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

Obesity-Related Hypertension in Pediatrics, the Impact of American Academy of Pediatrics Guidelines

The prevalence of primary hypertension in pediatric patients is increasing, especially as a result of the increased prevalence of obesity in children. New diagnostic guidelines for blood pressure were published by the American Academy of Pediatrics (AAP) in 2017 to better define classes of hypertension in children. The aim of our study is to evaluate the impact of new guidelines on diagnosis of hypertension in pediatrics and their capacity to identify the presence of cardiovascular and metabolic risk. Methods: Retrospective clinical and laboratory data from 489 overweight and obese children and adolescents were reviewed. Children were classified according to the 2004 and 2017 AAP guidelines for systolic and diastolic blood pressure. Lipid profile and glucose metabolism data were recorded; triglyceride/HDL ratio (TG/HDL) was calculated as an index of endothelial dysfunction. Hepatic steatosis was detected using the ultrasonographic steatosis score. Results: Children with elevated blood pressure increased from 12.5% with the 2004 AAP to 23.1% with the 2017 AAP criteria (p < 0.001). There was a statistically significant increase in children with high blood pressure in all age groups according to the new cut-off values. Notably, the diagnosis of hypertension according to 2017 AAP criteria had a greater positive association with Hepatic Steatosis (rho 0.2, p < 0.001) and TG/HDL ratio (rho 0.125, p = 0.025). Conclusions: The 2017 AAP tables offer the opportunity to better identify overweight and obese children at risk for organ damage, allowing an earlier and more impactful prevention strategy to be designed.

Association of Serum Bilirubin Level with Metabolic Syndrome and Non-Alcoholic Fatty Liver Disease: A Cross-Sectional Study of 1672 Obese Children

As in adults, obesity also plays a central role in the development of metabolic syndrome (MS) in children. Non-alcoholic fatty liver disease (NAFLD) is considered a manifestation of MS. Not only MS but also NAFLD seem to be inversely associated with serum bilirubin concentrations, an important endogenous tissue protector when only mild elevated. The aim of the study was to evaluate the association between serum bilirubin levels and the prevalence of MS and NAFLD in Italian obese children and adolescents. A retrospective cross-sectional study was performed in 1672 patients aged from 5 to 18 years. Clinical and laboratory parameters were assessed. NAFLD was measured by liver ultrasonography. The study was approved by the Ethical Committee of the Istituto Auxologico Italiano (research project code 1C021_2020, acronym BILOB). MS was present in 24% and fatty liver (FL) in 38% of this population. Bilirubin was not associated with FL and MS as a whole, but it was inversely associated only with selected components of MS, i.e., large WC, high blood pressure and high triglycerides. Our data suggest that bilirubin is not protective against MS and NAFLD in the presence of severe obesity.

Methodological approach to the assessment of the obesogenic environment in children and adolescents: A review of the literature

AIMS

Childhood and adolescent obesity has been defined as a planetary epidemic by WHO "globesity". The obesogenic environment, defined as a life environment promoting a high-energy intake and a sedentary lifestyle, significantly contributes to the genesis and the diffusion of the globesity. In the last decades, several authors and working groups tried to develop methodological instruments in order to guarantee a reliable analysis of an obesogenic environment. Their efforts have led to the production of a relatively large number of questionnaires with different characteristics. The general aim of these questionnaires is to identify the factors that significantly contribute to the creation of an obesogenic environment around children and adolescents. As a result of this work, a number of studies were carried out using such questionnaires. Aim of this review is to evaluate ad hoc questionnaires useful to identify and analyze obesogenic environment.

DATA SYNTHESIS

The search was carried out in February-March 2017 using the PubMed-Medline and Scopus databases (time interval: the last 10 years). After the selection and verification phases, a total of 14 studies were selected and therefore included in the present review.

CONCLUSIONS

The questionnaires constructed and validated to analyze multiple constitutive elements of an obesogenic environment at the same time are complex and must be administered by qualified and trained staff. On the other hand, when two or more questionnaires are used to analyze different factors, the questionnaires used are generally shorter, self-administered, and generally easier to understand and interpret.

Usefulness of the Waist Circumference-to-Height Ratio in Screening for Obesity and Metabolic Syndrome among Korean Children and Adolescents: Korea National Health and Nutrition Examination Survey, 2010-2014

The aims of this study were to assess the diagnostic value of the weight-to-height ratio (WHtR) for the detection of obesity and metabolic syndrome (MS) in Korean children and adolescents, and to determine the advantages of WHtR as a population-based screening tool in comparison with other obesity indicators, such as body mass index (BMI) and waist circumference (WC). We performed a cross-sectional analysis of data from 3057 children and adolescents (1625 boys, 1332 girls) aged 10-19 years who were included in the fifth Korean National Health and Nutrition Examination Survey (KNHANES, 2010-2012) up to the second year of the sixth KNHANES (2013-2014). Receiver operation characteristic (ROC) curves were generated to determine the optimal cutoff value and accuracy of WHtR for predicting individual obesity indicators or more than two non-WC components of MS. The area under the ROC curve (AUC) is a measure of the diagnostic power of a test. A perfect test will have an AUC of 1.0, and an AUC equal to 0.5 means that the test performs no better than chance. The optimal WHtR cutoff for the evaluation of general obesity and central obesity was 0.50 in boys and 0.47-0.48 in girls, and the AUC was 0.9. Regarding the assessment of each MS risk factor, the optimal WHtR cutoff was 0.43-0.50 in boys and 0.43-0.49 in girls, and these cutoffs were statistically significant only for the detection of high triglyceride and low High-density lipoprotein (HDL) cholesterol levels. When a pairwise comparison of the AUCs was conducted between WHtR and BMI/WC percentiles to quantify the differences in power for MS screening, the WHtR AUC values (boys, 0.691; girls, 0.684) were higher than those of other indices; however, these differences were not statistically significant (boys, p = 0.467; girls, p = 0.51). The WHtR cutoff value was 0.44 (sensitivity, 67.7%; specificity, 64.6%) for boys and 0.43 (sensitivity, 66.4%; specificity, 66.9%) for girls. There was no significant difference between the diagnostic power of WHtR and that of BMI/WC when screening for MS. Although the use of WHtR was not superior, WHtR is still useful as a screening tool for metabolic problems related to obesity because of its convenience.

Waist-to-height ratio, body mass index and waist circumference for screening paediatric cardio-metabolic risk factors: a meta-analysis

Waist-to-height ratio (WHtR) is superior to body mass index and waist circumference for measuring adult cardio-metabolic risk factors. However, there is no meta-analysis to evaluate its discriminatory power in children and adolescents. A meta-analysis was conducted using multiple databases, including Embase and Medline. Studies were included that utilized receiver-operating characteristics curve analysis and published area under the receiver-operating characteristics curves (AUC) for adiposity indicators with hyperglycaemia, elevated blood pressure, dyslipidemia, metabolic syndrome and other cardio-metabolic outcomes. Thirty-four studies met the inclusion criteria. AUC values were extracted and pooled using a random-effects model and were weighted using the inverse variance method. The mean AUC values for each index were greater than 0.6 for most outcomes including hypertension. The values were the highest when screening for metabolic syndrome (AUC > 0.8). WHtR did not have significantly better screening power than other two indexes in most outcomes, except for elevated triglycerides when compared with body mass index and high metabolic risk score when compared with waist circumference. Although not being superior in discriminatory power, WHtR is convenient in terms of measurement and interpretation, which is advantageous in practice and allows for the quick identification of children with cardio-metabolic risk factors at an early age.

Metabolic syndrome, hepatic steatosis, and cardiovascular risk in children

OBJECTIVES

Pediatric metabolic syndrome (MetS) is a well-recognized entity; however, there is no consensus on its exact value in predicting long-term cardiovascular (CV) risk. Hepatic steatosis (HS) is another emerging condition associated with pediatric obesity, and data have been reported suggesting a possible role of HS in CV risk linked to MetS. The aim of the present study was to evaluate the usefulness of HS and MetS cluster in predicting CV risk linked to pediatric obesity.

METHODS

We studied 803 overweight and obese children (395 girls and 408 boys, mean age 9.4 ± 2.5 y, body mass index z-score 2.2 ± 0.53) with complete clinical and biological assessment. MetS was defined using the modified criteria of the American Heart Association. The diagnosis and severity of the HS was based on ultrasound. To assess CV risk, all patients underwent ultrasonography to measure carotid intima-media thickness (cIMT)-a validated marker of subclinical vascular disease.

RESULTS

The overall prevalence of MetS was 13.07%; HS was significantly higher in patients with MetS (40.9 versus 18.5%; P < 0.001; odds ratio, 3.059; 95% confidence interval, 1.98-4.7). Spearman's correlation between HS grade and the number of MetS criteria met by each patient was significant (r = 0.285; P < 0.001). No statistical difference was recorded in cIMT and cIMT z-scores between patients with or without MetS, until inclusion of HS as an additional criterion for the diagnosis of MetS. In this case, there was a significant difference in cIMT z-scores between the two groups. In multiple linear regression analysis, the cIMT z-score value was better predicted with HS grade and the MetS cluster (adjusted R² = 2.6%; P = 0.002) than when using the MetS cluster only.

CONCLUSIONS

HS could be used as additional criterion in detecting pediatric MetS phenotype at higher risk for long-term CV morbidity.

Dyslipidaemia in overweight children and adolescents is associated with an increased risk of kidney stones

AIM

There is conflicting evidence about the role of obesity in paediatric nephrolithiasis. This Polish study explored the influence of nutritional status and lipid disturbances on urinary lithogenic factors and the risk of kidney stone formation in children and adolescents from three to 18 years of age.

METHODS

We carried out serum lipid profile evaluations and 24-h urine chemistry analyses on 493 overweight/obese paediatric participants (mean age 13 years) without nephrolithiasis and 492 healthy normal weight sex and age-matched controls.

RESULTS

A third (33%) of the study group had blood lipid disturbances, with more acidic urine, lower urinary citrate excretion and a higher fraction of ionised calcium and higher Bonn Risk Index than the controls. The participants' body mass index standard deviation score (BMI Z-score) was positively correlated with urinary oxalate and uric acid and negatively correlated with citrate excretion. Total cholesterol, low-density lipoprotein cholesterol and triglycerides correlated negatively with citraturia, while high-density lipoprotein cholesterol correlated positively.

CONCLUSION

The main factor that predisposed overweight and obese children to kidney stones was hypocitraturia. Urinary citrate excretion was related to both BMI Z-scores and all lipid fraction abnormalities. However, hypercholesterolaemia and particularly low-density lipoprotein hypercholesterolaemia seemed to play a major role.

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.

Interleukin-6, soluble interleukin-6 receptor/interleukin-6 complex and insulin resistance in obese children and adolescents

BACKGROUND/AIM

To study the characteristics of interleukin 6 (IL6), soluble form of interleukin 6 receptor (sILR)/IL6 complex in obese children and adolescents and its relationship with insulin resistance (IR).

SUBJECTS AND METHODS

66 obese children and adolescents [34 boys, mean age 10.3 ± 2.9 years, z-score of body mass index (BMI) 4.76 ± 1.36] and 24 non-obese healthy sex- and age-matched controls. Fasting levels of glucose, insulin, IL6, sIL6, sgp130 were measured. IR was assessed by homeostasis model assessment of IR (HOMA-IR).

RESULTS

Obese subjects showed increased levels of insulin and IL-6 and higher HOMA-IR compared to controls (117.67 ± 50.9 vs. 62.42 ± 29.4 pmol/L, 2.73 ± 0.98 vs. 1.07 ± 0.41 pg/ml and 4.03 ± 2.16 vs. 1.83 ± 1.05 for insulin, IL-6 and HOMA-IR, respectively, p < 0.01 in all cases). sIL-6R levels were significantly lower in obese subjects (34.7 ± 14.2 vs. 55.6 ± 15.2 ng/ml in controls, p = 0.005), whereas sgp130 levels were not significantly different. In obese subjects, IL-6 directly correlated with z-score BMI (r = 0.481, p = 0.009) and with waist-to-height ratio (r = 0.494, p = 0.007), while sIL6-R was inversely related to HOMA-IR (r = -0.522, p = 0.002). Insulin resistant subjects showed higher levels of IL6 and lower levels of sIL6R (3.31 ± 0.72 vs. 2.25 ± 0.64 pg/ml, p = 0.020 and 25.3 ± 9.3 vs. 42.5 ± 10.4 ng/ml, p = 0.013, respectively).

CONCLUSIONS

In obese children and adolescents, IR is associated with elevated levels of IL-6 and diminished values of sIL-6R.

Metabolic syndrome and nephrolithiasis: a systematic review and meta-analysis of the scientific evidence

The metabolic syndrome is a cluster of cardiometabolic alterations at least partly dependent on reduced insulin sensitivity and hyperinsulinemia that can have several renal implications. A systematic review and meta-analysis of studies available in the international literature in English language demonstrates that the metabolic syndrome occurrence is associated with a significantly higher prevalence of nephrolithiasis (odds ratio 1.29, 95% confidence intervals: 1.11-1.51). The pathophysiological bases of this association are currently not completely understood, however. Potential pathogenetic links between the two conditions include metabolic factors that promote insulin resistance as well as stone formation in urine, environmental factors such as diet, oxidative stress and inflammation, and molecular changes impacting the transport of some analytes in urine. Metabolic syndrome-related nephrolithiasis shows peculiar clinical and biochemical characteristics and should be considered a multifactorial systemic disorder needing a multidisciplinary approach for adequate prevention and management in pediatric and adult age.

The changing profile of patients with calcium nephrolithiasis and the ascendancy of overweight and obesity: a comparison of two patient series observed 25 years apart

BACKGROUND

Epidemiological data indicate an increasing incidence and prevalence of nephrolithiasis (NL) worldwide in the last few decades.

METHODS

The aim of this study was to compare the clinical and biochemical profiles of recurrent stone formers referred to a Kidney Stone Centre from March 1983 to June 1986 with the one featured by patients seen 25 years later in the same geographical area, Campania, southern Italy.

RESULTS

Idiopathic calcium stone formers made up the large majority of the patient population in both series. Those examined in 2008-11 showed higher age at the onset of NL, higher prevalence of overweight/obesity and higher urinary excretion of oxalate and phosphate compared with those seen in 1983-86. The differences in the urinary biochemical variables remained significant upon accounting for age, gender, creatinine clearance and body mass index (BMI), and were not observed in patients with primary hyperparathyroidism enrolled in the same periods. A greater prevalence of uric acid stone formers was also observed in the 2008-11 population.

CONCLUSIONS

The massive epidemics of overweight/obesity and the substantial modifications of dietary habits over the last few decades in most Western countries may be the factors underlying the changing clinical and biochemical profiles of patients with recurrent NL.

Does body mass index accurately reflect body fat? A comparison of anthropometric measures in the longitudinal assessment of fat mass

OBJECTIVE

To determine which anthropometric measure best correlates with change in fat mass (FM) over time.

METHODS

The authors performed a retrospective cohort study of 76 obese patients (mean body mass index [BMI] 38 kg/m(2) and mean age 13 years) presenting to an obesity clinic between 2005 and 2010. For each patient, during 2 visits, FM was measured by bioelectrical impedance analysis and the following measures obtained: BMI, waist circumference, hip circumference, and neck circumference. Correlation coefficients and linear regression analyses were calculated to examine the relationship between each measure and FM.

RESULTS

Change in BMI correlated better with change in FM than any other measure and had the strongest effect on change in FM (P < .01, R (2) = .887). The best regression model included BMI only (R (2) = .891); without BMI, the model was significantly worse (R (2) = .521).

DISCUSSION

In the clinical management of obese children, BMI is an adequate measure of change in FM.

Metabolic syndrome in italian obese children and adolescents: stronger association with central fat depot than with insulin sensitivity and birth weight

Aim. To evaluate whether body fat distribution, birth weight, and family history for diabetes (FHD) were associated with metabolic syndrome (MetS) in children and adolescents. Methods. A total of 439 Italian obese children and adolescents (5–18 years) were enrolled. Subjects were divided into 2 groups: prepubertal and pubertal. MetS was diagnosed according to the adapted National Cholesterol Education Program criteria. Birth weight percentile, central obesity index (measured by dual-energy X-ray absorptiometry), insulin sensitivity (ISI), and disposition index were evaluated. Multivariate logistic regression models were used to determine variables associated with MetS. Results. The prevalence of MetS was 17%, with higher percentage in adolescents than in children (21 versus 12%). In the overall population, central obesity index was a stronger predictor of MetS than insulin sensitivity and low birth weight. When the two groups were considered, central fat depot remained the strongest predictor of MetS, with ISI similarly influencing the probability of MetS in the two groups and birth weight being negatively associated to MetS only in pubertal individuals. Neither FHD nor degree of fatness was a significant predictor of MetS. Conclusion. Simple clinical parameters like increased abdominal adiposity and low birth weight could be useful tools to identify European obese adolescents at risk for metabolic complications.

The FIMP Medicines for Children Research Network

The European Paediatric Regulation (EUPR) calls for the fostering of high quality ethical research and medicinal products to be used in children. The EUPR provides the background, goals, and requirements for paediatric clinical trials. Paediatric clinical trials in children are mandatory to generate data on new drugs as well as on drugs used off-label or for unlicensed indications. The Family Paediatricians Medicines for Children Research Network (FIMP-MCRN) was established in 2003 with the aim of developing competence, infrastructure, networking and education for paediatric clinical trials. The network, consisting of twenty Paediatric Regional Networks has progressed very well and has achieved valuable improvements concerning the conduct of paediatric clinical trials. Furthermore, ad hoc training programs have incremented knowledge about clinical trials in Family Paediatrician Investigators (FPI) and have made medical professionals as well as the public aware of the need and advantages of trials in children.