Correlation of abdominal fat accumulation and stiffness of the abdominal aorta in obese children

Visceral fat and cardiometabolic future in children and adolescents: a critical update

Cardiovascular disease (CVD) is a process whose pathogenetic mechanisms start very early in life. Recently, the importance of visceral adipose tissue (VAT) has been highlighted in the development of CVD. VAT does not always depend on body mass index (BMI) and has been implicated in unfavorable metabolic activity and cardiovascular adverse events. Abnormally high deposition of VAT is associated with metabolic syndrome, obesity-associated phenotype, and cardiometabolic risk factors. Although the importance of visceral fat has not been studied broadly or extensively in long-term studies in children and adolescents, it appears that it does not have the same behavior as in adults, it is related to the appearance of cardiac risk factors. In adolescents, it plays a role in the pathogenesis of CVD that occur later in adulthood. Excess body weight and adiposity may lead to the development of early myocardial and pathological coronary changes in childhood. The purpose of this review is to summarize the risk factors, the clinical significance, and the prognostic role of visceral obesity in children and adolescents. In addition, extensive reference is made to the most commonly used techniques for the evaluation of VAT in clinical settings. IMPACT: Visceral obesity, plays an important role in cardiovascular health from very early in an individual's life. Visceral adipose tissue (VAT) distribution is not entirely related to body mass index (BMI) and provides additional prognostic information. There is a need to pay more attention to the assessment of VAT in young people, to develop methods that would go beyond the measurement of only BMI in clinical practice and to identify individuals with excess visceral adiposity and perhaps to monitor its changes.

Exploratory Longitudinal Analysis of the Circulating CHIT1 Activity in Pediatric Patients with Obesity

Macrophage activation and cytokine release play a pivotal role in inflammation-mediated metabolic disturbances in obesity. The proinflammatory macrophage secretes human chitotriosidase (CHIT1). The expression of the CHIT1 in visceral adipose tissue is associated with cytokine production. Our study aimed to assess whether the CHIT1 circulating activity, as a macrophage activation indicator, reflects the change of the adiposity level and the insulin resistance (IR) in children with obesity. We longitudinally (median follow-up period of 7 months; IQR [5 to 8.5] and {2 to 13} months) evaluated the CHIT1 circulating activity, the adiposity level (waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WtHR), and body mass index (BMI)-for-age z score), and two surrogate markers of IR (Homeostatic Model Assessment for Insulin Resistance, HOMA-IR and the triglycerides-to-high density lipoprotein cholesterol ratio, TG/HDLc) in 29 pediatric patients (16 girls and 13 boys) with obesity. We found a significant reduction in CHIT1 circulating activity (Wilcoxon test, p = 0.015) and a decrease in TG/HDLc at the follow-up evaluation (Wilcoxon test, p < 0.001). Indicators of adiposity were positively correlated with HOMA-IR at baseline, among which WC was the sole indicator associated with HOMA-IR (Spearman’s rank correlation coefficients, p < 0.05) at follow-up. Human chitotriosidase has the potential to be a valuable measure of the progression of subclinical inflammation in children with obesity. Subclinical inflammation, as expressed by the circulating CHIT1 activity, progresses independently of the abdominal adiposity, as measured by the clinical indicators, and is associated with a change in insulin resistance.

Effects of different exercise types on visceral fat in young individuals with obesity aged 6-24 years old: A systematic review and meta-analysis

Introduction: The prevalence of pediatric obesity remains high all over the world. Various exercise interventions have been applied to decrease the visceral fat in young individuals with obesity. But the evidence remains controversial on the effect of the exercise on visceral fat. Moreover, it is unclear which type of the exercise is the most effective for young individuals with overweight or obesity to reduce visceral fat. Objective: The objective of this review and meta-analysis is to evaluate and compare the effectiveness of different exercise interventions on visceral fat in young individuals with overweight or obesity. Methods: Four databases consisting of PubMed, Web of Science, EBSCO, and Cochrane Library were searched prior to May 2022. Fifteen studies with a total of 30 data points involving 1,134 participants were included in this meta-analysis. And the interventions were limited to 4 exercise types [i.e., aerobic exercise (AE), resistance exercise (RE), aerobic exercise combined with resistance exercise (CE), and high-intensity interval training (HIIT)]. Data Synthesis: The results showed that AE (Standardized Mean Difference = -0.32; 95% CI = -0.50 to -0.13; p = 0.0007; I² = 37%) and HIIT (SMD = -0.59; 95% CI = -0.87 to -0.31; p < 0.0001; I² = 0%) had a significant reduction effect on visceral fat. And the effect of HIIT seemed better than AE. However, RE (SMD = -0.58; 95% CI = -1.34 to 0.17; p = 0.13; I² = 76%) and CE (SMD = -0.21; 95% CI = -0.81 to 0.38; p = 0.48; I² = 63%) had a non-significant effect on visceral fat decline. Additionally, compared with the control group, exercise interventions had a significant effect on reducing visceral fat in adolescents (SMD = -0.54; 95% CI = -0.82 to -0.26; p = 0.0001; I² = 64%) and young adults (SMD = -0.42; 95% CI = -0.69 to -0.15; p = 0.003; I² = 0%) rather than children (SMD = -0.15; 95% CI = -0.32 to 0.02; p = 0.08; I² = 0%). And the gender-based subgroup analysis indicated that the effectiveness of the exercise on the reduction of visceral fat was more significant in males (SMD = -1.27; 95% CI = -1.67 to -0.87; p < 0.00001; I² = 0%) than that in females (SMD = -0.31; 95% CI = -0.48 to -0.14; p = 0.0004; I² = 0%). Conclusion: This review and meta-analysis demonstrates that exercise interventions are efficient to decrease visceral fat in adolescents (12-18 years old) and young adults (18-24 years old). Among different exercise types, AE and HIIT are helpful for young individuals with overweight or obesity to reduce visceral fat and HIIT appears to be the most effective exercise intervention. In addition, the effect of exercise interventions on the consumption of visceral fat is more significant in males than that in females. Systematic Review Registration: [http://www.crd.york.ac.uk/PROSPERO], identifier [CRD42022310878].

Abdominal Fat Distribution Among Breastfed and Formula-Fed Infants

OBJECTIVES

To compare abdominal subcutaneous and preperitoneal fat thickness among breastfed, mixed-fed, and formula-fed infants during the first 6 months of life.

STUDY DESIGN

A cohort study started with 94 healthy newborns and 76 were followed during the whole first semester of life. Breastfeeding status was assessed by a personal interview. Abdominal subcutaneous and preperitoneal fat thickness was measured by ultrasound at the first, third, and sixth month of life.

RESULTS

Subcutaneous and preperitoneal fat thickness showed no differences from the first to the sixth month of life among breastfed, mixed-fed,s and formula-fed infants, respectively; subcutaneous: 26.1 ± 10.2 to 57.4 ± 10.3 cm, 27.7 ± 10.5 to 55.4 ± 1.4, and 28.1 ± 10.9 to 52.7 ± 10.6; p = 0.344; preperitoneal: 10.6 ± 2.0 to 15.2 ± 1.7, 10.3 ± 2.8 to 15.5 ± 1.7, and 9.7 ± 2.6 to 15.6 ± 1.6; p = 0.623). No differences were observed among male and female infants.

CONCLUSION

Abdominal fat distribution measured by ultrasound seems not to be different among breastfed and formula-fed infants during the first semester of life.

Investigating a Liver Fat

Objective—

To investigate the relationship between hepatic fat content, circulating triglyceride levels and aortic stiffness in adult and childhood obesity.

Approach and Results—

Seventy-seven adults and 18 children across a wide range of body mass index (18.5–52.6 kg/m 2 ; percentile 8–100) with no identifiable cardiac risk factors underwent; 1H- magnetic resonance spectroscopy to quantify hepatic fat content and magnetic resonance imaging to assess aortic pulse wave velocity (PWV) and regional distensibility. In adults, multivariable regression showed age (β=0.09; P =0.02), liver fat (β=2.5; P =0.04), and serum triglyceride (β=0.47; P =0.01) to be independent predictors of PWV. Age and blood pressure–adjusted, moderated regression showed that 43% of the total negative effect of hepatic fat on PWV is attributable to indirect effects via increased triglyceride ( P =0.005). In addition, regional distensibility was positively correlated with hepatic fat (ascending; r =−0.35; descending, r =−0.23; abdominal, r =−0.41; all P <0.001). Similar to that seen in adults, PWV ( r =0.72; P <0.001) and abdominal regional distensibility ( r =−0.52; P <0.001) were correlated with liver fat in children.

Conclusions—

Increasing age, liver fat, and triglyceride are all related to increased aortic stiffness in adults. Even when controlling for the effects of age and blood pressure, hepatic fat has a negative effect on PWV, with substantial indirect effect occurring via increased circulating triglyceride level. This relationship between hepatic fat and aortic stiffness occurs early in the obesity process and is also seen in children. As such, hepatic fat content is a potential therapeutic target to treat the elevated vascular risk in obesity.

Best single-slice location to measure visceral adipose tissue on paediatric CT scans and the relationship between anthropometric measurements, gender and VAT volume in children

OBJECTIVE

Visceral adipose tissue (VAT) is a significant risk factor for obesity-related metabolic diseases. This study investigates (1) the best single CT slice location for predicting total abdominal VAT volume in paediatrics and (2) the relationship between waist circumference (WC), sagittal diameter (SD), gender and VAT volume.

METHODS

A random sample of 130 paediatric abdomen CT scans, stratified according to age and gender, was collected. Three readers measured VAT area at each intervertebral level between T12 and S1 using ImageJ analysis (National Institute of Health, Bethesda, MD) software by thresholding -190 to -30 HU and manually segmenting VAT. Single-slice VAT measurements were correlated with total VAT volume to identify the most representative slice. WC and SD were measured at L3-L4 and L4-L5 slices, respectively. Regression analysis was used to evaluate WC, SD and gender as VAT volume predictors.

RESULTS

Interviewer and intraviewer reliability were excellent (intraclass correlation coefficient = 0.99). Although VAT measured at multiple slices correlated strongly with abdominal VAT, only one slice in females at L2-L3 and two slices in males at L1-L2 and L5-S1 were strongly correlated across all age groups. Linear regression analysis showed that WC was strongly correlated with VAT volume (beta = 0.970, p < 0.001).

CONCLUSION

Single-slice VAT measurements are highly reproducible. Measurements performed at L2-L3 in females and L1-L2 or L5-S1 in males were most representative of VAT. WC is indicative of VAT.

ADVANCES IN KNOWLEDGE

VAT should be measured at L2-L3 in female children and at either L1-L2 or L5-S1 in males. WC is a strong indicator of VAT in children.

Obesity and Arterial Stiffness in Children

Objective—

Childhood obesity is associated with risk factors for cardiovascular disease. Arterial stiffness is considered one of the earliest detectable measures of vascular damage. There is controversy in the literature regarding the effects of childhood obesity on arterial stiffness. The objective of this study is to systematically review the literature and to conduct a meta-analysis comparing measures of central arterial stiffness in children and adolescents with obesity to healthy body mass index controls.

Approach and Results—

Literature searches were conducted using databases (eg, MEDLINE, EMBASE) and citations cross-referenced. Studies assessing central pulse wave velocity or β-stiffness index were included. A random effects meta-analysis of the standardized mean difference and 95% confidence intervals in arterial stiffness between children with obesity and control children was performed for each arterial stiffness measure. A total of 523 studies were identified. Fifteen case–control studies were included, with 2237 children/adolescents (1281 with obesity, 956 healthy body mass index controls) between 5 and 24 years of age. All studies measuring carotid and aortic β-stiffness index and 10/12 studies measuring central pulse wave velocity reported greater arterial stiffness in children/adolescents with obesity compared with controls. A random effects meta-analysis was performed revealing a significant effect of obesity on pulse wave velocity (standardized mean difference=0.718; 95% confidence interval=0.291–1.415), carotid β-stiffness index (0.862; 0.323–1.402), and aortic β stiffness index (1.017; 0.419–1.615).

Conclusion—

These findings indicate that child/adolescent obesity is associated with greater arterial stiffness. However, further research is needed to address confounders, such as pubertal status, that may affect this relationship in children. In the future, these techniques may be useful in risk stratification and guiding clinical management of obese children to optimize cardiovascular outcomes.

Preperitoneal fat tissue may be associated with arterial stiffness in obese adolescents

Vascular aging is a chronic process, and many negative effects of obesity in this process have been well defined. We assessed arterial stiffness in obese adolescents and evaluated the relationship between intra-abdominal fat distribution and arterial stiffness. Arterial stiffness parameters and pulse wave velocity (PWV) were evaluated in 61 obese adolescents and 58 healthy controls. Carotid-femoral PWV was calculated by arterial tonometry. Additionally, all obese children were evaluated for metabolic syndrome and insulin resistance. Intra-abdominal fat distribution, including subcutaneous, preperitoneal and visceral fat thicknesses, was assessed by ultrasonography. PWVs of obese children were significantly higher than those of healthy controls (5.0 ± 0.7 m/s vs. 4.7 ± 0.5 m/s). Parameters affecting PWV were evaluated by regression analysis. The independent variable in the regression analysis model was PWV, and the dependent variables were age, metabolic syndrome, body mass index and Homeostasis Model Assessment--Insulin Resistance, as well as subcutaneous, preperitoneal and visceral fat tissue thicknesses measured by ultrasonography. The only parameter associated with PWV was preperitoneal fat tissue thickness. Vascular changes related to obesity may begin in adolescence, as illustrated by the increased PWV. Preperitoneal fat tissue may be related to arterial stiffness. Intra-abdominal fat distributions obtained by ultrasonography may provide clinicians with valuable information needed to determine cardiovascular disease risk factors in obese adolescents.

Effect of maternal obesity with and without gestational diabetes on offspring subcutaneous and preperitoneal adipose tissue development from birth up to year-1

Background

Maternal obesity and gestational diabetes mellitus (GDM) may independently influence offspring fat mass and metabolic disease susceptibility. In this pilot study, body composition and fat distribution in offspring from obese women with and without GDM and lean women were assessed within the 1st year of life, and maternal and newborn plasma factors were related to offspring adipose tissue distribution.

Methods

Serum and plasma samples from pregnant obese women with (n = 16) or without (n = 13) GDM and normoglycemic lean women (n = 15) at 3rd trimester and offspring cord plasma were used for analyzing lipid profiles, insulin and adipokine levels. At week-1 and 6, month-4 and year-1, offspring anthropometrics and skinfold thickness (SFT) were measured and abdominal subcutaneous (SCA) and preperitoneal adipose tissue (PPA) were determined by ultrasonography.

Results

Cord insulin was significantly increased in the GDM group, whereas levels of cord leptin, total and high molecular weight (HMW) adiponectin were similar between the groups. Neonates of the GDM group showed significantly higher SFT and fat mass until week-6 and significantly increased SCA at week-1 compared to the lean group that persisted as strong trend at week-6. Interestingly, PPA in neonates of the GDM group was significantly elevated at week-1 compared to both the lean and obese group. At month-4 and year-1, significant differences in adipose tissue growth between the groups were not observed. Multiple linear regression analyses revealed that cord insulin levels are independently related to neonatal PPA that showed significant relation to PPA development at year-1. Maternal fasted C-peptide and HMW adiponectin levels at 3rd trimester emerged to be determinants for PPA at week-1.

Conclusion

Maternal pregravid obesity combined with GDM leads to newborn hyperinsulinemia and increased offspring fat mass until week-6, whereas pregravid obesity without GDM does not. This strongly suggests the pivotal role of GDM in the adverse offspring outcome. Maternal C-peptide and HMW adiponectin levels in pregnancy emerge to be predictive for elevated PPA in newborns and might be indicative for the obesity risk at later life. Altogether, the findings from our pilot study warrant evaluation in long-term studies.

Trial registration

German Clinical Trials Register DRKS00004370

Central adiposity and protein intake are associated with arterial stiffness in overweight children

Being overweight is associated with vascular abnormalities, which are important in the development of atherosclerosis. However, little is known about dietary and lifestyle determinants of vascular function in overweight children. In adults, dietary protein and milk intake are associated with reduced blood pressure and reduced risk of metabolic syndrome. This study examined the associations between dietary protein, milk intake, physical activity, and adiposity on arterial stiffness in overweight children. In a cross-sectional study, overweight children with habitual milk intakes ≤ 250 mL/d were examined by DXA scans, pedometer counts, anthropometry, and metabolic variables. Dietary intake was registered for 4 d. The outcomes were arterial stiffness measured by pulse wave velocity (PWV) (n = 182) and augmentation index (Aix) (n = 183). The PWV (mean ± SD) was 4.78 ± 0.72 m/s and the Aix was -0.77 ± 9.44%. In multivariate models, the android fat:gynoid fat and android fat:body fat ratios were positively associated with PWV (β = 1.49 and β = 10.3, both P < 0.05) and Aix (β = 28.3, P < 0.01 and β = 153, P < 0.05), whereas the gynoid fat:body fat ratio was negatively associated with the Aix (β = -134; P < 0.001). Protein intake (percentage energy) was positively associated with PWV (β = 0.05; P < 0.01). Milk intake (L/d) tended to be negatively associated with PWV (β = -0.64; P = 0.05). Pedometer counts were negatively associated with the Aix; however, the association became nonsignificant after controlling for HOMA, which was positively associated with the Aix (β = 0.95; P < 0.01). In conclusion, central adiposity and protein intake are associated with increased arterial stiffness measured as PWV in overweight children independent of blood pressure and heart rate. The effect of protein intake may be caused by meat, because the milk intake was low.

Morphological and functional vascular changes induced by childhood obesity

BACKGROUND

To investigate endothelial dysfunction and morphological vascular changes in childhood obesity.

METHODS

93 overweight/obese children (body mass index 26 ± 5 kg/m(2); median 26 kg/m(2); interquartile range 22-28 kg/m(2)), mean age 10.9 ± 2.7 years, underwent a check-up of total, high-density lipoprotein- and low-density lipoprotein-cholesterol, triglycerides, C-reactive protein, erythrocyte sedimentation rate, and white blood cell count, together with ultrasound measures of flow-mediated dilatation, carotid intima-media thickness, and anterior-posterior diameter of the abdominal aorta.

RESULTS

The body mass index of overweight/obese children had a statistically significant linear relationship (p < 0.05) with triglycerides, erythrocyte sedimentation rate, carotid intima-media thickness, anterior-posterior diameter of the abdominal aorta, and flow-mediated dilatation values.

CONCLUSIONS

Overweight/obese children have an initial endothelial dysfunction and vascular damage, i.e., the first stage in the development of atherosclerosis.

Wall motion velocities of ascending aorta measured by tissue Doppler imaging in obese children

BACKGROUND

Obesity is associated with the development of early cardiovascular abnormalities such as atherosclerotic lesions. Arterial stiffness may be an indicator of early vascular changes signaling the development of vascular disease. The objective of the current study was to screen aortic elastic properties with tissue Doppler imaging in obese children.

METHODS

We examined 37 obese children and 30 age- and sex-matched normal subjects. Anthropometric measurements and metabolic risk profile were assessed in a physical examination and with blood taking. The subjects were divided into two subgroups: those with and without metabolic syndrome. Internal aortic systolic and diastolic diameters by M-mode echocardiography and aortic systolic upper-wall tissue velocity by tissue Doppler imaging were measured 3 cm above the aortic valve. Aortic distensibility and aortic stiffness index were calculated using accepted formulae.

RESULTS

Aortic stiffness parameters and both tissue Doppler peak systolic and diastolic velocities differed significantly in obese children compared to controls. Among the subgroups, children with metabolic syndrome had a lower aortic stiffness index, aortic distensibility and tissue Doppler velocities. However, only peak diastolic velocities significantly differed between obese children without metabolic syndrome and controls. Homeostatic model scores, diastolic blood pressures and pulse pressures were the strongest to correlate with peak diastolic velocity (r=-0.88, P < 0.001, r=-0.62, P= 0.001 and, r= 0.55, P= 0.001, respectively).

CONCLUSIONS

Tissue Doppler imaging is a feasible and sensitive method to identify aortic stiffness in obese children. Reduced aortic diastolic velocity is the most prominent early vascular change detected in obese children before metabolic syndrome occurs.

Visceral adipose tissue in children and adolescents: a review

Research conducted among adults has mainly shown that visceral adipose tissue (VAT) is strongly linked to insulin resistance, type 2 diabetes, hypertension and dyslipidaemia, leading to increased risk of CVD or the metabolic syndrome. However, little is known about the aetiology, determinants and consequences of VAT in children. The present article reviews the current literature relating to the factors influencing visceral fat accumulation in children and adolescents. The literature used in the present study was collected by searching a PubMed database, in which studies up to 2008 exploring the factors influencing accumulation of visceral fat among children and youth were found on the basis of appropriate keywords. Further studies concerning different factors influencing deposition of VAT among children and youth should first of all concentrate on: carrying out long-term analyses among children of different ethnical groups, which should begin in the period of prepuberty and which should cover the whole period of puberty till adulthood; drawing up norms specifying the amount of VAT among healthy children; identification of anthropometric indicators which will help to determine the VAT:subcutaneous adipose tissue ratio in the most precise way; broader studies of the influence of eating habits on developing VAT deposit among children and youth.

Metabolic syndrome in the pediatric population: a short overview

The metabolic syndrome (MS) in adults is defined as a concurrence of obesity, disturbed glucose and insulin metabolism, hypertension and dyslipidemia, and is associated with increased morbidity and mortality from cardiovascular diseases and type 2 diabetes. Studies now indicate that many of its components are also present in children and adolescents. Moreover, the clustering of these risk factors has been documented in some children, who are at increased cardiovascular risk in adulthood. The MS is highly prevalent among overweight children and adolescents. Identifying these children is important for early prevention and treatment of different components of the syndrome. The first-line treatment comprises lifestyle modification consisting of diet and exercise. The most effective tool for prevention of the MS is to stop the development of childhood obesity. The first attempt at consensus-based pediatric diagnostic criteria was published in 2007 by the International Diabetes Federation. Nevertheless, national prevalence data, based on uniform pediatric definition, protocols for prevention, early recognition and effective treatment of pediatric MS are still needed.The aim of this article is to provide a short overview of the diagnosis and treatment options of childhood MS, as well as to present the relationships between MS and its individual components.