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

Quantitative computed tomography analysis of body composition changes in paediatric patients with acute lymphoblastic leukaemia

Children with acute lymphoblastic leukaemia (ALL) are at risk for obesity and cardiometabolic diseases. To gain insight into body composition changes among children with ALL, we assessed quantitative computed tomography (QCT) data for specific body compartments (subcutaneous adipose tissue [SAT], visceral adipose tissue [VAT], total adipose tissue [TAT], lean tissue [LT], LT/TAT and VAT/SAT at lumbar vertebrae L1 and L2) at diagnosis and at off-therapy for 189 children with ALL and evaluated associations between body mass index (BMI) Z-score and clinical characteristics. BMI Z-score correlated positively with SAT, VAT and TAT and negatively with LT/TAT and VAT/SAT. At off-therapy, BMI Z-score, SAT, VAT and TAT values were higher than at diagnosis, but LT, LT/TAT and VAT/SAT were lower. Patients aged ≥10 years at diagnosis had higher SAT, VAT and TAT and lower LT and LT/TAT than patients aged 2.0-9.9 years. Female patients had lower LT and LT/TAT than male patients. Black patients had less VAT than White patients. QCT analysis showed increases in adipose tissue and decreases in LT during ALL therapy when BMI Z-scores increased. Early dietary and physical therapy interventions should be considered, particularly for patients at risk for obesity.

Simple anthropometric measures to predict visceral adipose tissue area in middle-aged Indonesian men

The diagnosing of central obesity requires ethnic-specific cut-offs of waist circumference (WC) and body mass index (BMI). This study aims to develop formulas to predict visceral adipose tissue (VAT) area based on WC and BMI to determine the cut-off points of central obesity in Indonesia. We conducted a cross-sectional study among 32 middle-aged Indonesian men. VAT area was measured using an abdominal CT scan, whereas WC and BMI were assessed through anthropometric measurements. Linear regression analysis was performed to define the formulas to predict VAT area using WC and BMI. Next, the optimal cut-off values of WC and BMI were determined using ROC curve analysis. Strong positive correlations were found between WC and VAT as well as BMI and VAT (r = 0.78; r = 0.67, p <0.001). The formula to predict VAT area from WC was -182.65 + (3.35 × WC), whereas the formula to predict VAT area from BMI was -57.22 + (6.95 × BMI). These formulas predicted WC of 88.5 cm and BMI of 23.9 kg/m2 as the optimal cut-off values for central obesity in middle-aged Indonesian men.

Diagnostic accuracy of anthropometric indices for discriminating elevated blood pressure in pediatric population: a systematic review and a meta-analysis

BACKGROUND

Childhood obesity is more likely to increase the chance of many adult health problems. Numerous studies have shown obese children to be more prone to elevated blood pressure (BP) and hypertension. It is important to identify an obesity anthropometric index with good discriminatory power for them in pediatric population.

METHODS

MEDLINE/PubMed, Web of Science, and Cochrane databases were retrieved comprehensively for eligible studies on childhood obesity and hypertension/elevated BP through June 2021. The systematic review and meta-analysis of studies used receiver operating characteristics (ROC) curves for evaluating the discriminatory power of body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) in distinguishing children with elevated BP and hypertension.

RESULTS

21 cross-sectional studies involving 177,943 children and 3-19 years of age were included in our study. Meta-analysis showed that the pooled area under the reporting receiver-operating characteristic curves (AUC) and 95% confidence intervals (CIs) for BMI, WC, and WHtR to detect hypertension of boys were 0.68 (0.64, 0.72), 0.69 (0.64, 0.74), 0.67 (0.63, 0.71), for elevated BP, the pooled AUCs and 95% CIs were 0.67 (0.61, 0.73), 0.65 (0.58, 0.73), 0.65 (0.61, 0.71). The pooled AUCs and 95% CIs for BMI, WC and WHtR of predicting hypertension were 0.70 (0.66, 0.75), 0.69 (0.64, 0.75), 0.67 (0.63, 0.72) in girls, the pooled AUCs and 95% CIs of predicting elevated BP were 0.63 (0.61, 0.65), 0.62 (0.60, 0.65), 0.62 (0.60, 0.64) respectively. There was no anthropometric index was statistically superior in identifying hypertension and elevated BP, however, the accuracy of BMI predicting hypertension was significantly higher than elevated BP in girls (P < 0.05). The subgroup analysis for the comparison of BMI, WC and WHtR was performed, no significant difference in predicting hypertension and elevated BP in pediatric population.

CONCLUSIONS

This systematic review showed that no anthropometric index was superior in identifying hypertension and elevated BP in pediatric population. While compared with predicting elevated BP, all the indicators showed superiority in predicting hypertension in children, the difference was especially obvious in girls. A better anthropometric index should be explored to predict children's early blood pressure abnormalities.

Waist circumference and waist-to-height ratio in 7-year-old children-WHO Childhood Obesity Surveillance Initiative

Childhood obesity is a serious global health problem. Waist circumference (WC) and waist-to-height ratio (WHtR) reflect body fat distribution in children. The objectives of this study were to assess WC and WHtR in 7-year-old children and to determine body mass index (BMI), WC, and WHtR differences in children from 10 selected countries across Europe (Bulgaria, Czechia, Greece, Ireland, Latvia, Lithuania, North Macedonia, Norway, Spain, and Sweden) participating in the World Health Organization (WHO) Europe Childhood Obesity Surveillance Initiative (COSI). The 50th and 90th percentile of WC (according to COSI and "Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS" (IDEFICS) cutoff values) and WHtR above 0.5 were used as measures of abdominal obesity in a unique sample of 38,975 children aged 7.00-7.99 years. Southern European countries, including Greece and Spain, showed significantly higher BMI, WC, and WHtRin both genders (p < 0.0001) than Eastern and Northern Europe. The highest values for WC were observed in Greece (60.8 ± 7.36 cm boys; 60.3 ± 7.48 cm girls), North Macedonia (60.4 ± 7.91 cm boys; 59.0 ± 8.01 cm girls), and Spain (59.7 ± 6.96 cm boys; 58.9 ± 6.77 cm girls). WC and WHtRin may add an information about the occurrence of central obesity in children.

MRI-Derived Subcutaneous and Visceral Adipose Tissue Reference Values for Children Aged 6 to Under 18 Years

The assessment of body composition in pediatric population is essential for proper nutritional support during hospitalization. However, currently available methods have limitations. This study aims to propose a novel approach for nutrition status assessment and introduce magnetic resonance imaging (MRI)-derived subcutaneous and visceral fat normative reference values. A total of 262 healthy subjects aged from 6 to 18 years underwent MRI examinations and anthropometric measurements. MRI images at the second lumbar vertebrae were used by two radiologists to perform the semi-automatic tissue segmentation. Based on obtained adipose tissue surface areas and body mass index (BMI) scores sex-specific standard percentile curves (3rd, 10th, 25th, 50th, 75th, 90th, 97th) and z-scores were constructed using LMS method. Additionally, 85th and 95th centiles of subcutaneous and visceral adipose tissue were proposed as equivalents of overweight and obesity. Bland-Altman plots revealed an excellent intra-observer reproducibility and inter-observer agreement. In conclusion, our findings demonstrate highly reproducible method and suggest that MRI-derived reference values can be implemented in clinical practice.

A random forest model predicts responses to infliximab in Crohn's disease based on clinical and serological parameters

BACKGROUND

Infliximab (IFX) has revolutionised the treatment for Crohn's disease (CD) recently, while a part of patients show no response to it at the end of the induction period. We developed a random forest-based prediction tool to predict the response to IFX in CD patients.

METHODS

This observational study retrospectively enrolled the patients diagnosed with active CD and received IFX treatment at the Gastroenterology Department in Xiangya Hospital of Central South University between January 2017 and December 2019. The baseline data were recorded in the beginning and were used as predictor variables to construct models to forecast the outcome of the response to IFX.

RESULTS

Our cohort identified a total of 174 patients finally with a response rate of 29.3% (51/174). The area under the receiver operating characteristic curve (AUC) for the model, based on the random forest was 0.90 (95%CI: 0.82-0.98), compared to the logistic regression model with AUC of 0.68 (95%CI: 0.52-0.85). The optimal cut-off value of the random forest model was 0.34 with the specificity of 0.94, the sensitivity of 0.81 and the accuracy of 0.85. We demonstrated a strong association of IFX response with the levels of complement C3 (C3), high density lipoprotein, serum albumin, Controlling Nutritional Status (CONUT) score and visceral fat area/subcutaneous fat area ratio (VSR).

CONCLUSION

A novel random forest model using the clinical and serological parameters of baseline data was established to identify CD patients with baseline inflammation to achieve IFX response. This model could be valuable for physicians, patients and insurers, which allows individualised therapy.

Evaluation of Ethnic Variations in Visceral, Subcutaneous, Intra-Pancreatic, and Intra-Hepatic Fat Depositions by Magnetic Resonance Imaging among New Zealanders

Anthropometric indices, such as body mass index (BMI), waist circumference (WC), and waist to height ratio (WHtR), have limitations in accurately predicting the pathophysiology of diabetes mellitus, cardiovascular diseases, and metabolic syndrome due to ethnic differences in fat distribution. Recent studies showed that the visceral adipose tissue (VAT) deposition and fat content of internal organs, most notably intra-hepatic and intra-pancreatic fat, has emerged as a more important parameter. In this study, we aimed to assess the coordination between the traditional anthropometric indices and the various fat depositions within different ethnicities in New Zealand. We recruited 104 participants with different ethnic backgrounds, including New Zealand Europeans, Māori (the indigenous people of New Zealand), Pacific Islanders (PI), and Asians. Their weight, height, and WC were measured, and subcutaneous, visceral, intra-hepatic, and intra-pancreatic fat depositions were obtained by magnetic resonance imaging (MRI). The result showed VAT, but not subcutaneous adipose tissue (SAT) depositions at all levels were significantly varied among the three groups. BMI was associated best with L23SAT in NZ Europeans (30%) and L45VAT in Māori/PI (24.3%). WC and WHtR were correlated well with L45SAT in the total population (18.8% and 12.2%, respectively). Intra-pancreatic fat deposition had a positive Pearson relationship with NZ European BMI and Māori/PI WC, but no regression correlation with anthropometric indices. Conventional anthropometric indices did not correspond to the same fat depositions across different ethnic groups.

Added values of DXA-derived visceral adipose tissue to discriminate cardiometabolic risks in pre-pubertal children

BACKGROUND

The new generation of dual energy X-ray absorptiometry (DXA) scanners provide visceral adipose tissue (VAT) estimates by applying different algorithms to the conventional DXA-derived fat parameters such as total fat, trunk fat and android fat for the same image data.

OBJECTIVE

This cross-sectional study aimed to investigate whether VAT estimates from Hologic scanners are better predictors of VAT than conventional DXA parameters in pre-pubertal children, and to explore the discrimination ability of these VAT methods for cardiometabolic risks.

METHODS

Healthy pre-pubertal children aged 7-10 years were recruited for basic anthropometric, DXA and magnetic resonance imaging (MRI) measurements. Laboratory tests included lipid profile, glycaemic tests and blood pressure.

RESULTS

All VAT methods had acceptable to excellent performance for the diagnosis of dyslipidaemia (area under the curve [AUC] = 0.753-0.837) and hypertensive risk (AUC = 0.710-0.821) in boys, but suboptimal performance for these risks in girls, except for VAT by MRI in the diagnosis of dyslipidaemia. In both sexes, all VAT methods had no or poor discrimination ability for diabetes risk.

CONCLUSIONS

DXA-derived VAT estimates are very highly correlated with standard methods but has equivalent discrimination abilities compared to the existing DXA-derived fat estimates.

Alternative waist-to-height ratios associated with risk biomarkers in youth with diabetes: comparative models in the SEARCH for Diabetes in Youth Study

BACKGROUND/OBJECTIVES

The waist-to-height ratio (WHtR) estimates cardiometabolic risk in youth without need for growth charts by sex and age. Questions remain about whether waist circumference measured per protocol of the National Health and Nutrition Examination Survey (WNHAHtR) or World Health Organization (WWHOHtR) can better predict blood pressures and lipid parameters in youth.

PARTICIPANTS/METHODS

WHtR was measured under both anthropometric protocols among participants in the SEARCH Study, who were recently diagnosed with diabetes (ages 5-19 years; N = 2 773). Biomarkers were documented concurrently with baseline anthropometry and again ~7 years later (ages 10-30 years; N = 1 712). For prediction of continuous biomarker outcomes, baseline WNHAHtR or WWHOHtR entered semiparametric regression models employing restricted cubic splines. To predict binary biomarkers (high-risk group defined as the most adverse quartile) linear WNHAHtR or WWHOHtR terms entered logistic models. Model covariates included demographic characteristics, pertinent medication use, and (for prospective predictions) the follow-up time since baseline. We used measures of model fit, including the adjusted-R2 and the area under the receiver operator curves (AUC) to compare WNHAHtR and WWHOHtR.

RESULTS

For the concurrent biomarkers, the proportion of variation in each outcome explained by full regression models ranged from 23 to 46%; for the prospective biomarkers, the proportions varied from 11 to 30%. Nonlinear relationships were recognized with the lipid outcomes, both at baseline and at follow-up. In full logistic models, the AUCs ranged from 0.75 (diastolic pressure) to 0.85 (systolic pressure) at baseline, and from 0.69 (triglycerides) to 0.78 (systolic pressure) at the prospective follow-up. To predict baseline elevations of the triglycerides/HDL cholesterol ratio, the AUC was 0.816 for WWHOHtR compared with 0.810 for WNHAHtR (p = 0.003), but otherwise comparisons between alternative WHtR protocols were not significantly different.

CONCLUSIONS

Among youth with recently diagnosed diabetes, measurements of WHtR by either waist circumference protocol similarly helped estimate current and prospective cardiometabolic risk biomarkers.

Validation of a DIXON-based fat quantification technique for the measurement of visceral fat using a CT-based reference standard

PURPOSE

The purpose of the study is to determine whether a novel semi-automated DIXON-based fat quantification algorithm can reliably quantify visceral fat using a CT-based reference standard.

METHODS

This was an IRB-approved retrospective cohort study of 27 subjects who underwent abdominopelvic CT within 7 days of proton density fat fraction (PDFF) mapping on a 1.5T MRI. Cross-sectional visceral fat area per slice (cm²) was measured in blinded fashion in each modality at intervertebral disc levels from T12 to L4. CT estimates were obtained using a previously published semi-automated computational image processing system that sums pixels with attenuation - 205 to - 51 HU. MR estimates were obtained using two novel semi-automated DIXON-based fat quantification algorithms that measure visceral fat area by spatially regularizing non-uniform fat-only signal intensity or de-speckling PDFF 2D images and summing pixels with PDFF ≥ 50%. Pearson's correlations and Bland-Altman analyses were performed.

RESULTS

Visceral fat area per slice ranged from 9.2 to 429.8 cm² for MR and from 1.6 to 405.5 cm² for CT. There was a strong correlation between CT and MR methods in measured visceral fat area across all studied vertebral body levels (r = 0.97; n = 101 observations); the least (r = 0.93) correlation was at T12. Bland-Altman analysis revealed a bias of 31.7 cm² (95% CI [- 27.1]-90.4 cm²), indicating modestly higher visceral fat assessed by MR.

CONCLUSION

MR- and CT-based visceral fat quantification are highly correlated and have good cross-modality reliability, indicating that visceral fat quantification by either method can yield a stable and reliable biomarker.

Decreased Expression of Prox1 Is Associated With Postoperative Recurrence in Crohn's Disease

BACKGROUND

Prox1 is a transcription factor necessary for lymphangiogenesis and lymphatic function. The aim of the study was to assess the correlation between the expression of Prox1 and postoperative recurrence in Crohn's disease [CD].

METHODS

Forty CD patients who underwent ileo-colonic resection were included. Expression levels of Prox1 and D2-40 were detected using immunohistochemistry. Expression levels of Prox1, VEGFR3, and VEGFC protein were also detected in fresh CD specimens using western blotting and quantitative polymerase chain reaction [Q-PCR]. Endoscopic recurrence was used as the endpoint. Patients comprised two groups: endoscopic recurrence [Group R+] and no endoscopic recurrence [Group R-].

RESULTS

Prox1 protein expression was significantly higher in CD than in normal tissues [p <0.05], as detected using both immunohistochemistry and western blotting. Analysis of inter-relationships revealed significant correlation between Prox1 expression and lymphatic vessel density [p <0.001, r = 0.823]. There was also significant correlation between Prox1 expression and the visceral fat area [VFA] [p = 0.002, r = -0.469]. The Group R- patients had significantly higher Prox1 expression than the Group R+ patients [21.08 ± 1.61 versus 15.64 ± 1.17, p = 0.011]. Also, the lymphatic vessel density value was lower in Group R+ than in Group R- patients [6.02 ± 0.39 versus 8.13 ± 0.59, p = 0.004]. Moreover, there was a significant difference in the VFA between Group R- and Group R+ patients [64.43 ± 7.76 versus 90.44 ± 6.11, p = 0.016]. In addition to Prox1, VEGFC/VEGFR3 was found to increase, which was further confirmed using Q-PCR.

CONCLUSIONS

Prox1 expression could be useful as a protective factor against recurrence in CD patients. The therapeutic role of Prox1 may lead to improved treatments.

Estimation of visceral fat in 9- to 13-year-old girls using dual-energy X-ray absorptiometry (DXA) and anthropometry

OBJECTIVES

Accumulation of visceral fat (VF) in children increases the risk of cardiovascular disease and type 2 diabetes, and measurement of VF in children using computed tomography and magnetic resonance imaging (MRI) is expensive. Dual-energy X-ray absorptiometry (DXA) may provide a low-cost alternative. This study aims to determine if DXA VF estimates can accurately estimate VF in young girls, determine if adding anthropometry would improve the estimate and determine if other DXA fat measures, with and without anthropometry, could be used to estimate VF in young girls.

METHODS

Visceral fat was measured at lumbar intervertebral sites (L1-L2, L2-L3, L3-L4 and L4-L5) using 3.0T MRI on 32 young girls (mean age 11.3 ± 1.3 years). VF was estimated using the GE CoreScan application. Measurement of DXA android and total body fat was performed. Weight, height and waist circumference (WC) measurements were also obtained.

RESULTS

Waist circumference and body mass index were both strongly correlated with MRI, although WC was the best anthropometric covariate. Per cent fat (%fat) variables had the strongest correlation and did best in regression models. DXA %VF (GE CoreScan) and DXA android %fat and total body %fat accounted for 65% to 74% of the variation in MRI VF.

CONCLUSION

Waist circumference predicted MRI VF almost as well as DXA estimates in this population, and a combination of WC and DXA fat improves the predictability of VF. DXA VF estimate was improved by the addition of WC; however, DXA android %fat with WC was better at predicting MRI VF.

Visceral Fat Is Associated With Mucosal Healing of Infliximab Treatment in Crohn's Disease

BACKGROUND

Visceral fat is the pathogenesis of Crohn's disease and is associated with disease status.

OBJECTIVE

This study aimed to evaluate the effect of the visceral fat on mucosal healing in patients with Crohn's disease after infliximab induction therapy DESIGN:: This was a retrospective study.

SETTINGS

The study was conducted in a tertiary referral hospital.

PATIENTS

Between 2011 and 2017, 97 patients with Crohn's disease with the presence of ulcers underwent infliximab therapy.

MAIN OUTCOME MEASURES

We studied them retrospectively. Mucosal healing was the end point. Patients composed 2 groups: mucosal healing and no mucosal healing. Univariate, multivariate, and receiver operating characteristic curve analyses determined the predictive value of the visceral fat area.

RESULTS

Univariate analysis showed a statistically significant difference in the smoking history between the groups. Mucosal healing rates after infliximab were lower among active smokers (p = 0.022). Healed patients had significantly less visceral fat area before therapy (47.76 ± 4.94 vs 75.88 ± 5.55; p = 0.000) and a lower mesenteric fat index (0.52 ± 0.04 vs 0.89 ± 0.07; p = 0.000). There was no significant difference in the subcutaneous fat area (87.39 ± 5.01 vs 93.31 ± 6.95; p = 0.500). Multivariate analysis showed that only visceral fat area (OR = 0.978 (95% CI, 0.964-0.992); p = 0.002) and smoking history (OR = 0.305 (95% CI, 0.089-0.996); p = 0.041) were independent factors for mucosal healing. Receiver operating characteristic curve analysis showed predictive cutoff values of 61.5 cm and 0.62 for visceral fat area and mesenteric fat index.

LIMITATIONS

This was a retrospective study.

CONCLUSIONS

There was an association between increased visceral fat area and attenuated mucosal healing after infliximab therapy in biologically naive patients with Crohn's disease, indicating a need for earlier increased infliximab doses among patients with increased visceral fat. See Video Abstract at http://links.lww.com/DCR/A590.

Abdominal Visceral Fat Area and Chronic Pouchitis after Ileal Pouch-Anal Anastomosis

Chronic pouchitis (CP) after ileal pouch-anal anastomosis is a significant clinical problem. Adipose tissues produce antiinflammatory cytokines and chemokines. We evaluated the association between abdominal visceral fat area (VFA) and CP. Patients with a preoperative CT evaluation were included. The diagnosis of CP was confirmed in all cases by endoscopy with afferent ileal limb intubation. Patients were allocated into groups of high VFA and low VFA. The study cohort of 52 patients had a median body mass index of 22 (range, 14–32). Indications for surgery were medically refractory disease in 46 (88%) patients and cancer/dysplasia in six (12%) patients. Median VFA was 27.1 (range, 1–144). Six (12%) patients developed CP. Low VFA patients were significantly younger (29 vs 45 years; P < 0.0001), had lower body mass index (20.4 vs 24.7; P < 0.0001), had surgery more commonly for medically refractory disease than for cancer or dysplasia (100 vs 77%; P = 0.02), and had a higher incidence of CP than high VFA patients (23 vs 0%; P = 0.02). Multiple linear regression analysis demonstrated that only low VFA was associated with CP (P = 0.009). An association is present between VFA and CP after ileal pouch-anal anastomosis, implicating adipocytes in the pathogenesis of inflammatory bowel disease.

Performance of obesity indices for screening elevated blood pressure in pediatric population: Systematic review and meta-analysis

BACKGROUND

Hypertension is closely related with obesity in pediatric population. Obesity indices were used for screening elevated blood pressure (BP) in children and adolescents. The present study was to perform a meta-analysis to assess the performance of obesity indices, body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR), for identifying elevated BP in children and adolescents.

METHODS

Data sources were PubMed, EMBASE, Web of Science, Cochrane, and SCOPUS up to May 2016. Studies providing measures of diagnostic performance of obesity indices and using age-, sex-, and height-specific BP 95% as reference standard (the definition of United State Fourth Report) were included. We extracted available data on true-positive, false-positive, true-negative, and false-negative to construct a 2 × 2 contingency table and computed the pooled summary statistics for the sensitivities and specificities to estimate the diagnostic performance.

RESULTS

Nine eligible studies that evaluated 25,424 children and adolescents aged 6 to 18 years were included in the meta-analysis. The pooled sensitivities were 42% (BMI), 42% (WC), and 43% (WHtR). The pooled specificities were 80% (BMI), 75% (WC), and 77% (WHtR). The areas under the curve (AUCs) of obesity indices were 0.7780 (BMI), 0.7181 (WC), and 0.6697 (WHtR), respectively. In this meta-analysis, the BP measurements were based on 3 visits in only 1 study. The prevalence of hypertension may be overestimated in these studies.

CONCLUSIONS

The present meta-analysis showed that the performance of obesity indices for identifying elevated BP was poor. Our findings do not support the performance of WC and WHtR is superior to BMI to help identify children with elevated BP.