Metabolic syndrome in obese Caucasian children: prevalence using WHO-derived criteria and association with nontraditional cardiovascular risk factors

Prevalence of metabolic syndrome in children and adolescents with obesity: a systematic review and meta-analysis

OBJECTIVE

This study investigated the prevalence trends of metabolic syndrome (MetS) in children and adolescents with obesity by systematically analyzing global data. Additionally, it aimed to compare regional disparities and criteria used to identify at-risk subpopulations among this demographic group.

METHODS

We searched three major databases, i.e., PubMed-Medline, Scopus, and Web of Science, from inception to August 31, 2023, yielding 2432 articles. We included original research papers reporting MetS prevalence among children and adolescents with obesity, irrespective of their regions and MetS diagnostic criteria used. We aggregated prevalence estimates using random-effects models to obtain the overall prevalence and conducted subgroup analyses for MetS criteria and study regions.

RESULTS

We included 57 studies, amounting to 27,923 participants. The overall prevalence of MetS in participants with obesity varied greatly across studies, ranging from 2.1% to 74.4%, with an average prevalence of 29.4%. This high prevalence of MetS was further supported by a meta-analysis comprising 57 studies that further strengthened the observation of a high prevalence of MetS, revealing an overall prevalence of 26% (95% CI: 0.22-0.30; I2 = 98%).

CONCLUSIONS

Children and adolescents with obesity face a heightened risk of developing MetS. There is a pressing need for heightened attention to this issue, particularly in low- and middle-income countries such as those in sub-Saharan Africa.

Lifestyle intervention improves cardiometabolic profiles among children with metabolically healthy and metabolically unhealthy obesity

BACKGROUND

In recent years, there has been a surge of interest in the metabolic phenotype among children with obesity characterized by the absence of associated cardiometabolic risk factors (CRFs), known as metabolically healthy obesity (MHO), as opposed to those with metabolically unhealthy obesity (MUO). This study investigated the effect of lifestyle intervention on CRFs among children with MHO and MUO.

METHODS

A total of 102 school-aged children with obesity (54 girls and 48 boys) aged 8-16 years completed a 16-week school-based lifestyle modification intervention program, MyBFF@school Phase I. The intervention consisted of physical activity, healthy eating promotion, and psychological empowerment. MHO and MUO statuses were defined based on the 2018 consensus-based criteria. Fasting venous blood collection, body composition measurement, clinical assessment and physical fitness testing were conducted at baseline and at the end of week 16.

RESULTS

After the intervention, the CRFs of the children with MUO improved with significant decreases in systolic (p < 0.001) and diastolic (p = 0.01) blood pressure and a significant increase in high-density lipoprotein cholesterol (HDL-C) (p = 0.005), while the CRFs of the children with MHO had a significant decrease in uric acid (p = 0.04). Additionally, 51.6% of the children with MHO transitioned to the MUO, while 26.8% of the children with MUO crossed over to the MHO at the end of the intervention. Furthermore, the odds of having high systolic blood pressure among children with MUO were 59% lower at week-16 than at baseline (OR = 0.41 (95% CI = 0.18, 0.92), p = 0.03).

CONCLUSIONS

Our findings demonstrated that CRFs improved more prominently among children with MUO following the intervention. More importantly, our findings indicate that MHO in children is transient, hence, strategies to protect children against MUO are warranted.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02212873.

C-Reactive Protein as a Marker of Inflammation in Children and Adolescents with Metabolic Syndrome: A Systematic Review and Meta-Analysis

Metabolic syndrome (MetS) in the pediatric population has been reported in many studies to be associated with an inflammatory response. However, to our knowledge, there is no definitive conclusion in the form of a meta-analysis. The issue we aimed to address is whether C-reactive protein (CRP) is a trustworthy marker in detecting inflammation in children and adolescents with MetS. We systematically searched PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, the ISI Web of Science, and SCOPUS until 31 June 2023 for studies involving children and adolescents with MetS where hsCRP or CRP were measured. After the screening process, we identified 24 full-text articles that compared 930 patients with MetS with either healthy (n = 3782) or obese (n = 1658) controls. The risk of bias in the included studies was assessed using the Begg's rank correlation test and Egger's regression test. Statistical analysis was carried out based on pooled mean differences (MDs) and an associated 95% CI. Data analysis showed that MetS is associated with higher levels of CRP than those in healthy controls (MD = 1.28, 95% CI: (0.49-2.08), p = 0.002) in obese patients (MD = 0.88, 95% CI: (0.38-1.39), p = 0.0006). However, conventional methods of CRP analysis were found to be more accurate in differentiating between children and adolescents with obesity and those with MetS, compared with hsCRP (MD = 0.60, 95% CI: (-0.08-1.28), p = 0.08). No risk of bias was assessed. In conclusion, CRP is a reliable inflammatory marker for differentiating pediatric patients with MetS from healthy ones. On the other hand, it did not prove to be very accurate in distinguishing between patients who had MetS and those who were obese. There should be more research performed in this field.

The Effect and Prevalence of Comorbidities in Adolescents With CKD and Obesity

Adolescent obesity and CKD are both significant public health issues independently. When seen as comorbid conditions, they can cause deleterious health outcomes that put them on the fast track to necessitate dialysis or transplantation. This paper analyzes the effects of various biomarkers and comorbidities seen in the intersection of obesity and CKD in the adolescent population. We illustrate the estimated prevalence of these biomarkers and comorbidities through a review of the literature, available treatment, and obesity-related glomerulopathies. We found significant prevalence of the biomarkers, microalbuminuria (9.42% ± 9.31% and interquartile range [IQR] of 9.5%), hypertension (23.60% ± 22.5% and IQR of 9.5%), low high-density lipoprotein (14.34% ± 5.46% and IQR of 5%), hyperfiltration (3.12% ± 5.16% and IQR of 4%), and lower estimated glomerular filtration rate 4.59 ± 2.75 and IQR of 3%. Identification of prevalent biomarkers and their manifestations can serve to inform clinicians what to look for in daily setting and help elucidate the magnitude of this growing issue. Additionally, pertinent treatment options from pharmacotherapy to bariatric surgery are outlined to provide care providers with the full spectrum of treatment options for obesity in adolescent populations.

Prevalence and clinical characteristics of metabolically healthy obese versus metabolically unhealthy obese school children

INTRODUCTION

Children with obesity in the absence of traditional cardiometabolic risk factors (CRF) have been described as metabolically healthy obese (MHO). Children with MHO phenotype has a favorable metabolic profile with normal glucose metabolism, lipids, and blood pressure compared to children with metabolically unhealthy obese (MUO) phenotype. This study aimed to compare several parameters related to obesity between these two groups and to examine the predictors associated with the MHO phenotype.

METHODS

This study included a cross-sectional baseline data of 193 children with obesity (BMI z-score > +2 SD) aged 8-16 years enrolled in MyBFF@school program, a school-based intervention study conducted between January and December 2014. Metabolic status was defined based on the 2018 consensus-based criteria with MHO children had no CRF (HDL-cholesterol > 1.03 mmol/L, triglycerides ≤ 1.7 mmol/L, systolic and diastolic blood pressure ≤ 90^th percentile, and fasting plasma glucose ≤ 5.6 mmol/L). Those that did not meet one or more of the above criteria were classified as children with MUO phenotype.

RESULTS

The prevalence of MHO was 30.1% (95% CI 23.7 - 37.1) among schoolchildren with obesity and more common in younger and prepubertal children. Compared to MUO, children with MHO phenotype had significantly lower BMI, lower waist circumference, lower uric acid, higher adiponectin, and higher apolipoprotein A-1 levels (p < 0.01). Multivariate logistic regression showed that adiponectin (OR: 1.33, 95% CI 1.05 - 1.68) and apolipoprotein A-1 (OR: 1.02, 95% CI 1.01 - 1.03) were independent predictors for MHO phenotype in this population.

CONCLUSIONS

MHO phenotype was more common in younger and prepubertal children with obesity. Higher serum levels of adiponectin and apolipoprotein A-1 increased the possibility of schoolchildren with obesity to be classified into MHO phenotype.

High uric acid levels in overweight and obese children and their relationship with cardiometabolic risk factors: what is missing in this puzzle?

OBJECTIVES

The prevalence of hyperuricemia, a common disorder, has been increasing. Moreover, the association between obesity, serum uric acid levels, and cardiometabolic markers in children is unclear. Therefore, this study aimed to analyze the inter-relationships between these factors in a sample of children aged 6-12 years.

METHODS

We evaluated 764 children and stratified them according to their body mass index (BMI). Blood pressure and uric acid, creatinine, lipid, and glycemic profiles were evaluated, and the estimated glomerular filtration rate (eGFR) and the homeostatic model assessment for insulin resistance (HOMA-IR) index were calculated.

RESULTS

There was a significant linear trend of increasing systolic blood pressure (SBP), diastolic blood pressure (DBP), triglycerides (TG), total cholesterol, low-density lipoprotein cholesterol (LDLc), uric acid, insulin levels, and HOMA-IR index values corresponding with overweight and obese groups; however, high-density lipoprotein cholesterol (HDLc) levels decreased with increasing obesity. The mean creatinine level and eGFR were similar across all BMI groups. Uric acid levels were significantly correlated with BMI (r=0.527), waist circumference (r=0.580), SBP (r=0.497), DBP (r=0.362), TG (r=0.534), total cholesterol (r=0.416), LDLc (r=0.286), HDLc (r=-0.248), insulin (r=0.613), and HOMA-IR index (r=0.607). Multiple regression analyses showed that BMI (B=0.071; SE=0.012; p<0.001), TG (B=0.004; SE=0.001; p<0.001), LDLc (B=0.003; SE=0.001; p=0.006), and insulin (B=0.066; SE=0.007; p<0.001) (R²=0.460) were significant predictors of increased uric acid levels and explained 46% of the variability in uric acid in these children.

CONCLUSIONS

Our findings suggest that overweight or obese children are more likely to have higher uric acid levels. Moreover, several cardiometabolic risk factors were strongly associated with high uric acid levels.

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.

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.

Cardiovascular Risk Factors Associated With the Metabolically Healthy Obese (MHO) Phenotype Compared to the Metabolically Unhealthy Obese (MUO) Phenotype in Children

Background: In pediatric age the prevalence of obesity is high. Obese children who do not have other risk factors than excess weight have been defined as "metabolically healthy obese" (MHO). Aim: The aim of this study is to evaluate, in a population of obese children, the prevalence of the MHO and "metabolically unhealthy obese" (MUO) phenotype. Furthermore, we evaluated the distribution of Uric Acid, HOMA index and Waist-Height ratio (W-Hr) in the MHO and MUO sub-groups and the impact of these non-traditional risk factors on the probability to be MUO. Methods: In 1201 obese children and adolescents [54% males, age (±SD) 11.9 (±3.0) years] weight, height, waist circumference, systolic (SBP) and diastolic (DBP) blood pressure, pubertal status, glucose, insulin, HDL cholesterol, triglycerides and Uric Acid serum values were assessed. MUO phenotype was defined as the presence of at least one of the following risk factors: SBP or DBP ≥ 90th percentile, glycaemia ≥ 100 mg/dl, HDL cholesterol <40 mg/dl, triglycerides ≥100 mg/dl (children <10 years) or ≥130 mg/dl (children ≥10 years). A multivariate logistic regression analysis was used to estimate the association between MUO phenotype and non-traditional cardiovascular risk factors. Results: The prevalence of the MUO status was high (61%). MUO subjects were more often male, older and pubertal (p < 0.001). The levels of the three non-traditional risk factors were significantly higher in MUO children compared to MHO children (p < 0.001) and all of them were independent predictors of the fact of being MUO [OR 1.41 (95% CI 1.24-1.69); 1.15 (95% CI 1.06-1.23) and 1.03 (95% CI1.01-1.05) for Uric Acid, HOMA index and W-Hr, respectively]. About 15% of MHO subjects had serum Uric Acid, HOMA index and W-Hr values within the highest quartile of the study population. Conclusion: The prevalence of MUO subjects in a large pediatric population is high and serum Uric Acid, HOMA index and W-Hr values are independent predictors of the probability of being MUO. A non-negligible percentage of subjects MHO has high values of all three non-traditional risk factors.

High-normal estimated glomerular filtration rate and hyperuricemia positively correlate with metabolic impairment in pediatric obese patients

BACKGROUND

Childhood obesity represents a major health concern worldwide due to its well established detrimental effect on cardiovascular and its potential negative effect on kidney functions. However, biomarkers that can help diagnose early stages of kidney damage in obese children represent an unmet clinical need.

OBJECTIVES

In this study, we asked whether the prevalence of microalbuminuria, estimated glomerular filtration rate (eGFR) or hyperuricemia recorded in a wide cohort of obese children and adolescents would positively correlate with cardiometabolic dysfunction in these subjects.

METHODS

We carried out a cross-sectional study on 360 obese children and adolescents between the ages of 3-18 years, enrolled in a tertiary care center. Clinical and biochemical evaluations including oral glucose tolerance tests (OGTTs) were performed on all patients. Microalbuminuria was defined as urinary albumin-to-creatinine ratio (u-ACR) of 30-300 mg/g. All data are expressed as mean ± standard deviation (SD), absolute values or percentages. Sex age-specific and eGFR SDs were used for statistical analyses. Serum uric acid ≥ 5.5 mg/dL was considered abnormal.

RESULTS

The prevalence of microalbuminuria was 6.4%. Except for a lower insulinogenic-index, no correlations between microalbuminuria and cardiometabolic risk factors were detected. eGFR was < -1 SD and > 1 SD in 1.4% and 60.8% of subjects, respectively. Subjects with an eGFR > 1 SD had higher systolic blood pressure, liver enzymes, insulin resistance, glucose and insulin during OGTT, lower insulin sensitivity and a more prevalent microalbuminuria. Hyperuricemia (27.5%) increased the odds of hypertension, HDL ≤ 10th percentile and glucose ≥ 155.0 mg/dL after 60 minutes of OGTT.

CONCLUSIONS

A worse cardiometabolic profile was observed in subjects with an eGFR > 1 SD compared to other subgroups. Therefore, pediatric obese patients with eGFR > 1 SD or hyperuricemia should be closely monitored for microalbuminuria and post-challenge glucose and insulin secretion, all potential indicators of renal dysfunction in these young patients.

Microalbuminuria Is Associated with Lower Weight and Taller Height in Adolescence

Microalbuminuria (MA) is a well-known predictor of cardiovascular disease and mortality in adults. However, these relationships remain unclear in adolescents. A few studies on association between MA and obesity have been conducted in adolescents. However, the association between MA and growth parameters such as height has not been studied, despite the fact that adolescence is a period of rapid physiological change. We, therefore, aimed to evaluate the association between MA and growth parameters, and the association between MA and obesity related cardiovascular risk factors after adjusting for growth. The study included 1,459 adolescents (847 boys and 612 girls) aged 12-18 years who participated in the Korean National Health and Nutrition Examination Survey (2011-2013). A urine albumin/creatinine ratio (UACR) of 30-299 mg/g in a morning urine sample was considered to reflect MA. MA was detected in 53 (3.6%) including 24 girls. Height z-score of adolescents with MA was greater than that of normoalbuminuric adolescents (0.87 vs. 0.38; P < 0.01). Upon multiple regression analysis, UACR was associated with lower weight z-score (β = -0.100, P < 0.01) and higher height z-score (β = 0.069, P < 0.01). In term of cardiovascular risk factors, the UACR was not associated with fasting glucose, high-density-lipoprotein cholesterol, or triglyceride levels. Adolescents with MA tend to be thin and tall. MA is not a useful screening method for obesity-related cardiovascular risk in adolescents, but instead MA is associated with taller height and lower weight, growth-related parameters in adolescence.

Prevalence of microalbuminuria and its associated cardiometabolic risk factors in Korean youth: Data from the Korea National Health and Nutrition Examination Survey

Background

Microalbuminuria is a known early predictive factor for renal and cardiovascular diseases, not only for patients with diabetes mellitus or hypertension but also in the general population. However, the prevalence and risk factors associated with microalbuminuria in Korean youth are unknown.

Objectives

The aims of this study are to evaluate the prevalence of microalbuminuria and the association between microalbuminuria and obesity or cardiometabolic risk factors in Korean children and adolescents without diabetes.

Methods

This study examines data obtained from the Korea National Health and Nutrition Examination Survey (between 2011 and 2014). It includes a total of 1,976 participants aged between 10 and 19 years (boys 1,128 and girls 848). Microalbuminuria was defined as a urine albumin-to-creatinine ratio (UACR) of ≥ 30 mg/g and < 300 mg/g. Association between microalbuminuria and the risk factors for cardiometabolic diseases including insulin resistance was evaluated.

Results

The prevalence of microalbuminuria was found to be 3.0% in Korean children and adolescents over this time period. The mean UACR for non-obese youth was significantly greater than that found in obese youth (3.2 ± 0.1 mg/g in the non-obese group vs. 2.1 ± 0.2 mg/g in the obese group; P < 0.001). In multiple logistic regression analysis, microalbuminuria was associated with hyperglycemia (OR 2.62, 95% CI 1.09–6.30) and hemoglobin A1c (OR 3.34, 95% CI 1.09–10.17) in the non-obese group and hypertension (OR 14.10, 95% CI 1.12–177.98) and HbA1c (OR 6.68, 95% CI 1.87–23.95) in the obese group.

Conclusions

The prevalence of microalbuminuria is not prominent in obese children and adolescents. Our findings demonstrated that the presence of hypertension and hyperglycemia was associated with microalbuminuria. Especially Hemoglobin A1c was associated with microalbuminuria in youths regardless of weight status. Microalbuminuria in pediatric population can be a helpful marker for the risk of cardiovascular disease.

Uric acid, carotid intima-media thickness and body composition in prepubertal children

BACKGROUND

Increased uric acid is an independent biomarker for cardiovascular disease in obese adolescents and adults.

OBJECTIVE

We investigated whether uric acid relates to carotid intima-media thickness (cIMT) in prepubertal children, and whether body mass index (BMI) and preperitoneal fat modulate this association.

METHODS

359 asymptomatic prepubertal Caucasian children were stratified according to BMI categories (171 with BMI-SDS < 0; 188 with BMI-SDS ≥ 0) and according to preperitoneal fat levels (180 with preperitoneal fat <50th centile; 179 with preperitoneal fat >50th centile). Uric acid levels, insulin resistance (homeostasis model assessment insulin resistance; HOMA-IR), C-reactive protein (CRP), triacylglycerol (TG), systolic blood pressure (SBP), abdominal fat and cIMT (both by ultrasound) were assessed.

RESULTS

Uric acid was associated with several cardiovascular risk factors, namely higher HOMA-IR, CRP, TG, BMI, waist, SBP, preperitoneal fat and cIMT (all P < 0.001 to P < 0.0001). Significant BMI and preperitoneal fat interactions were documented in the relationship between uric acid and cIMT (both P < 0.05), as uric acid was preferentially related to cIMT in heavier children (β = 0.247, P < 0.001, r(2)  = 9.1%) and in children with more preperitoneal fat (β = 0.263, P < 0.0001, r(2)  = 11.9%).

CONCLUSIONS

Serum uric acid is associated with cIMT in asymptomatic prepubertal children. Both higher BMI and preperitoneal fat aggravate the potential risk of atherosclerotic disease imposed by higher concentrations of uric acid.

Incremental Predictive Value of Serum AST-to-ALT Ratio for Incident Metabolic Syndrome: The ARIRANG Study

Aims

The ratio of aspartate aminotransferase (AST) to alanine aminotransferase (ALT) is of great interest as a possible novel marker of metabolic syndrome. However, longitudinal studies emphasizing the incremental predictive value of the AST-to-ALT ratio in diagnosing individuals at higher risk of developing metabolic syndrome are very scarce. Therefore, our study aimed to evaluate the AST-to-ALT ratio as an incremental predictor of new onset metabolic syndrome in a population-based cohort study.

Material and Methods

The population-based cohort study included 2276 adults (903 men and 1373 women) aged 40–70 years, who participated from 2005–2008 (baseline) without metabolic syndrome and were followed up from 2008–2011. Metabolic syndrome was defined according to the harmonized definition of metabolic syndrome. Serum concentrations of AST and ALT were determined by enzymatic methods.

Results

During an average follow-up period of 2.6-years, 395 individuals (17.4%) developed metabolic syndrome. In a multivariable adjusted model, the odds ratio (95% confidence interval) for new onset of metabolic syndrome, comparing the fourth quartile to the first quartile of the AST-to-ALT ratio, was 0.598 (0.422–0.853). The AST-to-ALT ratio also improved the area under the receiver operating characteristic curve (AUC) for predicting new cases of metabolic syndrome (0.715 vs. 0.732, P = 0.004). The net reclassification improvement of prediction models including the AST-to-ALT ratio was 0.23 (95% CI: 0.124–0.337, P<0.001), and the integrated discrimination improvement was 0.0094 (95% CI: 0.0046–0.0143, P<0.001).

Conclusions

The AST-to-ALT ratio independently predicted the future development of metabolic syndrome and had incremental predictive value for incident metabolic syndrome.

Review: Obesity and cardiometabolic syndrome in children

The cardiometabolic syndrome is highly prevalent among overweight youth. The risk of developing the cardiometabolic syndrome is likely triggered or exacerbated by concurrent obesity, unhealthy lifestyle/eating habits, and hormonal changes (puberty). Current screening recommendations include measurement of blood pressure, fasting insulin and glucose, and total cholesterol. However, limiting assessments to these measures underestimates cardiometabolic risk in overweight youth, particularly minorities. Early identification of cardiometabolic risk in its incipient stages may justify early and more aggressive intervention to prevent progression and complications. This review provides rationale for additional assessments to determine cardiometabolic risk in overweight youth and recommends treatment options.

Elevated Urinary T Helper 1 Chemokine Levels in Newly Diagnosed Hypertensive Obese Children

OBJECTIVE

Increasing evidence suggests that T helper (Th) cells play a significant role in the pathogenesis of hypertension. The aim of this study was to evaluate the effect of obesity and anti-hypertensive treatment on urinary Th1 chemokines.

METHODS

The study groups consisted of three types of patients: hypertensive obese, healthy, and non-hypertensive obese. Pre-treatment and post-treatment samples of the hypertensive obese group and one sample from the other two groups were evaluated for urinary chemokine: regulated on activation, normal T cell expressed and secreted (RANTES), interferon-gamma-inducible protein 10 (IP10), and monokine induced by interferon-gamma (MIG). In the hypertensive obese group, urine microalbumin: creatinine ratio was examined before and after treatment. We recommended lifestyle changes to all patients. Captopril was started in those who could not be controlled with lifestyle changes and those who had stage 2 hypertension.

RESULTS

Twenty-four hypertensive obese (mean age 13.1), 27 healthy (mean age 11.2) and 22 non-hypertensive obese (mean age 11.5) children were investigated. The pre-treatment urine albumin: creatinine ratio was positively correlated with pre-treatment MIG levels (r=0.41, p<0.05). RANTES was significantly higher in the pre-treatment hypertensive and non-hypertensive obese group than in the controls. The urinary IP10 and MIG levels were higher in the pre-treatment hypertensive obese group than in the non-hypertensive obese. Comparison of the pre- and post-treatment values indicated significant decreases in RANTES, IP10, and MIG levels in the hypertensive obese group (p<0.05).

CONCLUSION

Th1 cells could be activated in obese hypertensive children before the onset of clinical indicators of target organ damage. Urinary RANTES seemed to be affected by both hypertension and obesity, and urinary IP10 and MIG seemed to be affected predominantly by hypertension.

Paediatrics, insulin resistance and the kidney

Systemic insulin resistance is becoming more prevalent in the young due to modern lifestyles predisposing to the metabolic syndrome and obesity. There is also evidence that there are critical insulin-resistant phases for the developing child, including puberty, and that renal disease per se causes systemic insulin resistance. This review considers the factors that render children insulin resistant, as well as the accumulating evidence that the kidney is an insulin-responsive organ and could be affected by insulin resistance.

Severity of non-alcoholic fatty liver disease is associated with high systemic levels of tumor necrosis factor alpha and low serum interleukin 10 in morbidly obese patients

Morbid obesity has been shown to increase the risk to develop hepatic steatosis, also referred to as non-alcoholic fatty liver disease (NAFLD). Emerging evidence suggests that the severity of NAFLD may associate with increased serum levels of inflammatory markers as well as decreased concentration of mediators with anti-inflammatory actions, such as tumor necrosis factor alpha (TNF-α) and interleukin (IL) 10, respectively. We thus examined the serum levels of TNF-α and IL-10 in 102 morbidly obese women and men (body mass index > 40 kg/m(2)), exhibiting different grades of NAFLD. Blood glucose, glycated hemoglobin, insulin, the homeostatic model assessment of insulin resistance (HOMA-IR), total cholesterol, triglycerides, high- and low-density lipoproteins, parameters of liver function, TNF-α, and IL-10 were measured in each subject. The stage of NAFLD was estimated by abdominal ultrasound imaging. In comparison with morbidly obese subjects without steatosis, morbidly obese patients with NAFLD showed increased age (39.23 ± 9.80 years), HOMA-IR (6.74 ± 1.62), total cholesterol (219.7 ± 9.58 mg/dl), aspartate aminotransferase (36.25 ± 3.24 UI/l), gamma-glutamyl transpeptidase (37.12 ± 3.41 UI/l), and TNF-α (37.41 ± 1.72 pg/ml) as well as decreased serum levels of IL-10 (61.05 ± 2.43 pg/ml). Interestingly, the systemic levels of TNF-α increased, while IL-10 decreased in accordance with the severity of NAFLD, which supports a role for systemic inflammatory mediators in promoting steatosis progression. Further clinical prospective studies need to be addressed to elucidate the role of TNF-α and IL-10 in the development of NAFLD while also establishing their clinical utility in the assessment of morbidly obese patients at higher risk to develop severe steatosis.

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.

Is Neck Circumference an Indicator for Metabolic Complication of Childhood Obesity?

BACKGROUND:

The possible role of neck circumference (NC) for screening childhood obesity and its complication is not well characterized.

AIM:

To assess NC and to explore its increase as risk factor with metabolic syndrome (MS) variables.

METHODS:

Cross sectional case-control study included 50 obese children (BMI ≥95^th percentile) and 50 healthy (BMI 15^th-‹85^th percentile). All were subjected to clinical examination, measuring blood pressure (BP), body weight, height, NC, waist (WC) and hip (HC)., fasting blood glucose, insulin and lipid profile.

RESULTS:

MS was detected among 52% of obese participants, but not among controls (0%). Clinical parameters and most of the laboratory values were higher in subjects with MS than in non-metabolic subjects, with statistical significance only in blood pressure and triglycerides. Among obese without MS, NC showed significantly positive correlations with age, weight, height, WC, HC and negative with LDL. While among Obese with MS, NC showed significantly positive correlations with age, weight, height, BMI-SDS, WC, HC and DBP.

CONCLUSION:

NC can be considered as a good indicator and predictor for obesity, especially central obesity. However, NC has no relation with lipid profile or fasting blood sugar.

Hyperuricaemia in congenital heart disease patients

INTRODUCTION

Hyperuricaemia is associated with traditional cardiovascular risk factors such as type 2 diabetes or dyslipidaemia and a higher mortality.

METHODS

Out of 528 congenital heart disease patients, 329 patients, including 190 male and 139 female patients, in whom uric acid determination was performed, were studied and followed up to determine survival.

RESULTS

Male congenital heart disease patients with high serum uric acid concentrations (>7 mg/dl) showed significantly (p < 0.05) higher body mass index, serum creatinine, total cholesterol, low-density lipoprotein-cholesterol, triglycerides, and C-reactive protein concentrations than those male congenital heart disease patients with lower serum uric acid levels (≤7 mg/dl). Meanwhile, female congenital heart disease patients with higher serum uric acid concentrations (>5.7 mg/dl) were significantly (p < 0.05) younger, more hypoxaemic, more obese, and with higher C-reactive protein and N-terminal-pro-B-type natriuretic peptide levels than those female congenital heart disease patients with lower serum uric acid concentrations (≤5.7 mg/dl). During a median follow-up of 90 months, 16 out of 528 congenital heart disease patients died - 14 patients of cardiac origin and two patients of non-cardiac origin - of whom 10 were hypoxaemic. Kaplan-Meier analysis showed no significant differences in mortality between male and female congenital heart disease patients with high and low serum uric acid level concentrations.

CONCLUSIONS

Hypoxaemia, body mass index, and C-reactive protein concentrations are higher in hyperuricaemic congenital heart disease patients, although no significant differences were seen in mortality between congenital heart disease patients with high and low serum uric acid concentrations.

A Family History of Diabetes Modifies the Association between Elevated Urine Albumin Concentration and Hyperglycemia in Nondiabetic Mexican Adolescents

We examined the frequency of elevated urine albumin concentration (UAC) and its association with metabolic syndrome (MetS) and metabolic markers in 515 nondiabetic Mexican adolescents stratified by family history of diabetes (FHD). UAC was measured in a first morning urine sample and considered elevated when excretion was ≥20 mg/mL. MetS was defined using International Diabetes Federation criteria. Fasting insulin, insulin resistance, and lipids were evaluated. Multivariate logistic regression was performed. Elevated UAC was present in 12.4% and MetS was present in 8.9% of the adolescents. No association was found between elevated UAC and MetS. Among adolescents with FHD, 18.4% were overweight and 20.7% were obese, whereas, among those without a FHD, 15.9% were overweight and 7.5% were obese. Hyperglycemia was higher in those with elevated UAC than in those without (44.4% versus 5.1%, p = 0.003). Hyperglycemia (OR = 9.8, 95% CI 1.6-59.4) and number of MetS components (OR = 4.5, 95% CI 1.5-13.3) were independently associated with elevated UAC. Among female participants, abdominal obesity was associated with elevated UAC (OR = 4.5, 95% CI 1.2-16.9). Conclusion. Elevated UAC was associated neither with MetS nor with any metabolic markers in nondiabetic adolescents. However, FHD modified the association of elevated UAC with hyperglycemia and the number of MetS components.

Obese children and adolescents have elevated nighttime blood pressure independent of insulin resistance and arterial stiffness

BACKGROUND

Insulin resistance has been related to elevated blood pressure (BP) in obese children and may adversely affect the vasculature by arterial stiffening. The objective was to investigate whether daytime and nighttime BP were elevated and related to insulin resistance and arterial stiffness in obese children and adolescents.

METHODS

Ninety-two obese patients aged 10-18 years were compared with 49 healthy control individuals. Insulin resistance was measured as the homeostatic assessment model (HOMA), and arterial stiffness was measured as carotid-femoral pulse wave velocity (cfPWV).

RESULTS

Mean ± SD daytime systolic BP (SBP) (obese: 125±8.3mm Hg; control: 121±10.1mm Hg; P = 0.03) and nighttime SBP (obese: 108±10.7mm Hg; control: 102±8.2mm Hg; P = 0.0001) were higher in the obese group when compared with the control group. No difference was found in daytime diastolic BP (DBP), whereas nighttime DBP (obese: 60±6.6mm Hg; control: 57±4.8mm Hg; P = 0.001) and night-to-day BP ratios were higher in the obese group. Nighttime SBP was related to BMI z score (β = 6.0; 95% confidence interval (CI) = 2.9-9.1; P = 0.0002) and waist/height ratio (β = 36.7; 95% CI = 5.6-67.9; P = 0.02) in the obese group. HOMA index (obese: median = 3.7, interquartile range (IQR) = 2.3-6.0; control: median = 2.6, IQR = 1.8-3.4; P = 0.002) was higher, whereas cfPWV (obese: 4.8±0.8 m/s; control: 5.1±0.6 m/s; P = 0.03) was lower in the obese group. CfPWV was not related to logHOMA index. In multiple regression analyses, the higher nighttime BP in the obese group was independent of logHOMA and cfPWV.

CONCLUSIONS

Obese children had a higher nighttime BP when compared with the control group independently of insulin resistance and arterial stiffness. No relationship was found between insulin resistance and arterial stiffness. CLINICAL TRIAL REGISTRATION Clinicaltrials.gov identifier NCT01310088.

Limited value of routine microalbuminuria assessment in multi-ethnic obese children

BACKGROUND

To determine the prevalence of microalbuminuria and its association with cardiometabolic risk factors in a multi-ethnic cohort of overweight and obese children.

CASE-DIAGNOSIS/TREATMENT

A retrospective analysis of prospectively collected data was performed using data from 408 overweight and obese children (age 3-19 years). In addition to administering an oral glucose tolerance test, we measured anthropometric variables, plasma lipid levels, alanine aminotransferase and the urinary albumin/creatinine ratio (ACR). Microalbuminuria was defined as an ACR of between 2.5 and 25 mg/mmol in boys and 3.5 and 25 mg/mmol in girls. In total, only 11 (2.7 %) of the children analyzed presented with microalbuminuria, with no differences between ethnic groups, sex or in the prevalence of hypertension compared to the children with normoalbuminuria. After adjustment for confounders, the body mass index Z-score tended to be different between the group with microalbuminuria versus that without (3.6 vs. 3.2, respectively; P = 0.054). ACR was not associated with hypertension, impaired glucose tolerance, high triglycerides or low high-density lipoprotein-cholesterol.

CONCLUSIONS

In a large multi-ethnic cohort of overweight and obese children, we found a low prevalence of microalbuminuria (11 children, 2.7 %), and in this small number of individuals, we found no association with any of the cardiometabolic risk factors assessed. Therefore, our data do not support the routine measurement of microalbuminuria in asymptomatic overweight and obese children and adolescents.

Metabolic syndrome in youth: chimera or useful concept?

Metabolic syndrome (MetS) is a cluster of cardiometabolic risk factors associated with an increased risk for the development of cardiovascular diseases and type 2 diabetes. The prevalence of the MetS is not particularly high in the overall pediatric population (3 %-4 %) but it is as high as 30 %-50 % among overweight youth. Several definitions of the MetS have been used, thus, generating confusion and difficulties in defining the true prevalence of this syndrome. The recent definition of the International Diabetes Federation has tried to standardize the diagnostic criteria. However, there are still some concerns about use of cut-offs values and dichotomous variables, and some debate as to whether a continuous cardiometabolic risk score could be more appropriate for the pediatric population. Although there are some studies that have shown the association between childhood and adolescent MetS with long-term outcomes, further prospective studies are needed to clarify the true value of diagnosing MetS in youth.

The prevalence of metabolic syndrome in children: a systematic review of the literature

BACKGROUND

Metabolic syndrome has been identified as a condition of childhood relatively recently. The aim in this study was to describe the prevalence of metabolic syndrome in children allowing for differences in metabolic syndrome definitions.

METHODS

This was a systematic review of the OVID, EMBASE, and CINAHL databases, capturing details of overall prevalence and prevalence within groups categorized by obesity, gender, age, and ethnicity.

RESULTS

In all, 378 studies published since 2003 were identified, and of these 85 papers were included in the present review. When all studies were considered, the median prevalence of metabolic syndrome in whole populations was 3.3% (range 0%-19.2%), in overweight children was 11.9% (range 2.8%-29.3%), and in obese populations was 29.2% (range 10%-66%). Within-study analyses confirmed higher prevalence for obese compared to overweight (P=0.012) and obese compared to nonobese, nonoverweight children (P<0.001). Within-study analyses also revealed higher median metabolic syndrome prevalence for boys compared to girls (5.1% versus 3.0%, P<0.001) and also in older compared with younger children (5.6% versus 2.9%, P=0.001). Limited evidence was found to suggest differences between ethnic groups, and there were insufficient studies to determine whether metabolic syndrome prevalence was increasing over time.

CONCLUSIONS

This is the first systematic review of all of the relevant literature. It describes the magnitude of associations between metabolic syndrome and obesity, age, and gender. We find evidence that ethnicity and geography may be important to metabolic syndrome prevalence in children and these associations require further study.

The Qingdao Twin Registry: a status update

In 1998, the Qingdao Twin Registry was initiated as the main part of the Chinese National Twin Registry. By 2005, a total of 10,655 twin pairs had been recruited. Since then new twin cohorts have been sampled, with one longitudinal cohort of adolescent twins selected to explore determinants of metabolic disorders and health behaviors during puberty and young adulthood. Adult twins have been sampled for studying heritability of multiple phenotypes associated with metabolic disorders. In addition, an elderly twin cohort has been recruited with a focus on genetic studies of aging-related phenotypes using twin modeling and genome-wide association analysis. Cross-cultural collaborative studies have been carried out between China, Denmark, Finland, and US cohorts. Ongoing data collection and analysis for the Qingdao Twin Registry will be discussed in this article.

Distribution and association of hs-CRP with cardiovascular risk variables of metabolic syndrome in adolescent learners

OBJECTIVE

Metabolic syndrome (MetS) and its associated cardiovascular risk are on the increase in children. High-sensitivity C-reactive protein (hs-CRP) has emerged as a useful marker for inflammation associated with atherosclerosis and cardiovascular disease. Our aim was to determine the distribution of hs-CRP in an effort to identify the MetS variable that is critical in modulating plasma CRP levels in a population of South African adolescents.

DESIGN

A cross-sectional analytical study design was used for this investigation, where the dependent and independent variables were measured simultaneously.

METHODS

Anthropometric variables, blood pressure, fasting blood glucose and lipids were performed on 324 consenting learners aged 15-18 years from three different ethnic groups (Black, White and Coloured). The National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) for ages 15-18 year olds was used to define MetS.

RESULTS

The prevalence of MetS and obesity was 3.7% and 7.1%, respectively. The hs-CRP levels were significantly higher in subjects with a waist-circumference greater than the 90th percentile (p < 0.01) and in obese learners with MetS, but was lower in adolescents with normal weight and MetS. Median hs-CRP levels increased with an increasing number of metabolic abnormalities and exceeded 3 mg/L in 19% of adolescents. Gender and ethnic differences were observed.

CONCLUSION

Our findings suggest that obesity and waist circumference appear to be major mediators of hs-CRP levels in South African adolescents.

Modernization and cardiometabolic risk in Samoan adolescents

OBJECTIVE

To describe the prevalence of cardiometabolic risk factor clustering in Samoan adolescents and to relate risk factor clustering to weight status and general modernization.

METHODS

Anthropometric and biochemical data collected from adolescents aged 12-17.9 years who participated in the Samoan Family Study of Overweight and Diabetes were used to describe the prevalence of cardiometabolic risk factors (high waist circumference, high blood pressure, high triglyceride level, low-high-density lipoprotein cholesterol, and high fasting serum glucose). A total of 436 adolescents were included in this analysis; 237 (54.4%) from American Samoa (n = 123 males) and 199 (45.6%) from Samoa (n = 90 males). Risk factor clustering was indicated by the presence of ≥ 3 risk factors.

RESULTS

Cardiometabolic risk factor clustering was greater in American Samoan adolescents (17.9% males, 21.9% females) than Samoan adolescents (1.1% males, 2.8% females). The frequency of risk factor clustering varied according to body mass index status. In males, risk factor clustering was entirely confined to obese adolescents, whereas female adolescents who were overweight or obese were at risk.

CONCLUSIONS

Cardiometabolic risk factor clustering is prevalent in the young American Samoan population and is likely to become more prevalent with increasing modernization in Samoan youth. Screening and intervention should be targeted at this age group to reduce the non-communicable disease burden faced by these populations.

Metabolic syndrome in a sample of the 6- to 16-year-old overweight or obese pediatric population: a comparison of two definitions

Purpose

The purpose of this study was to estimate the presence of metabolic syndrome (MS) in a group of children and adolescents with a body mass index (BMI) above the 85th percentile for their age and sex in Qazvin Province, Iran; to evaluate the relationship between obesity and metabolic abnormalities; and to compare two proposed definitions of MS.

Patients and methods

The study was conducted on 100 healthy subjects aged between 6 and 16 years (average age, 10.52 ± 2.51 years) with a high BMI for their age and sex. Fifty- eight percent of subjects were female. Physical examination including evaluation of weight, height, BMI, and blood pressure measurement was performed (“overweight” was defined as a BMI between the 85th and 95th percentiles for children of the same age and sex; “obese” was defined as a BMI over the 95th percentile for children of the same age and sex). Blood levels of glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, and uric acid were measured after a 12-hour overnight fast. The authors used and compared two definitions of MS: the National Cholesterol Education Program’s Adult Treatment Panel III (NCEP ATP III) criteria and a modified definition by Weiss et al. Variables were compared using the Student’s t-test and chi-square and Mann-Whitney U tests, and agreement between the two definitions was analyzed using kappa values.

Results

The subjects had a mean BMI of 26.02 ± 4.38 and 80% had obesity. Insulin resistance was found in 81% of the study population. MS was present in ten (50%) of the overweight and 53 (66.2%) of the obese subjects using the NCEP ATP III criteria. MS was present in five (25%) of the overweight and 34 (42.5%) of the obese subjects using the definition by Weiss et al. The overall kappa value for the two definitions of MS was 0.533. There were no statistically significant differences between the two definitions of MS in participants.

Conclusion

The prevalence of MS in children and adolescents depends on the criteria chosen and their respective cutoff points. The NCEP ATP III criteria, the parameters of which include higher cutoff values for high-density lipoprotein cholesterol and triglycerides, detected the higher prevalence and therefore the NCEP ATP III criteria are able to diagnose a larger number of children and adolescents at metabolic risk.

Non-traditional markers of metabolic risk in prepubertal children with different levels of cardiorespiratory fitness

OBJECTIVE

To assess classical and non-classical metabolic risk biomarkers in prepubertal children with different levels of cardiorespiratory fitness (CRF).

DESIGN

CRF was assessed by the 20 m shuttle run test. To estimate physical activity, participants were observed while engaged in an after-school programme. Additionally, a short test based on a validated questionnaire was used to obtain information about physical activity practice and sedentary habits. Anthropometric parameters, blood pressure, and classical and non-traditional metabolic risk biomarkers--plasma lipid profile, glucose and insulin, homeostasis model assessment-insulin resistance index (HOMA-IR), plasma uric acid, transaminases and C-reactive protein (CRP)--were measured.

SETTING

The study was conducted in local elementary schools in Córdoba, Spain.

SUBJECTS

One hundred and forty-one healthy children (eighty-eight boys, fifty-three girls) aged 7-12 years, in Tanner stage I, were recruited. They were divided into two groups after they performed the 20 m shuttle run test: equal or higher cardiovascular fitness (EHCF) group and low cardiovascular fitness (LCF) group.

RESULTS

The LCF group displayed significantly higher TAG (P = 0.004) and lower HDL cholesterol levels (P = 0.001), as well as significantly lower values for the non-traditional lipid marker apo-A1 (P = 0.001) compared with the EHCF group. The LCF children displayed higher plasma glucose (P = 0.003) and insulin levels, higher HOMA-IR scores (P < 0.001) and higher plasma uric acid and CRP levels (P < 0.05). After adjustment for BMI, age and sex, no statistically significant differences were found between groups for the biomarkers analysed.

CONCLUSIONS

The study provides new information to understand the role not only of weight status but also of the level of CRF on the metabolic health profile of prepubertal children.

The association of metabolic syndrome, insulin resistance and non-alcoholic fatty liver disease in overweight/obese children

BACKGROUND/AIM

To study the prevalence of metabolic syndrome (MS), insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD) in overweight/obese children with clinical hepatomegaly and/or raised alanine aminotransferase (ALT).

PATIENTS AND METHODS

Thirty-three overweight and obese children, aged 2-13 years, presenting with hepatomegaly and/or raised ALT, were studied for the prevalence of MS, IR and NAFLD. Laboratory analysis included fasting blood glucose, serum insulin, serum triglycerides (TG), total cholesterol, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c) and liver biochemical profile, in addition to liver ultrasound and liver biopsy.

RESULTS

Twenty patients (60.6%) were labeled with MS. IR was present in 16 (48.4%). Fifteen (44%) patients had biopsy-proven NAFLD. Patients with MS were more likely to have NAFLD by biopsy (P=0.001). Children with NAFLD had significantly higher body mass index, waist circumference, ALT, total cholesterol, LDL-c, TG, fasting insulin, and lower HDL-c compared to patients with normal liver histology (P< 0.05) and fitted more with the criteria of MS (80% vs. 44%). IR was significantly more common among NAFLD patients (73% vs. 28%).

CONCLUSION

There is a close association between obesity, MS, IR and NAFLD. Obese children with clinical or biochemical hepatic abnormalities are prone to suffer from MS, IR and NAFLD.

Cardiometabolic risk variables in overweight and obese children: a worldwide comparison

The growing prevalence rate of pediatric obesity, which is frequently accompanied by several cardiometabolic risk factors, has become a serious global health issue. To date, little is known regarding differences for cardiometabolic risk factors (prevalence and means) in children from different countries. In the present review, we aimed to provide a review for the available evidence regarding cardiometabolic risk factors in overweight pediatric populations. We therefore provided information with respect to the prevalence of impaired fasting glucose/impaired glucose tolerance, high triglycerides, low HDL-cholesterol and hypertension (components of the metabolic syndrome) among cohorts from different countries. Moreover, we aimed to compare the means of glucose and lipid levels (triglycerides and HDL-cholesterol) and systolic/diastolic blood pressure values. After careful selection of articles describing cohorts with comparable age and sex, it was shown that both prevalence rates and mean values of cardiometabolic risk factors varied largely among cohorts of overweight children. After ranking for high/low means for each cardiometabolic risk parameter, Dutch-Turkish children and children from Turkey, Hungary, Greece, Germany and Poland were in the tertile with the most unfavorable risk factor profile overall. In contrast, cohorts from Norway, Japan, Belgium, France and the Dominican Republic were in the tertile with most favorable risk profile. These results should be taken with caution, given the heterogeneity of the relatively small, mostly clinical cohorts and the lack of information concerning the influence of the values of risk parameters on true cardiometabolic outcome measures in comparable cohorts. The results of our review present a fair estimation of the true differences between cardiometabolic risk profiles among pediatric cohorts worldwide, based on available literature.

Microalbuminuria: causes and implications

Management strategies are increasingly focused on tackling the increasing burden of cardiovascular disease worldwide. Microalbuminuria is a powerful predictor of cardiovascular disease and mortality in adults. This holds true in the general adult population but is particularly recognized in those with diabetes, where it identifies those likely to develop progressive atherosclerotic vascular disease and renal impairment. The atherosclerotic process begins in childhood with likely consequences in later life. In-depth understanding of the mechanisms through which microalbuminuria occurs holds promise for designing therapies to arrest its development in the future. Microalbuminuria arises from increased leakage of albumin through the complex glomerular sieve known as the glomerular filtration barrier. This requires changes in the physio-chemical properties of components of this barrier. However, the increased glomerular permeability confirmed in disease does not necessarily correlate with recognized histological changes in the glomerulus, suggesting that perhaps more subtle ultrastructural changes may be relevant. The epidemiology of microalbuminuria reveals a close association between systemic endothelial dysfunction and vascular disease, also implicating glomerular endothelial dysfunction in microalbuminuria. This review discusses the mechanisms of microalbuminuria in disease, particularly the emerging role of the glomerular endothelium and its glycocalyx, and examines its implications for cardiovascular disease in the pediatric population.

Adherence to the Mediterranean diet and albuminuria levels in Greek adolescents: data from the Leontio Lyceum ALbuminuria (3L study)

BACKGROUND/OBJECTIVES

Mediterranean diet has favorable effects on the cardiovascular system, whereas albuminuria is associated with atherosclerosis progression. The aim of the study was to assess the relationships of adherence rates to the Mediterranean diet with albumin to creatinine ratio (ACR), in a cohort of Greek adolescents who participated in the Leontio Lyceum ALbuminuria (3L) study.

SUBJECTS/METHODS

In a total of 365 adolescents 12-17 years of age included in 3L study, ACR values were determined in a morning-spot urine.

RESULTS

The Mediterranean diet Quality Index for children and adolescents (KIDMED) was estimated and accordingly subjects were divided into those with high (≥ 8), average (4-7) and low (≤ 3) score. Adolescents with low (n=153, 42%) compared with those with average (n=187, 51.2%) and high (n=25, 6.8%) KIDMED score were characterized by greater ACR values (22.4 vs 13.4 vs 12.1 mg/g, P<0.05) even after adjustment for confounders. In the total population, KIDMED score was related to body mass index (r=0.122, P=0.02), waist circumference (r=0.118, P=0.02), systolic blood pressure (BP) (r=0.119, P=0.023), whereas it was negatively associated with ACR (r=-0.111, P=0.041). Regarding ACR, it was associated with age (r=-0.11, P=0.044), male sex (r=0.16, P=0.003), body mass index (r=-0.131, P=0.016) and systolic BP (r=-0.144, P=0.008).

CONCLUSIONS

Adolescents who adhere to the Mediterranean diet exhibit lower levels of albuminuria, independently of demographic and hemodynamic confounders. The inverse relation of KIDMED index with ACR suggests a close link of accelerated vascular damage reflected by albuminuria with low adherence to this favorable diet of the Mediterranean basin.

Preclinical manifestations of organ damage associated with the metabolic syndrome and its factors in outpatient children

BACKGROUND

To evaluate whether the pediatric metabolic syndrome (MetS) or its factors are useful to detect subclinical abnormalities of cardiac, liver, and glomerular damage in an outpatient population.

METHODS

The population study included 799 children (age 10 ± 3 years, mean ± SD), 24% of whom were normalweight, 25% overweight, and 51% obese. Alanine-aminotransferase (ALT) levels, estimated glomerular filtration rate (eGFR) and HOMA-IR were analyzed in all children. Microalbuminuria (MA) and left ventricular (LV) geometry and function were evaluated in 501 and 247 children, respectively. MetS was defined using Cook's criteria.

RESULTS

MetS was diagnosed in 131 children (16%). Children with MetS+ and MetS- were similar for age, gender and Tanner stage distribution. Children with MetS+ showed higher ALT levels (31 ± 19 vs 21 ± 11 IU/L, p<0.0001), LV mass (39 ± 10 vs 34 ± 10 g/h(2.7), p<0.001) and relative wall thickness (0.37 ± 0.06 vs 0.35 ± 0.05, p<0.01) than MetS-. The two groups were similar for MA and eGFR. At multiple logistic regression analysis, children MetS+ showed a higher risk (OR, 95% Cl) adjusted for confounding factors, of high ALT levels (1.71, 1.12-2.59, p=0.012) and concentric LV hypertrophy (2.17, 1.01-4.66, p=0.047) than children MetS-. The risk of preclinical liver and cardiac damage associated with the MetS phenotype was not higher than predicted by its single components.

CONCLUSIONS

Children with MetS show a 2-fold greater risk of having high ALT levels and concentric LV hypertrophy. However, the risk of subclinical manifestations of liver and cardiac damage can be predicted equally well by the single components of the syndrome.

Gender-specific association of serum uric acid with metabolic syndrome and its components in juvenile obesity

BACKGROUND

Hyperuricemia has been implicated in the pathogenesis of obesity and related metabolic abnormalities. Studies on the association between serum uric acid (sUA) and metabolic syndrome (MetS) in juvenile obesity are scant. The effect of gender has not been evaluated.

METHODS

sUA (uricase method), anthropometric and biochemical indices were measured in gender-stratified children/adolescents consisting of 113 overweight/obese and 71 lean individuals.

RESULTS

In males, sUA was significantly elevated in overweight as well as obese patients. sUA was strongly associated with obesity indices and reflected sexual development, decreases in high density lipoprotein-cholesterol, and moderately, the number of MetS components. Waist circumference (WC) and Tanner stage explained 40% of sUA variability. Controlling for body mass index (BMI) and other MetS components, sUA was associated with abdominal obesity, explaining 30% of variability in WC. In females, sUA was significantly increased in obesity, high blood pressure (BP), and MetS and corresponded with the number of MetS components, indices of glucose metabolism, triglycerides (TG), and the atherogenecity index. Insulin-resistance (IR) (homeostasis model assessment; HOMA) and high BP explained 29% of sUA variability, whereas sUA, while controlling for BMI, age, and other MetS components, was associated with hypertriglyceridemia, hyperglycemia, high BP, and abdominal obesity. IR mediated the associations with high TG and glucose.

CONCLUSIONS

The association between sUA and MetS components in juvenile obesity is gender-specific, with females being related more closely and to more metabolic abnormalities. It may explain why, despite its lower concentrations, sUA is an independent predictor of mortality from all causes and from vascular diseases exclusively in females. Our findings may help in identifying metabolic abnormalities which may possibly be targeted by reducing sUA in males and females.

Is albuminuria associated with obesity in school children?

BACKGROUND

Different studies in adults have shown that obesity is an independent risk factor for end-stage renal disease.

OBJECTIVE

It was to (i) determine the association between albuminuria and age, gender, BMI, waist circumference (WC), and blood pressure (ii) relate albuminuria to gender and age in healthy school children.

METHODS

Over 1564 students (806 males) aged 9.35 +/- 2.00 yr from 9 elementary schools in Buenos Aires, were examined between April and September 2005. BMI, WC, blood pressure, urinary albumin excretion and albumin/creatinine ratio (ACR) were determined.

RESULTS

Over 220 (14.1%) children were obese (OB), and 300 (19.2%) overweight (OW) using centers for disease control (CDC) norms. Median ACR and urinary albumin levels were higher in normal weight children than in OW/OB children (p < 0.01). Median values for ACR were higher in girls than in boys (p < 0.001). OW/OB proved to be a protective factor against ACR [OR, 0.77 (95% CI 0.64-0.92)], whereas female gender [OR, 2.72 (95% CI 2.13-3.47)] was associated with a higher ACR adjusted for age systolic and diastolic blood pressure in the multiple logistic regression analysis. Therefore, children with OW/OB had 23% lower odds of having ACR >or= III quartile and girls had more than two and half times the risk of having high ACR.

CONCLUSIONS

Our results suggest that OW/OB is inversely associated with childhood albuminuria while female gender is positively associated. Whether the results can be explained by the increased physical activity in lean children should be the subject of future investigations. These results suggest that micro-albuminuria in children may not be a useful tool in the early identification of children at risk for future renal and cardiovascular disease (CVD).

The possible role of liver steatosis in defining metabolic syndrome in prepubertal children

Insulin resistance is a key component of the metabolic syndrome (MS) and is strongly associated with liver steatosis. Our aim was to evaluate whether MS should be diagnosed already in obese prepubertal children and whether its prevalence is influenced by the inclusion of hepatic steatosis as a diagnostic criterion. Eighty-nine obese children (43 boys; age median [range], 8.5 [6-10] years) were enrolled. Metabolic syndrome was diagnosed according to a classic definition: presence of 3 or more of the following criteria-body mass index greater than 2 standard deviation score, triglycerides greater than the 95th percentile, high-density lipoprotein cholesterol less than the fifth percentile, blood pressure greater than the 95th percentile, and impaired glucose tolerance. Afterward, liver steatosis was included as an additional criterion to this definition. Metabolic syndrome was diagnosed in 12 children (13.5%) according to the first definition and in 18 children (20.2%) when liver steatosis was included. The prevalence of MS increased across homeostasis model assessment of insulin resistance tertiles (P for trend = .01). The prevalence of the single components of the MS was as follows: obesity, 100%; hypertriglyceridemia, 27%; low high-density lipoprotein cholesterol, 2.2%; hypertension, 34.8%; impaired glucose tolerance, 4.5%; and nonalcoholic fatty liver disease, 21.3%. In conclusion, MS is common already among prepubertal obese children, particularly when liver steatosis is included among the diagnostic criteria. Therefore, screening for the MS should be performed in this age group; and hepatic steatosis should be considered as an additional diagnostic criterion.

Carotid intima-media thickness, dietary intake, and cardiovascular phenotypes in adolescents: relation to metabolic syndrome

Little is known about the interrelationships between metabolic syndrome (MS), uric acid, and early carotid atherosclerosis with diet in adolescents. We investigated associations among diet, carotid intima-media thickness (cIMT), MS, uric acid, and other cardiovascular risk factors in adolescents. Two hundred forty-nine adolescents from 3 high schools in Central California-a predominately Hispanic (n = 119, 16.1 +/- 0.9 years old, 94% Hispanic), a mixed-ethnicity (n = 94, 15.7 +/- 1.2 years old), and a Seventh-day Adventist (SDA) (n = 33, 17.0 +/- 1.3 years old) high school-were assessed for cIMT, blood lipids, uric acid, blood glucose, systolic and diastolic blood pressure, body mass index (BMI), and dietary intake. Compared with SDA adolescents, the predominately Hispanic and mixed-ethnicity high school adolescents exhibited higher low-density lipoprotein and BMI percentile, whereas adolescents from the SDA and mixed-ethnicity high schools exhibited lower uric acid and fasting glucose levels than those from the Hispanic high school. After adjusting for age and sex, cIMT was only correlated with systolic blood pressure percentile (r = 0.16, P < .01). Controlling for age, levels of uric acid were correlated with BMI percentile (males: r = 0.59, P < .001; females: r = 0.24, P < .01), low-density lipoprotein (males: r = 0.40, P < .001; females: r = 0.20, P < .01), and total cholesterol in males (r = 0.38, P < .001). Despite no significant differences in the high school frequency of MS risk factors, 59% of adolescents had one or more MS risk factors. A relationship was noted between the number of MS risk factors and uric acid (P < .002). Most of the adolescents presented MS risk factors independent of ethnicity or a purportedly healthier lifestyle (SDA). Uric acid association with MS and its risk factors suggests its potentially heightened importance for the assessment of adolescent cardiovascular health.

Prevalence of the metabolic syndrome among extremely obese adolescents in Italy and Germany

Juvenile metabolic syndrome (MetS) is a growing major medical problem in industrialised countries. We estimated its prevalence among two similar clinic-based sequentially recruited cohorts of extremely obese adolescents (age: 12-18 years) from Italy (N=665, males=271, females=394) and Germany (N=661, males=261, females=400) using the recent IDF paediatric criteria. The prevalence of the MetS was 23.3% among the Italians and 40.4% among the Germans. A multivariate logistic regression revealed an increased risk related to age (adjusted odd ratio (AOR): 2.24; 95% confidence interval (CI): 1.59-3.16; p<0.001), BMI SDS (AOR: 3.61; 95% CI: 2.33-5.60; p<0.001), male gender (AOR: 2.36; 95% CI: 1.80-3.10; p<0.001), and in German adolescents (AOR: 2.56; 95% CI: 1.98-3.31; p<0.001). Among Italian adolescents having the MetS, 83% had 3 abnormalities, 16% had 4 abnormalities while less than 1% had all the 5 abnormalities. In the German cohort, 67%, 28% and 5% of affected individuals had 3, 4 and 5 abnormalities, respectively. These results indicate that MetS is highly prevalent among extremely obese adolescents, and suggest that (besides age, obesity and gender) national sociocultural factors, as alimentary trends, could be important. Further tools should be developed to understand international epidemiological differences concerning obesity and its comorbidities in relation to lifestyles in the countries of European Union.

Association between physical activity and metabolic syndrome: a cross sectional survey in adolescents in Ho Chi Minh City, Vietnam

Background

The emerging epidemic of overweight/obesity in adolescents in Ho Chi Minh City, Vietnam underlines the importance of studying the metabolic syndrome in Vietnamese adolescents who are becoming progressively more inactive. No study in Vietnam has examined the association of metabolic syndrome with moderate to vigorous physical activity (PA) levels among adolescents. We aimed to examine this association in a sample of urban adolescents from Ho Chi Minh City.

Methods

A cross-sectional assessment was conducted in 2007 on a representative sample of 693 high-school students from urban districts in Ho Chi Minh City. Metabolic syndrome was defined according to the International Diabetes Federation criteria and physical activity was measured with Actigraph accelerometers. The association between physical activity and metabolic syndrome was assessed by using multiple logistic regression models.

Results

Overall 4.6% of the adolescents and 11.8% of the overweight/obese adolescents had metabolic syndrome. Elevated BP was the most common individual component of the metabolic syndrome (21.5%), followed by hypertriglyceridemia (11.1%). After adjusting for other study factors, the odds of metabolic syndrome among youth in the lowest physical activity group (<43 minutes of physical activity/day) were five times higher than those in the highest physical activity group (>103 minutes/day) (AOR = 5.3, 95% CI: 1.5, 19.1). Metabolic syndrome was also positively associated with socioeconomic status (AOR = 9.4, 95% CI: 2.1, 42.4).

Conclusions

A more physically active lifestyle appears to be associated with a lower odds of metabolic syndrome in Vietnamese adolescents. Socio-economic status should be taken into account when planning interventions to prevent adolescent metabolic syndrome.

Diet intervention on obese children with hypertension in China

BACKGROUND

Obesity has made obesity-related diseases a worldwide problem. This study was undertaken to evaluate the effects of diet-oriented intervention on obese children with hypertension in China and to determine the relationship between anthropometric indexes and hypertension.

METHODS

A total of 469 obese children, aged 6 to 18 years, were evaluated between January 2001 and December 2005; 184 of them were diagnosed with hypertension. Hypertensive children were provided with individual diet-oriented intervention for more than 6 months. Physical exercises were recommended for obese children at least 30 minutes per day. Height, body weight, waist circumference, systolic blood pressure, and diastolic blood pressure were taken for each subject before and after intervention.

RESULTS

Of the 184 children enrolled, 139 (75.5%; 86 boys) completed the study. Weight, body mass index (BMI), waist circumference, and hip circumference all decreased after a 6-month intervention, despite a 2.1 cm increase in height. Systolic and diastolic pressures decreased by 16.6 and 13.3 mmHg compared with baseline levels. Of the 139 children, 103 (74.1%) who had blood pressure in the normal range (<90th percentile for age and sex) were taken as a response group. The other 36 children who remained hypertensive showed no obvious differences in anthropometric measurements and were taken as a non-response group. Weight, BMI, BMI%, waist circumference, hip circumference and blood pressure in the 139 children showed significant differences after the intervention compared with baseline values. Weight, BMI, BMI%, waist circumference, and hip circumference were positively correlated with both systolic and diastolic blood pressures; they were correlated more strongly with systolic pressure than with diastolic pressure.

CONCLUSIONS

Diet-oriented intervention can decrease blood pressure in most obese children with hypertension. Weight, height, BMI, BMI%, waist circumference, and hip circumference are closely associated with blood pressure.

Family history of diabetes, parental body mass index predict obesity in Latino children

PURPOSE

The purpose of this study is to examine the association between family history of diabetes (FHD), body mass index (BMI), and acculturation with children's BMI status.

METHODS

Baseline data from a randomized community intervention trial promoting healthy eating and physical activity were collected in children living in San Diego, California. A self-administered survey was completed by primary caregivers at each school assessing maternal diabetes, BMI, acculturation, and socioeconomic status (SES). Anthropometric data (height, weight, and BMI) from mothers and children were also collected.

RESULTS

A total of 812 caregivers completed the baseline survey. Adjusting for maternal age, marital status, and socioeconomic level, women who had been diagnosed with diabetes or gestational diabetes or who received diabetes treatment were significantly more likely to have overweight children. Maternal BMI was also associated with children's weight. Maternal acculturation level was marginally associated with children's BMI.

CONCLUSIONS

FHD, gestational diabetes, and BMI were associated with children's overweight status. More comprehensive interventions are needed to prevent obesity in Latino children and adults.

Screening of metabolic syndrome in obese children: a primary care concern

OBJECTIVE

To determine the prevalence of metabolic syndrome (MS) in a primary care pediatric setting and to collect clinical and biochemical data, allowing for a prediction of its presence in a supposedly healthy population.

METHODS

Belonging to a pediatric population followed by pediatricians of the Italian National Health Service, 415 subjects with obesity as a unique selection criterion were enrolled. The entire cohort was screened for MS, which was defined as the presence of at least 2 other findings out of obesity: fasting hyperglycemia, low levels of high-density lipoproteins cholesterol, hypertriglyceridemia, and hypertension.

RESULTS

The overall prevalence of MS was 30.8%. Major findings (out of obesity) were low high-density lipoproteins cholesterol levels (46.2%), hypertension (23.6%), hypertriglyceridemia (22.2%), and fasting hyperglycemia (16.6%). Waist-to-height ratio was the only clinical parameter directly related to MS, with the same predictive power of insulin resistance.

CONCLUSIONS

Metabolic syndrome can be present in a significant percentage of "healthy" obese children, and a simple clinical parameter could identify at-risk subjects. This observation justifies the development and implementation of pediatric networks for obesity screening programs.

Prevalence of the metabolic syndrome among obese adolescents enrolled in a multidisciplinary weight management program: clinical correlates and response to treatment

OBJECTIVE

The aim of this study was to determine the prevalence of the metabolic syndrome at baseline and after 6 months of lifestyle modification among obese adolescents referred to a multidisciplinary weight management program.

METHODS

A total of 165 obese adolescents were evaluated at baseline, and measurements were repeated in 57 subjects who completed 6 months of the program. Metabolic syndrome was defined as having three or more of the following: a body mass index (BMI) >97(th) percentile, hypertension, low high-density lipoprotein cholesterol (HDL-C), hypertriglyceridemia, and impaired fasting glucose (IFG).

RESULTS

The prevalence of a BMI >97(th) percentile, hypertension, hypertriglyceridemia, low HDL-C, and IFG was 92.7, 54.5, 29.1, 26.7, and 2.4%, respectively. The prevalence of the metabolic syndrome at baseline was 30.3%. After 6 months of lifestyle modification, BMI z scores, percent body fat, total cholesterol, and low-density lipoprotein cholesterol (LDL-C) decreased significantly from baseline; however, there was no significant change in the number of subjects demonstrating >or=three criteria of the metabolic syndrome.

CONCLUSIONS

Approximately one third of the study subjects met the criteria of the metabolic syndrome, emphasizing the growing concern for the future development of premature cardiovascular disease in this high-risk population. Our data suggest that new strategies for lifestyle modification may be needed to improve cardiovascular risk factors significantly among adolescents with obesity.