Serum resistin correlates with central obesity but weakly with insulin resistance in Chinese children and adolescents

Circulating exosomal circRNA-miRNA-mRNA network in a familial partial lipodystrophy type 3 family with a novel PPARG frameshift mutation c.418dup

Familial partial lipodystrophy 3 (FPLD3) is a rare genetic disorder caused by loss-of-function mutations in the PPARG gene, characterized by a selective absence of subcutaneous fat and associated metabolic complications. However, the molecular mechanisms of FPLD3 remain unclear. In this study, we recruited a 17-yr-old Chinese female with FPLD3 and her family, identifying a novel PPARG frameshift mutation (exon 4: c.418dup: p.R140Kfs*7) that truncates the PPARγ protein at the seventh amino acid, significantly expanding the genetic landscape of FPLD3. By performing next-generation sequencing of circular RNAs (circRNAs), microRNAs (miRNAs), and mRNAs in plasma exosomes, we discovered 59 circRNAs, 57 miRNAs, and 299 mRNAs were significantly altered in the mutation carriers compared with the healthy controls. Integration analysis highlighted that the circ_0001597-miR-671-5p pair and 18 mRNAs might be incorporated into the metabolic regulatory networks of the FPLD3 induced by the novel PPARG mutation. Functional annotation suggested that these genes were significantly enriched in glucose- and lipid metabolism-related pathways. Among the circRNA-miRNA-mRNA network, we identified two critical regulators, early growth response-1 (EGR1), a key transcription factor known for its role in insulin signaling pathways and lipid metabolism, and 1-acylglycerol-3-phosphate O-acyltransferase 3 (AGPAT3), which gets involved in the biosynthesis of triglycerides and lipolysis. Circ_0001597 regulates the expression of these genes through miR-671-5p, potentially contributing to the pathophysiology of FPLD3. Overall, this study clarified a circulating exosomal circRNA-miRNA-mRNA network in a FPLD3 family with a novel PPARG mutation, providing evidence for exploring promising biomarkers and developing novel therapeutic strategies for this rare genetic disorder.NEW & NOTEWORTHY Through the establishment of a ceRNA regulatory networks in a novel PPARG frameshift mutation c.418dup-induced FPLD3 pedigree, this study reveals that circ_0001597 may contribute to the pathophysiology of FPLD3 by sequestering miR-671-5p to regulate the expression of EGR1 and AGPAT3, pivotal genes situated in the triglyceride (TG) synthesis and lipolysis pathways. Current findings expand our molecular understanding of adipose tissue dysfunction, providing potential blood biomarkers and therapeutic avenues for lipodystrophy and associated metabolic complications.

The associations of adipokines with hypertension in youth with cardiometabolic risk and the mediation role of insulin resistance: The BCAMS study

The mechanisms link obesity and hypertension are not well understood. One possibility is the alterations in adipose-derived adipokines that modulate insulin resistance (IR) and cardiovascular homeostasis. We aimed to assess the associations between hypertension and four adipokine levels in Chinese youth, and to examine to what extent the associations are mediated by IR. We utilized cross-sectional data from the Beijing Children and Adolescents Metabolic Syndrome (BCAMS) Study Cohort (n = 559, mean age = 20.2 years). Plasma leptin, adiponectin, retinol binding protein 4 (RBP4) and fibroblast growth factor 21 (FGF21) levels were assayed. The relationships between adipokines and hypertension and the possible mediation effect of IR were evaluated. Youth with hypertension have lower adiponectin and higher leptin, FGF21 (all P < 0.001) and RBP4 levels (p = 0.06) compared to their counterparts. Moreover, the co-existence of these two or more adipokine abnormalities in youth leads to a 9-fold increased risk for hypertension (OR: 9.19; 95% CI, 4.01-21.08) compared with these without abnormalities. However, in the fully adjusted and BMI-adjusted analyses, only FGF21 was a significant predictor of hypertension (OR: 2.12; 95% CI, 1.34-3.36). Mediation analysis revealed that the associations between leptin, adiponectin, RBP4 and hypertension are totally mediated by IR (proportion: 63.9%, 65.4%, and 31.6%, respectively), while BMI and IR partly mediated the association between FGF21 and hypertension (proportion: 30.6%, 21.2%). Our findings suggest that dysregulation of adipokines might result in hypertension in youth. Leptin, adiponectin and RBP4 may exert their functions in hypertension through adiposity-related IR, whereas FGF21 might be used as an independent marker of hypertension in youth.

Impact of inflammatory cytokine and adipokine gene variations in the development of HIV-associated lipodystrophy

Cytokines affect lipid and glucose metabolism and also alter the body's habitus. They play a role in the development of lipodystrophy syndrome. Adipocytes secrete the pro-inflammatory cytokines IL-1, TNF-α and IL-6. The plasma cytokine concentration is associated with the percentage and distribution of fat tissue in the body. The metabolic disturbances are strongly associated with increased levels of pro-inflammatory cytokines (IL-1, IL-6 and TNF-α). Plasma levels of cytokines such as TNF-α, IL-6 and leptin were found to be increased while plasma resistin levels were found to be variable in patients suffering from obesity and type II diabetes mellitus. Until now, limited information has been available on the polymorphism of cytokine and adipokine genes in patients of HIV-associated lipodystrophy (HIVLD), which can contribute to individual variations in susceptibility to metabolic diseases, especially to HIVLD. Hence, we studied the association of cytokine and adipokine gene polymorphisms in various diseases and their impact on HIVLD. We carry out an extensive search using several databases, including PubMed, EMBASE and Google Scholar. The distribution of cytokine and adipokine gene polymorphisms and their expression levels varied among various populations. We examined the variants of cytokine and adipokine genes, which can contribute to individual variations in susceptibility to metabolic diseases, especially to HIVLD. In the current review, we present a brief account of the risk factors of HIVLD, the pathogenesis of HIVLD and the polymorphism of cytokine and adipokine genes in various diseases with special reference to their impact on HIVLD.

Metabolic, inflammatory and adipokine differences on overweight/obese children with and without metabolic syndrome: A cross-sectional study

BACKGROUND

Obesity is associated with low-grade inflammation and metabolic syndrome (MetS) in both children and adults. Our aim was to describe metabolic, inflammatory and adipokine differences on overweight/obese children with and without MetS.

METHODS

This was an observational study. A total of 107 children and adolescents aged 6-18 years were included. Among this sample, n = 21 had normal body weight, n = 22 had overweight/obesity without MetS, and n = 64 had overweight/obesity with MetS. Anthropometric data and biochemical, adipokine, and inflammatory markers were measured. Different ratios were then assessed for estimate the probability of MetS. ROC analysis was used to estimate the diagnostic accuracy and optimal cutoff points for ratios.

RESULTS

Serum CRP levels were higher among children with overweight/obesity with MetS. Adipokines like PAI-1 and leptin were significantly lower in children with normal body weight. The Adipo/Lep ratio was highest in the group with normal body weight. TG/HDL-C and TC/HDL-C ratios were significantly correlated with BMI, DBP, PCR, and PAI-1. TC/HDL-C ratio was significantly correlated with SBP and resistin. TGL/HDL-C ratio was significantly correlated with waist and hip circumferences, fasting glucose, and MCP-1. The AUC for TG/HDL-C at the optimal cutoff of 2.39 showed 85.71% sensitivity and 71.43% specificity. CT/HDL-C at the optimal cutoff of 3.70 showed 65.08% sensitivity and 81.82% specificity. Levels of both ratios increased significantly as additional MetS criteria were fulfilled.

CONCLUSION

Low-grade inflammation is correlated with MetS in children with overweight/obesity. TGL, HDL-C and TGL/HDL-C ratio, obtainable from routine lab tests, allows identification of MetS in children with overweight or obesity.

Temporal trends in cardiovascular health among Chinese urban children and adolescents, 2004-2019 pre-pandemic COVID-19

Objective

Little is known about pre-pandemic cardiovascular health (CVH) status and its temporal variation in Chinese children. Thus, we aimed to evaluate the secular trends and associated factors of CVH in Chinese urban children from 2004 to 2019.

Methods

We identified 32,586 individuals in Beijing, aged 6 to 18 years, from three independent cross-sectional studies conducted in 2004, 2014, and 2019, respectively. CVH was assessed by 7 metrics according to modified American Heart Association criteria, including smoking, physical activity, diet, body mass index, total cholesterol, blood pressure, and fasting glucose. Multivariable logistic regression was used to assess the associations between sociodemographic characteristics and the ideal CVH status.

Results

The proportion of ideal CVH decreased from 27.7% (boys 26.6%, girls 28.9%) in 2004 to 4.2% (boys 3.8%, girls 4.8%) in 2014, and then increased to 16.2% (boys 13.5%, girls 18.9%) in 2019. Overall, ideal smoking was the most prevalent CVH component during 2004-2019 (2004, 97.5%; 2014, 92.9%; 2019, 98.0%), while ideal physical activity (2004, 27.6%; 2014, 14.4%; 2019, 28.0%) and dietary intake (2004, 26.0%; 2014, 10.7%; 2019, 23.5%) were the least prevalent components. Notably, the proportion of ideal body mass index (2004, 77.5%; 2019, 59.7%) and blood pressure (2004, 73.6%; 2019, 67.3%) continuously decreased from 2004 to 2019. Girls, parental normal weight status, free of family CVD history, and lower levels in fat mass were associated with higher odds of ideal CVH.

Conclusion

The cardiovascular health in Chinese urban children deteriorated during 2004-2019. Distinct strategies are required to mitigate socioeconomic inequity in the intervention of CVH promotion.

Genetic variations in adiponectin levels and dietary patterns on metabolic health among children with normal weight versus obesity: the BCAMS study

BACKGROUND/OBJECTIVES

Adiponectin represents an important link between adipose tissue dysfunction and cardiometabolic risk in obesity; however, there is a lack of data on the effects of adiponectin-related genetic variations and gene-diet interactions on metabolic disorders in children. We aimed to investigate possible interactions between adiponectin-related genetic variants and habitual dietary patterns on metabolic health among children with normal weight versus overweight/obesity, and whether these effects in childhood longitudinally contribute to metabolic risk at follow-up.

SUBJECTS/METHODS

In total, 3,317 Chinese children aged 6-18 at baseline and 339 participants at 10-year follow-up from the Beijing Child and Adolescent Metabolic Syndrome study cohort were included. Baseline lifestyle factors, plasma adiponectin levels, and six adiponectin-related genetic variants resulting from GWAS in East Asians (loci in/near ADIPOQ, CDH13, WDR11FGF, CMIP, and PEPD) were assessed for their associations with the metabolic disorders. Being metabolically unhealthy was defined by exhibiting any metabolic syndrome component.

RESULTS

Among the six loci, ADIPOQ rs6773957 (OR 1.26, 95% CI:1.07-1.47, P = 0.004) and adiponectin receptor CDH13 rs4783244 (0.82, 0.69-0.96, P = 0.017) were correlated with metabolic risks independent of lifestyle factors in normal-weight children, but the associations were less obvious in those with overweight/obesity. A significant interaction between rs6773957 and diet (P_interaction = 0.004) for metabolic health was observed in normal-weight children. The adiponectin-decreasing allele of rs6773957 was associated with greater metabolic risks in individuals with unfavorable diet patterns (P < 0.001), but not in those with healthy patterns (P > 0.1). A similar interaction effect was observed using longitudinal data (P_interaction = 0.029).

CONCLUSIONS

These findings highlight a novel gene-diet interaction on the susceptibility to cardiometabolic disorders, which has a long-term impact from childhood onward, particularly in those with normal weight. Personalized dietary advice in these individuals may be recommended as an early possible therapeutic measure to improve metabolic health.

Obesity cardiomyopathy: evidence, mechanisms, and therapeutic implications

The prevalence of heart failure is on the rise and imposes a major health threat, in part, due to the rapidly increased prevalence of overweight and obesity. To this point, epidemiological, clinical, and experimental evidence supports the existence of a unique disease entity termed “obesity cardiomyopathy,” which develops independent of hypertension, coronary heart disease, and other heart diseases. Our contemporary review evaluates the evidence for this pathological condition, examines putative responsible mechanisms, and discusses therapeutic options for this disorder. Clinical findings have consolidated the presence of left ventricular dysfunction in obesity. Experimental investigations have uncovered pathophysiological changes in myocardial structure and function in genetically predisposed and diet-induced obesity. Indeed, contemporary evidence consolidates a wide array of cellular and molecular mechanisms underlying the etiology of obesity cardiomyopathy including adipose tissue dysfunction, systemic inflammation, metabolic disturbances (insulin resistance, abnormal glucose transport, spillover of free fatty acids, lipotoxicity, and amino acid derangement), altered intracellular especially mitochondrial Ca²⁺ homeostasis, oxidative stress, autophagy/mitophagy defect, myocardial fibrosis, dampened coronary flow reserve, coronary microvascular disease (microangiopathy), and endothelial impairment. Given the important role of obesity in the increased risk of heart failure, especially that with preserved systolic function and the recent rises in COVID-19-associated cardiovascular mortality, this review should provide compelling evidence for the presence of obesity cardiomyopathy, independent of various comorbid conditions, underlying mechanisms, and offer new insights into potential therapeutic approaches (pharmacological and lifestyle modification) for the clinical management of obesity cardiomyopathy.

Puberty Status Modifies the Effects of Genetic Variants, Lifestyle Factors and Their Interactions on Adiponectin: The BCAMS Study

BACKGROUND

Hypoadiponectinemia has been associated with various cardiometabolic disease states. Previous studies in adults have shown that adiponectin levels were regulated by specific genetic and behavioral or lifestyle factors. However, little is known about the influence of these factors on adiponectin levels in children, particularly as mitigated by pubertal development.

METHODS

We performed a cross-sectional analysis of data from 3,402 children aged 6-18 years from the Beijing Child and Adolescent Metabolic Syndrome (BCAMS) study. Pubertal progress was classified as prepubertal, midpuberty, and postpuberty. Six relevant single nucleotide polymorphisms (SNPs) were selected from previous genome-wide association studies of adiponectin in East Asians. Individual SNPs and two weighted genetic predisposition scores, as well as their interactions with 14 lifestyle factors, were analyzed to investigate their influence on adiponectin levels across puberty. The effect of these factors on adiponectin was analyzed using general linear models adjusted for age, sex, and BMI.

RESULTS

After adjustment for age, sex, and BMI, the associations between adiponectin levels and diet items, and diet score were significant at prepuberty or postpuberty, while the effect of exercise on adiponectin levels was more prominent at mid- and postpuberty. Walking to school was found to be associated with increased adiponectin levels throughout puberty. Meanwhile, the effect of WDR11-FGFR2-rs3943077 was stronger at midpuberty (P = 0.002), and ADIPOQ-rs6773957 was more effective at postpuberty (P = 0.005), while CDH13-rs4783244 showed the strongest association with adiponectin levels at all pubertal stages (all P < 3.24 × 10^-15). We further found that effects of diet score (P_interaction = 0.022) and exercise (P_interaction = 0.049) were stronger in children with higher genetic risk of hypoadiponectinemia, while higher diet score and exercise frequency attenuated the differences in adiponectin levels among children with different genetic risks.

CONCLUSIONS

Our study confirmed puberty modulates the associations between adiponectin, and genetic variants, lifestyle factors, and gene-by-lifestyle interactions. These findings provide new insight into puberty-specific lifestyle suggestions, especially in genetically susceptible individuals.

Impact of parental smoking on adipokine profiles and cardiometabolic risk factors in Chinese children

BACKGROUND AND AIMS

The mechanisms by which passive smoking leads to cardiometabolic risks, and the tissues involved still require elucidation. We aimed to evaluate the association of parental smoking exposure (PSE) with the secretion of adipocyte-derived hormones and cardiometabolic risk factors in Chinese children.

METHODS

We included 3150 school children aged 6-18 years from the Beijing Child and Adolescent Metabolic Syndrome (BCAMS) study. Data on PSE and potential confounders were collected. Six adipokines related to insulin resistance and metabolic syndrome (MetS) were measured.

RESULTS

PSE was reported in nearly two-thirds of the children. After adjusting for covariates, including age, sex, pubertal stages, lifestyle factors, and family history, PSE was independently associated with increases of 39.2% in leptin and 3.9% in retinol binding protein-4 and decreases of 11.4% in fibroblast growth factor 21 and 4.6% in adiponectin levels (p < 0.05 for all), plus risks for central obesity (OR 1.59, 95% CI 1.33-1.90), elevated blood pressure (1.22, 1.02-1.46) and MetS (1.43, 1.11-1.85). However, the associations of PSE with hypertension and MetS were abolished when adjusted for adiposity parameters or the above-mentioned adipokine profiles.

CONCLUSIONS

PSE was associated with dysregulation of adipokine levels, which might mediate the development of MetS in early life.

Insulin resistance, beta-cell function, adipokine profiles and cardiometabolic risk factors among Chinese youth with isolated impaired fasting glucose versus impaired glucose tolerance: the BCAMS study

OBJECTIVE

Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) may convey disparate risks of metabolic consequences. Fasting plasma glucose (FPG), while an expedient screening procedure, may not adequately assess metabolic risk, particularly among youths. In order to inform a strategy for screening Chinese youth for pre-diabetes, we examined the relative value of IFG versus IGT to define metabolic risk by assessing their association with insulin resistance, beta-cell dysfunction, adverse adipokine profiles and other cardiometabolic risk factors.

RESEARCH DESIGN AND METHODS

We recruited 542 subjects (age 14-28 years) from the Beijing Child and Adolescent Metabolic Syndrome study for an in-depth assessment of cardiometabolic risk factors, including a 2-hour oral glucose tolerance test, liver ultrasound and serum levels of four adipokines.

RESULTS

FPG failed to identify nearly all (32/33) youths with IGT, whereas 2-hour plasma glucose (2 h PG) missed 80.8% (21/26) of subjects with IFG. Impaired beta-cell function was evident from decreased oral disposition indices in those with isolated impaired fasting glucose (iIFG) or isolated impaired glucose tolerance (iIGT) versus normal glucose tolerance (NGT) (all p<0.001), whereas reduced insulin sensitivity (Matsuda) index was most pronounced in the iIGT group (p<0.01). Moreover, alterations in adipokine levels (fibroblast growth factor 21, adiponectin and leptin/adiponectin ratio) were associated with iIGT (p<0.05) but not iIFG. Youths with iIGT had a 2-fold to 32-fold increased incidence of hypertriglyceridemia, hypertension and metabolic syndrome (MetS) compared with those with NGT. In addition, subgroup analyses of participants with normal FPG revealed that the odds of having IGT increased 3-fold to 18-fold among those with elevated TGs, hypertension, moderate-to-severe non-alcoholic fatty liver disease or MetS.

CONCLUSIONS

Chinese youth with iIGT exhibit a higher cardiometabolic risk profile than those with iIFG. Thus, 2 h PG is preferred over FPG to identify the pre-diabetes phenotype at greatest risk of subsequent development of cardiovascular disease.

TRIAL REGISTRATION NUMBER

NCT03421444.

Circulating Osteonectin and Adipokine Profiles in Relation to Metabolically Healthy Obesity in Chinese Children: Findings From BCAMS

Background The role of adipokine dysregulation in determining the metabolic fate of obesity is not well studied. We aimed to examine whether the matricellular protein osteonectin and the profiles of certain adipokines could differentiate metabolically healthy obese ( MHO ) versus metabolically unhealthy obese phenotypes in childhood. Methods and Results This study included 1137 obese children and 982 normal-weight healthy ( NWH ) controls recruited from the BCAMS (Beijing Child and Adolescent Metabolic Syndrome) study. MHO was defined by the absence of insulin resistance and/or any metabolic syndrome components. Six adipokines-osteonectin, leptin, adiponectin, resistin, FGF21 (fibroblast growth factor 21), and RBP-4 (retinol binding protein 4)-were assessed. Approximately 20% of obese children displayed the MHO phenotype. MHO children had a more favorable adipokine profile than metabolically unhealthy obese children, with lower osteonectin, leptin, and RBP -4 and higher adiponectin (all P<0.05). Compared with normal-weight healthy controls, MHO children displayed increased leptin, resistin, and RBP -4 levels and reduced adiponectin concentrations (all P<0.05) but similar osteonectin and FGF 21 levels. Among obese subjects, decreased osteonectin (odds ratio [OR]: 0.82; 95% confidence interval [CI] per standard deviation, 0.70-0.97), RBP -4 (OR: 0.77; 95% CI per standard deviation, 0.64-0.93), and leptin/adiponectin ratio (OR: 0.58; 95% CI per standard deviation, 0.43-0.77) were independent predictors of MHO . In addition, compared with children without abnormalities, those with any 3 adipokine abnormalities were 80% less likely to exhibit the MHO phenotype ( OR : 0.20; 95% CI , 0.10-0.43) and 3 times more likely to have metabolic syndrome ( OR : 2.77; 95% CI , 1.52-5.03). Conclusions These findings suggest that dysregulation of adipokines might govern the metabolic consequences of obesity in children. Low osteonectin levels, along with a healthy adipokine profile, might be used as an early marker of the MHO phenotype.

Childhood sleep duration modifies the polygenic risk for obesity in youth through leptin pathway: the Beijing Child and Adolescent Metabolic Syndrome cohort study

BACKGROUND/OBJECTIVES

Short sleep is an obesity risk factor, however, little is known about its interplay with genetic predisposition and pathways involved in obesity pathogenesis, especially in the longitudinal setting. We aimed to investigate a possible sleep-gene interaction for childhood obesity risk, and whether the interaction in childhood longitudinally contributes to obesity risk at a 10-year follow-up and further to test if there is any mediation through the leptin pathway.

SUBJECTS/METHODS

A total of 3211 children from China (6-18 years) at baseline and 848 participants at 10-year follow-up from the Beijing Child and Adolescent Metabolic Syndrome (BCAMS) cohort study were analyzed. Baseline leptin concentrations and 12 established adult body mass index (BMI) loci were examined for the associations with habitual sleep duration.

RESULTS

After adjusting for covariates, including pubertal stages and behavioral factors, short sleep duration at baseline was significantly associated with increased overweight/obesity risk at both baseline and follow-up. Genetic predisposition scores (GPS), particularly consisting of leptin-related SNPs (GPSleptin), were robustly associated with baseline overweight/obesity in children who slept ≤8 h/day (P < 0.001), whereas the association was ablated in those who slept ≥10 h/day (P > 0.05). Comparable observations were made at follow-up. Mediation analysis revealed a modest direct effect of the GPSleptin-sleep interaction on BMI at baseline, while a significant indirect effect of this interaction was found to be mediated principally through elevated leptin (proportion: 52.6%); moreover, the mediation effect via leptin remained stable over 10 years.

CONCLUSIONS

This study suggests that shorter sleep duration in children from China (< 8h/day), compared to longer sleep duration (≥10 h/day), has a long-term impact on the association of polygenic risk for obesity from childhood to young adulthood and leptin pathway explains a key mechanism via a modification effect. Therefore, adequate sleep duration during childhood is important for the early prevention of obesity, especially if there is a genetic predisposition to this trait.

Adipose Tissue Mediates Associations of Birth Weight with Glucose Metabolism Disorders in Children

OBJECTIVE

This study aimed to examine the associations between low birth weight (LBW) versus high birth weight (HBW) and dysglycemia, including insulin resistance (IR) and impaired fasting glucose (IFG) in children, and aimed to explore the role of adipose tissue in these relationships.

METHODS

A total of 2,935 subjects aged 6 to 18 years were recruited to examine the relationship between birth weight and IR (defined as homeostasis model assessment of IR > 2.3) and IFG. Mediation analyses were conducted to examine the roles of various adipokines and anthropometrics in these relationships.

RESULTS

Children with LBW had a nearly twofold increased risk of IR and IFG compared with children with normal birth weight, even after adjusting for BMI. Decreased circulating adiponectin levels contributed to 21.2% of the LBW-IR relationship, whereas none of the selected adipose markers mediated the LBW-IFG relationship. In contrast, after controlling for current BMI or waist circumference, HBW reduced the risk of IR by 34%, but it was not associated with IFG. The HBW-IR relationship was significantly mediated by reduced leptin levels (21.4%) and fat mass percentage (8.8%), after controlling for BMI.

CONCLUSIONS

These findings suggest the potential role of adipose tissue dysfunction as an underlying mechanism for the birth weight-type 2 diabetes relationship.

Vitamin D levels are associated with metabolic syndrome in adolescents and young adults: The BCAMS study

BACKGROUND AND AIMS

The relationship between vitamin D deficiency and metabolic syndrome (MS) remains controversial with relatively sparse data among youth. Therefore, we attempted to explicate the association of 25-hydroxyvitamin D [25(OH)D] levels with MS in Chinese adolescents and young adults.

METHODS

A cohort of 559 subjects at elevated risk of MS were recruited at 14-28 years of age as a follow-up to the Beijing Child and Adolescent Metabolic Syndrome Study. Subjects underwent clinical assessment including a 2h-oral glucose tolerance test. The concentrations of 25(OH)D, glucose, insulin and lipids were determined. MS was defined using the 2009 harmonized definition.

RESULTS

The prevalence of vitamin D deficiency (< 20 ng/ml) was 78.3%. After adjusting for age, gender and season, 25(OH)D concentrations were negatively correlated with neck circumference, percent body fat, LDL cholesterol, fasting and 2h-glucose levels (all P < 0.05). 25(OH)D levels were significantly lower in participants with obesity, high triglycerides, type 2 diabetes, or MS, compared to their respective counterparts (all P < 0.05). After adjusting for potential confounders (e.g., body mass index), participants in the lowest 25(OH)D tertile were 2.5 times more likely to exhibit MS than were those in the highest tertile (Odds Ratio: 2.48; 95% CI: 1.13-5.45, P < 0.05).

CONCLUSIONS

Vitamin D deficiency was very common in this young Chinese population at risk for MS. Given this association between low vitamin D levels and MS, the role of vitamin D supplementation in Chinese youths needs further examination, particular in those at risk for MS.

Evaluation of ADA HbA1c criteria in the diagnosis of pre-diabetes and diabetes in a population of Chinese adolescents and young adults at high risk for diabetes: a cross-sectional study

OBJECTIVE

We aimed to assess haemoglobin A1c (HbA1c) for the diagnosis of pre-diabetes and diabetes in a population of Chinese youths at risk of metabolic syndrome.

SETTING

Beijing, China.

PARTICIPANTS

A total of 581 subjects aged 14-28 years underwent evaluation including an oral glucose tolerance test (OGTT). Insulin sensitivity, β-cell function and a number of cardiovascular disease risk factors were evaluated. Receiver operating characteristic (ROC) curves were used to assess the screening efficacy of HbA1c.

RESULTS

Using OGTT data as a standard, the majority (70.0%, 7/10) of subjects with diabetes would have been diagnosed with HbA1c ≥6.5%. In contrast, only 28.1% (16/57) of subjects with pre-diabetes possessed elevated HbA1cs, while the majority (68.4%) had normal HbA1cs. On the contrary, a total of 8.1% (39/479) of youths in the normal HbA1c category (<5.7%) and 21.3% in the pre-diabetes category had pre-diabetes. In the ROC analysis, the area under the curve (AUC) for HbA1c identifying pre-diabetes was 0.680(95% CI 0.640 to 0.719); the optimal threshold was 5.5%, with a sensitivity of 61.4% and specificity of 68.5%. For type 2 diabetes mellitus, the AUC for HbA1c was 0.970 (0.952 to 0.982), and the optimal threshold was 6.1%, with a sensitivity of 90.0% and a specificity of 98.7%. Applying these new cut-offs, pre-diabetic participants (HbA1c 5.5%-6.1%) had lower disposition index and higher risk of dyslipidaemia (OR=1.61,95% CI 1.10 to 2.37) and metabolic syndrome (OR=2.09, 1.27 to 3.45) than those with normal HbA1c (<5.5%).

CONCLUSION

The American Diabetes Association's established HbA1c criteria for pre-diabetes and diabetes (5.7% and 6.5%) may not be appropriately applied to adolescents and young adults in China. Our findings suggest that those with HbA1c of 5.5%-6.1% already exhibit impaired β-cell function and increased cardiometabolic risk factors which may warrant intervention.

TRIAL REGISTRATION NUMBER

NCT03421444.

Role of adipokines FGF21, leptin and adiponectin in self-concept of youths with obesity

The mechanisms by which obesity increases the risk of psychosocial disorders remain unclear. We aimed at exploring the association between obesity and self-concept in Chinese youths and the role of adipokines. Data for 559 participants (aged 14-28 years) were analyzed. Self-concept was assessed by utilizing the Self-Description Questionnaire II (SDQ-II). Subjects with obesity had higher leptin, FGF21 and lower adiponectin levels (all p < 0.001). They also had lower SDQ-II scores especially in the domains of general school, physical abilities, physical appearance and opposite-sex relations (all p < 0.001). Both elevated FGF21 and leptin were correlated with lower scores in math (p < 0.01), physical abilities (p < 0.01), and opposite-sex relations (p < 0.05), meanwhile FGF21 negatively correlated with the scores in general school and honesty/trustworthiness, and leptin negatively correlated with physical appearance (p < 0.01) but positively with verbal (p < 0.01). In contrast, decreased adiponectin was correlated with poorer physical abilities (p < 0.05), physical appearance (p < 0.05), and parent relations (p < 0.01). Moreover, these associations of leptin, FGF21 and adiponectin with certain domains remained significant after adjustment for BMI and other metabolic confounders. In conclusion, youths with obesity experienced poorly on self-concept, and these associations may be explained in part by adipokines leptin, FGF21 and adiponectin.

Loss of Cardio-Protective Effects at the CDH13 Locus Due to Gene-Sleep Interaction: The BCAMS Study

Left ventricular mass index (LVMI) provides a metric for cardiovascular disease risk. We aimed to assess the association of adiponectin-related genetic variants resulting from GWAS in East Asians (loci in/near CDH13, ADIPOQ, WDR11FGF, CMIP and PEPD) with LVMI, and to examine whether sleep duration modified these genetic associations in youth. The 559 subjects aged 15–28 years were recruited from the Beijing Child and Adolescent Metabolic Syndrome study. Among the six loci, CDH13 rs4783244 was significantly correlated with adiponectin levels (p = 8.07 × 10⁻⁷). The adiponectin-rising allele in rs4783244 locus was significantly associated with decreased LVMI (p = 6.99 × 10⁻⁴) after adjusting for classical cardiovascular risk factors, and further for adiponectin levels, while no significant association was found between the other loci and LVMI. Moreover, we observed a significant interaction effect between rs4783244 and sleep duration (p = .005) for LVMI; the genetic association was more evident in long sleep duration while lost in short sleep duration. Similar interaction was found in the subgroup analysis using longitudinal data (p = .025 for interaction). In this young Chinese population, CDH13 rs4783244 represents a key locus for cardiac structure, and confers stronger cardio-protection in longer sleep duration when contrasted with short sleep duration.

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CDH13 rs4783244 represents a key locus for cardiac structure.

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The effect of CDH13 rs4783244 on reduced left ventricular mass index is significantly modified by sleep duration.

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Short sleep may contribute to the loss of CDH13 locus-mediated cardio-protective effects.

We analyzed the associations of five adiponectin-associated genetic variants with left-ventricular mass index (LVMI), a cardiovascular risk factor, in a population of 559 youth. We found a significant protective association of CDH13 rs4783244 with decreased LVMI, independent of adiponectin and other conventional risk factors. Sleep duration has previously been described as a risk factor for increased LVMI in this population, therefore, we assessed modification of this association in CDH13 by sleep duration, and found that short sleep attenuated the cardio-protective effect of this SNP. Our study provides important insights into pathologic mechanisms and prevention strategies for early risk of cardiovascular disease.

Childhood retinol-binding protein 4 (RBP4) levels predicting the 10-year risk of insulin resistance and metabolic syndrome: the BCAMS study

Background

Elevated retinol-binding protein 4 (RBP4) levels may contribute to the development of metabolic abnormalities, but prospective studies evaluating the association between childhood RBP4 levels and metabolic syndrome (MS) in adulthood are lacking. We investigated whether RBP4 levels during childhood predict cardiometabolic risk at 10-year follow-up.

Methods

The relationships between RBP4 levels, the established adipokines (leptin and adiponectin) and the components of MS were examined in 3445 school-aged children recruited in 2004 for the Beijing Child and Adolescent Metabolic Syndrome study. In 2015, 352 of these individuals completed an in-depth follow-up examination.

Results

Participants with higher childhood RBP4 levels had adverse cardiometabolic profiles at follow-up. Those with incident or persistent MS had higher baseline RBP4 levels than those who never exhibited the elements of MS. Moreover, baseline RBP4 predicted hyperglycemia (OR per SD increase = 1.48, P = 0.009), elevated triglyceride (OR = 1.54, P < 0.001), elevated blood pressures (OR = 1.46, P = 0.015), MS (OR = 1.68, P = 0.002) and insulin resistance (OR = 1.44, P = 0.015) in the 10-year follow-up phase, independent of baseline BMI. Significant improvements were seen for the net reclassification improvement and integrated discrimination index after adding childhood RBP4 levels into the risk models using conventional cardiometabolic risk factors in predicting MS at follow-up (P < 0.05). Leptin and adiponectin demonstrated the expected associations with metabolic disorders.

Conclusions

Childhood RBP4 serves as a risk factor for subsequent development of MS and its components, independent of pediatric obesity. Incorporating childhood RBP4 into conventional cardiometabolic risk assessment models significantly improves the prediction of MS.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0707-y) contains supplementary material, which is available to authorized users.

Sleep Duration and Cardiometabolic Risk Among Chinese School-aged Children: Do Adipokines Play a Mediating Role?

Study Objectives

To assess the associations between sleep duration and cardiometabolic risk factors in Chinese school-aged children and to explore the possible mediating role of adipokines.

Methods

Sleep duration was collected in 3166 children from the Beijing Child and Adolescent Metabolic Syndrome study. Glucose homeostasis and other cardiometabolic risk factors were assessed. Serum adipokines including leptin, total and high-molecular-weight (HMW) adiponectin, resistin, fibroblast growth factor 21 (FGF21), and retinol binding protein 4 (RBP4) were determined.

Results

Among the 6- to 12-year-old children, after adjusting for covariates including puberty, short sleep duration was associated with increased body mass index (BMI), waist circumference, fasting glucose, insulin and homeostasis model assessment of insulin resistance (all p < .0001), higher triglyceride and lower high-density lipoprotein cholesterol (p < .05), along with increased leptin (p < .0001), FGF21 (p < .05) and decreased HMW-adiponectin (p ≤ .01); the association with leptin remained significant after further adjustment for BMI. However, these associations, except for glucose (p < .0001), disappeared after further adjusted for leptin. For the 13-18 years old group, short sleep duration was associated with higher BMI, waist circumference, and RBP4 (all p < .05), but the association with RBP4 was attenuated after adjusting for BMI (p = .067).

Conclusions

Short sleep duration is strongly associated with obesity and hyperglycemia (in 6-12 years old), along with adverse adipokine secretion patterns among Chinese children. The associations with cardiometabolic risk factors appear to be more pronounced in younger children, and could be explained, at least partially, by leptin levels.

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.

The role of established East Asian obesity-related loci on pediatric leptin levels highlights a neuronal influence on body weight regulation in Chinese children and adolescents: the BCAMS study

Genome-wide association studies have identified multiple variants associated with adult obesity, mostly in European-ancestry populations. We aimed to systematically assess the contribution of key loci, which had been previously shown to be associated in East Asian adults, to childhood obesity, related adipokine profiles and metabolic traits in a Chinese pediatric population. Twelve single-nucleotide polymorphisms (SNPs) plus metabolic profiles and levels of five adipokines (leptin, adiponectin, resistin, fibroblast growth factor 21 and retinol binding protein 4) were evaluated in 3,506 Chinese children and adolescents aged 6-18. After correction for multiple comparisons, six of these SNPs were robustly associated with childhood obesity: FTO-rs1558902 (P=5.6×10⁻⁵), MC4R-rs2331841 (P=4.4×10⁻⁴), GNPDA2-rs16858082 (P = 3.4×10⁻⁴), PCSK1-rs261967 (P = 0.001), SEC16B-rs516636 (P = 0.004) and MAP2K5-rs4776970 (P = 0.004), with odds ratios ranging from 1.211 to 1.421; while ITIH4-rs2535633 and BDNF-rs2030323 yielded nominal association with the same trait (P < 0.05). Moreover, the risk alleles of six SNPs displayed significant (P < 0.004) or nominal (P < 0.05) association with leptin levels, namely at in/near PCSK1, MC4R, FTO, MAP2K5, GNPDA2 and BDNF plus their cumulative genetic score yielded stronger association with increased leptin levels (P = 6.2×10⁻¹¹). Our results reveal that key obesity-associated loci previously reported in Europeans, but also associated with East Asian adults, are also associated with obesity and/or metabolic quantitative traits in Chinese children. These associations coincide with six brain-expressed loci that correlate with leptin levels, thus may point to an important neuronal influence on body weight regulation in the pediatric setting.

Serum adipokines and vitamin D levels in patients with type 1 diabetes mellitus

INTRODUCTION

Adiponectin, leptin and resistin are adipokines that play important roles in the regulation of lipid and carbohydrate metabolism in type 2 diabetes (T2DM). However, their influence in type 1 diabetes mellitus is still unknown. The aim of this study was to measure serum adiponectin, leptin and resistin levels and to investigate their relationships with vitamin D and other clinical and laboratory parameters in patients with type 1 diabetes.

MATERIAL AND METHODS

Fifty subjects with type 1 diabetes and 50 healthy age- and sex-matched subjects were selected from the Endocrinology Outpatient Clinic of Cairo University Pediatrics Hospital. Enzyme-linked immunosorbent assay was used to measure the levels of leptin, adiponectin and resistin. Vitamin D levels were measured using electro-chemiluminescence immunoassay.

RESULTS

There were no significant differences in adiponectin and leptin levels between diabetic and control subjects (p = 0.6 and p = 0.5 respectively). Resistin levels were significantly higher in the diabetic group compared to controls (p < 0.001) and in postpubertal patients compared to prepubertal patients (p < 0.04). Serum resistin in type 1 diabetes showed a negative correlation with vitamin D (p < 0.001) and a positive correlation with glycated hemoglobin (HbA_1c) (p = 0.006), while other adipokines were not interrelated.

CONCLUSIONS

These results strongly support a role of resistin and vitamin D deficiency in the pathophysiology of type 1 diabetes. Vitamin D may be involved in resistin regulation through an unknown mechanism. Further studies are recommended to understand resistin regulation in type 1 diabetes.

FGF21 deficiency is associated with childhood obesity, insulin resistance and hypoadiponectinaemia: The BCAMS Study

OBJECTIVE

Fibroblast growth factor 21 (FGF21) exerts beneficial effects on metabolic homoeostasis and has been reported to be regulated by adiponectin, leptin and resistin. However, while an association between increased circulating FGF21 and metabolic disorders has been reported in adults, paediatric-specific data are lacking.

DESIGN AND METHODS

This study investigated the relationship between FGF21 levels and obesity, insulin resistance (IR), the metabolic syndrome (MetS) and adipokines (adiponectin, leptin and resistin) in a cohort of 3231 Chinese youngsters aged 6-18.

RESULTS

There were gender- and puberty-related differences in FGF21 levels. Unexpectedly, FGF21 levels were decreased in children with obesity, and negatively correlated with insulin, HOMA-IR and leptin levels after adjusting for age, gender, puberty and lifestyle factors. Moreover, multiple regression analyses showed that serum FGF21 positively predicted adiponectin levels while resistin positively predicted FGF21 levels independent of BMI (P<0.05). Children in the lowest FGF21 quintile were more likely to have IR (OR: 1.85, 95% CI: 1.41-2.42; P=0.002) and MetS (OR: 1.62, 95% CI: 1.14-2.28; P=0.007) than those in the highest quintile. Further adjusting for BMI and/or the three adipokines modified the association of FGF21 with MetS (P>0.10) but not with IR (P<0.01).

CONCLUSION

Although the associations between adiponectin, leptin, resistin and metabolic abnormalities in our paediatric population were similar to those in adults, correlations of FGF21 levels with obesity, IR and MetS were the inverse of those found in adults. Our present findings suggest that FGF21 deficiency, rather than resistance, contribute to IR and hypoadiponectinaemia independently of obesity in young people.

Association between sleep duration and cardiac structure in youths at risk for metabolic syndrome

The evidence for a link between sleep duration and cardiovascular risk is accumulating in youths, but no study has yet investigated the relationship between sleep duration and change of cardiac structure. In this study, we recruited 559 youths aged 14–28 years from the cohort of Beijing Child and Adolescent Metabolic Syndrome Study. Questionnaire, color Doppler echocardiography, oral glucose tolerance test and blood biomarkers analyses were performed. We found that sleep duration was negatively correlated with body mass index, waist circumstance, and HbA1c (all P < 0.05), but not with adiponectin and leptin. Meanwhile, participants with shorter sleep duration (≤7 h) had larger interventricular septal diastolic thickness, left ventricular (LV) end-diastolic diameter, LV posterior wall thickness, LV mass (LVM), and LV mass index (LVMI), compared to participants in 7–9 h/night or >9 h/night group. Findings remained significant after adjustment for the major confounding factors (P < 0.05). Multivariate regression modeling revealed that each additional hour of sleep was associated with smaller LVM (β: −3.483, P < 0.0001) and LVMI (β: −0.815, P < 0.0001). Our findings suggest that short sleep has a possible direct effect on cardiac remodeling, occurring already at young ages.

Cardiovascular Disease Risk Factors Profile in Individuals With Diabetes Compared With Non-Diabetic Subjects in North-East of Iran

Background

Diabetes mellitus is assumed to be a strong risk factor for cardiovascular diseases (CVD) and is frequently associated with other CVD risk factors.

Objectives

The aims of this study were to assess the prevalence of different patterns of dyslipidemia in individuals with diabetes compared with non-diabetic subjects and evaluate other accompanied CVD risk factors between the two groups.

Patients and Methods

This was an analytical cross-sectional study on 230 participants, aged 28 - 66 years old, who were referred to different urban health centers of Khorasan Razavi province (north-east of Iran). Data from the participants were collected during their first visit by primary care physicians. Statistical package for social science (version 11.5) was used to analyze the data. The chi-square or Fisher’s exact, student’s t or the Mann-Whitney U and correlation tests were used in the analysis.

Results

The age and gender of the participants were not different between the two groups (P = 0.1 and P = 0.4, respectively). The most common patterns of dyslipidemia in both groups were isolated dyslipidemia followed by combined dyslipidemia. Prevalence of dyslipidemia as a whole (one, two or three lipid profile abnormalities) in patients with diabetes and non-diabetic participants was 89.3% and 82.6%, respectively and the difference between the two groups was not statistically significant (P = 0.1). Subjects with diabetes had higher systolic blood pressure (P < 0.001), higher diastolic blood pressure (P = 0.002) and higher body mass index (P = 0.09) compared to non-diabetics. Moreover, they were more likely to have higher levels of total cholesterol (P = 0.01), triglycerides (P = 0.001) and low density lipoprotein cholesterol (P = 0.009) and lower levels of high density lipoprotein cholesterol (P = 0.2).

Conclusions

Cardiovascular diseases risk factors are more common in patients with diabetes; however, non-diabetic individuals also had a high prevalence of risk factors in our region, predisposing them to diabetes. Therefore, further attention by the medical community is necessary to choose effective strategies for a more a aggressive approach to prevent and manage these risk factors.

Vitamin D modifies the associations between circulating betatrophin and cardiometabolic risk factors among youths at risk for metabolic syndrome

Background

Betatrophin has been recently reported to play a role in glucose homeostasis by inducing beta-cell proliferation in mice. However, studies in human are inconsistent. As a nutritionally-regulated liver-enriched factor, we hypothesize that betatrophin might be regulated by vitamin D, and ignorance of vitamin D status may explain the discrepancy in previous human studies. The aims of this study were to assess the association between circulating betatrophin and glucose homeostasis as well as other cardiometabolic variables in a cohort of youths at risk for metabolic syndrome and test the possible influence of vitamin D status on the association.

Methods

559 subjects aged 14–28 years were recruited from Beijing children and adolescents metabolic syndrome study. All underwent a 2 h-oral glucose tolerance test. Serum levels of betatrophin, 25-hydroxy-vitamin D as well as adipokines including adiponectin and fibroblast growth factor 21 (FGF21) were measured by immunoassays. The relationships between betatrophin and insulin resistance, beta-cell function, other cardiometabolic variables and vitamin D status were evaluated.

Results

Participants in the highest quartile of betatrophin levels had the highest levels of total cholesterol (P < 0.001), triglyceride (P < 0.001) and low-density lipoprotein cholesterol (P < 0.001) and the lowest levels of vitamin D (P = 0.003). After stratification by vitamin D status, betatrophin in subjects with vitamin D deficiency were positively correlated with unfavorable metabolic profiles including high blood pressures, dyslipidemia and hyperglycemia, whereas betatrophin in those with higher vitamin D levels only showed negative association with fasting insulin, 2 h-insulin, and insulin resistance. In addition, adiponectin and FGF21 demonstrated the expected associations with metabolic parameters.

Conclusions

Elevated betatrophin levels were associated with cardiometabolic risk factors in this young population, but the association was largely dependent on vitamin D status. These findings may provide valuable insights in the regulation of betatrophin and help explain the observed discrepancies in literature.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0461-y) contains supplementary material, which is available to authorized users.

Obstructive Sleep Apnea Syndrome is Associated with Metabolic Syndrome among Adolescents and Youth in Beijing: data from Beijing Child and Adolescent Metabolic Syndrome Study

Background:

Obstructive sleep apnea (OSA) syndrome has a negative impact on the health of millions of adolescents and youth. The aim of this study was to evaluate the associations of OSA syndrome with obesity and cardiometabolic risk factors among adolescents and youth at risk for metabolic syndrome (MS).

Methods:

A total of 558 subjects aged 14–28 years were recruited from the Beijing Child and Adolescent Metabolic Syndrome Study. Each underwent a 2-h oral glucose tolerance test (OGTT), echocardiography, and liver ultrasonography. Anthropometric measures, blood levels of glucose, lipids, and liver enzymes were assessed. Subjects with high or low risk for OSA were identified by Berlin Questionnaire (BQ).

Results:

Among the subjects in obesity, 33.7% of whom were likely to have OSA by BQ. Subjects with high risk for OSA had higher neck and waist circumference and fat mass percentage compared to those with low risk for OSA (P < 0.001). Moreover, significant differences in levels of lipids, glucose after OGTT, and liver enzymes, as well as echocardiographic parameters were found between the two groups with high or low risk for OSA (P < 0.05). The rates of nonalcoholic fatty liver disease (71.0% vs. 24.2%), MS (38.9% vs. 7.0%), and its components in high-risk group were significantly higher than in low-risk group.

Conclusions:

The prevalence of OSA by BQ was high in obese adolescents and youth. A high risk for OSA indicates a high cardiometabolic risk. Mechanisms mediating the observed associations require further investigation.

Effects of regular exercise on obesity and type 2 diabete mellitus in Korean children: improvements glycemic control and serum adipokines level

[Purpose] The aim of the study was to clarify the effects of regular exercise on lipid profiles and serum adipokines in Korean children. [Subjects and Methods] Subjects were divided into controls (n=10), children who were obese (n=10), and children with type 2 diabetes mellitus (n=10). Maximal oxygen uptake (VO₂max), body composition, lipid profiles, glucagon, insulin and adipokines (leptin, resistin, visfatin and retinol binding protein 4) were measured before to and after a 12-week exercise program. [Results] Body weight, body mass index, and percentage body fat were significantly higher in the obese and diabetes groups compared with the control group. Total cholesterol, triglycerides, low-density lipoprotein cholesterol and glycemic control levels were significantly decreased after the exercise program in the obese and diabetes groups, while high-density lipoprotein cholesterol levels were significantly increased. Adipokines were higher in the obese and diabetes groups compared with the control group prior to the exercise program, and were significantly lower following completion. [Conclusion] These results suggest that regular exercise has positive effects on obesity and type 2 diabetes mellitus in Korean children by improving glycemic control and reducing body weight, thereby lowering cardiovascular risk factors and adipokine levels.

Changes in adipokine levels in autism spectrum disorders

BACKGROUND AND OBJECTIVE

The etiopathogenesis of autism spectrum disorders (ASD) is largely unknown, but it seems to involve dysfunction in several biological systems. Among many possible biological pathways, the immune system has emerged as potentially involved. Recent studies have shown association between cytokines (molecules that mediate immune cell interaction) and ASD. Adipokines are cytokines secreted mainly by adipose tissue and may have systemic effects. The main objective of this study was to compare the plasma levels of three adipokines between patients with ASD and healthy controls. Another aim was to correlate the levels of these adipokines and the severity of autistic symptoms as measured by the Social Responsiveness Scale (SRS).

METHODS

We collected plasma from 30 patients and 19 controls and measured the levels of adiponectin, leptin and resistin using a commercially available kit. We also used the SRS as a tool to assess the severity of autistic symptoms.

RESULTS

We found decreased levels of resistin, increased levels of leptin and unaltered levels of adiponectin in plasma from ASD subjects in comparison with controls. There was also a negative correlation between the levels of adiponectin and the severity of symptoms as assessed by the SRS.

CONCLUSION

There are significant changes in the plasma levels of adipokines from patients with ASDs. They suggest the occurrence of systemic changes in ASD and may be hallmarks of the disease.

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.

Waist-to-height ratio, inflammation and CVD risk in obese children

OBJECTIVE

To evaluate the association between waist-to-height ratio (WHtR) and specific biomarkers of inflammation, CVD risk and endothelial dysfunction in prepubertal obese children.

DESIGN

Prospective, multicentre case-control study matched by age and sex.

SETTING

Children were recruited between May 2007 and May 2010 from primary-care centres and schools in three cities in Spain (Cordoba, Santiago de Compostela and Zaragoza).

SUBJECTS

Four hundred and forty-six (223 normal weight and 223 obese) Caucasian prepubertal children aged 6-12 years.

RESULTS

WHtR was higher in the obese than in the normal-weight children. Blood pressure, waist circumference, weight, height, insulin, plasma lipids, leptin, resistin, abnormal neutrophil and monocyte counts, C-reactive protein, IL-6, IL-8, TNF-α, myeloperoxidase, soluble intercellular adhesion molecule-1, selectin and plasminogen activator inhibitor-1 levels were higher in the obese than in the normal-weight group. Adiponectin and HDL-cholesterol were lower and glucose and metalloproteinase-9 showed no differences. Resistin, TNF-α and active plasminogen activator inhibitor-1 were associated with WHtR, a sensitive indicator of central obesity.

CONCLUSIONS

Our results lead to the hypothesis that changes in biomarker levels of insulin resistance, inflammation and CVD risk before puberty might induce metabolic consequences of obesity in obese children before reaching adulthood.

Metabolic syndrome in young people

PURPOSE OF REVIEW

The prevalence of obesity is on the increase, and consequently metabolic syndrome is also becoming a serious health problem in children and adolescents all over the world. This review attempts to summarize the recent literature on metabolic syndrome in children and adolescents.

RECENT FINDINGS

To date, a standard definition of metabolic syndrome for the pediatric population is not available. Recently, the International Diabetes Federation has proposed a new set of criteria to define metabolic syndrome in children and adolescents aged 6-16 years. The relationships between obesity, insulin resistance and metabolic syndrome may be explained by the pattern of lipid partitioning. Fatty liver plays a central role in the insulin-resistant state in obese adolescents. Although insulin resistance has been proposed as the central factor leading to the abnormalities observed in metabolic syndrome, most definitions of metabolic syndrome use impaired fasting glucose as a marker. Nutrition impairment during both prenatal and early postnatal life can cause metabolic disturbances leading to insulin-resistance, type 2 diabetes, hypertension and cardiovascular disease.

SUMMARY

Metabolic syndrome prevalence in children and adolescents is on the increase. Therefore, the emphasis in all studies and programs related to metabolic syndrome should be focused on prevention, early detection of metabolic risk factors and interventions that will have a significant impact on future adult health.

The association of fasting blood glucose (FBG) and waist circumference in northern adults in Iran: a population based study

OBJECTIVES

The aim of this study was to evaluate the association between Fasting Blood Glucose (FBG) level and Waist Circumference (WC) in men and women among 25-65 years old people in the north of Iran.

MATERIAL AND METHODS

This was a cross-sectional and analytical research gender that carried out on the 1797 subjects (941 males and 856 females) between 25-65 years old using multistage cluster sampling technique. FBG was measured in the morning after a 12-hour fast and was determined by using laboratory kits (enzymatic methods) and spectrophotometry technique. Central obesity was defined based on World Health Organization criteria: waist circumference ≥102 cm and ≥88 cm in men and women, respectively. The SPSS.16 software was used for statistical analysis.

RESULTS

As whole, the mean of FBG in women (98.3 ± 40.1 mg/dl) was higher than in men (94.6 ± 32.2 mg/dl). Also, the mean of WC in men 4.5 cm was lower than in women. In men, the mean of FBG statistically differs between normal and central obese subjects both in 35-45 year-age group (P = 0.001) and in 45-55 year-age group (P = 0.042). As whole, in men, the FBG level increased up 2.82 mg/dl in each 10 cm of WC with the highest rate in 35-45 year-age group. In totally, in women, the FBG level increased up 3.48 mg/dl in each 10 cm of WC and in 25-35 year-age group and it was higher than in other age groups. In men, the regression coefficients were constant with age increasing while in women it was decreased. Constant trend in men and decreasing trend in women with age was shown between FBG and WC. The cut-off point of WC for detecting of diabetes obtained 89 cm and 107 cm in men and women, respectively.

CONCLUSION

The positive correlation was seen between WC and FBG level and it was declined with age in women. Cut-off point for detecting of diabetes in men was less than in women. WC is useable as a predictor of type 2 diabetes mellitus risk among adults in the north of Iran.

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

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

Elevated plasma SPARC levels are associated with insulin resistance, dyslipidemia, and inflammation in gestational diabetes mellitus

Objective

Recent studies suggested that secreted protein acidic and rich in cysteine (SPARC), a novel adipokine, is a key player in the pathology of obesity and type 2 diabetes. We aimed to determine whether concentrations of SPARC were altered in patients with gestational diabetes mellitus (GDM) compared to normal glucose tolerance (NGT) controls and to investigate the relationships between SPARC and metabolic parameters in pregnant women.

Design/Methods

Cross-sectional study of 120 pregnant women with GDM and 60 controls with NGT, in a university hospital setting. Plasma levels of SPARC, adiponectin, fibroblast growth factor 21 (FGF21), insulin and proinsulin were determined by ELISA.

Results

GDM women had higher SPARC and lower adiponectin than NGT subjects; no difference was found in FGF21. SPARC levels were the lowest in subjects in the third tertile of insulin sensitivity index (ISI_OGTT) and correlated positively with pre-pregnant BMI, insulin and 3 h glucose during 100-g OGTT, HOMA-IR, fasting proinsulin, hsCRP and white blood cells count, and negatively with ISI_OGTT, when adjusting for gestational age. Triglyceride (TG), Apolipoprotein A1, apolipoprotein B and lipoprotein (a) correlated with SPARC in partial Pearson correlation. Correlations between SPARC with adiponectin, systolic blood pressure and TG were marginally significant in partial Spearman correlation analysis. In multivariate regression analysis, SPARC was an independent negative indicator of ISI_OGTT.

Conclusions

SPARC levels are correlated significantly with inflammation and may also be correlated with dyslipidemia and represent an independent determinant of insulin resistance in late pregnancy, indicating a potential role of SPARC in the pathophysiology of GDM.

Insulin resistance determined by Homeostasis Model Assessment (HOMA) and associations with metabolic syndrome among Chinese children and teenagers

OBJECTIVE

The aim of this study is to assess the association between the degree of insulin resistance and the different components of the metabolic syndrome among Chinese children and adolescents. Moreover, to determine the cut-off values for homeostasis model assessment of insulin resistance (HOMA-IR) at MS risk.

METHODS

3203 Chinese children aged 6 to 18 years were recruited. Anthropometric and biochemical parameters were measured. Metabolic syndrome (MS) was identified by a modified Adult Treatment Panel III (ATP III) definition. HOMA-IR index was calculated and the normal reference ranges were defined from the healthy participants. Receiver operating characteristic (ROC) analysis was used to find the optimal cutoff of HOMA-IR for diagnosis of MS.

RESULTS

With the increase of insulin resistance (quintile of HOMA-IR value), the ORs of suffering MS or its related components were significantly increased. Participants in the highest quintile of HOMA-IR were about 60 times more likely to be classified with metabolic syndrome than those in the lowest quintile group. Similarly, the mean values of insulin and HOMA-IR increased with the number of MS components. The present HOMA-IR cutoff point corresponding to the 95th percentile of our healthy reference children was 3.0 for whole participants, 2.6 for children in prepubertal stage and 3.2 in pubertal period, respectively. The optimal point for diagnosis of MS was 2.3 in total participants, 1.7 in prepubertal children and 2.6 in pubertal adolescents, respectively, by ROC curve, which yielded high sensitivity and moderate specificity for a screening test. According to HOMA-IR > 3.0, the prevalence of insulin resistance in obese or MS children were 44.3% and 61.6% respectively.

CONCLUSIONS

Our data indicates insulin resistance is common among Chinese obese children and adolescents, and is strongly related to MS risk, therefore requiring consideration early in life. As a reliable measure of insulin resistance and assessment of MS risk, the optimal HOMA-IR cut-off points in this cohort were developed with variation regarding puberty. HOMA-IR may be useful for early evaluating insulin resistance in children and teenagers and could have a long-term benefit of preventive and diagnostic therapeutic intervention.

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

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

Plasma resistin levels are associated with homocysteine, endothelial activation, and nitrosative stress in obese youths

OBJECTIVE

To evaluate whether serum resistin levels are related to cardiovascular risk in obese children.

DESIGN AND METHODS

Cross-sectional study of 110 children (40 normal weight and 70 severely obese). Clinical and biochemical parameters, including lipid profile, fasting glucose and insulin, and homocysteine, were determined. The levels of adipokines (adiponectin, leptin, and resistin), markers of inflammation (high-sensitivity C-reactive protein (hs-CRP)), endothelial activation (serum concentrations of soluble intercellular and vascular cellular adhesion molecule-1 (sICAM-1, sVCAM-1)), and oxidative/nitrosative stress (malondialdehyde and urinary nitrate/nitrite) were measured.

RESULTS

A partial correlation adjusted by gender, Tanner stage, and body mass index in obese children showed that resistin was significantly related to central obesity (p<0.002), insulin resistance (p<0.005), and homocysteine (p<0.001). No association was found with other metabolic risk factors or hs-CRP levels. Malondialdehyde (p<0.043) and sVCAM-1 (p<0.002) were positively correlated whereas urinary nitrate/nitrite was negatively correlated (p<0.007). In multiple regression analysis homocysteine, sVCAM-1, and urinary nitrate/nitrite remained independent determinants of resistin levels (R(2) adjusted=0.347, p=0.000).

CONCLUSIONS

Resistin could be considered as a promising marker for future cardiovascular disease in obese children.

Relationship of adipokines (adiponectin, resistin and RBP4) with metabolic syndrome components in pubertal obese children

Aim: To investigate the relationship between serum adiponectin, resistin and RBP4 levels and the components of metabolic syndrome. Patients & methods: Serum adiponectin, resistin and RBP4 levels were detected and analyzed in 148 8–18-year-old Turkish obese pubertal children with/without metabolic syndrome. Results: Adiponectin and resistin concentrations were significantly inversely correlated with BMI standard deviation score, homeostatic model assessment insulin resistance, waist circumference, triglyceride levels and diastolic and systolic blood pressure, and were directly correlated with high-density lipoprotein cholesterol. RBP4 concentrations were directly correlated with homeostatic model assessment insulin resistance, waist circumference, triglyceride levels and diastolic and systolic blood pressure, and inversely correlated with high-density lipoprotein cholesterol. Conclusion: Adiponectin, RBP4 and, in particular, resistin levels may be used as suitable predictive biomarkers of metabolic syndrome.

Effects of resistin on porcine ovarian follicle steroidogenesis in prepubertal animals: an in vitro study

BACKGROUND

Resistin was first reported to be an adipocyte-specific hormone, but recent studies have indicated a connection between resistin and reproductive function. However, it is not yet known if resistin is expressed by the ovary and if it can affect steroidogenesis in ovarian follicles from prepubertal pigs.

METHODS

In this study, using real time PCR, immunoblotting, and ELISA, we quantified resistin expression and concentration in maturing ovarian follicles (small, 3-4 mm; medium, 4-5 mm; large, 6-7 mm) collected from prepubertal pigs. In addition, the dose-responsive effects of recombinant human resistin (0.1, 1, 10, and 100 ng/ml) on steroid hormone (i.e., progesterone [P4], androstendione [A4], testosterone [T], and estradiol [E2]) secretion in culture medium and steroidogenic enzyme (i.e., CYP11A1, 3betaHSD, CYP17A1, 17betaHSD, and CYP19A1) expression in ovarian follicles were determined.

RESULTS

We observed that resistin gene and protein expression increased significantly (P < 0.05) during follicular growth, with large follicles expressing the highest level of this adipokine. Recombinant resistin also increased P4, A4, and T secretion by up-regulating the steady state levels of CYP11A1, 3betaHSD, CYP17A1, and 17betaHSD. Recombinant resistin had no effects on E2 secretion and CYP19A1 expression in ovarian follicles.

CONCLUSION

Our results show resistin expression in ovarian follicles from prepubertal pigs for the first time. We also show that recombinant resistin stimulates steroidogenesis in ovarian follicles by increasing the expression of CYP11A1, 3betaHSD, CYP17A1, and 17betaHSD. The presence of resistin in the porcine ovary and its direct effects on steroidogenesis suggest that resistin is a new regulator of ovary function in prepubertal animals.

Prevalence of metabolic syndrome in a cohort of Chinese schoolchildren: comparison of two definitions and assessment of adipokines as components by factor analysis

BACKGROUND

Although attention to metabolic syndrome (MetS) in children has increased, there is still no universally accepted definition and its pathogenesis remains unclear. Our aim was to compare the current definitions of childhood MetS in a Chinese cohort and to examine the clustering pattern of MetS risk factors, particularly inclusion of leptin and adiponectin as additional components.

METHODS

3373 schoolchildren aged 6 to 18 years were recruited. Anthropometric and biochemical parameters and adipokines were measured. MetS was identified using both the International Diabetes Federation (IDF) and a modified Adult Treatment Panel III (ATP III) definitions. Exploratory factor analysis was performed to establish grouping of metabolic characteristics.

RESULTS

For children ≥ 10 years, the prevalence of MetS was 14.3% in the obese group and 3.7% in the overweight group according to the new IDF definition, and 32.3% in the obese group and 8.4% in the overweight group according to the modified ATPIII definition. Frequency of hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-C), impaired fasting glucose, elevated blood pressure, and central obesity according to the new IDF definition was 16.7%, 20.7%, 15.8%, 25.5% and 75.5% in obese boys and 14.7%, 24.0%, 12.0%, 11.0% and 89.0% in obese girls, respectively. Metabolic abnormalities in children under 10 years of age were also noted. Using factor analysis on eight conventional variables led to the extraction of 3 factors. Waist circumference (WC) provided a connection between two factors in boys and all three factors in girls, suggesting its central role in the clustering of metabolic risk factors. Addition of leptin and adiponectin also led to the extraction of 3 factors, with leptin providing a connection between two factors in girls. When using WC, mean arterial pressure, triglyceride/HDL-C ratio, HOMA-IR and leptin/adiponectin ratio as variables, a single-factor model was extracted. WC had the biggest factor loading, followed by leptin/adiponectin ratio.

CONCLUSIONS

MetS was highly prevalent amongst obese children and adolescents in this cohort, regardless of the definition used. Central obesity is the key player in the clustering of metabolic risk factors in children, supporting the new IDF definition. Moreover, our findings suggest that a common factor may underlie MetS. Leptin/adiponectin ratio as a possible component of MetS deserves further consideration.

[Adipokines in healthy and obese children]

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

Efficacy and safety of traditional chinese medicine for diabetes: a double-blind, randomised, controlled trial

BACKGROUND

Treatment of diabetes mellitus with Traditional Chinese Medicine has a long history. The aim of this study is to establish the safety and efficacy of traditional Chinese medicine combined with glibenclamide to treat type 2 diabetes mellitus.

METHODS

In a controlled, double blind, multicentre non-inferiority trial, 800 patients with unsatisfactory glycemic control (fasting glucose 7-13 mmol/L and HbA1c 7-11%) were randomly assigned to receive Xiaoke Pill, a compound of Chinese herbs combined with glibenclamide, or Glibenclamide in two study groups - drug naive group, and patients previously treated with metformin monotherapy (metformin group). Outcome measures at 48 weeks were the incidence and rate of hypoglycemia, mean difference in HbA1c, and proportion of patients with HbA1c<6.5%.

FINDINGS

In drug naïve group, the total hypoglycemia rate and the mild hypoglycemic episode in the Xiaoke Pill arm were 38% (p = 0.024) and 41% (p = 0.002) less compared to Glibenclamide arm; in Metformin group, the average annual rate of hypoglycemia was 62% lower in Xiaoke Pill arm (p = 0.003). Respective mean changes in HbA1c from baseline were -0.70% and -0.66% for Xiaoke Pill and Glibenclamide, with a between-group difference (95% CI) of -0.04% (-0.20, 0.12) in the drug naïve group, and those in metformin group were -0.45% and -0.59%, 0.14% (-0.12, 0.39) respectively. The respective proportions of patients with a HbA1c level <6.5% were 26.6% and 23.4% in the drug naïve group and 20.1% and 18.9% in the metformin group.

INTERPRETATION

In patients with type 2 diabetes and inadequate glycaemic control, treatment with Xiaoke Pill led to significant reduction in risk of hypoglycemia and similar improvements in glycemic control after 48 weeks compared to Glibenclamide.

TRIAL REGISTRATION

Chinese Clinical Trial Register number, ChiCTR-TRC-08000074.

Adipokines in childhood obesity

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

Correlation of resistin with inflammatory and cardiometabolic markers in obese adolescents with and without metabolic syndrome

OBJECTIVE

The link between plasma resistin and obesity-related cardiometabolic disorders in children remains debatable. This study assessed the relationships of plasma resistin with cardiovascular risk factors, pro-inflammatory markers and insulin resistance index (HOMA-IR) in obese (Ob) adolescents and obese adolescents with metabolic syndrome (Ob-MS) compared to healthy controls (CO).

METHODS

114 obese adolescents (60 Ob, age 13.6 ± 0.9 years, BMI 28.0 ± 2.2 kg/m(2), and 54 Ob-MS, age 13.8 ± 1.0 years, BMI 32.5 ± 4.8 kg/m(2)) and 37 CO (age 13.7 ± 0.8 years, BMI 22.8 ± 0.8 kg/m(2)) were studied. Anthropometrics, cardiac variables as well as fasting plasma concentrations of lipids, glucose, insulin, and adipocytokines (resistin, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP)) were measured. HOMA-IR was calculated, and the presence of MS was assessed.

RESULTS

Plasma resistin was significantly higher in Ob-MS than in both Ob and CO and was correlated with anthropometric, cardiovascular, pro-inflammatory markers and several components of MS as was HOMA-IR in Ob and Ob-MS. With increasing the number of MS components, plasma resistin, pro-inflammatory markers, and HOMA-IR were also increased. Multiple regression models highlighted significant correlation between resistin and both HOMA-IR (r = 0.40, p < 0.05) and systolic blood pressure (r = 0.63, p < 0.01) in Ob-MS.

CONCLUSION

These results support the hypothesis that there is an association between circulating resistin and childhood obesity-related inflammatory and cardiometabolic events.

Plasma adiponectin levels in relation to prognosis in patients with angiographic coronary artery disease

OBJECTIVE

The objective was to study the associations between adiponectin levels and cardiovascular adverse clinical outcomes in patients with angiographic coronary artery disease (CAD) within the Han Chinese population in Beijing.

MATERIALS/METHODS

A total of 449 hospitalized patients with angiographic CAD who were Han Chinese in Beijing participated in the study. Plasma adiponectin levels were examined from blood samples using a type of unique enzyme-linked immunosorbent assay that was developed by our laboratory. All of the patients' clinical data, including previously identified cardiovascular risk factors, creatinine clearance and left ventricle ejection fraction, were recorded after admission, and patients were followed up for 19±8 months. The primary end-point was marked by the occurrence of major adverse cardiovascular events (MACE), which included death, targeted vascular revascularization, acute coronary syndrome, heart failure, and transient ischemic attack (TIA) / stroke.

RESULTS

A total of 109 cases of MACE occurred: 15 cases of death, 66 cases of acute coronary syndrome, 4 cases of TIA/stroke, 6 cases of targeted vessel revascularization, and 18 cases of heart failure. Among all the patients, 173 were assigned to the high adiponectin group and 276 were assigned to the low adiponectin group according to their baseline plasma adiponectin levels. The incidence of MACE was significantly higher in the low adiponectin group (P=.037). In a multivariate Cox regression analysis for adiponectin levels, previously documented risk factors, coronary artery stenosis scores, and low adiponectin levels were indicated as independent predictors of MACE in patients with CAD (RR 1.75; 95% CI, 1.066-2.865; P=.027). Further adjustment for hsCRP, Ccr, LVEF, fasting glucose and lipid profile did not attenuate this association (RR=2.36; 95% CI 1.338-4.167; P=.003). The relative risk for low adiponectin levels after additional adjustment for the coronary score was 2.42 (95% CI 1.367-4.279; P=.002). The Kaplan-Meier survival analysis curve suggested that patients with lower adiponectin concentrations had a decreased event-free survival ratio (log-rank χ(2) =4.592, P=.032).

CONCLUSIONS

The results indicate a potential association between plasma adiponectin levels and cardiovascular prognosis in patients with CAD.

Serum resistin and inflammatory and endothelial activation markers in obese adolescents

OBJECTIVES

To assess the level of serum resistin in obese and lean children and to establish a relationship with circulating inflammatory and vascular markers.

STUDY DESIGN

This is a cross-sectional study including 67 obese and 62 lean children (mean age 10.9 ± 2.8 years, age range 5.4-16.6 years). We assessed circulating hormones (insulin, leptin, insulin-like growth factor 1), markers of inflammation (resistin, high sensitivity C-reactive protein, interleukin-6, chemokine ligand 2), and endothelial cell activation (vascular and intercellular adhesion molecules: vascular cell adhesion molecule 1 and intercellular adhesion molecule; E-selectin; P-selectin; endothelin 1).

RESULTS

Body weight, body mass index (BMI), insulin, leptin, high-sensitivity C-reactive protein, vascular adhesion molecule 1, and E-selectin levels were significantly higher in obese than in lean subjects. Resistin was similar among the groups in the prepubertal period, but increased significantly in the obese adolescents (18.6 ± 24.9) compared with lean subjects (7.9 ± 10.7 ng/mL; P = .038). Resistin was not associated with BMI z score (P > .05). Subjects with resistin levels above 9 (ng/mL) had higher concentration of interleukin-6, chemokine ligand 2, endothelin-1, and insulin-like growth factor 1 but not of leptin, insulin, or BMI.

CONCLUSION

Resistin was increased in obese adolescents independently of the quantity of the adipose tissue. In this population, increased resistin levels were related to inflammation and endothelial activation. We may hypothesize that interventions aiming to diminish resistin expression may slow down atherogenesis in adolescents.

Cross-sectional and predictive associations between plasma adipokines and radiographic signs of early-stage knee osteoarthritis: data from CHECK

OBJECTIVE

To investigate cross-sectional and predictive associations of plasma adipokines with biochemical markers of systemic joint metabolism and radiographic signs of early-stage knee osteoarthritis (OA).

DESIGN

The adipokines pLeptin, pAdiponectin, and pResistin, the cartilage markers C-terminal telopeptide of type II collagen (uCTX-II), N-terminal propeptide of type IIA procollagen (sPIIANP), chondroitin sulfate 846 (sCS846), and cartilage oligomeric matrix protein (sCOMP), and the synovial markers hyaluronic acid (sHA) and N-terminal propeptide of type III procollagen (sPIIINP) were assessed by enzyme-linked immunosorbent assay or radioactive immunoassay in baseline samples of Cohort Hip and Cohort Knee (CHECK), a cohort of 1002 subjects with early-stage symptomatic knee and/or hip OA. Knee radiographs were obtained at baseline and after 2 and 5 years and scored according to Kellgren & Lawrence.

RESULTS

pLeptin showed positive associations with uCTX-II, sCOMP, sPIIANP, sHA, and sPIIINP, and with presence and progression of radiographic knee OA. Associations expectedly disappeared after adjustment for body mass index. pResistin showed positive associations with sPIIINP and present and incident radiographic knee OA that were largely independent of BMI. pAdiponectin showed positive associations with uCTX-II and sCOMP. Furthermore, pAdiponectin did not show associations with radiographic knee OA on itself, but associations of pResistin with present radiographic knee OA were stronger in higher pAdiponectin tertiles (P = 0.024 for interaction between pAdiponectin and pResistin). Although statistically significant, all associations were weak.

CONCLUSIONS

Adipokines may have aggravating, although may be minor, structural effects in early-stage knee OA.

Association between childhood obesity and metabolic syndrome: evidence from a large sample of Chinese children and adolescents

Data about metabolic syndrome (MetS) in children is limited in China. We aimed to assess the prevalence of MetS related components, and their association with obesity. Data were collected as part of a representative study on MetS among 19593 children, aged 6-18 years old in Beijing. General obesity was assessed by body mass index (BMI) and central obesity by waist circumference. Finger capillary blood tests were used to assess triglyceride (TG), total cholesterol (TC) and impaired fasting glucose (IFG). Vein blood samples were collected from a subsample of 3814 children aged 10-18 years to classify MetS. MetS was defined according to the International Diabetes Federation 2007 definition. The associations between MetS related components and the degree and type of obesity were tested using logistic regression models. The prevalence of overweight, obesity, high blood pressure, elevated TG, TC and IFG were 13.6%, 5.8%, 8.5%, 8.8%, 1.2% and 2.5%, respectively. Compared with normal weight children, overweight and obese children were more likely to have other MetS related components. In the subsample of 3814 children aged 10-18 years, the prevalence of MetS was much higher in obese subjects than in their normal weight counterparts (27.6% vs. 0.2%). Children with both general and central obesity had the highest prevalence of MetS. Compared with normal weight children, overweight and obese children were more likely to have MetS (overweight: OR=67.33, 95%CI=21.32-212.61; obesity: OR=249.99, 95% CI=79.51-785.98). Prevalence of MetS related components has reached high level among Beijing children who were overweight or obese. The association between metabolic disorders and obesity was strong.

Effects of an in-patient treatment program based on regular exercise and a balanced diet on high molecular weight adiponectin, resistin levels, and insulin resistance in adolescents with severe obesity

Adiponectin, the most abundant hormone produced by adipose tissue, circulates in 3 isoforms, including high molecular weight (HMW) adiponectin. The latter has been suggested to be a better predictor of metabolic disturbances and insulin resistance associated with obesity. This study investigated changes in total and HMW adiponectin, resistin, and homeostasis model assessment (HOMA) during a 9-month in-patient treatment program based on physical exercise and a balanced diet in 32 severely obese adolescents. Total and HMW adiponectin, resistin, and HOMA were measured at baseline (month 0) and during the program (months 3, 6, 9). In addition, a control group of 15 teenagers served as a reference for the baseline assessments. At baseline, HMW adiponectin was more markedly decreased in obese adolescents than total adiponectin, and both were lower than in controls. Conversely, resistin and HOMA were higher in obese adolescents. During the program, there was a significant change in body composition and improved insulin sensitivity among obese teenagers. In addition, HMW adiponectin and the ratio of HMW-to-total adiponectin increased throughout the study, whereas total adiponectin only increased up until the sixth month. On the contrary, resistin did not show any significant change. In obese adolescents, a long-term combination of aerobic exercise and a balanced diet, inducing change in body composition and improved insulin sensitivity, markedly increased HMW adiponectin compared with total adiponectin, without any change in resistin concentrations. Our results thus suggest that the determination of HMW adiponectin could be more useful than measurement of total adiponectin in clinical settings.