Methods of estimation of visceral fat: advantages of ultrasonography

Reproducibility of abdominal fat assessment by ultrasound and computed tomography

Objective:

To test the accuracy and reproducibility of ultrasound and computed tomography (CT) for the quantification of abdominal fat in correlation with the anthropometric, clinical, and biochemical assessments.

Materials and Methods:

Using ultrasound and CT, we determined the thickness of subcutaneous and intra-abdominal fat in 101 subjects-of whom 39 (38.6%) were men and 62 (61.4%) were women-with a mean age of 66.3 years (60-80 years). The ultrasound data were correlated with the anthropometric, clinical, and biochemical parameters, as well as with the areas measured by abdominal CT.

Results:

Intra-abdominal thickness was the variable for which the correlation with the areas of abdominal fat was strongest (i.e., the correlation coefficient was highest). We also tested the reproducibility of ultrasound and CT for the assessment of abdominal fat and found that CT measurements of abdominal fat showed greater reproducibility, having higher intraobserver and interobserver reliability than had the ultrasound measurements. There was a significant correlation between ultrasound and CT, with a correlation coefficient of 0.71.

Conclusion:

In the assessment of abdominal fat, the intraobserver and interobserver reliability were greater for CT than for ultrasound, although both methods showed high accuracy and good reproducibility.

Risk factors associated with abdominal obesity in suburban adolescents from a Malaysian district

INTRODUCTION

We aimed to determine the risk factors associated with abdominal obesity (AO) in suburban adolescents.

METHODS

This cross-sectional study included adolescents aged 15-17 years from five randomly selected secondary schools in the Hulu Langat district of Selangor state, Malaysia. Waist circumference (WC) was measured at the midpoint between the lower margin of the last palpable rib and the top of the iliac crest. Information on sociodemographic data, dietary habits, physical activity levels and duration of sleep was obtained via interviewer-administered questionnaires. Participants' habitual food intake was determined using a 73-item Food Frequency Questionnaire.

RESULTS

Among 832 participants, 56.0% were girls; 48.4% were Malay, 40.5% Chinese, 10.2% Indian and 0.8% of other ethnic groups. Median age and WC were 16 (interquartile range [IQR] 15-16) years and 67.9 (IQR 63.0-74.6) cm, respectively. Overall prevalence of AO (> 90th percentile on the WC chart) was 11.3%. A higher proportion (22.4%) of Indian adolescents were found to have AO compared with Malay and Chinese adolescents. Logistic regression analysis showed that female gender (adjusted odds ratio [OR] 7.064, 95% confidence interval [CI] 2.087-23.913; p = 0.002), Indian ethnicity (adjusted OR 10.164, 95% CI 2.182-47.346; p = 0.003), irregular meals (adjusted OR 3.193, 95% CI 1.043-9.774; p = 0.042) and increasing body mass index (BMI) (adjusted OR 2.867, 95% CI 2.216-3.710; p < 0.001) were significantly associated with AO.

CONCLUSION

AO was common among Malaysian adolescents. Female gender, Indian ethnicity, irregular meals and increasing BMI were significant risk factors.

Novel and Simple Ultrasonographic Methods for Estimating the Abdominal Visceral Fat Area

OBJECTIVES

To evaluate the abdominal visceral fat area (VFA), we developed novel ultrasonographic (US) methods for estimating.

METHODS

100 male volunteers were recruited, and their VFA was calculated by two novel US methods, the triangle method and the ellipse method. The VFA calculated by these methods was compared with the VFA calculated by CT.

RESULTS

Both the VFA calculated by the triangle method (r = 0.766, p < 0.001) and the ellipse method (r = 0.781, p < 0.001) showed a high correlation coefficient with the VFA calculated by CT. Also, the VFA calculated by our novel methods were significantly increased in subjects with one or more metabolic risk factors than in those without any risk factors. Furthermore, the correlation coefficients obtained using the two methods were enhanced by the addition of multiple regression analysis (with the triangle method, r = 0.8586, p < 0.001; with the ellipse method, r = 0.8642, p < 0.001).

CONCLUSIONS

The VFA calculated by the triangle or ellipse method showed a high correlation coefficient with the VFA calculated by CT. These US methods are easy to use, they involve no radiation exposure, and the measurements can be conducted frequently. We hope that our simple methods would be widely adopted for the evaluation of VFA.

Ultrasound measurement of pediatric visceral fat thickness: correlations with metabolic and liver profiles

PURPOSE

Abdominal obesity is a fundamental factor underlying the development of metabolic syndrome. Because of radiation exposure and cost, computed tomography or dual-energy X-ray absorptiometry to evaluate abdominal adiposity are not appropriate in children. Authors evaluated whether ultrasound results could be an indicator of insulin resistance and nonalcoholic fatty liver disease (NAFLD).

METHODS

We enrolled 73 subjects (aged 6-16 years) who were evaluated abdominal adiposity by ultrasound. Subcutaneous fat thickness was defined as the measurement from the skin-fat interface to the linea alba, and visceral fat thickness (VFT) was defined as the thickness from the linea alba to the aorta. Anthropometric and biochemical metabolic parameters were also collected and compared. The subjects who met 2 criteria, radiologic confirmed fatty liver and alanine aminotransferase >40, were diagnosed with NAFLD.

RESULTS

There was a strong positive correlation between VFT and obesity. VFT was highly correlated with the homeostasis model assessment for insulin resistance score (r=0.403, P<0.001). The area under the curve for VFT as a predictor of NAFLD was 0.875 (95% confidence interval [CI], 0.787-0.964). VFT of 34.3 mm was found to be the discriminating cutoff for NAFLD (sensitivity, 84.6%; specificity, 71.2%, respectively).

CONCLUSION

Ultrasound could be useful in measuring VFT and assessing abdominal adiposity in children. Moreover, increased VFT might be an appropriate prognostic factor for insulin resistance and NAFLD.

Ultrasound: Which role in body composition?

Ultrasound is a non-invasive, fast, relatively inexpensive and available tool for estimating adiposity in clinical practice, and in several research settings. It does not expose patients to ionizing radiation risks, making the method ideal for the evaluation, and for follow-up studies. Several parameters and indexes based on adipose tissue thickness have been introduced and tested, and these have been correlated with clinical and laboratoristic parameters. Moreover, ultrasound can also be directed to the estimation of adipose tissue and intracellular fat indirectly, at cellular-molecular level: an opportunity for many radiologists who already and sometimes unconsciously perform "body composition" assessment when looking at the liver, at muscle as well as at other organs. However, standardized procedure and parameters are needing to improve accuracy and reproducibility. The purposes of this review are: 1) to provide a complete overview of the most used and shared measurements of adiposity; 2) to analyze technical conditions, accuracy, and clinical meaning of ultrasound in the study of body composition; 3) to provide some elements for the use of ultrasound in the evaluation of intra-cellular lipids accumulation, in two hot spots: liver and skeletal muscle.

Analysis of subcutaneous and visceral fat after gastric balloon treatment

Background and Objectives:

This project is a continuation of a larger project entitled “Treatment with intragastric balloon (IGB) in patients with overweight and obesity in Recife” developed by Professor Dr. Gustavo Lopes de Carvalho. It is a project studying the effectiveness of treatment with IGB evaluating the loss of weight and body mass index and its impact on blood pressure, blood glucose, triglycerides, total cholesterol and fractions. It also assesses the lifestyle of patients studying whether treatment with IGB interferes in smoking, alcohol consumption, eating habits and physical exercises performed by patients.

The present study added a larger project, the separate evaluation of the different types of abdominal fat—visceral fat and subcutaneous cell tissue fat — and was conducted to discover which of the 2 types of fat undergoes the greater reduction after IGB treatment. To measure these 2 types of fat, we used the ultrasonography technique, because it has been shown to be accurate and noninvasive.

Methods:

Twenty-five patients were evaluated before and after 6 months of IGB treatment.

Results:

The patients' ages ranged from 20 to 61 years, with 60% being 40 years of age or older. The majority (72%) were women. All variables (weight, body mass index [BMI], VF, and SCTF) showed a significant reduction (P < .05) in mean values after treatment. The difference was highest in the SCTF (17.5%) and ranged from an 11.4% to an 11.6% reduction in all other variables. The average loss of SCTF was highest among the patients who had lost up to 10.0% of their initial weight (19.2% for the ≤10.0% group vs 15.9% for the >10.0% group); however, the difference was not significant (P = .66). The average loss of VF was higher in the subgroup of patients who had lost >10.0% of their initial weight (16.2% vs 6.3%; P = .003). The Pearson correlation between the reductions in SCTF vs VF was negative, low, and nonsignificant (−0.17; P = .41).

Conclusions:

After 6 months of IGB treatment, there was no significant difference between the reduction in abdominal SCTF and VF, but the results signify a possible correlation between the percentage of body weight loss and the type of abdominal fat reduced, as the impact on the VF was higher when the patients lost >10.0% of their initial weight.

Relationship between visceral obesity and plasma fibrinogen in obese children

BACKGROUND

The prevalence of obesity in children and adolescents has increased significantly worldwide with an alarming rise of its co-morbidities. The excess of visceral adipose tissue is associated with hypertension, prothrombotic and pro-inflammatory states. Our aim was to find a possible association between visceral obesity and plasma fibrinogen, as one of the cardiovascular risk factors, in obese children.

METHODS

Forty-three obese children and 40 non-obese controls were studied regarding their history, complete physical examination, anthropometric assessment, body composition analysis, ultrasonographic measurement of visceral adipose tissue and subcutaneous fat as well as laboratory measurement of plasma fibrinogen.

RESULTS

Our study revealed significant higher levels of fibrinogen in obese children than controls (14.5+5.1 and 2.9+0.52 mg/mL, respectively) with p-value <0.01. Moreover, the obese group had statistically significant difference in visceral fat (5.96+0.77 cm) and subcutaneous fat (2.66+0.70 cm) than controls (2.45+0.65 and 0.70+0.18 mg/mL, respectively) with p-value <0.01. In addition, fibrinogen had significant positive correlation with body mass index (r=0.327), waist/hip ratio (r=0.394), fat percentage (r=0.301), visceral adipose tissue (r=0.323) and subcutaneous fat (r=0.301).

CONCLUSIONS

There was highly significant increase in the fibrinogen level, visceral and subcutaneous abdominal fat in the obese group with insignificant sex differences. Fibrinogen had a significant positive correlation with the different adiposity markers, blood pressure, visceral and subcutaneous fat. Visceral adipose tissue is a stronger predictor for cardiovascular risk compared to subcutaneous fat.

Metabolic correlates of subcutaneous and visceral abdominal fat measured by ultrasonography: a comparison with waist circumference

BACKGROUND

The relative contribution of visceral (VAT) and subcutaneous (SAT) adipose tissue to cardiometabolic disease is controversial. The aim of this study was to evaluate whether dissecting abdominal fat in VAT and SAT using US may detect stronger and more specific association with MS, MS components, hyperuricemia and altered liver enzymes compared to waist circumference.

METHODS

We performed a cross-sectional study on 2414 subjects aged 18 to 66 years (71 % women) followed at the International Center for the Assessment of Nutritional Status (ICANS, Milan, Italy). VAT and SAT were measured using ultrasonography. Multivariable logistic regression controlling for age and gender was used to evaluate the association of the parameters of interest (waist circumference (WC), VAT, SAT and VAT + SAT) with the MS (international harmonized definition), its components (high triglycerides, low HDL, high blood pressure, high glucose), high uric acid (≥7 mg/dl), high alanine transaminase (ALT, ≥ 30 U/l) and high gamma-glutamyl-transferase (GGT, ≥ 30 U/l).

RESULTS

VAT was independently associated with all the outcomes of interest, while SAT was independently associated with MS and only with high blood pressure and high ALT when we considered the single parameters of MS and NAFLD. VAT had the strongest association with high triglycerides, high ALT and high GGT. The VAT + SAT association had the strongest association with MS. WC had the strongest association with low HDL and high blood pressure. VAT and WC were similarly associated to high glucose and high uric acid.

CONCLUSION

US-determined VAT and SAT are both independently associated with MS. Moreover, to our knowledge, we are the first to show that VAT, being associated to all of the MS components in addition to hyperuricemia and altered liver enzymes, performs equally or better than WC except for high blood pressure and low HDL.

Sonographically Assessed Intra-Abdominal Fat And Cardiometabolic Risk Factors in Adolescents with Extreme Obesity

OBJECTIVE

The metabolic and cardiovascular risk of obesity is predominantly defined through the amount of intra-abdominal fat (IAF). Regarding this risk and the benefits of weight reduction gender-specific differences have been described. The aim of this study was to examine the gender-specific relationship between IAF assessed via ultrasound and the cardiometabolic risk profile in extremely obese adolescents before and after weight loss.

METHODS

In 107 consecutively admitted adolescents (n = 59 girls, mean age 15.4 ± 2.6 years boys and 15.1 ± 2.1 years girls, mean BMI z-score 3.2 ± 0.6 boys and 3.5 ± 0.6 girls) anthropometric and fasting laboratory chemical parameters were measured before and after an in-patient long-term therapy (mean durance 5.6 ± 2.3 months). IAF was determined by measuring the intra-abdominal depth (IAD) via ultrasound.

RESULTS

IAD was higher in boys as compared to girls (58.0 ± 22.4 mm vs. 51.3 ± 16.0 mm). IAD values were positively associated with BMI-z scores, waist circumferences, HOMA-IR and serum levels of x03B3;GT, hs-CRP and IL-6 in both genders. In boys, but not in girls, IAD was significantly correlated with systolic and diastolic blood pressure, serum levels of triglycerides, ALT as well as adiponectin and HDL-cholesterol. After a marked mean weight loss of -27.1 ± 16.2 kg (-20.1 ± 7.9%) in boys and of -20.5 ± 11.5 kg (-17.3 ± 7.1%) in girls, IAD decreased by -20.7 ± 16.2 mm (--32.4 ± 16.9%) in boys and by -18.4 ± 12,7 mm (-34.3 ± 18.4%) in girls, resulting in more pronounced ameliorations of cardiovascular risk factors in boys than in girls.

CONCLUSIONS

The present study indicates that IAF assessed by ultrasound is a good indicator for the cardiometabolic risk factor profile in extremely obese adolescents. Associations between IAF and risk factors are more pronounced in boys than in girls.

Comparison of Abdominal Visceral Adipose Tissue Area Measured by Computed Tomography with That Estimated by Bioelectrical Impedance Analysis Method in Korean Subjects

We evaluated the concordance between visceral fat area (VFA) estimated by bioelectrical impedance analysis (BIA) or computed tomography (CT) in Korean subjects with a wide range in age and body mass index (BMI). In 1006 individuals (mean age 55.2 ± 11.8 (19-87) years, mean BMI 26.0 ± 3.5 (17-46) kg/m², 48.9% men), VFA quantified by CT was compared with VFA using multifrequency BIA machines within 15 days. Concordance rates were compared by age or BMI using correlation analysis, Bland-Altman plots, and intraclass correlation coefficient (ICC). Using BIA data, we established a regression formula to reflect CT-VFA. The mean VFAs by CT and BIA were 131.9 ± 57.3 cm² and 110.5 ± 33.9 cm², respectively (r = 0.605, p < 0.001). The mean difference was 21.4 ± 45.6 cm², tending to increase with BMI. In women with BMI <25 kg/m² or age <50 years, the VFAs by BIA were similar to those by CT (ICC = 0.496 in BMI <25 kg/m² and ICC = 0.638 in age <50 years). However, the difference was greater in men with BMI ≥25 kg/m² or age ≥50 years. Applying our formula, the difference between estimations decreased to 0.2 ± 38.2cm². VFA estimated by BIA correlated well with that by CT, but a more accurate formula is needed to match CT data, particularly in older men or subjects with a high BMI.

Ultrasound evaluation of visceral and subcutaneous fat reduction in morbidly obese subjects undergoing laparoscopic gastric banding, sleeve gastrectomy, and Roux-en-Y gastric bypass: a prospective comparison study

BACKGROUND

Visceral fat (VF) plays a major role in the development of metabolic syndrome associated with obesity. The aim of our study is to compare VF and subcutaneous fat (SCF) reduction measured by ultrasonography (US) after laparoscopic adjustable gastric banding (LAGB), laparoscopic sleeve gastrectomy (LSG), and laparoscopic Roux-En-Y gastric bypass (LRYGB).

METHODS

Thirty-nine morbidly obese patients were prospectively evaluated by US before surgery and 3, 6, and 12 months following surgery to determine VF and SCF thickness.

RESULTS

Three statistically comparable groups of morbidly obese patients underwent LRYGB (n = 13), LSG (n = 15), and LAGB (n = 11). The three groups did not differ in initial age, gender, body mass index (BMI), VF, or SCF. Final excess weight loss (EWL%) was highest after LSG and LRYGB followed by LAGB (81 ± 5.8 vs. 69.5 ± 4.5 vs. 43.4 ± 5.2, p < 0.001). LSG and LRYGB were significantly more efficient in VF reduction (ΔVF) compared with LAGB (7.1 ± 0.5 vs. 5.6 ± 0.6 vs. 3.6 ± 0.8, p = 0.004). SCF reduction (ΔSCF) was also highest after LSG followed by LRYGB and LAGB (3 ± 0.2 vs. 2.2 ± 0.4 vs. 1.9 ± 0.4, p = 0.08). The change in fat distribution, determined as Δ(VF/SCF), showed a preferential VF reduction in the LSG and LRYGB patients compared with patients that underwent LAGB (0.59 ± 0.1 vs. 0.52 ± 0.2 vs. 0.19 ± 0.2, p = 0.42). In a subgroup analysis comparing only LSG to LRYGB, no statistically significant difference was seen in EWL%, ΔVF, ΔSCF, or in fat distribution Δ(VF/SCF).

CONCLUSION

LSG and LRYGB show better preferential and overall VF reduction than LAGB. US may serve as a simple tool of evaluating postoperative fat distribution.

Apolipoprotein B polymorphism distribution among a sample of obese Egyptian females with visceral obesity and its influence on lipid profile

Background

Regional distribution of adipose tissue is more important than total amount of body fat in predicting complications associated with obesity. Apolipoprotein B (Apo B) plays a central role in lipid metabolism.

Aim

To investigate the importance of the XbaI polymorphism of Apo B gene (C7673T) as risk factor for visceral obesity and its influence on lipid profile.

Subjects and methods

Total of 122 obese adult females (BMI ⩾ 30 kg/m²): 56 of them with visceral obesity (⩾7 cm by abdominal Ultrasound) and 66 without visceral obesity and 36 age matched non-obese (BMI ⩽ 25 kg/m²) without visceral obesity were studied. Anthropometric assessment, body composition, visceral obesity and lipid profile evaluation were attempted. Genetic analysis of Apo B XbaI was performed using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP).

Results

Visceral obesity was associated significantly with the presence of the heterozygous (CT) genotype of the XbaI Apo B gene (p < 0.001). Frequency of homozygous (CC) was significantly the least genotype found in females with visceral obesity, while homozygote (TT) genotype was more frequent in those without visceral obesity. T allele (about 70%) was more frequent than C allele (about 30%) in all groups. Significant lowest values of visceral obesity, triglyceride and HDL-C were associated with the presence of (CC) genotype and the highest values were associated with the presence of the heterozygous (CT) genotype; except HDL-C with (TT) genotype.

Conclusions

Study reveals considerable association of Apo B XbaI gene polymorphism with visceral obesity and some lipid profile parameters (TG and HDL-C) among Egyptian females.

Reliability tests and guidelines for B-mode ultrasound assessment of central adiposity

INTRODUCTION

Ultrasound represents a validated and relatively inexpensive diagnostic device for assessing central adiposity; however, widespread adoption has been impeded by the lack of reliable standard operating procedures.

PURPOSE

To examine the reliability of, and describe guidelines for, ultrasound-derived recording of intra-abdominal fat thickness (IAT) and maximal preperitoneal fat thickness (PFT).

METHODS

Ultrasound scans were obtained from 20 adults (50% female, 26 ± 7 years, 24·5 kg/m(2) ) on three different mornings. IAT was assessed 2 cm above the umbilicus (transverse plane) measuring from linea alba to: (i) anterior aorta, (ii) posterior aorta and (iii) anterior aspect of the vertebral column. PFT was measured from linea alba to visceral peritoneum in (i) sagittal and (ii) transverse planes, immediately over and inferior to the xiphi-sternum, respectively.

RESULTS

For IAT, the criterion intraclass correlation coefficient (ICC) of 0·75 was exceeded for measurements to anterior aorta (0·95), posterior aorta (0·94) and vertebra (0·96). The reliability coefficient expressed as a percentage of the mean (RC%) was lowest (better) for measurement to vertebrae (9·8%). For PFT, mean thickness was comparable for sagittal (1·74 cm) and transverse (1·76 cm) planes; ICC values were also comparable for both planes (0·98 vs. 0·98, respectively), as were RC% (7·5% vs. 7·1%, respectively).

CONCLUSIONS

IAT assessments to the vertebra were marginally more reliable than those to other structures. While PFT assessments were equally reliable for both measurements planes, precise probe placement was easier for the sagittal plane. Based on these findings, guidelines for the reliable measurement of central adiposity using ultrasound are presented.

Adherence to the Mediterranean diet is inversely associated with visceral abdominal tissue in Caucasian subjects

BACKGROUND

& aim: Adherence to the Mediterranean dietary pattern (MDP) is inversely related with abdominal adiposity as detected by waist circumference but the specific association to subcutaneous and visceral abdominal tissue has not been investigated. To this purpose we evaluated the association between MDP, visceral (VAT) and subcutaneous (SAT) abdominal tissue in a large sample of Italian adults.

METHODS

A cross-sectional study was carried out on 4388 consecutive adults (73.2% women) followed as outpatients at Nutritional Research Centre in Milan, ICANS. VAT and SAT were measured by ultrasonography. MDP was evaluated using a Mediterranean dietary score (MEDscore) obtained from a validated 14-item questionnaire.

RESULTS

At multiple linear regression adjusted for sex, age, smoking and physical activity, a 1-unit increase in MEDscore was associated with a -0.118 kg/m(2) decrease in BMI (p < 0.01), a -0.292 cm decrease in waist circumference (p < 0.01), a -0.002 cm:cm decrease in waist to height ratio (p < 0.001), a -1.125 mm decrease in the sum of 4 skinfolds (p < 0.001), and with a -0.045 cm decrease in VAT (p < 0.05). MEDscore was, however, not associated with SAT. Finally, the adherence to the MDP was a protective factor for obesity (OR = 0.717, 95%CI: 0.555-0.922) and VAT excess (OR = 0.717, 95%CI: 0.530-0.971).

CONCLUSION

Our study confirms the inverse association between MDP, BMI and waist circumference and adds that the association with abdominal obesity as detected by waist circumference is due to an association with VAT and not with SAT.

Epicardial and pericardial fat in type 2 diabetes: favourable effects of biliopancreatic diversion

PURPOSE

Ectopic fat is often identified in obese subjects who are susceptible to the development of type 2 diabetes mellitus (T2DM). The ectopic fat favours the decrease in insulin sensitivity (IS) and adiponectin levels. We aimed to evaluate the effect of biliopancreatic diversion (BPD) on the accumulation of ectopic fat, adiponectin levels and IS in obese with T2DM.

MATERIALS AND METHODS

A nonrandomised controlled study was performed on sixty-eight women: 19 lean-control (23.0 ± 2.2 kg/m(2)) and 18 obese-control (35.0 ± 4.8 kg/m(2)) with normal glucose tolerance and 31 obese with T2DM (36.3 ± 3.7 kg/m(2)). Of the 31 diabetic women, 20 underwent BPD and were reassessed 1 month and 12 months after surgery. The subcutaneous adipose tissue, visceral adipose tissue, epicardial adipose tissue and pericardial adipose tissue were evaluated by ultrasonography. The IS was assessed by a hyperglycaemic clamp, applying the minimal model of glucose.

RESULTS

One month after surgery, there was a reduction in visceral and subcutaneous adipose tissues, whereas epicardial and pericardial adipose tissues exhibited significant reduction at the 12-month assessment (p < 0.01). Adiponectin levels and IS were normalised 1 month after surgery, resembling lean-control values and elevated above the obese-control values (p < 0.01). After 12 months, the improvement in IS and adiponectin was maintained, and 17 of the 20 operated patients exhibited fasting glucose and glycated haemoglobin within the normal range.

CONCLUSIONS

After BPD, positive physiological adaptations occurred in grade I and II obese patients with T2DM. These adaptations relate to the restoration of IS and decreased adiposopathy and explain the acute (1 month) and chronic (12 months) improvements in the glycaemic control.

Does Upper Extremity Training Influence Body Composition after Spinal Cord Injury?

Spinal cord injury (SCI) leads to serious body composition adaptations characterized by increasing whole body fat mass and decreased soft tissue lean mass (LM). These adaptations in body composition may lead to several cardio-metabolic disorders that reduce the quality of life, increase patients' and caregivers' burden and eventually leads to mortality. Exercise, an appropriate dietary regimen, and an active lifestyle may alleviate several of the negative effects on body composition after a SCI. Today however, there is no established consensus on the recommended dose, frequency or type of exercise to ameliorate several of the body composition sequelae after an acute SCI. Resistance training has been previously recommended as an effective strategy to restore soft tissue LM and decrease fat mass (FM). The strategy can be simply implemented as a routine home-based training program using free weights or resistance bands after a SCI. Additionally, upper extremity (UE) circuit resistance training has been previously used to improve cardiovascular and metabolic parameters after a SCI; however compared to the vast knowledge regarding the able-bodied (AB) population, the effects of UE circuit resistance training on body composition after a SCI is not well established. In summary, the available evidence does not support the rationale that UE circuit resistance training can lead to positive adaptations in body composition after a SCI. Further studies are suggested to examine the effects of UE circuit resistance training on body composition.

Reduction in saturated fat intake improves cardiovascular risks in obese adolescents during interdisciplinary therapy

BACKGROUND/OBJECTIVES

Obesity is related to inflammation and cardiovascular disease. The increase in saturated fatty acid intake (SFA) can potentiate cardiovascular risks. The aim of this study was to assess the influence of change in SFA on carotid intima-media thickness (cIMT), metabolic profile and anti/pro-inflammatory adipokines in obese adolescents.

METHODS

Sixty obese adolescents were subjected to 1 year of interdisciplinary intervention (nutrition, psychology, physical exercise and clinical therapy). Blood glucose, insulin, lipid profile, leptin and adiponectin were analysed. Insulin resistance was estimated by HOMA-IR and HOMA-AD. cIMT was measured by ultrasonography. Dietetic intake was calculated by 3-day dietary record. Volunteers were analysed according to tertiles of change (Δ) in SFA intake: Low-SFA reduction<3.68 g; Moderate-SFA reduction 3.68-13.67 g; and High-SFA reduction>13.67 g.

RESULTS

Moderate and High-SFA tertiles presented reduction in insulin, leptin/adiponectin ratio, cIMT and increase in adiponectin and adiponectin/leptin ratio. Adiponectin/leptin ratio was predictor of cIMT. HOMA-IR, total cholesterol and LDL-cholesterol reduced only in High-SFA tertile, and was associated with SFA independent of visceral fat. Negative correlations between Δ of SFA and adiponectin and adiponectin/leptin ratio were observed.

CONCLUSION

Obese adolescents with moderate and high reduction in SFA presented improvements on pro/anti-inflammatory biomarkers and cIMT, leading to reduction in cardiovascular risks.

The role of multicomponent therapy in the metabolic syndrome, inflammation and cardiovascular risk in obese adolescents

Obesity is characterised by low-grade inflammation, which increases the metabolic syndrome (MetS) and cardiovascular risks. The aim of the present study was to verify the role of multicomponent therapy in controlling the MetS, inflammation and carotid intima-media thickness (cIMT) in obese adolescents. The second aim was to investigate the relationships between adipokines, the MetS parameters and cIMT. A total of sixty-nine obese adolescents participated in the present study and completed 1 year of multicomponent therapy (a combination of strategies involving nutrition, psychology, physical exercise and clinical therapy), and were divided according to their MetS diagnosis as follows: MetS (n 19); non-MetS (n 50). Blood analyses of glucose, lipid and adipokine concentrations (adiponectin, leptin, plasminogen activator inhibitor 1 (PAI-1) and C-reactive protein) were collected. Insulin resistance was assessed using the homeostasis model assessment for insulin resistance, quantitative insulin sensitivity check index and homeostasis model assessment-adiponectin. cIMT and visceral and subcutaneous fat were estimated using ultrasonography. At baseline, the MetS group presented higher waist circumference, glucose and insulin levels, and systolic and median blood pressures compared with the non-MetS group. After therapy, both groups showed improvements in the anthropometric profile, body composition, insulin level, insulin resistance, insulin sensibility, TAG and VLDL-cholesterol, adiponectin, leptin and PAI-1 levels, blood pressure and cIMT. The prevalence of the MetS was reduced from 27·5 to 13·0 %. Metabolic syndrome patients showed resistance in the attenuation of total cholesterol and LDL-cholesterol (LDL-C) levels and leptin:adiponectin and adiponectin:leptin ratios. In the MetS group, the variation in the adiponectin:leptin ratio was correlated with variations in glucose, insulin sensibility, total cholesterol, LDL-c and systolic blood pressure. Additionally, the number of MetS parameters was correlated with the carotid measurement. Moreover, the variation in cIMT was correlated with the variations in insulin sensibility, total cholesterol and LDL-c. For the entire group, the number of MetS alterations was correlated with the leptin level and leptin:adiponectin ratio and adiponectin:leptin ratio after therapy. In conclusion, multicomponent therapy was effective in controlling the MetS, inflammation and cIMT in the obese adolescents. However, the MetS patients showed resistance in the attenuation of the atherogenic lipid profile and leptin:adiponectin ratio and adiponectin:leptin ratio. These results suggest that the MetS patients have increased cardiovascular risks, and that it is important to attempt to control the inflammatory process that occurs due to obesity in clinical practice in order to improve the health of adolescents.

Is there a role for leptin in the reduction of depression symptoms during weight loss therapy in obese adolescent girls and boys?

Several studies have sought to clarify the association between adolescent obesity and psychological distress. Recently, a biological link between leptin resistance and depression has been proposed. The aim of the present study was to examine changes in leptin concentrations as a potential predictor of reduced depression symptoms in obese adolescents during long-term interdisciplinary weight loss therapy. Seventy-five obese adolescents (age: 16.28±2.37 years; BMI: 35.65±4.64 kg/m2) engaged in a long-term interdisciplinary therapy for weight loss. They were evaluated at baseline and after 1 year of treatment for body composition, serum analyses and depression symptomatology. After therapy, body mass BMI, fat mass (% and kg), waist circumference, visceral, subcutaneous and visceral/subcutaneous fat and depression symptoms decreased and lean mass (%) increased significantly. There was an improvement in inflammatory profiles with a significant reduction in leptin and increase in adiponectin. Regression analyses showed that decreased leptin predicted amelioration in depression symptoms independent of age, gender and changes in visceral fat, body mass, fat mass (%) and leptin/adiponectin ratio. These associations appear stronger in girls than boys. The attenuation of hyperleptinemia appears to play an important role in the association between weight loss and depression, particularly in obese girls.

Linear and undulating periodized strength plus aerobic training promote similar benefits and lead to improvement of insulin resistance on obese adolescents

The present study compares the effectiveness of three types of physical training for obesity control in adolescents submitted to a long-term interdisciplinary therapy. Forty-five post-puberty obese adolescents (15-18yo) were randomly placed in three different groups of physical trainings: aerobic training (AT n=20), aerobic plus strength training with linear periodization (LP n=13) and aerobic plus strength training with daily undulating periodization (DUP n=12). The body composition was evaluated by air-displacement plethysmography; the rest metabolic rate was measured by indirect calorimetry; serum analysis was collected after an overnight fasting. The most important finding of this study was that both LP and DUP groups improved lipid profile, insulin sensitivity and adiponectin concentration (p<0.01). The linear regression showed a negative association between delta (%) adiponectin and delta (%) insulin (p<0.05). Each group presented a significant reduction in body mass, body mass index and fat mass (kg) after short and long-term intervention (p<0.01). However, the AT group reduced the fat-free mass after short-term intervention (p<0.01) and enhanced protein oxidation (p<0.01), whereas only LP group was able to increase the fat-free mass and maintain the rest metabolic rate (RMR). There was a negative correlation between percentage of protein oxidation and RMR (r=-0.75) in all groups. The interdisciplinary therapy models that included aerobic plus strength training were more effective than only aerobic training to improve lipid profile and insulin sensitivity, as well as the inflammatory state by increasing adiponectin. In all groups were observed an improvement on anthropometric profile.

The Relation between Visceral and Subcutaneous Fat to Bone Mass among Egyptian Children and Adolescents

BACKGROUND: The relation between fat distribution and bone mass is still being debated in children and adolescents.AIM: To verify the influence of both visceral and subcutaneous fat on bone mass among Egyptian children and adolescents.SUBJECTS AND METHODS: The study involved 78 (38 boys and 40 girls) individuals from children (42) and adolescents (36), aged 8-17 years. They were divided into 2 age groups: children group (20 boys and 22 girls) aged 8-12 years and adolescent group (18 boys and 18 girls) aged 13-17 years. Anthropometric measurements, visceral and subcutaneous fat (measured by ultrasound), body composition, BMD and BMC (Measured by DXA), were attempted.RESULTS: Among children, significant positive correlations between visceral fat; in males; and subcutaneous fat; in females; with total BMC, BMD and its Z-score were revealed. After exclusion of age effect, the association between visceral fat in females with total BMD and its Z-score and lumbar BMD-Z-score became significant.  For adolescents, no correlation was observed between either visceral or subcutaneous fat with any parameter of bone mass.CONCLUSIONS: Visceral and subcutaneous fat had significant positive association with bone mass in children; males and females respectively. On the contrary such association disappeared during adolescence.

Reproducibility and validity of ultrasound for the measurement of visceral and subcutaneous adipose tissues

BACKGROUND

Ultrasound represents a low-cost and widely available field method for assessing visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) but its measurement properties are uncertain. The aim of the current study was to examine the reproducibility and validity of ultrasound to quantify abdominal fat compartments.

METHODS

In two study centers, VAT and SAT thicknesses were quantified by ultrasound two times by two observers each among 127 adults aged 20-70 years. In a separate sample of 30 adults, the ultrasound method was validated by comparing VAT and SAT thicknesses with VAT and SAT areas at vertebrae L2/L3 as obtained by a single magnetic resonance imaging (MRI) slice.

RESULTS

For VAT, the intra-rater reproducibility values for observers 1 and 2 were r=0.996 (95% CI=0.994-0.997) and r=0.999 (95% CI=0.999-0.999), respectively. For SAT, the intra-rater reproducibility values were r=0.992 (95% CI=0.989-0.994) and r=0.993 (95% CI=0.990-0.995), respectively. The inter-rater reproducibility values for VAT and SAT were r=0.998 (95% CI=0.997-0.999) and r=0.990 (95% CI=0.986-0.993), respectively. For VAT and SAT, the correlation coefficients between ultrasound and MRI measurements were r=0.898 (P<0.001) and r=0.705 (P<0.001), respectively.

CONCLUSION

Ultrasound provides reproducible and valid estimates of VAT and SAT and represents a useful method to assess abdominal fat in large scale epidemiologic studies.

The relationship between the postprandial lipemic response and lipid composition in persons with spinal cord injury

OBJECTIVE

To determine the influence of lipid concentration, lipid particle size, and total abdominal fat (TAF) on postprandial lipemic response (PPLr) in persons with spinal cord injury (SCI).

METHODS

Thirty-five persons with SCI (17 paraplegia, 18 tetraplegia) and 18 able-bodied (AB) individuals participated. Following a 10-hour fast, blood was drawn for lipids, apolipoprotein (apo) A1 and B concentrations, and low-density (LSP) and high-density (HSP) lipoprotein particle sizes. A high-fat milkshake was consumed (∼1.3 g fat/kg). Blood was drawn at 2, 4, and 6 hours to determine PPLr, (triglyceride (TG) area under the curve). TAF and visceral (VF) fat were measured by ultrasonography; total body fat (TBF) by dual-energy X-ray absorptiometry. Differences between the groups were determined by independent sample t-tests. Pearson correlation coefficients determined the relationship among PPLr and lipids, and TAF.

RESULTS

There were no significant differences in fasting TG, low-density lipoprotein (LDL), apoB, TAF, or PPLr values between the groups. In SCI, PPLr significantly correlated with: apoB (r = 0.63, P < 0.01, LSP (r = 0.57, P < 0.01), and TAF (r = 0.36, P < 0.01). After controlling for age and duration of injury, PPLr significantly correlated with apoB (r = 0.66, P = 0.001), TBF (r = 0.45, P = 0.03), VF (r = 0.66, P = 0.02), and TAF (r = 0.56, P = 0.007).

CONCLUSIONS

Although concentrations of LDL cholesterol and apoB were not different between SCI and AB groups, LSP, apoB, and TAF correlated with PPLr in persons with SCI. ApoB was associated with a greater PPLr in those with motor complete SCI, after controlling for age and duration of injury.

Correlation of abdominal adiposity with components of metabolic syndrome, anthropometric parameters and Insulin resistance, in obese and non obese, diabetics and non diabetics: A cross sectional observational study. (Mysore Visceral Adiposity in Diabetes Study)

OBJECTIVES

To measure Visceral Fat (VF) and Subcutaneous Fat (SCF) by ultrasound, in obese and non-obese diabetics and obese and non-obese non diabetics, in a South Indian (Asian Indian) Population and correlate them with Body Mass Index (BMI), Waist Circumference (WC), components of metabolic syndrome and Insulin Resistance (IR).

RESEARCH DESIGN AND METHODS

This was a prospective observational study, 80 diabetics (40 obese and 40 non obese) and 80 non diabetics (40 obese and 40 non obese) a total of 160 subjects were enrolled, out of whom 153 completed the study. The subjects were evaluated with respect to BMI, WC, Blood Pressure (BP); Fasting Blood Sugar (FBS) Fasting Insulin levels (FIL), HbA1C and Lipid profile. The SCF and VF were measured by Ultrasonography.The results were statistically analyzed.

RESULTS

WC correlated significantly with VF in all the groups. Diabetics had more VF compared to non-diabetics. Insulin resistance was significant in all the groups; however diabetics had greater levels of IR, BMI, WC, VF and SCF had no correlation with IR and had no significant correlation with metabolic parameters.

CONCLUSIONS

In this study population, WC was found to be a useful surrogate measure of VF conforming to its well established applicability in other populations. Contrary to other studies elsewhere, SCF and VF were found to be poor indicators of Insulin Resistance. BMI, WC, VF and SCF were not useful in the prediction of metabolic syndrome. Ultrasound was found to be an easier and economic method of measuring abdominal adiposity and actual measurement of abdominal fat was more informative than anthropometric measurements.

Grading scale of visceral adipose tissue thickness and their relation to the nonalcoholic fatty liver disease

CONTEXT

The mesenteric fat is drained by the portal system, being related to the metabolic syndrome which is an impor-tant risk factor for non-alcoholic fatty liver disease (NAFLD).

OBJECTIVES

Graduate of visceral fat thickness and correlate with the NAFLD degree through ultrasonography method.

METHODS

We studied 352 subjects for age, gender, measures of subcutaneous fat thickness and visceral fat thickness as well as the presence and degree of liver fatty. Was analyzed the independent relationship between visceral fat thickness and NAFLD, and linear regression analysis was used in order to predict the visceral fat thickness from subcutaneous fat thickness.

RESULTS

The mean age of 225 women (63.9%) and 127 men (36.1%) was 47.5 ± 14.0 (18-77) years, 255 subjects had normal examinations, 97 had NAFLD thus distributed, 37 grade 1, 32 grade 2, and 28 grade 3. The subcutaneous fat thickness ranged from 0.26 to 3.50 cm with a mean of 1.3 ± 0.6 cm and visceral fat thickness ranged from 0.83 to 8.86 cm with a mean of 3.6 ± 1.7 cm. Linear regression showed that for every increase of 1 cm in subcutaneous fat thickness the visceral fat thickness will increase 0.9 cm.

CONCLUSIONS

The visceral fat thickness measured by ultrasonography is a useful and seems to be able to help estimate the risk of NAFLD.

Aerobic plus resistance training was more effective in improving the visceral adiposity, metabolic profile and inflammatory markers than aerobic training in obese adolescents

The purpose of this study was to determine whether aerobic plus resistance training (AT + RT) is more effective than aerobic training (AT) at reducing inflammatory markers and cardiovascular risk in obese adolescents. A total of 139 obese adolescents were enrolled, aged 15-19 years, body mass index (BMI) ≥ 95th percentile and participated in 1 year of interdisciplinary intervention. They were randomised into two groups: AT (n = 55), AT + RT (n = 61). Blood samples were collected to analyse glycaemia, insulin, the lipid profile, leptin and adiponectin concentrations. Insulin resistance was measured by homeostasis model assessment of insulin resistance index (HOMA-IR). The AT + RT group showed better results with regard to decreased body fat mass, low-density lipoprotein concentration (LDL-c) levels, subcutaneous and visceral fat and increased body lean mass. Indeed, a reduction of hyperleptinaemia and an increase in adiponectin concentrations, promoting an improvement in the leptin/adiponectin ratio, was observed. Important clinical parameters were improved in both types of exercise; however, AT + RT was more effective in improving the visceral adiposity, metabolic profile and inflammatory markers than AT alone, suggesting clinical applications for the control of intra-abdominal obesity and cardiovascular risk in the paediatric population.

Relationship between viseral fat thickness measured by ultrasonography and nonalcoholic fatty liver disease

AIM: To investigate relationship between visceral fat thickness measured by ultrasonography and nonalcoholic fatty liver disease (NAFLD).

METHODS: One hundred and seventy subjects were enrolled and divided into two groups: a NAFLD group (n = 110) and a healthy control group (n = 60). Blood pressure (BP), height, weight, waist circumference (WC), hip circumference, body mass index (BMI), waist-hip ratio (WHR), triglycerides (TG), total cholesterol (TC), fasting blood glucose, liver function and fasting insulin were measured in each subject, and the homeostasis model assessment of insulin resistance (HOMA-IR) was calculated according to the typical HOMA model. Visceral fat thickness was measured by ultrasonography.

RESULTS: The visceral fat thickness, BMI, WHR and HOMA-IR were significantly higher in the NAFLD group than in the normal control group (P < 0.05 for all). The visceral fat thickness had significant statistical difference between the mild, moderate and severe NAFLD groups. Correlation analysis showed that there were significantly positive correlations between visceral fat thickness and BMI, WHR and HOMA-IR (r = 0.62, 0.509, 0.596, P < 0.05 for all).

CONCLUSION: Visceral fat thickness measured by ultrasonography may be an important index for diagnosing nonalcoholic fatty liver disease.

Age-related differences in abdominal fat distribution in premenopausal and postmenopausal women with cardiovascular disease

OBJECTIVE

The aim of this study was to determine the effect of sex and the menopausal transition on age-related differences in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) among patients with cardiovascular disease.

METHODS

A cross-sectional study of 997 women and 3,409 men with cardiovascular disease was performed. VAT and SAT were measured by ultrasonography. Differences in abdominal fat per decade in premenopausal and postmenopausal women were analyzed with linear regression and compared with men younger and older than the mean menopause age of women.

RESULTS

VAT increased gradually across advancing age groups. For postmenopausal women, the 10-year differences in VAT were smaller than those for premenopausal women (0.24 cm [β = 0.24; 95% CI, 0.05 to 0.43] vs 0.71 cm [β = 0.71; 95% CI, 0.29 to 1.12]). There were no differences in SAT (β = -0.12; 95% CI, -0.37 to 0.13) in premenopausal women, and SAT decreased across the age groups of postmenopausal women (-0.36 cm per decade [β = -0.36; 95% CI, -0.47 to -0.26]). Postmenopausal women showed 10-year differences in VAT that were larger than those for men 48 years or older (0.24 cm per decade [β = 0.24; 95% CI, 0.05 to 0.43] vs -0.01 cm per decade [β = -0.01; 95% CI, -0.12 to 0.10]). In addition, 10-year differences in SAT were larger in postmenopausal women than in men 48 years or older (-0.36 cm [β = -0.36; 95% CI, -0.47 to -0.26] vs -0.22 cm [β = -0.22; 95% CI, -0.27 to -0.18]).

CONCLUSIONS

Menopause is not associated with accelerated fat gain in women with cardiovascular disease. Compared with similar-aged men, postmenopausal women show a steeper increase in VAT and a steeper decrease in SAT. These ongoing changes might add to an unfavorable metabolic profile associated with an increased risk of recurrent cardiovascular events.

The impact of visceral obesity on surgical outcomes of laparoscopic surgery for colon cancer

PURPOSE

Although obesity is considered as a risk factor for postoperative morbidity in abdominal surgery, its effect on the outcomes of laparoscopic-assisted colectomy (LAC) is still unclear. The technical difficulty and risk factor for postoperative complication in LAC are thought to be influenced by visceral obesity. The aim of this prospective study was to evaluate the impact of visceral fat on the surgical outcomes of LAC.

METHODS

Between April 2005 and December 2010, consecutive patients with preoperatively diagnosed colon cancer, excluding medium and low rectal cancer, who underwent LAC, were enrolled. Their visceral fat area (VFA) and body mass index (BMI) were prospectively collected. The VFA was assessed by Fat Scan software. The patients were classified into two groups as follows: VFA nonobese with VFA <100 cm(2) (VNO) and VFA obese with VFA ≧100 cm(2) (VO). The predictive factors for surgical complications of LAC were evaluated by univariate and logistic regression analyses.

RESULTS

A total of 338 consecutive patients were enrolled in this study. Of the 338 patients, 194 (57.4 %) and 138 (42.6 %) were classified into the VNO and VO groups, respectively. Logistic regression analysis showed that high BMI (≧25 kg/m(2)) and VO independently predicted the incidence of overall postoperative complications (p = 0.040 and 0.007, respectively). VO was more highly related to the incidence of overall postoperative complications, anastomotic leakage (p = 0.021), and surgical site infection (SSI) (p = 0.013) than high BMI.

CONCLUSIONS

VFA is a more useful parameter than BMI in predicting surgical outcomes after LAC.

Body composition variables as predictors of NAFLD by ultrasound in obese children and adolescents

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a disorder associated with excessive fat accumulation, mainly in the intra-abdominal region. A simple technique to estimate abdominal fat in this region could be useful to assess the presence of NAFLD, in obese subjects who are more vulnerable to this disease. The aim of this cross-sectional study was to verify the reliability of waist circumference and body composition variables to identify the occurrence of NAFLD in obese children and adolescents.

METHODS

Sample was composed of 145 subjects, aged 11 to 17 years. Assessments of waist circumference (WC), trunk fat mass (TFM) and fat mass (FM) by dual-energy X-ray absorptiometry (DXA) and ultrasound for diagnosis of NAFLD and intra-abdominal adipose tissue (IAAT) were used. Correlation between variables was made by Spearman's coefficients; ROC curve parameters (sensitivity, specificity, area under curve) were used to assess the reliability of body composition variables to assess the presence of NAFLD. Statistical significance was set at 5%.

RESULTS

Significant correlations were observed between NAFLD and WC (p = 0.001), TFM (p = 0.002) and IAAT (p = 0.001). The higher values of area under the ROC curve were for WC (AUC = 0.720), TFM (AUC = 0.661) and IAAT (AUC = 0.741).

CONCLUSIONS

Our findings indicated that TFM, IAAT and WC present high potential to identify NAFLD in obese children and adolescents.

Validation of ultrasound examination for assessment of the abdominal visceral fat in clinically serious obese patient

BACKGROUND

Computerized tomography is the gold-standard for measurement of abdominal visceral fat. However, it is costly and involves submitting patients to ionizing radiation.

AIM

To validate the use of ultrasonography in assessing abdominal visceral fat among clinically serious obese patients of both genders.

METHODS

The sample included adult patients with clinically serious obesity with body mass index of 40 kg/m2 or from 35 kg/m(2) to 40 kg/m2 with co-morbidities. Abdominal visceral fat thickness was measured using ultrasound and tomography. Two ultrasonographic exams were conducted to assess the interobserver reproducibility among a patient subsample. Validation was done by comparing these results with the tomographic findings.

RESULTS

The study included 13 patients (61.54% female) with an average BMI of 38.82 kg/m2. In terms of validation, the result obtained from applying the Pearson correlation coefficient was equal to 0.94 (p = 0.0005), showing a strong positive correlation between the two measurements. As for the results for reproducibility, the interobserver was equal to 0.822, with a confidence interval of 95% (-0.076 to 0.980), revealing good interobserver agreement. The average difference between the two ultrasound interobserver examination was equal to 0.10 ± 1.51 (p=0.8898) and so not significant. Interobserver bias was also not significant.

CONCLUSION

The validation of ultrasonographic examination to replace tomographic method in assessing abdominal visceral fat among clinically serious obese patients was effective. The ultrasound measurement is independent of the examiner.

Effects of black tea on body composition and metabolic outcomes related to cardiovascular disease risk: a randomized controlled trial

This randomised controlled double-blind 6 month parallel-designed trial indicates that ingestion of black tea over 3 months can improve body weight and body composition.

Cut-Off Values of Visceral Adiposity to Predict NAFLD in Brazilian Obese Adolescents

Objectives. The present study aimed at determining cut-off points of visceral fat to predict NAFLD and analyzed metabolic disorders of obese adolescents. Methods. Cross-sectional study involved 165 obese adolescents ranged in age from 15 to 19 years. Glycemia, hepatic transaminases, lipid profile, and insulin resistance were analyzed. Visceral and subcutaneous fat were measured by ultrasound and body composition by plesthysmography. Results. The NAFLD adolescents had significantly higher values for body mass, BMI-for-age, BMI, total fat, waist circumference, and visceral fat when compared with non-NAFLD obese adolescents in both genders. Moreover, there were significant positive correlations between visceral fat with the variables BMI-for-age (r = 0.325,), TG (r = 0.277), AST (r = 0.509), ALT (r = 0.519), WC (r = 0.390), and visceral/subcutaneous ratio (r = 0.790) for NAFLD group. Total fat, triglycerides, and visceral fat were the independent predictors to NAFLD. Analysis of the ROC curves revealed cut-off points of visceral fat of 4.47 cm for girls and 4.21 cm for boys. Conclusions. The results may suggest that abdominal ultrasonography procedure may be a safe alternative method of assessing visceral adiposity aiming to be considered to the development of preventive and treatment strategies in obese individuals. This clinial trial is registered with ClinicalTrial.gov (NCT01358773).

Visceral adiposity in the first half of pregnancy predicts newborn weight among adolescent mothers

OBJECTIVE

Maternal obesity is a strong risk factor for gestational diabetes mellitus and fetal macrosomia. We assessed the association between maternal visceral adiposity tissue (VAT) depth in the first half of pregnancy and both glucose tolerance in late pregnancy and newborn weight in pregnant adolescents.

METHODS

We completed a prospective cohort study of 73 pregnant adolescents aged 10 to 19 years, without pre-pregnancy diabetes. VAT depth was measured by ultrasound at 12 to 20 weeks' gestation, followed by a two-hour 75-g oral glucose tolerance test at 36 to 39 weeks' gestation, to determine the glucose area under the curve (AUC glucose0-120). The association between VAT depth and newborn weight was evaluated by multiple linear regression analysis, controlling for maternal age, parity, smoking, gestational age at delivery, infant sex, pre-pregnancy BMI, weight gain in pregnancy, and fasting serum glucose at 36 to 39 weeks' gestation. The relation between VAT depth and AUC glucose0-120 was assessed by linear regression analysis, adjusting for maternal age, parity, smoking, pre-pregnancy BMI, and weight gain in pregnancy.

RESULTS

A 1 cm increase in VAT depth was associated with a 206 g (95% CI 101 to 311) adjusted increase in mean birth weight. VAT depth and the other model covariates together explained more of the variance in birth weight (r(2) = 0.282; P < 0.001) than pre-pregnancy BMI with the other covariates in the same model (r(2) = 0.081; P = 0.076). All three glucose tolerance test measures were performed at 36 to 39 weeks' gestation in 51 of the 73 participants. The relationship between VAT depth and AUC glucose0-120 was not significant (P = 0.43).

CONCLUSION

VAT depth in the first half of pregnancy predicts newborn weight better than BMI, but is not associated with glucose tolerance in late pregnancy.

Automatic distance measurement of abdominal aorta for ultrasonography-based visceral fat estimation

Ultrasonography-based visceral fat estimation is a promising method to assess central obesity, which is associated with metabolic syndrome. The key to this method is to measure three types of distance in the ultrasound image. The most important one is the distance from the skin surface to the posterior wall of the abdominal aorta. We present a novel automatic measurement method to calculate this distance using 1D ultrasound signal processing. It is different from the conventional 2D image processing based methods which have high failure rate when the target is blurred or partially imaged. The proposed method identifies the waveforms of the aorta along a group of ultrasound scan lines and a rating mechanism is introduced to choose the best waveform for distance calculation. The robustness and accuracy of the method were evaluated by experiments based on clinical data.

The role of ultrasonography in the evaluation of abdominal fat: analysis of technical and methodological issues

RATIONALE AND OBJECTIVES

Ultrasonography (US) is becoming popular for the assessment of adiposity, but no one has studied this tool in the light of its potential limitations. Our purpose was to investigate the impact of technical conditions on the evaluation of abdominal fat by US.

MATERIALS AND METHODS

Forty-five healthy males and 45 healthy females were consecutively enrolled in the study, randomly assigned to three groups equally distributed by sex, and examined accordingly to three technical points: fasting state (before and after meal [A]), breathing (expiration and inspiration [B]), and US equipment from different generations: 2003 and 1998 (C). Two blinded radiologists performed US in the these opposite conditions, acquiring five parameters representative of subcutaneous and visceral adiposity in two times. Student's t-test and Lin's correlation coefficient were used for statistical analysis to assess differences in the measures as well as in inter- and intra-observer agreements.

RESULTS

The maximum and the only statistically significant changes were observed for intra-abdominal fat thickness regarding fasting state and breathing (Δ% = 24.1 ± 21.3 and Δ% = 9.2 ± 20.4, respectively; P < .0001). Reproducibility and repeatability, especially for visceral fat, were proved more stable in the following conditions: fasting state, expiration, and newer machine (2003).

CONCLUSION

This article provides essential information and "range of confidence" for variations that can be expected from using different conditions in the measurement of abdominal adiposity by US to be carefully addressed as well as considered by US users and by researchers involving this technique in the field of body composition.

Nonalcoholic fatty liver disease in prepubertal children born small for gestational age: influence of rapid weight catch-up growth

BACKGROUND/AIMS

We studied the association of low birth weight with ultrasound-assessed nonalcoholic fatty liver disease (NAFLD) to test the hypothesis that fetal growth retardation followed by a rapid weight catch-up growth might be an additional factor responsible for liver steatosis via insulin resistance (IR) and/or intra-abdominal fat.

METHODS

We enrolled 23 children born small for gestational age (SGA) with a rapid catch-up growth within the first 6-12 months, and 24 appropriate for gestational age (AGA) children as controls. All children underwent anthropometric, body composition measurements and evaluation of liver function tests, lipid profile, plasma glucose and insulin levels. Abdominal ultrasonography was performed in order to asses liver steatosis and thickness of subcutaneous and visceral adipose tissue.

RESULTS

NAFLD were observed in 8 out of the 23 SGA children (34.8%). IR and visceral fat were significantly increased in children with hepatic steatosis compared to those without. IR index was significantly related to liver steatosis, independently of body mass index standard deviation score and visceral fat.

CONCLUSIONS

NAFLD should be recognized as an emerging problem in SGA prepubertal children who presented a rapid weight gain in postnatal life, and IR plays the key role. An appropriate diet during pregnancy and in the first year of life might prevent metabolic syndrome and NAFLD in these subjects.

Ectopic fat and cardiometabolic and vascular risk

Given that the variation in how regional adipose tissue handles and stores excess dietary energy has substantial cardiometabolic implications, ectopic fat distribution might be an important predictor of cardiometabolic and vascular risk, in addition to overall obesity itself. Conceptually, ectopic fat depots may be divided into systemically acting fat depots and locally acting fat depots. Systemically acting fat depots include visceral fat, fat in the liver, muscle, or neck, and subcutaneous fat. Accumulation in the abdominal visceral area, compared with overall obesity, has an equally or more important role in the development of cardiometabolic risk. Fat depots in liver/muscle tissue cause adverse cardiometabolic effects by affecting energy metabolism. Fat depots in lower-body subcutaneous areas may be protective regarding cardiometabolic risk, by trapping remnant energy. Fat accumulation in the neck is a unique type of fat depot that may increase cardiovascular risk by increasing insulin resistance. Locally acting fat depots include pericardial fat, perivascular fat, and renal sinus fat. These fat depots have effects primarily on adjacent anatomic organs, directly via lipotoxicity and indirectly via cytokine secretion. Pericardial fat is associated with coronary atherosclerosis. Perivascular fat may play an independent role in adverse vascular biology, including arterial stiffness. Renal sinus fat is a unique fat depot that may confer additional cardiometabolic risk. Thus, ectopic fat depots may contribute to the understanding of the link between body composition and cardiometabolic risk. In this review, we focus on the role and clinical implications of ectopic fat depots in cardiometabolic and vascular risk.

Feasibility of using ultrasound to measure preterm body composition and to assess macronutrient influences on tissue accretion rates

BACKGROUND AND AIMS

To assess ultrasound as a method for (i) measuring body composition (BC) of preterm infants and for (ii) assessing the influence of macronutrient intakes on tissue accretion rates.

METHODS

Preterm ultrasound studies of four anatomical sites were performed approximately every three weeks from birth to corrected-term age. Preterm measurements were compared to foetal reference data. Duplicate scans at each site were taken on a subset of infants to test the reproducibility of the method, assessed as the coefficient of variation (CV). The influence of measured macronutrient intakes on preterm BC was assessed by regression analysis.

RESULTS

Median (range) gestation and birth weight of 40 preterm infants were 27 (23-29) weeks and 1022 (480-1475) g, respectively. Accretion rates of adipose and muscle tissues were not uniform across the four sites. Relative to the foetus, preterm adipose tissue thickness was reduced at an equivalent (corrected) gestation, but towards term, a faster accretion rate of subcutaneous abdominal adipose and limb muscle tissue was evident. Timing of fortification (p=0.012), enteral carbohydrate intake (p=0.008) and the protein energy ratio of intakes (p=0.038) moderated the ratio of adipose to muscle tissue accretion over the four sites by -0.004, -0.048 and -0.042, respectively.

CONCLUSIONS

Ultrasound provides a non-invasive, portable method of assessing changes in subcutaneous adipose tissue and muscle accretion and appears sufficiently sensitive to detect influences of macronutrient intakes on accretion rates from birth. The method warrants further investigation as a bedside tool for measuring BC of preterm infants.