independently associated with diastolic BP in both sexes. For each 1 SD increase in insulin, there was a 1 mmHg increase in mean diastolic BP in boys. Similar to systolic BP, the magnitude of the effect of insulin Z-scores on diastolic BP increased as a function of BMI Z-scores in girls.

CONCLUSION

Independently of BMI, insulin is a strong correlate of systolic and diastolic BP in youth. Although animal studies support a role for leptin and adiponectin in controlling BP, they are not independently associated with BP in youth.

Adipokines as novel biomarkers in paediatric systemic lupus erythematosus

OBJECTIVES

Patients with SLE are at risk for premature atherosclerosis and metabolic syndrome. Cytokines produced by adipocytes, adipokines, are important in glucose/lipid metabolism and the development of atherosclerosis. The objectives of this study were to evaluate leptin, adiponectin and ghrelin concentrations in paediatric SLE (pSLE) and to correlate these concentrations with measures of disease activity, serum lipid concentrations, measures of insulin resistance and serum homocysteine concentrations.

METHODS

Two hundred and eight samples from 105 patients with pSLE and 77 samples from 77 healthy paediatric controls were evaluated by ELISA to measure leptin, adiopnectin and ghrelin. Students' t-test was used for analysis. Concentrations of adipokines were correlated with disease activity, serum lipids, insulin resistance and homocysteine.

RESULTS

Overall 35 SLE patients (34%) had an abnormally elevated leptin level. The only significant correlation of leptin concentrations was with homocysteine concentrations but not disease activity, prednisone dose, lipids or insulin resistance. There was no difference in the mean adiponectin concentrations between the control and patient groups and none of the patient samples were below the normal lower limit while seven were elevated. There was a significant correlation of adiponectin concentrations with prednisone dose, lipid concentrations and insulin resistance but not with disease activity or homocysteine. Elevated ghrelin concentrations were found in 20% of the pSLE patients. The only correlation of ghrelin concentrations was with homocysteine.

CONCLUSIONS

Adipokines are novel biomarkers in pSLE. They may represent cardiovascular risk and are not just surrogate markers for disease activity, therapy or serum lipids. Their correlation with atherosclerosis needs to be explored.

Metabolic syndrome in children and adolescents--risk for sleep-disordered breathing and obstructive sleep-apnoea syndrome?

The clinical relevance of the term "metabolic syndrome", the definition criteria, and predictive power are being disputed. Inclusion of sleep-disordered breathing and sleep apnoea into a definition of metabolic syndrome is also controversial once children and/or adolescents are affected. Nevertheless, along with the increasing prevalence of childhood obesity, the prevalence of the metabolic syndrome in obese children is reported at 30%, irrespective of the definition applied. Moreover, childhood obesity is associated with sleep-disordered breathing. Adipocytokines, cytokines secreted from adipose tissue, are thought to play a major role in the pathophysiology of metabolic syndrome. Leptin was initially suggested as a promising "anti-obesity" hormone. New concepts indicate that in humans leptin and its soluble receptor may be more important in states of energy deficiency rather than a predictor of the metabolic syndrome. Adiponectin, on the other hand, is not only related to obesity and insulin resistance, but appears to be the strongest predictor for metabolic syndrome, even in children. In newborns and infants, both adipocytokines occur in high concentrations, even though this cannot completely explain the increased risk for ensuing metabolic disease later in life. Finally, low-grade systemic inflammation may underlie the clustering of metabolic risk factors. Overall factors from the adipose tissue may constitute not only markers but also mediators of metabolic sequelae of obesity.

Adiponectin levels, cardiometabolic risk factors and markers of subclinical atherosclerosis in children

BACKGROUND

Low levels of adiponectin have been associated with metabolic risk factors (RF) and cardiac disease. Minimal data is available about the relationship between adiponectin and subclinical atherosclerosis.

OBJECTIVES

To determine the relationship of adiponectin to cardiometabolic RF, C-reactive protein (CRP), anthropometric parameters of obesity, and subclinical atherosclerosis in children.

METHODS

Cross-sectional study in 103 children. We determined body mass index (BMI), waist circumference, percent fat mass, systolic and diastolic blood pressures, fasting lipid profile, glycemia and insulinemia, and CRP. Subclinical atherosclerosis was determined by carotid intima-media thickness (IMT) and flow-mediated dilation of the brachial artery (FMD).

RESULTS

Mean age of the group was 12.4+/-1.9 years (47% girls; 20.4% prepubertal; 45 eutrophic, 23 overweight and 35 obese). Adiponectin levels were not statistically significantly different in eutrophic children versus obese+overweight: 17.7+/-5.6 and 15.9+/-5.3 microg/mL, respectively. Adiponectin levels in boys were no different from those in girls. Adiponectin correlated significantly with age, BMI, zBMI, waist circumference, systolic and diastolic blood pressures, HDL, insulinemia, and HOMA index. No statistically significant association with adiponectin was found for CRP, FMD or IMT. After adjusting by sex, pubertal status, and degree of obesity, the adiponectin levels associated significantly with HDL cholesterol and the HOMA index (r(2)=0.34, p<0.0001).

CONCLUSIONS

Adiponectin levels were inversely correlated with anthropometric parameters of obesity and insulin resistance and directly correlated with HDL levels. However, no relationship with subclinical atherosclerosis was demonstrated in this study.

Prevalence and Cluster of Cardiometabolic Biomarkers in Overweight and Obese Schoolchildren: Results from a Large Survey in Southwest Germany

Background: Obesity is associated with substantial metabolic changes and subclinical inflammation. We explored associations between body mass index (BMI) and cardiometabolic biomarkers and their clustering in overweight and obese schoolchildren.

Methods: In this population-based, cross-sectional study among 450 children 10 years old, we measured adiponectin, leptin, inflammatory markers, apolipoprotein (apo) AI and B, and lipoprotein-associated phospholipase A2 (Lp-PLA2). Except for adiponectin and apoAI (10th percentile) the 90th percentile was used as cutoff point. Body weight was categorized in age- and sex-specific BMI percentiles and overweight and obesity according to International Obesity Task Force definitions.

Results: In linear regression models, all cardiometabolic markers except apoB were statistically significantly associated with overweight. In logistic regression models, compared with the reference category (25th–75th percentile of BMI), overweight was associated with increased concentrations of leptin [odds ratio (OR) 59.80; 95% CI 16.68–214.39], C-reactive protein (6.30; 2.95–13.45), fibrinogen (2.82; 1.33–6.01), and low apoAI (2.62; 1.19–5.75). Overweight was positively associated with interleukin-6, Lp-PLA2, and apoB concentrations and inversely with adiponectin concentrations. Most importantly, in obese children 35% showed one, 20% two, 10% three, and 15% four or more abnormal cardiometabolic biomarkers. The number of abnormal cardiometabolic markers increased in overweight (ptrend &lt;0.001) and obese (ptrend &lt;0.001) children.

Conclusions: Overweight and obesity in children are associated with complex metabolic changes and a low-grade inflammatory response, and thus might not only accelerate cardiovascular disease later on, but may also be associated with the initiation of atherosclerosis in early life.

New predictors of the metabolic syndrome in children--role of adipocytokines

There is ample discussion of the relevance of the metabolic syndrome, the definition criteria, and predictive power. Nevertheless, along with the increasing prevalence of childhood obesity, the prevalence of the metabolic syndrome in obese children is reported at 30%, irrespective of the definition applied. Because children are otherwise relatively free of co-morbidities, they constitute an interesting population in which to study the sequence of events of obesity-related pathology. The adipocytokines appear to be important in this respect. Leptin was initially suggested as a promising "antiobesity" hormone. New concepts indicate that, in humans, leptin and its soluble receptor may be more important in states of energy deficiency rather than a predictor of the metabolic syndrome. Adiponectin, on the other hand, is not only related to obesity and insulin resistance, but appears to be the strongest predictor for metabolic syndrome, even in children. In newborns and infants, both adipocytokines occur in high concentrations, even though this cannot completely explain the increased risk for ensuing metabolic disease later in life. Finally, low-grade systemic inflammation may underlie the clustering of metabolic risk factors, but their role in children remains to be specified. Overall factors from the adipose tissue may constitute not only markers but also mediators of metabolic sequelae of obesity.

The beneficial effects of high-density lipoprotein on adipocytes may relate to its anti-atherogenic properties

High-density lipoprotein (HDL) has significant anti-atherogenic properties, whereas the underlying mechanisms are complex and have not been completely elucidated. Adipocytes produce a variety of adipokines with cardiovascular effects. The dysregulated secretion of adipokines by adipocytes may contribute to the increased risk of atherosclerosis associated with obesity. Clinical evidences indicate that higher plasma HDL-C levels are associated with a favourable adipokines secretion profile, suggesting that HDL might improve the dysregulated adipokines secretion. HDL may diminish lipid accumulation in adipocytes through phosphorylation of PPARgamma and inhibition of aP2 expression, which possibly account for the favourable effects of HDL on adipokines secretion. Therefore, we hypothesize that HDL might exert several beneficial effects on adipocytes, which may relate to its anti-atherogenic properties.