Metabolic syndrome in a Mediterranean pediatric cohort: prevalence using International Diabetes Federation-derived criteria and associations with adiponectin and leptin

Disparities in the Prevalence of Childhood Obesity-Related Comorbidities: A Systematic Review

Background

Non-communicable diseases among children are serious consequences of childhood obesity. However, less is known about the disparities in childhood obesity comorbidities burden. This review describes the salient pattern of disparities in the prevalence of childhood obesity-related non-communicable diseases and relevant inequalities in both high- and low/medium-income countries.

Method

A systematic literature search was performed in MEDLINE, Embase, CINAHL, PsycInfo, Scopus, and Web of Science databases by two independent reviewers. Inclusion criteria were as follows: age 2–18 years; the prevalence or incidence of childhood obesity comorbidities reported; and studies published in English from January 2010 to date. No restrictions on the setting. The prevalence data were analyzed using range and median for subgroups based on the country's development status, gender, and geographical region.

Results

Our search identified 6,837 articles, out of which we examined 145 full-text articles and included 54 articles in the analysis. The median prevalence of childhood obesity-related hypertension was 35.6 vs. 12.7% among middle- and low-income countries compared with high-income countries; 37.7 vs. 32.9% among boys compared with girls; and 38.6, 25.3, and 20.1% in Asia, South America, and Europe, respectively. For metabolic syndrome, the median prevalence was 26.9 vs. 5.5% among middle- and low-income countries compared with high-income countries; 55.2 vs. 12.0% among boys compared with girls; and 40.3, 25.8, and 7.7% in South America, Asia, and Europe, respectively. The prevalence of childhood obesity-related non-alcoholic fatty liver disease was 47.5 vs. 23% among middle- and low-income countries compared with high-income countries; and 52.1, 39.7, and 23.0% in Asia, South America, and Europe, respectively. The median prevalence of dyslipidemia was 43.5 vs. 63% among middle- and low-income countries compared with high-income countries; 55.2 vs. 12.0% among boys compared to girls; and 73.7 and 49.2% in Australia and Europe, respectively.

Conclusion

There are disparities in the prevalence of childhood obesity-related hypertension, metabolic syndrome, and non-alcoholic fatty liver disease, with middle- and low-income countries, boys, and Asian region having higher prevalence. Implementing targeted interventions for childhood obesity comorbidities should consider socioeconomic disparities and strengthening of research surveillance methods for a better understanding of non-communicable disease burden in the pediatric population.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42021288607.

Prevalence of metabolic syndrome and its components in Brazilian adolescents: a systematic review and meta-analysis

OBJECTIVE

To determine the prevalence of metabolic syndrome (MS) and its components among Brazilian adolescents.

DATA SOURCE

Databases, such as LILACS, MEDLINE, and SciELO, were searched for original cross-sectional studies published between 2010 and 2021. The inclusion criteria were determined based on the mnemonic CoCoPop - Condition, Context, and Population: studies determining the prevalence of MS and its components (condition) in the general population of Brazilian adolescents, female and male (population), enrolled in public or private schools in rural or urban areas (context). Reviews, editorials, and articles that did not directly relate to the prevalence of MS or that included non-adolescent age groups or groups with specific health conditions (obesity/overweight and others) were excluded.

DATA SYNTHESIS

A total of 15 studies, including 43,227 adolescents, were identified. MS prevalence (95% confidence interval [95%CI]) was 2.9% (2.65-3.18) and 2.4% (1.90-2.90) (p<0.001) in males and females, respectively, by using the International Diabetes Federation (IDF) criteria. There was a significant difference in MS prevalence among Brazilian regions (Q=24.7; p<0.001). The lowest MS prevalence (95%CI) was determined for North Region of Brazil, 1.8% (1.52-2.13), and the highest for Northeast Region of Brazil, 2.9% (2.62-3.23). Regarding MS components, a higher prevalence (95%CI) was found for low high-density lipoprotein (HDL), 22.1% (12.49-36.17), followed by abdominal obesity, 11.0% (8.05-14.94), and arterial hypertension, 10.3% (7.84-13.48).

CONCLUSIONS

This study allowed the determination of the prevalence of MS and the MS components in Brazilian adolescents, highlighting relevant aspects to be addressed on public health management.

Identification of Factors Influencing Cholesterol Changes in Elementary-School Children: A Longitudinal Study

Changes in serum cholesterol levels during childhood may affect the risk of cardiovascular disease in adulthood. However, cholesterol level changes in Japanese children and adolescents and the factors that influence them have not been completely elucidated. This study aimed to determine whether cholesterol levels changed due to the effects of growth and identify factors. This cohort study included elementary-school children in the fourth grade (9−10-year-old) who underwent assessments of cholesterol levels and demographic and lifestyle characteristics. The participants were followed up in their first year of junior high school with the same laboratory, demographic, and lifestyle assessments. From the fourth year of elementary school to the first year of junior high school, children’s cholesterol levels decreased (p < 0.0001). Regarding bowel movements, cholesterol level reduction was significant in individuals with regular bowel movements but not significant in those with infrequent bowel movements. Weight was the factor that most strongly negatively predicted cholesterol level reduction (p < 0.001). The study demonstrated the significance of lifestyle factors for growth-related changes of total cholesterol levels and identified weight as the factor that most strongly influenced total cholesterol level changes. Guidance regarding lifestyle improvements should be imparted to children from the fourth grade of elementary school.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Prevalence of Metabolic Syndrome among Children and Adolescents in High-Income Countries: A Systematic Review and Meta-Analysis of Observational Studies

Introduction. Metabolic syndrome (MetS) is an assemblage of interconnected cardiovascular risk factors that are prevalent among children and adolescents in high-income countries (HICs). Despite the presence of several studies on the issue, the study findings are incongruent due to the absence of a gold standard diagnostic method of MetS in children. Thus, the findings of the original studies are inconclusive for policy makers and other stakeholders. This systematic review and meta-analysis is aimed at giving conclusive evidence about MetS among children and adolescents in HICs. Methods. We conducted searches using electronic databases (PubMed, Scopus, Web of Science, CINAHL (EBSCOhost), EMBASE (Elsevier), and Medline (EBSCOhost)) and other sources (Google Scholar and Google) up to September 2020. Observational studies reporting the prevalence of MetS were eligible in this study. The pooled estimates were computed in fixed and random effect models using six diagnostic methods (IDF, ATP III, de Ferranti et al., WHO, Weiss et al., and Cruz and Goran). Publication bias was verified using funnel plots and Egger’s regression tests. Subgroup and sensitivity analysis were performed in case of higher heterogeneities among the included studies. Result. In this study, 77 studies with a total population of 125,445 children and adolescents were used in the final analysis. Metabolic syndrome among the overweight and obese population was computed from 28 studies with the pooled prevalence of 25.25%, 24.47%, 39.41%, 29.52%, and 33.36% in IDF, ATP III, de Ferranti et al., WHO, and Weiss et al. criteria, respectively. Likewise, 49 studies were eligible to compute the pooled prevalence of MetS in the general population of children and adolescents. Hence, MetS was found in 3.70% (IDF), 5.40% (ATP III), 14.78% (de Ferranti et al.), 3.90% (WHO), and, 4.66% (Cruz and Goran) of study participants. Regarding the components of MetS, abdominal obesity in the overweight and obese population, and low HDL-C in the general population were the most common components. Besides, the prevalence of Mets among males was higher than females. Conclusion. This study demonstrates that MetS among children and adolescents is undoubtedly high in HICs. The prevalence of MetS is higher among males than females. Community-based social and behavioral change communications need to be designed to promote healthy eating behaviors and physical activities. Prospective cohort studies could also help to explore all possible risk factors of MetS and to design specific interventions accordingly.

Comparison of different criteria for the definition of insulin resistance and its relationship to metabolic risk in children and adolescents

PURPOSE

Childhood obesity frequently persists into adulthood and is associated with insulin resistance (IR) and increased long-term morbidity and mortality. We compared IR criteria concerning 'age-specific cutoff point' (ACOP) and 'fixed cutoff point' (FCOP) for the identification of IR and investigated their correlation with metabolic syndrome (MS).

METHODS

Data were acquired from the 5th Korea National Health and Nutrition Examination Survey (2010-2011). Participants ranged from 10 to 17 years of age and underwent fasting plasma glucose, insulin concentration, and lipid panel measurements. High fasting plasma insulin levels or increased homeostatic model assessment insulin resistance (HOMA-IR) were defined as IR. We analyzed MS and IR frequencies according to FCOP or ACOP.

RESULTS

Among 719 participants, 165 (22.9%) were overweight or obese based on their body mass index. We found no prevalence of MS in underweight/normal weight participants and 12.7% prevalence rate in overweight or obese participants. IR according to ACOP was more closely associated with MS than IR according to FCOP. No differences were found in predicting the frequency of MS using FCOP or ACOP in both fasting plasma insulin and HOMA-IR.

CONCLUSION

The frequency of MS in participants with IR defined using ACOP and FCOP was similar. However, IR using ACOP was more closely associated with MS than IR using FCOP.

Novel Insights into the Pathogenesis and Management of the Metabolic Syndrome

The metabolic syndrome, by definition, is not a disease but is a clustering of individual metabolic risk factors including abdominal obesity, hyperglycemia, hypertriglyceridemia, hypertension, and low high-density lipoprotein cholesterol levels. These risk factors could dramatically increase the prevalence of type 2 diabetes and cardiovascular disease. The reported prevalence of the metabolic syndrome varies, greatly depending on the definition used, gender, age, socioeconomic status, and the ethnic background of study cohorts. Clinical and epidemiological studies have clearly demonstrated that the metabolic syndrome starts with central obesity. Because the prevalence of obesity has doubly increased worldwide over the past 30 years, the prevalence of the metabolic syndrome has markedly boosted in parallel. Therefore, obesity has been recognized as the leading cause for the metabolic syndrome since it is strongly associated with all metabolic risk factors. High prevalence of the metabolic syndrome is not unique to the USA and Europe and it is also increasing in most Asian countries. Insulin resistance has elucidated most, if not all, of the pathophysiology of the metabolic syndrome because it contributes to hyperglycemia. Furthermore, a major contributor to the development of insulin resistance is an overabundance of circulating fatty acids. Plasma fatty acids are derived mainly from the triglycerides stored in adipose tissues, which are released through the action of the cyclic AMP-dependent enzyme, hormone sensitive lipase. This review summarizes the latest concepts in the definition, pathogenesis, pathophysiology, and diagnosis of the metabolic syndrome, as well as its preventive measures and therapeutic strategies in children and adolescents.

Metabolic Syndrome and Insulin Resistance in Schoolchildren From a Developing Country

Background: Overweight and obesity are prevalent in schoolchildren due to dietary habits and lack of exercise. These children are prone to metabolic syndrome (MS) and future risk of type 2 diabetes mellitus and cardiovascular diseases.

Materials and Methods: This cross-sectional study was conducted in Bhubaneswar City, Eastern India, among schoolchildren. Obesity and overweight were determined by the Indian Academy of Pediatrics guideline. Fasting venous blood samples were taken for insulin, blood glucose, and lipid levels measurement. Blood pressure was measured as per the protocol. The International Diabetic Federation (IDF) criteria for the definition of MS were followed. Insulin resistance was determined by a homeostatic model assessment (HOMA-IR).

Results: A total of 1,930 children were screened, of which 545 (28.2%) were overweight and obese. The male to female ratio was 1.27. The overall prevalence of MS was 21.8% (11% in 6 to ≤10 years old and 30.6% in 11 to 16 years old). A history of cardiovascular disease, diabetes, obesity, and hypertension in the family was present in 42.7%. Acanthosis nigricans was present in 46.4%. A history of exclusive breast feeding for 6 months was present in 68.1%. The mean HOMA-IR in children with MS was 5.46 compared to 2.18 in those without MS (insulin resistance was more common in children with MS).

Conclusions: The present study found a higher prevalence of MS and insulin resistance in schoolchildren from Eastern India who are overweight/obese.

A systematic review and meta-analysis estimating the population prevalence of comorbidities in children and adolescents aged 5 to 18 years

Evidence for the health impact of obesity has largely focussed on adults. We estimated the population prevalence and prevalence ratio of obesity-associated comorbidities in children and adolescents aged 5 to 18 years. Five databases were searched from inception to 14 January 2018. Population-based observational studies reporting comorbidity prevalence by weight category (healthy weight/overweight/obese) in children and adolescents aged 5 to 18 years from any country were eligible. Comorbidity prevalence, stratified by weight category, was extracted and prevalence ratios (relative to healthy weight) estimated using random effects meta-analyses. Of 9183 abstracts, 52 eligible studies (1 553 683 participants) reported prevalence of eight comorbidities or risk markers including diabetes and nonalcoholic fatty liver disease (NAFLD). Evidence for psychological comorbidities was lacking. Meta-analyses suggested prevalence ratio for prediabetes (fasting glucose ≥ 100 mg/dL) for those with obesity relative to those of a healthy weight was 1.4 (95% confidence interval [CI], 1.2-1.6) and for NAFLD 26.1 (9.4-72.3). In the general population, children and adolescents with overweight/obesity have a higher prevalence of comorbidities relative to those of a healthy weight. This review provides clinicians with information when assessing children and researchers a foundation upon which to build a comprehensive dataset to understand the health consequences of childhood obesity.

Metabolic Syndrome and Its Associated Early-Life Factors among Chinese and Spanish Adolescents: A Pilot Study

Metabolic syndrome (MetS) is a growing problem worldwide in adolescents. This study compared two sample populations of young people in Spain and China, and analyzed the association of birth weight and breastfeeding duration with MetS. A cross-sectional study was conducted in adolescents (10–15 years old); 1150 Chinese and 976 Spanish adolescents. The variables analyzed were anthropometric characteristics, biochemical markers, and demographic characteristics using the same methodology and data collection protocol. Also, birth weight and breastfeeding were retrospectively analyzed during the first year of life. The results showed statistically significant differences between the two groups in reference to body mass index (BMI), blood pressure, triglyceride, glucose, and high-density lipoprotein cholesterol (HDL-C) levels. The MetS prevalence was higher in Spanish adolescents (2.5%) than in the Chinese group (0.5%). Breastfeeding duration was inversely associated with hypertriglyceridemia, low HDL-C, and MetS, whereas higher birth weight was associated with hyperglycemia, low HDL-C, hypertriglyceridemia, and abdominal obesity. Spanish adolescents showed more altered MetS components, and consequently, a higher MetS prevalence than the Chinese adolescents. This made them more vulnerable to cardiometabolic risk. Our results highlight the need for interventions designed by health professionals, which would encourage pregnant women to breastfeed their children.

Telemedicine screening adolescent metabolic syndrome in Greek schools

BACKGROUND

Using telemedicine in the school setting in Greece, we screened a representative adolescent sample for MetS (International Diabetes Federation criteria) and explored its associations with anthropometric, sociodemographic and behavioural parameters.

MATERIALS AND METHODS

Cross-sectional data were obtained from 12- to 17-year-old high school students.

RESULTS

The prevalence of MetS in 1578 adolescents (mean age ± SD 14.4 ± 1.7 years) was 2.6% (3.4% among males; 2.0% among females), highest (4.3%) at age 13 years and lowest (1.3%) at 16 years. Adolescents with MetS had significantly higher mean body mass index (BMI) ± SD than those without MetS (30.2 ± 4.2 vs 21.3 ± 3.2 kg/m² , respectively; P < 0.001); among participants with obesity, 31.6% had MetS. Abdominal obesity, elevated triglycerides, low HDL-cholesterol, impaired fasting blood glucose (FBG) and elevated blood pressure (BP) were detected in 9.5%, 2.3%, 10.7%, 25.9% and 21.8% of participants, respectively. Additional analysis (modified NCEP:ATPIII youth criteria) demonstrated similar overall prevalence of MetS (2.9%). Statistically significant correlations were found between most anthropometric and MetS characteristics, with the exception of FBG, which was correlated only with systolic BP. BMI was strongly correlated with waist and hip circumferences (r = 0.818, P < 0.001; r = 0.825, P < 0.001, respectively). Single parenthood and older maternal age (>60 years) were risk factors for MetS. Although counterintuitive, body image distortion, body dissatisfaction and bullying about weight were more prevalent in normal weight girls.

CONCLUSIONS

The overall prevalence of MetS was low but 12-fold higher when obesity was taken into account. Impaired FBG and elevated BP were the most prevailing features. Telemedicine services were used effectively in Greek schools for screening youth MetS.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Effect of Nutrition and Sleep Habits on Predisposition for Metabolic Syndrome in Greek Children

PURPOSE

To investigate the effect of lifestyle habits in childhood Metabolic Syndrome (MTS).

DESIGN AND METHODS

Descriptive correlation study with 480 participants (5-12 years old) using a specially designed questionnaire was conducted. Anthropometric and biochemical analyses were performed.

RESULTS

Fifteen percent of children exhibited predisposition for MTS. Regarding sleep habits, logistic regression analysis (LRA) showed that hour of sleep -before 22:00- was associated with decreased waist circumference (WC%) (p = .026). Midday siesta was negatively correlated with systolic (SBP) (p = .001) and diastolic blood pressure (DBP) (p = .046). In children without MTS, lack of sleep and night time sleep was positively correlated with DBP (p = .044) and fasting blood glucose (FBG) (p = .005). Regarding nutrition habits, fast food consumption was positively correlated with SBP (p = .006) and meat consumption was positively correlated with both Body Mass Index% (BMI%) (p = .038) and WC% (p = .023). LRA showed that fruit (p = .001) and legume (p = .040) consumption was associated with decreased FBG; fish consumption with decreased Low Density Lipoprotein (LDL) cholesterol (p = .031), vegetable (p = .054) and cereal consumption (p = .012) with decreased DBP. In children with MTS, fruits were associated with increased FBG (p = .034). In children without MTS, meat consumption was associated with increased LDL (p = .024), cereal with increased WC% (p = .002) and olive products with increased High Density Lipoprotein (HDL) cholesterol and BMI% (p = .037).

CONCLUSIONS

The adoption of both balanced diet and sleep habits seemed to be crucial for the prevention of MTS.

PRACTICE IMPLICATIONS

Clinical health nurses could develop and implement preventive intervention programs in order to avoid metabolic complications in adulthood.

Adiponectin levels in Brazilian adolescents: Distribution and associated factors in ERICA survey

BACKGROUND

The aim of this study was to evaluate the distribution of adiponectin and associated factors with low adiponectin levels in a large sample of adolescents from different Brazilian regions.

METHODS

This is a national, school-based, cross-sectional multicenter study of cardiovascular risk factors in Brazilian adolescents aged 12 to 17 years. Serum adiponectin levels (μg/ml) were measured by enzyme-linked immunosorbent assay kit. Given the lack of reference values, sex-and age-specific median was adopted as the cutoff point, with the values below the median representing a higher-risk profile. Associated factors with low levels of adiponectin were investigated using Poisson regression.

RESULTS

The sample consisted of 4546 adolescents, the majority female (61.2%). The prevalence of overweight/obesity and abdominal obesity was 30% and 13.4%, respectively. The medians of adiponectin were 13.4 μg/ml (95%CI: 12.8-14.0) in males and 14.2 μg/ml (95%CI: 13.3-15.0) in females. Lower adiponectin levels were associated with both overweight (Prevalence Ratios (PR) = 1.17; 95%CI 1.01-1.36) and obesity (PR = 1.36; 95%CI 1.16-1.56) in males, while, in females, adiponectin levels were associated only with obesity (PR = 1.45; 95% CI 1.26-1.66). Increased waist circumference in both males and females was inversely associated with adiponectin level.

CONCLUSIONS

Adiponectin levels were lower among adolescents with weight excess and abdominal obesity. Male adolescents who live in rural areas and study at private schools also showed lower adiponectin concentrations.

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.

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

BACKGROUND AND AIMS

Adipokines may play a role in the pathogenesis of the metabolic syndrome (MetS) in children. We aimed to evaluate the association of leptin, adiponectin, and its ratio (L/A ratio) with the metabolic syndrome (MetS) in a subsample of the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) cohort.

METHODS AND RESULTS

Leptin, adiponectin and MetS parameters were measured in a subsample of 1253 children (3-9.9 years) participating to the IDEFICS study, grouped as: Non-OW (underweight/normal weight) and OW/Ob (overweight/obese). MetS was defined using the sex- and age-specific cut-offs based on the distribution of MetS components in the IDEFICS cohort. The prevalence of the MetS among OW/Ob was 24.8% and 27.1% in boys and girls respectively, whereas ≤2% among Non-OW. OW/Ob had significantly higher leptin and L/A ratio as compared to Non-OW. Significantly higher leptin was found in OW/Ob with MetS as compared with OW/Ob without MetS. Significantly lower adiponectin was observed only in OW/Ob girls as compared to Non-OW. A 1SD increase in leptin and L/A ratio z-scores or a 1SD decrease in adiponectin z-score were significantly associated with higher risk of MetS. After adjustment for BMI or body fat mass (BFM) the association remained significant only for leptin.

CONCLUSION

We showed that in European children, higher leptin concentration is associated with MetS, even after adjusting for BMI or BFM, confirming an early role of leptin in MetS, while the association of adiponectin with MetS seems be mediated by body fat in this age range.

Leptin as a predictor of metabolic syndrome in prepubertal children

OBJECTIVE

Leptin has been suggested as a potential biomarker of cardiovascular risk. This paper aims to ascertain, based on a sample of prepubertal children, which serum leptin value best suited to identify metabolic syndrome (MS).

SUBJECTS AND METHODS

This observational, cross-sectional study recruited children from the outpatient pediatrics clinic, with the purpose of validating serum leptin level cutoffs to identify MS. All obese and overweight children who met eligibility criteria were included in the study, as was a sample of normal-weight children. The sample underwent clinical assessment and blood fasting glucose, lipid profile, insulin, and leptin were measured. Sensitivity and specificity were estimated for each leptin measurement, using MS as the outcome. These values were used to construct a receiver operating characteristic (ROC) curve. The association between MS and leptin was assessed using logistic models to predict MS.

RESULTS

A total of 65 normal weight, 46 overweight, and 164 obese children were analyzed (160 boys, 115 girls; age: 93.7 ± 17.8 months). The most appropriate leptin cutoff was 13.4 ng/mL (sensitivity 67.6%; specificity 68.9%; accuracy 72.1%). The logistic model indicated that leptin levels above 13.4 ng/dL were significantly associated with MS and that, for every 1 ng/dL increase in leptin levels, the odds of MS increase by 3% (p = 0.002; OR 1.03; 95% CI 1.01-1.05).

CONCLUSIONS

Leptin may be a useful biomarker of cardiovascular risk in prepubertal children, with an optimal cutoff of 13.4 ng/mL. Identification of potential new risk markers for cardiovascular disease in children could contribute to the development of preventive strategies.

Fatores de risco associados ao desenvolvimento da síndrome metabólica em crianças e adolescentes

Resumo Objetivo Analisar a frequência de fatores de risco cardiovascular, entre crianças e adolescentes, e sua associação com a síndrome metabólica. Métodos Estudo analítico e quantitativo em uma amostra estratificada de 421 crianças e adolescentes de 9 a 19 anos selecionados por amostragem aleatória simples em 12 escolas públicas municipais localizadas na Região Nordeste do Brasil. Investigaram-se os fatores sedentarismo e excesso ponderal. A síndrome metabólica foi identificada a partir dos critérios adaptados para a idade. Resultados Houve prevalência de 4,1% de síndrome metabólica. Eram sedentários 30,2% e 20,5% apresentaram excesso ponderal, sendo que valores mais elevados de índice de massa corporal estiveram associados à presença de síndrome. Pressão arterial média, triglicerídeos, glicemia e circunferência abdominal estavam aumentados em 11,9%, 20,9%, 0,5%, 8,6% dos investigados, respectivamente; 26,1% apresentaram HDL-c baixo. Conclusão Parcela substancial dos envolvidos apresentou fatores de risco avaliados, bem como associação do excesso ponderal com componentes da síndrome.

The combined action of omega-3 polyunsaturated fatty acids and grape proanthocyanidins on a rat model of diet-induced metabolic alterations

It has been suggested that food components such as ω-3 polyunsaturated fatty acids (ω-3 PUFAs) and (poly)phenols counteract diet-induced metabolic alterations by common or complementary mechanisms. To examine the effects of a combination of ω-3 PUFAs and (poly)phenols on such alterations, adult Wistar-Kyoto rats were fed an obesogenic high-fat high-sucrose diet supplemented, or not, for 24 weeks with: eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) 1 : 1 (16.6 g kg(-1) feed); proanthocyanidin-rich grape seed extract (GSE, 0.8 g kg(-1) feed); or EPA/DHA 1 : 1 + GSE. Body weight, feed intake, and plasma glucose were evaluated every 6 weeks, while adipose tissue weight, insulin, glucagon, ghrelin, leptin, adiponectin, cholesterol, and triglycerides were evaluated at the end of the experiment. ω-3 PUFAs reduced plasma leptin and cholesterol levels, but did not modify diet-induced perigonadal fat or plasma insulin levels; while GSE increased plasma triglyceride levels. The combined action of ω-3 PUFAs and the proanthocyanidins reduced plasma insulin and leptin, as well as partially prevented perigonadal fat accumulation. While separate supplementation with ω-3 PUFAs or grape proanthocyanidins may not counteract all the key metabolic changes induced by a high-energy-dense diet, the combination of both supplements reverts altered insulin, leptin and triglyceride levels to normal.

An Overweight Preventive Score associates with obesity and glycemic traits

PURPOSE

To develop a multidimensional, simple index which incorporates targeted dietary and lifestyle behaviors for the prevention and evaluation of treatment of childhood and adolescent obesity.

METHODS

A total of 1072 (53.8% females) healthy children and 857 (54.8% females) adolescents from GENDAI and TEENAGE studies respectively were included in the analysis. Both studies are cross-sectional, population-based studies. Dietary and lifestyle behaviors - either with negative or positive impact on obesity, based on the recommendations of Barlow and the Expert Committee - were assessed with use of two non-consecutive 24-h recalls and a dietary questionnaire. For each individual, cumulative exposures to 6 of these obesity-related behaviors, namely consumption of fruits and vegetables, breakfast and family meals, consumption of sugar sweetened beverages and fast-food meals, and screen time, were assessed through calculation of the Overweight Preventive Score. Obesity and glycemic control traits were also available for all individuals from both cohorts.

RESULTS

Overweight Preventive Score was significantly associated (P<0.05) with all obesity traits and with decreased likelihood of becoming overweight [OR (95% CI): 0.90 (0.84, 0.97), P=0.003] in all individuals after adjustment for potential confounders and exclusion of low-energy reporters. Associations were also significant in stratified analyses by sex (P<0.05). The score was also associated with glycemic control traits in all individuals independently of body mass index, but these associations remained significant (P<0.05) only in males and after adjustment for potential confounders and exclusion of low-energy reporters.

CONCLUSIONS

The proposed Overweight Preventive Score is a simple index and could be proven as a useful tool for the assessment of preventive and therapeutic interventions in child and adolescent overweight and insulin resistance.

The Prevalence of Metabolic Syndrome and Cardiovascular Risk Factors in Obese Children and Adolescents in Dalmatia: A Hospital Based Study

Obesity and metabolic syndrome (MS) are one of the biggest public health issues in child and adolescent population. To the best of the authors' knowledge, this hospital based study is the first report on the prevalence of MS in obese children and adolescents in Dalmatia, the Mediterranean part of Croatia. The objectives of this study were to determine the prevalence of individual cardiovascular risk factors and MS. Between January 2009 and June 2014, 201 obese subjects aged 6 to 18 were analyzed retrospectively from our Pediatric Endocrine Unit database. The subjects were then classified in two groups of obesity; subjects with BMI z score 2.0-3.0 were classified as moderately obese and subjects with BMI z score > 3.0 were classified as severely obese. The overall prevalence of MS using the modified IDF criteria was 30.3%. The most common component of MS in both groups was arterial hypertension, while impaired fasting glucose was the least common component of MS. Our finding of high prevalence of MS underlines the importance of early childhood obesity treatment.

Insulin resistance and cardiometabolic risk factors in obese children and adolescents: a hierarchical approach

BACKGROUND

This study aims to globally assess the network of insulin resistance (IR)-related factors in a sample of overweight and obese Greek youths.

METHODS

A total of 185 subjects were examined, and IR was quantified by homeostasis model assessment (HOMA-IR). Multivariate hierarchical approach was performed, and five distinct levels were recognized, namely, immutable demographic features and early life parameters, current anthropometric measures, IR, unfavorable clinical conditions, and social parameters. Two analyses were performed based on HOMA-IR cut-off values (3.16 and, as an alternative, 3.99).

RESULTS

Obesity was associated with IR (adjusted OR=3.19, 95% CI: 1.12-9.09). IR steadily predicted low HDL (adjusted OR=5.75, 95% CI: 1.58-20.87), hypertriglyceridemia (adjusted OR=10.28, 95% CI: 1.18-89.55), and systolic hypertension. At the alternative analysis, IR was also associated with older age, older age at menarche, hyperuricemia, and low school grades.

CONCLUSION

Emerging on the grounds of obesity, IR confers risks for dyslipidemia and hypertension at a relatively early age. Along with weight loss, interventions targeted at IR are required to prevent cardiometabolic risk in adolescence.

Predictors of metabolic risk in childhood obesity

Most of the complications of juvenile obesity are due to metabolic disturbances induced by an excessive accumulation of fat which leads to chronic diseases like type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Finding effective ways of identifying obese paediatric patients who are at increased risk of developing cardiovascular and metabolic complications has been recognised to be a promising strategy to improve prevention of complications of early obesity. Moreover, correctly identifying obese children who are already affected by metabolic co-morbidities should be a clinical priority. According to the state of the art summarised in this review, traditional metabolic variables included in the definitions of metabolic syndrome (MS), pre-diabetes, non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steato-hepatitis and, in obese girls, the presence of polycystic ovary syndrome are the best available longitudinal predictors of CVD and T2DM among obese children and adolescents. In clinical practice, traditional metabolic variables included in the definitions of MS should be assessed in all obese children and adolescents; fasting metabolic variables have been proposed to identify obese patients likely to be affected by impaired glucose tolerance or T2DM, and ultrasound has proved to be a valid surrogate for biopsy in the diagnosis of NAFLD. Further large longitudinal and cross-sectional studies are needed to improve our chances of identifying obese youth at the highest metabolic risk.

Nutritional Status Associated with Metabolic Syndrome in Middle-School Children in the City of Montes Claros - MG, Brazil

The aim of this study was to investigate the association between nutritional status and prevalence of metabolic syndrome (MS) in middle-school students in the city of Montes Claros - MG. The sample consisted of 382 students, aged 10-16 years. Nutritional status was evaluated using the Body Mass Index (BMI). Metabolic syndrome (MS) was defined as the presence of two or more criteria in accordance with definition of the International Diabetes Federation. The overall prevalence of MS was 7.9%. 9.7% of students with MS were overweight and 72.4% were obese. Therefore, it can be inferred that carrying excess weight considerably increases the chances for a child to develop MS, and concomitantly increases the child's risk for developing cardiovascular disease.

Associations between central obesity and asthma in children and adolescents: a case-control study

INTRODUCTION

Evidence supports a significant yet weak association between high-body weight and asthma in children. However, most studies investigating the obesity-asthma link use Body Mass Index (BMI) to evaluate body fatness. The relationship between body fat distribution and asthma remains largely unknown, especially in children. This pediatric case-control investigation examined associations between central obesity/high-body weight and asthma diagnosis.

METHODS

Five-hundred and fourteen children (217 physician diagnosed asthma cases and 297 healthy controls) of 5-11 years were recruited. Height, weight and waist circumference were measured. Asthma symptoms, past medical history, personal lifestyle, socioeconomic status, diet and physical activity history were also collected.

RESULTS

A higher proportion of children with asthma were centrally obese [(≥90th waist percentile) 15.2 vs. 9.4%, p<0.0001; (≥90th waist-to-height ratio percentile) 39.6 vs. 24.2%, p<0.0001)]. Regression analyses revealed that centrally obese children were more likely to have asthma (high-waist circumference (OR = 1.99, 95% CI: 1.07-3.68) and high-waist circumference to height ratio (OR = 2.24, 95% CI: 1.47-3.40), following adjustment for various confounders. Overweight/obese participants (BMI defined) were more likely to be asthmatic [odds ratio (OR) = 1.52, 95% confidence interval (CI): 1.03-2.70)] when compared to controls.

CONCLUSIONS

Presence of central obesity and high-body weight (at least overweight) as assessed by waist circumference, waist-to-height ratio, and BMI are associated with asthma diagnosis. More studies are needed, especially in children and adolescents, to confirm these findings and better understand how body fat distribution impacts the obesity-asthma relationship.

Correlation of serum adiponectin and adiponectin gene polymorphism with metabolic syndrome in Chinese adolescents

BACKGROUND/OBJECTIVES

To investigate the association of adiponectin and its gene polymorphisms with metabolic syndrome (MetS) and cardiovascular disease (CVD) risk factors in Chinese adolescents.

SUBJECTS/METHODS

This cross-sectional study enrolled 919 healthy middle school students (aged 11-16 years; 46.7% females). All participants underwent anthropometric and biochemical examinations, and MetS was diagnosed using 2007 International Diabetes Federation criteria. The presence of adiponectin and its genotypes of single nucleotide polymorphisms (SNPs) rs266729 (-11377C/G), rs2241766 (+45T/G) and rs1501299 (+276G/T) was detected.

RESULTS

(1) Serum adiponectin levels were negatively correlated with numerous CVD risk factors (all P<0.05), and following adjustments for confounding factors, a lower adiponectin level was an independent risk factor for MetS (odds ratio=5.59; 95% confidence interval: 1.90, 16.41). Central obesity and low levels of high-density lipoprotein cholesterol were positively associated with MetS and reduced serum adiponectin levels. (2) The genotype and frequencies of SNP-11377 and SNP+276 in a MetS group and non-MetS group were not significantly different. Subjects with genotype SNP+45 GG were at higher risk for MetS compared with subjects with genotypes SNP+45 TT (P=0.033) or TT+TG (P=0.021). Subjects with genotype SNP+276 TT or TT+TG had higher levels of serum adiponectin compared with subjects with SNP+276 GG (P=0.012 and 0.014, respectively).

CONCLUSIONS

Adiponectin may be used as a predictive biomarker of MetS, and shows a significant association with CVD risk factors in Chinese adolescents. Adiponectin gene polymorphisms are associated with serum adiponectin concentrations and the presence of MetS.

Ethnic disparities in the prevalence of the metabolic syndrome in American adults: data from the Examination of National Health and Nutrition Examination Survey 1999-2010

Data from the National Health and Nutrition Examination Survey were stratified by weight, gender, and ethnicity for six survey years from 1999 to 2010 for variables that satisfy the criteria for metabolic syndrome (MS). Results showed that 34% of the US adult population had MS. No significant gender disparities in MS prevalence were found. Black men had a significantly lower prevalence of MS than Black women and White men from 1999 to 2008 (P < 0.05). Women had a 60% higher abdominal adiposity than men in the US population (P = 0.00048; pregnant females were excluded). Although there seem to be ethnic differences in the prevalence of MS, the expression of MS is not a sufficient risk to culminate in cardiovascular disease; rather, nutritional, genetic, and environmental factors are necessary to finalize its expression into overt disease.

Trends in metabolic syndrome risk factors among adolescents in rural Crete between 1989 and 2011

OBJECTIVE

To investigate all the important factors contributing to the development of metabolic syndrome (MetS) as well as to explore the changes of these factors, over time, by comparing adolescent populations of rural areas of Heraklion, Crete, for the years 2011 and 1989.

DESIGN

This study was carried out within two rural areas of the Heraklion region in Crete, Greece. The 1989 study was conducted in the village of Agia Varvara and the respective 2011 study within the municipality of Minoa Pediados. The study population consisted of 150 high school students (97 girls and 69 boys) in 1989 and 66 (30 girls and 36 boys) elementary (6th grade) and high school students in 2011, aged from 12 to 14 years old. Anthropometric, blood pressure and biochemical information was obtained.

RESULTS

Of the MetS risk factors studied, only obesity incidence was found higher in 2011 compared to 1989 (obese adolescents 1.3% in 1989 versus 21.2% in 2011, p<0.001). On the other hand, hypertension levels were higher in 1989 compared to 2011 (46.7% versus 6.3%, respectively, p<0.001). In addition, glucose and LDL-C levels were lower in 2011.

CONCLUSIONS

The present study supports the fact that there are significant changes in metabolic risk factors through time in adolescent populations of Crete, mainly due to the rise in obesity levels as well as to the decrease in hypertension, total cholesterol and LDL- cholesterol, as observed from the comparison of the years 1989 and 2011.

Plasma leptin and adiponectin concentrations correlate with cardiometabolic risk and systemic inflammation in healthy, non-obese children

BACKGROUND

Plasma adipocytokines are associated with metabolic profile and cardiovascular risk in obese children.

OBJECTIVE

To investigate the association of plasma leptin and adiponectin concentrations with cardiometabolic risk profile and systemic inflammation in non-obese children.

SUBJECTS

We studied 170 healthy, non-obese children (86 males, mean age 10±2 years).

METHODS

Children's current body mass index (BMI), plasma leptin and adiponectin concentrations, lipid profile, fasting plasma glucose and high sensitivity C reactive protein (hsCRP) were measured.

RESULTS

After adjustment for age, gender and BMI, plasma leptin concentrations were positively associated with hsCRP (t=2.72, p=0.009) and fasting plasma glucose (t=4.27, p<0.0001); plasma adiponectin concentrations were negatively associated with hsCRP (t=-3.31, p=0.0016); and positively with high density lipoprotein cholesterol (t=2.32, p=0.02). Children in the highest quartile of leptin/adiponectin (L/A) ratio demonstrated significantly higher BMI, systolic blood pressure, hsCRP, triglycerides and fasting glucose and the lowest high density lipoprotein (HDL) compared to lower L/A ratio quartiles.

CONCLUSIONS

Alterations in plasma leptin and adiponectin may help to reclassify non-obese children, detecting those with more unfavorable risk profiles independent of BMI status.

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.

Prevalence of insulin resistance and cardiometabolic risk in Korean children and adolescents: a population-based study

AIMS

We aimed to establish normal reference values of serum insulin and the homeostasis model assessment of insulin resistance (HOMA-IR). We also aimed to verify HOMA-IR "cut-off values" in predicting cardiometabolic risk among Korean children and adolescents.

METHODS

Data from 2716 Korean subjects (1421 male and 1295 female, aged 10-20 years) were evaluated. Insulin resistance was defined as HOMA-IR >95th percentile. The odds ratios of cardiometabolic risk were assessed based on the state of insulin resistance.

RESULTS

Reference values of insulin and HOMA-IR were determined according to sex and age, based on data obtained from normal-weight subjects with normal fasting glucose levels. HOMA-IR values appeared to peak at the age of 14-15 years in male subjects and at the age of 12-13 years in female subjects. The prevalence of insulin resistance in the subjects was 9.8% (male=10.9%, female=8.6%). The prevalence of insulin resistance in normal-weight, overweight, and obese subjects were 4.7%, 25.6%, and 47.1% respectively. Subjects with insulin resistance had a higher prevalence of metabolic syndrome (odds ratios=18.33; 95% confidence interval, 9.62-34.94) and its components, especially hyperglycemia and hypertriglyceridemia.

CONCLUSION

We established reference values of serum insulin and HOMA-IR according to age and sex. Obesity is the most important risk factor for insulin resistance and metabolic syndrome. However, insulin resistance independently increases cardiometabolic risk. This information may be useful for Korean as well as other Asian in planning programs for the prevention of type 2 diabetes.

High-mobility group protein B1: a new biomarker of metabolic syndrome in obese children

INTRODUCTION

Obesity is associated with a chronic low-grade inflammation. High-mobility group box 1 protein (HMGB1) plays a key role in inflammation and immunostimulatory and chemotactic processes. The aim of the study was to assess the role of HMGB1 in obese children and to evaluate its diagnostic profile in identifying childhood obesity-related complications, such as the metabolic syndrome (MS).

PATIENTS AND METHODS

Sixty obese children were enrolled and compared with 40 healthy children (control). Homeostasis model assessment of insulin resistance (HOMA-IR), lipid profile, thyroid hormones, and pro- and anti-inflammatory peptides such as C-reactive protein (CRP), adiponectin, interleukin 6 (IL6), IL18, IL23, TNFα, resistin, and HMGB1 were evaluated. Receiver operating characteristics (ROC) analysis was employed to calculate the area under the curve (AUC) for HMGB1, IL6, and adiponectin to find the best cutoff values capable of identifying MS in obese children.

RESULTS

HMGB1 levels were statistically higher in obese patients than in the control group (19.4±6.8 vs 3.7±1.2 ng/ml; P<0.0001). In obese patients, IL18, IL6, and resistin levels were significantly high, while adiponectin levels were low. At multivariate analysis, HMGB1 was found to be independently correlated with BMI, IL23, IL6, free triiodothyronine, HDL, and HOMA-IR. At ROC analysis, HMGB1 showed higher sensitivity and specificity (AUC, 0. 992; sensitivity, 94.7%; specificity, 97.5%) than IL6 and adiponectin in identifying MS in obese children.

CONCLUSION

HMGB1 plays an important role in the inflammatory process associated with childhood obesity. This peptide may be an important diagnostic marker for obesity-related complications, such as MS.

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.

Adiponectin in eutrophic and obese children as a biomarker to predict metabolic syndrome and each of its components

BACKGROUND

Obesity is associated with the rise of noncommunicable diseases worldwide. The pathophysiology behind this disease involves the increase of adipose tissue, being inversely related to adiponectin, but directly related to insulin resistance and metabolic syndrome (MetS). Therefore, this study aimed to determine the relationship between adiponectin levels with each component of MetS in eutrophic and obese Mexican children.

METHODS

A cross sectional study was conducted in 190 school-age children classified as obese and 196 classified as eutrophic. Adiponectin, glucose, insulin, high density lipoprotein cholesterol (HDL-C) and triglycerides were determined from a fasting blood sample. Height, weight, waist circumference, systolic and diastolic blood pressures (BP) were measured; MetS was evaluated with the IDF definition. The study groups were divided according to tertiles of adiponectin, using the higher concentration as a reference. Linear regression analysis was used to assess the association between adiponectin and components of the MetS. Finally, stepwise forward multiple logistic regression analysis controlling for age, gender, basal HOMA-IR values and BMI was performed to determine the odds ratio of developing MetS according to adiponectin tertiles.

RESULTS

Anthropometric and metabolic measurements were statistically different between eutrophic and obese children with and without MetS (P <0.001). The prevalence of MetS in obese populations was 13%. Adiponectin concentrations were 15.5 ± 6.1, 12.0 ± 4.8, 12.4 ± 4.9 and 9.4 ± 2.8 μg/mL for eutrophic and obese subjects, obese without MetS, and obese with MetS, respectively (P <0.001). Obese children with low values of adiponectin exhibited a higher frequency of MetS components: abdominal obesity, 49%; high systolic BP, 3%; high diastolic BP, 2%; impaired fasting glucose, 17%; hypertriglyceridemia, 31%; and low HDL-C values, 42%. Adjusted odds ratio of presenting MetS according to adiponectin categories was 10.9 (95% CI 2.05; 48.16) when the first tertile was compared with the third.

CONCLUSION

In this sample of eutrophic and obese Mexican children we found that adiponectin concentrations and MetS components have an inversely proportional relationship, which supports the idea that this hormone could be a biomarker for identifying individuals with risk of developing MetS.

Body mass index correlates with waist circumference in school aged Italian children

This study demonstrates the existence of a linear correlation between Body Mass Index (BMI) and waist circumference in Italian school aged children and suggests an indirect method (from weight and height) to estimate waist circumference, whose increase may be indicative for the diagnosis of the metabolic syndrome.