Ultrasonography for the evaluation of visceral fat and the metabolic syndrome

Ultrasound-based measurement of central adiposity: Key considerations and guidelines

Central adiposity, which is visceral and subcutaneous adiposity in the abdominal region, is a known risk factor for developing chronic cardiometabolic diseases. Central adiposity can be measured relatively inexpensively using ultrasound. Ultrasound has been shown to be precise and reliable, with measurement accuracy comparable to computed tomography and magnetic resonance. Despite the advantages conferred by ultrasound, widespread adoption has been hindered by lack of reliable standard operating procedures. To consolidate the literature and bring clarity to the use of ultrasound-derived measures of central adiposity, this review outlines (i) the [patho]physiological importance of central adiposity to cardiometabolic disease risk; (ii) an overview of the history and main technical aspects of ultrasound methodology; (iii) key measurement considerations, including transducer selection, subject preparation, image acquisition, image analysis, and operator training; and (iv) guidelines for standardized ultrasound protocols for measuring central adiposity.

Sonographically Measured Adipose Tissue Thickness Correlates with Laboratory Test Abnormalities Reflecting Metabolic State in Elderly Women

Background: Accumulation of adipose tissue progresses to metabolic diseases. Sonography is a convenient modality for measuring the thickness of adipose tissue. The present study aimed to clarify the site of adipose tissue thickness that correlated best with laboratory test values reflecting metabolic abnormalities. Methods: Subjects comprised 37 elderly women with metabolic diseases or an almost healthy state (median age, 71 years; interquartile range, 62-78 years). Abdominal visceral adipose tissue (VAT), subcutaneous adipose tissue, peritoneal adipose tissue, perirenal adipose tissue, and epicardial adipose tissue (EAT) thicknesses were measured. Correlations were evaluated between laboratory test values and these adipose tissue thicknesses. Results: VAT thickness measured at the level of the umbilicus correlated positively with values of triglycerides (TGs) (r = 0.593, P = 0.0009) and hemoglobin A1c (r = 0.490, P = 0.0081) and negatively with the value of high-density lipoprotein cholesterol (r = -0.521, P = 0.0045), even after adjusting for body mass index. Significant positive correlations were also found between EAT thickness and TGs (r = 0.542, P = 0.0029). Conclusions: Among the adipose tissue thicknesses measured at several sites by sonography, VAT thickness correlated most closely with laboratory test values representing metabolic abnormalities in elderly women.

Measurement of total and visceral fat mass in young adult women: a comparison of MRI with anthropometric measurements with and without bioelectrical impedance analysis

OBJECTIVE

MRI is established for measurement of body fat mass (FM) and abdominal visceral adipose tissue (VAT). Anthropometric measurements and bioelectrical impedance analysis (BIA) have been proposed as surrogates to estimation by MRI. Aim of this work is to assess the predictive value of these methods for FM and VAT measured by MRI.

METHODS

Patients were selected from cohort study PPS-Diab (prediction, prevention and subclassification of Type 2 diabetes). Total FM and VAT were quantified by MRI and BIA together with clinical variables like age, waist and hip circumference and height. Least-angle regressions were utilized to select anthropometric and BIA parameters for their use in multivariable linear regression models to predict total FM and VAT. Bland-Altman plots, Pearson correlation coefficients, Wilcoxon signed-rank tests and univariate linear regression models were applied.

RESULTS

116 females with 35 ± 3 years and a body mass index of 25.1 ± 5.3 kg/m2 were included into the analysis. A multivariable model revealed weight (β = 0.516, p < 0.001), height (β = -0.223, p < 0.001) and hip circumference (β = 0.156, p = 0.003) as significantly associated with total FM measured by MRI. A additional multivariable model also showed a significant predictive value of FMBIA (β = 0.583, p < 0.001) for FM. In addition, waist circumference (β = 0.054, p < 0.001), weight (β = 0.016, p = 0.031) in one model and FMBIA (β = 0.026, p = 0.018) in another model were significantly associated with VAT quantified by MRI. However, deviations reached more than 5 kg for total FM and more than 1 kg for VAT.

CONCLUSION

Anthropometric measurements and BIA show significant association with total FM and VAT.

ADVANCES IN KNOWLEDGE

As these measurements show significant deviations from the absolute measured values determined by MRI, MRI should be considered the gold-standard for quantification.

l-Carnitine-induced amelioration of HFD-induced hepatic dysfunction is accompanied by a reduction in hepatic TNF-α and TGF-β1

In this study, we evaluated the possible mechanisms through which l-carnitine ameliorates the adverse effects from obesity in rats, induced with a high-fat diet (HFD). For this, 56 albino Wister rats were randomly assigned to 7 groups. The control group was fed a basal diet and injected with saline. The second group was fed the basal diet and injected with l-carnitine (200 mg/kg body mass, by intraperitoneal injection; i.p.). The third group were fed the HFD. The fourth group was fed the HFD and injected with l-carnitine (200 mg/kg body mass, i.p.) for 8 weeks. The fifth group was fed the HFD for 10 weeks. The sixth group were fed the HFD for 10 weeks and were also injected with l-carnitine (200 mg/kg body mass, i.p.) during the final 2 weeks. The seventh group was fed the HFD diet for 8 weeks then the basal diet for 2 weeks. The HFD induced significantly increased levels of hyperglycemia, lipid peroxidation, pathological changes, TNF-α and TGF-β1 protein expression in hepatic tissue, food intake, body weight gain, serum levels of total and non-high-density lipoprotein cholesterol, ketone bodies, triacylglycerol, urea, creatinine, AST, and ALT. However, the HFD diet significantly decreased serum levels of high-density lipoprotein (HDL) and hepatic levels of reduced glutathione. l-Carnitine ameliorated the effects of the HFD on the above-mentioned parameters. This study indicated that l-carnitine had protective and curative effects against HFD-induced hepatosteatosis by reducing hepatic oxidative stress and protein expression of TNF-α and TGF-β1.

Body fat index: A novel alternative to body mass index for prediction of gestational diabetes and hypertensive disorders in pregnancy

OBJECTIVES

To evaluate the association of ultrasound measurement of maternal abdominal subcutaneous and pre-peritoneal fat thickness in relation to the subsequent diagnosis of gestational diabetes (GDM), and to assess the association of body fat index (BFI), compared to conventional body mass index (BMI), with respect to the development of some obstetric related complications.

STUDY DESIGN

A prospective study included non-diabetic pregnant women who were scheduled for fetal anatomic survey. Women underwent fat measurements and BFI (pre-peritoneal fat x subcutaneous fat/height) was calculated. They underwent routine glucose screening and diagnostic tests for GDM. Obstetric complications, mode of delivery, and delivery related events were reported. Multivariable logistic regression was used to test potential predictors for development of obesity-related complications. Primary outcome was development of GDM. Secondary outcomes included development of hypertensive disorders during pregnancy and need for cesarean delivery due to labor dystocia. The optimal cut-off points for continuous variables were obtained using a receiver operating characteristic (ROC) curve analyses.

RESULTS

389 women met study criteria. Median gestational age at time of ultrasound evaluation was 19.1 weeks. Positive family history of diabetes (adjusted odds ratio "OR" 2.30, 95% CI 1.35-3.92), history of GDM (adjusted OR 6.87, 95% CI 3.03-15.61), subcutaneous fat≥13 mm (adjusted OR 4.63, 95% CI 1.60-13.38) and pre-peritoneal fat≥12 mm (adjusted OR 3.32, 95% CI 1.06-10.42) were significant predictors for development of GDM. ROC analysis demonstrated that a BFI > 0.5 was statistically superior to a BMI > 25 or 30 as a predictor of gestational diabetes (adjusted OR 6.24, 95% CI 1.86-20.96). A Similar ROC analysis demonstrated that a BFI > 0.8 was associated with a higher risk for the development of hypertensive disorders of pregnancy (adjusted OR 2.70 [95% CI 1.60-4.55]), and need for cesarean delivery (adjusted OR 2.01[95% CI 1.23-3.28]) than a BMI > 25 or 30.

CONCLUSION

Values obtained by ultrasound measurement of subcutaneous and pre-peritoneal fat are associated with development of GDM and hypertensive disorders in pregnancy. Our data suggest that BFI was a better predictor than BMI for development of GDM and hypertensive disorders in pregnancy and should be studied further.

Risk of Cardiovascular Events in Patients with Primary Biliary Cholangitis - Systematic Review

Background and Aims: Hypercholesterolemia is a common finding in patients with primary biliary cholangitis (PBC) and is a well-defined risk factor for cardiovascular disease. However, studies have been mixed on whether PBC patients do, in fact, have higher cardiovascular risk. The aim of this study is to review the current literature and provide an evidence-based assessment of cardiovascular risk in PBC patients. Methods: We performed a systematic literature search on PubMed regarding patients with PBC and cardiovascular events from the database inception to July 1, 2017. A total of 33 articles fulfilling our inclusion criteria were found. Results: The majority of the studies evaluated yielded no statistically significant difference in cardiovascular disease in the PBC population compared to the general public. However, some reports found a statistically significantly increase in coronary artery disease. Several studies have looked at the specific lipid profile of patients with PBC with hypocholesteremia. While these lipid abnormalities differ by stage of disease, there is evidence to suggest that the specific lipid profile in PBC may have lower atherogenicity than in patients with hypercholesterolemia without PBC. Studies looking at patients with PBC with other risk factors for cardiovascular disease, such as hypertension and metabolic syndrome, have consistently found a higher risk for cardiovascular disease in these patients. Statin treatment is effective in reducing lipid levels and possibly improving endothelial inflammation in patients with PBC with hypercholesterolemia. Conclusions: There is not enough evidence to suggest an increased risk of cardiovascular disease in patients with PBC with hypercholesterolemia, except for those individuals with concomitant features of metabolic syndrome. In patients with PBC with no additional cardiovascular risk factors, individual risk/benefit discussion on lipid-lowering treatment should be considered.

Measuring Abdominal Visceral Fat Thickness With Sonography: A Methodologic Approach

This methodological approach to assessing obesity is based on the prepilot work conducted on a small sample of men and women (25-58 years of age) in a laboratory setting. The use of skinfold calipers, body mass index, and sonographic imaging of adipose and visceral fat were obtained. In this pre-experimental work, the rigorous use of sonographic measures of visceral fat demonstrated better trend results than the other measurement tools. The sonographic methods employed were modeled after the work published by Hamagawa et al. All measurements were taken five times, and only the middle three were retained for mean data points. The data are compared and contrasted with a paucity of international studies using sonography to measure visceral adiposity. It is important to determine whether sonography could serve as a non-ionizing imaging technique for the assessment of body composition and a screening technique for cardiovascular disease prediction.

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.

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.

Abdominal fat sonographic measurement compared to anthropometric indices for predicting the presence of coronary artery disease

OBJECTIVES

Sonography for measuring intra-abdominal fat is more accurate than anthropometric measurements. Computed tomographic (CT) angiography has become an accurate noninvasive method for detection of coronary artery disease (CAD). We examined the associations between both sonographic and anthropometric measurements of abdominal adiposity and the presence of CAD on CT angiography.

METHODS

We evaluated 83 consecutive patients (70% men; mean age ± SD, 56 ± 10.8 years) who were referred for CT angiography. Clinical and laboratory variables were determined, and CT angiography was performed using a 64-slice scanner. The severity of CAD was defined by visual assessment of any plaque, either calcified or noncalcified. Preperitoneal fat, subcutaneous fat, and visceral fat thicknesses were determined on sonography, and the abdominal fat index was calculated as the preperitoneal fat thickness-to-subcutaneous fat thickness ratio.

RESULTS

Coronary artery disease was detected in 56 patients (67%). Patients with CAD had higher visceral fat thickness (9.3 ± 2.0 versus 8.2 ± 2.2 cm; P = .035) and a higher waist-to-hip ratio (0.97 ± 0.07 versus 0.92 ± 0.07; P = .018) than those without CAD. The preperitoneal fat thickness, subcutaneous fat thickness, and abdominal fat index were not correlated with the CAD status. After adjusting for traditional cardiovascular risk factors, however, only a waist-to-hip ratio higher than 0.95 remained significantly associated with the presence of CAD (odds ratio, 4.03; 95% confidence interval, 1.2-13.4).

CONCLUSIONS

This study shows that sonographically based obesity measurements are not superior to anthropometric indices in predicting the presence of CAD.

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.

Ultrasound estimates of visceral and subcutaneous-abdominal adipose tissues in infancy

Other imaging techniques to quantify internal-abdominal adiposity (IA-AT) and subcutaneous-abdominal adiposity (SCA-AT) are frequently impractical in infants. The aim of this study was twofold: (a) to validate ultrasound (US) visceral and subcutaneous-abdominal depths in assessing IA-AT and SCA-AT from MRI as the reference method in infants and (b) to analyze the association between US abdominal adiposity and anthropometric measures at ages 3 months and 12 months. Twenty-two infants underwent MRI and US measures of abdominal adiposity. Abdominal US parameters and anthropometric variables were assessed in the Cambridge Baby Growth Study (CBGS), n = 487 infants (23 girls) at age 3 months and n = 495 infants (237 girls) at 12 months. US visceral and subcutaneous-abdominal depths correlated with MRI quantified IA-AT (r = 0.48, P < 0.05) and SCA-AT (r = 0.71, P < 0.001) volumes, respectively. In CBGS, mean US-visceral depths increased by ~20 % between ages 3 and 12 months (P < 0.0001) and at both ages were lower in infants breast-fed at 3 months than in other infants. US-visceral depths at both 3 and 12 months were inversely related to skinfold thickness at birth (P = 0.03 and P = 0.009 at 3 and 12 months, resp.; adjusted for current skinfold thickness). In contrast, US-subcutaneous-abdominal depth at 3 months was positively related to skinfold thickness at birth (P = 0.004). US measures can rank infants with higher or lower IA-AT and SCA-AT. Contrasting patterns of association with visceral and subcutaneous-abdominal adiposities indicate that they may be differentially regulated in infancy.

Effect of chromium dinicocysteinate supplementation on circulating levels of insulin, TNF-α, oxidative stress, and insulin resistance in type 2 diabetic subjects: randomized, double-blind, placebo-controlled study

SCOPE

Chromium and cysteine supplementation have been shown to improve glucose metabolism in animal studies. This study examined the hypothesis that chromium dinicocysteinate (CDNC), a complex of chromium and l-cysteine, is beneficial in lowering oxidative stress, vascular inflammation, and glycemia in type 2 diabetic subjects.

METHODS AND RESULTS

Type 2 diabetic subjects enrolled in this study were given placebo for 1 month for stabilization and then randomized into one of three groups: placebo (P), chromium picolinate (CP), or CDNC, after which they received daily oral supplementation for 3 months. Of the 100 patients enrolled in the study, 74 patients completed it. There were 25 patients in the P supplemented group, 25 in the CP supplemented and 24 in the CDNC supplemented group who completed the study. Blood markers of glycemia, vascular inflammation, HOMA insulin resistance, and oxidative stress were determined at randomization and after 3 months of supplementation with P, CP, or CDNC. There was a significant decrease at 3 months in insulin resistance (p = 0.02) and in the levels of protein oxidation (p = 0.02) and TNF-α (p = 0.01) in the CDNC supplemented cohort compared to baseline. However, there was no statistically significant change in these markers in the CP supplemented group compared to baseline. Insulin levels significantly decreased (p = 0.01) for subjects receiving CDNC but not CP. There was no significant impact of supplementation on HbA(1c) or glucose levels in either of the groups.

CONCLUSION

CDNC supplementation lowers insulin resistance by reducing blood levels of TNF-α, insulin, and oxidative stress in type 2 diabetic subjects. Therefore, CDNC supplementation has potential as an adjunct therapy for individuals with type 2 diabetes.

Assessment of metabolic syndrome in patients with primary biliary cirrhosis

BACKGROUND

Primary biliary cirrhosis (PBC) is a chronic, progressive liver disease with elevated serum lipids. It remains unclear if hyperlipidemia increases the risk for atherosclerosis in PBC patients. Metabolic syndrome (MS) promotes the development of atherosclerotic cardiovascular disease due to abdominal obesity and insulin resistance.

AIMS

The aim of this study was to assess incidence and parameters of MS, as well as subcutaneous and visceral fat using noninvasive ultrasonographic measurement in patients with PBC in our population.

METHODS

We included 55 patients with PBC and 44 age- and sex-matched healthy controls (CG-control group). Anthropometric measurements (weight, height, and waist circumference), age, sex, and body mass index were recorded for patients and controls. Laboratory tests for assessing MS and liver function tests were analyzed. We used ultrasonography to determine subcutaneous and visceral fat diameter and area (SF, VF and SA, VA, respectively), as well as perirenal fat diameter (PF).

RESULTS

Patients with PBC had significantly higher levels of cholesterol and liver function tests. There were no statistically significant difference in serum insulin and HOMA levels, as well as incidence of MS was diagnosed in 30.9 % (17/55) PBC patients and 43.2 % (19/44) controls. We registered lower amount of VF (PBC:10.92 ± 3.63 mm, CG:16.84 ± 5.51 mm,p < 0.001), VA (PBC:403.64 ± 166.97 mm(2), CG:720.57 ± 272.50 mm(2),p < 0.001), and PF (PBC:7.03 ± 1.82 mm, CG 10.49 ± 2.70 mm,p < 0.001) in patients with PBC.

CONCLUSION

MS is not more frequent in patients with PBC compared with healthy volunteers in our population. Lower amount of VF could be related to lower risk for cardiovascular events in PBC patients.

Accuracy, reproducibility and repeatability of ultrasonography in the assessment of abdominal adiposity

RATIONALE AND OBJECTIVES

Despite improvements in the methods used in body composition analysis, some goals remain far from clinical practice. Among them, the most important is the quantification of intra-abdominal adipose tissue. Fat distribution is a key point in the assessment of cardiovascular and metabolic risk status. The aim of this study was to define the accuracy, reproducibility, and repeatability of ultrasonography in the evaluation of abdominal adiposity.

MATERIALS AND METHODS

Twenty-six nonobese patients (group A) who underwent computed tomographic (CT) abdominal imaging and 29 obese patients (group B) were enrolled. Patients from both groups were independently evaluated using ultrasound by three radiologists; computed tomography-like conditions were reproduced, and six main parameters of subcutaneous and internal adiposity were measured (as well as three derived indexes) with both linear and convex probes. In group A, the same measurements were also obtained on CT images. Time spent for every ultrasound session was recorded. Results were analyzed using Lin's concordance correlation (ρ), intraclass correlation, and linear regression analysis (and analysis of variance).

RESULTS

Three patients were excluded from group A after CT scans because of technical problems. Mesenteric fat thickness did not show significant correlations and reliability. Strong correlations between ultrasound and CT measurements were observed for all other visceral and subcutaneous parameters (ρ = 0.85-0.96). Intraobserver and interobserver agreement was excellent in both groups (repeatability: ρ = 0.83-0.99 for group A, ρ = 0.90-0.99 for group B; reproducibility: intraclass correlation coefficient = 0.90-0.99 for groups A and B). The mean time spent was 95 ± 21 seconds for group A (mean body mass index, 27.4 ± 2.4 kg/m(2)) and 129 ± 33 seconds for group B (mean body mass index, 37.3 ± 11.9 kg/m(2)).

CONCLUSIONS

Ultrasound is accurate, reproducible, and fast in the analysis of abdominal adiposity. It offers a regional, easy, and close-at-hand evaluation of subcutaneous and visceral fat compartments. This should be taken into consideration when clinical routine examinations are performed or to evaluate patients with specific metabolic diseases before and after treatment.

Assessment of measures for abdominal adiposity in persons with spinal cord injury

Ultrasound may be a useful tool to assess abdominal adiposity, but it has not been validated in the spinal cord injury (SCI) population. This study evaluated associations between abdominal ultrasound and other methods to assess adiposity in 24 men with SCI and 20 able-bodied (AB) men. Waist (WC) and hip circumference (HC) and waist-to-hip ratio (WHR) were measured. Trunk (TRK%), android (A%) and waist fat (W%) were determined by dual energy x-ray absorptiometry (DXA); ultrasonography determined abdominal subcutaneous (SF) and visceral fat (VF). The SCI group had greater TRK% (40.0 ± 9.6 vs. 32.0 ± 10.3), W% (47.0 ± 9.7 vs. 40.6 ± 9.4), A% (43.0 ± 9.8 vs. 35.8 ± 10.6) and WHR (0.99 ± 0.1 vs. 0.92 ± 0.06) than the AB group. WC and WHR correlated with VF in the SCI group. These associations suggest that ultrasound may be a useful tool in clinical practice for the measurement of VF in weight loss programs and for the assessment of cardiometabolic disorders.

Prevalência de esteatose hepática e consumo de álcool em participantes do Projeto Atividade Física na Vila

A esteatose hepática é um achado cada vez mais frequente em exames de rastreamento por estudo de imagem. Tem sido descrita associação entre esteatose, obesidade, resistência à insulina e síndrome metabólica (SM). Também parece existir sinergismo entre esteatose hepática, álcool e fibrose hepática. O objetivo foi descrever a prevalência de esteatose e de etilismo nos participantes do Projeto “Atividade Física na Vila” e avaliar sua associação com a presença de obesidade e obesidade visceral. Foi realizada ultrassonografia abdominal em 69 participantes, 53,02±1,26 anos, sendo avaliados a presença e o grau de esteatose e as medidas da gordura subcutânea e visceral (GV). Foram excluídos os pacientes com hepatite viral e com etilismo significativo na anamnese ou após teste AUDIT. Após análise inicial, 60 pacientes foram avaliados quanto aos dados antropométricos e divididos em 2 grupos: com e sem esteatose. A prevalência de etilismo foi de 8,7%. A esteatose hepática foi observada em 37% dos pacientes sendo a maioria classificada como leve e moderada (91%). O grupo com esteatose apresentou aumento significativo de IMC (34,±8,7 versus 29,8±6,5kg/m2), cintura abdominal (102,6±12,7 versus 95,3±12,3cm), peso (85,8±18,7 versus 74,5±17,7kg) e GV (47,9±10,5 versus 36,0±12,7mm). A esteatose hepática é comum em obesos, especialmente naqueles com obesidade visceral. Sabemos que o álcool e a obesidade visceral podem estar envolvidos em seu mecanismo fisiopatológico. Por isso, os pacientes com esteatose hepática e consumo excessivo de álcool podem apresentar maior chance de evoluir desfavoravelmente para a cirrose e insuficiência hepática.

Ultrasound measurement of visceral fat in patients with primary biliary cirrhosis

Background/Aim. Primary biliary cirrhosis (PBC) is a progressive, chronic liver disease with elevated serum lipids, but it is unclear whether hyperlipidemia in PBC patients is associated with atherosclerosis. Metabolic syndrome promotes development of atherosclerotic cardiovascular disease related to abdominal type obesity and insulin resistance. The aim of our study was to assess abdominal adiposity in patients with PBC. Methods. The study included 40 patients with PBC and 50 healthy controls. Age, sex and anthropometric measurements (weight, height, body mass index and waist circumference) were registered for all patients and controls. We used ultrasonography to measure subcutaneous (SF) and visceral fat (VF) diameter, subcutaneous area (SA) and visceral area (VA), as well as perirenal fat diameter (PF). Results. Values of SF, VF and PF thicknesses in PBC patients were 19.23 ? 5.85 mm, 10.92 ? 3.63 mm, and 7.03 ? 1.82 mm, respectively. In controls these measurements were 22.73 ? 6.70 mm, 16.84 ? 5.51 mm and 10.50 ? 2.70 mm respectively. In PBC patients SA and VA were calculated to 983.64 ? 322.68 mm2 and 403.64 ? 166.97 mm2 and in controls 1124.89 ? 366.01 mm2 and 720.57 ? 272.50 mm2 respectrively. Significant difference was found for VF, VA and RF values. Conclusions. Considering that the amount of visceral fat plays an important role in development of metabolic syndrome and cardiovascular diseases, we concluded that the lower amount of visceral fat in PBC patients could be related to lower incidence of cardiovascular events, despite hyperlipidemia.

Abdominal visceral fat thickness measured by ultrasonography predicts the presence and severity of coronary artery disease

Abdominal visceral fat plays a critical role in the pathogenesis of metabolic syndrome, which is a risk factor for coronary artery disease (CAD). Ultrasonography (US) distinctively quantifies visceral fat and subcutaneous fat. We measured the maximum preperitoneal visceral fat thickness (Vmax) and the minimum subcutaneous fat thickness (Smin) by US in 185 patients who underwent coronary angiography. Although the 144 patients with CAD had larger Vmax (8.8 ± 3.6 vs. 6.4 ± 2.8 mm; p < 0.001) than those without, there was no difference in Smin. Vmax of 6.9 mm or higher was an independent predictor of CAD (odds ratio, 3.710, p = 0.008) by multiple logistic regression analysis. Vmax significantly correlated with the number of diseased vessels. Assessment of abdominal visceral fat by US gives us incremental information beyond conventional risk factors for predicting CAD in routine clinical practice.

An NPC1L1 gene promoter variant is associated with autosomal dominant hypercholesterolemia

BACKGROUND AND AIMS

A substantial number of subjects with autosomal dominant hypercholesterolemia (ADH) do not have LDL receptor (LDLR) or apolipoprotein B (APOB) mutations. Some ADH subjects appear to hyperabsorb sterols from the intestine, thus we hypothesized that they could have variants of the Niemann-Pick C1-Like 1 gene (NPC1L1). NPC1L1 encodes a crucial protein involved in intestinal sterol absorption.

METHODS AND RESULTS

Four NPC1L1 variants (-133A>G, -18C>A, 1679C>G, 28650A>G) were analyzed in 271 (155 women and 116 men) ADH bearers without mutations in LDLR or APOB aged 30-70years and 274 (180 women and 94 men) control subjects aged 25-65years. The AC haplotype determined by the -133A>G and -18C>A variants was underrepresented in ADH subjects compared to controls (p=0.01). In the ADH group, cholesterol absorption/synthesis markers were significantly lower in AC homozygotes that in all others haplotypes. Electrophoretic mobility shift assay (EMSA) results revealed that the -133A-specific oligonucleotide produced a retarded band stronger than the -133G allele. Luciferase activity with NPC1L1 -133G variant was 2.5-fold higher than with the -133A variant.

CONCLUSION

The -133A>G polymorphism exerts a significant effect on NPC1L1 promoter activity. NPC1L1 promoter variants might explain in part the hypercholesterolemic phenotype of some subjects with nonLDLR/nonAPOB ADH.

Abdominal fat in children measured by ultrasound and computed tomography

The prevalence of childhood obesity is increasing rapidly. Visceral fat plays an important role in the pathogenesis of metabolic and cardiovascular diseases. Currently, computed tomography (CT) is broadly seen as the most accurate method of determining the amount of visceral fat. The main objective was to examine whether measures of abdominal visceral fat can be determined by ultrasound in children and whether CT can be replaced by ultrasound for this purpose. To assess whether preperitoneal fat thickness and area are good approximations of visceral fat at the umbilical level, we first retrospectively examined 47 CT scans of nonobese children (body mass index <30kg/m(2); median age 7.9 y [95% range 1.2 to 16.2]). Correlation coefficients between visceral and preperitoneal fat thickness and area were 0.58 (p<0.001) and 0.76 (p<0.001), respectively. Then, to assess how preperitoneal and subcutaneous fat thicknesses and areas measured by ultrasound compare with these parameters in CT, we examined 34 nonobese children (median age 9.5 [95% range 0.3 to 17.0]) by ultrasound and CT. Ultrasound measurements of preperitoneal and subcutaneous fat were correlated with CT measurements, with correlation coefficients ranging from 0.75-0.97 (all p<0.001). Systematic differences of up to 24.0cm(2) for preperitoneal fat area (95% confidence interval -29.9 to 77.9cm(2)) were observed when analyzing the results described by the Bland-Altman method. Our findings suggest that preperitoneal fat can be used as an approximation for visceral fat in children and that measuring abdominal fat with ultrasound in children is a valid method for epidemiological and clinical studies. However, the exact agreement between the ultrasound and CT scan was limited, which indicates that ultrasound should be used carefully for obtaining exact fat distribution measurements in individual children.

Mutations in HFE causing hemochromatosis are associated with primary hypertriglyceridemia

CONTEXT

Most cases of primary hypertriglyceridemia (HTG) are caused by the interaction of unknown polygenes and environmental factors. Elevated iron storage is associated with metabolic syndrome, diabetes, and obesity, and all of them are associated with HTG.

OBJECTIVE

The aim of the study was to analyze whether HFE mutations causing hereditary hemochromatosis (HH) are associated with primary HTG.

DESIGN

Genetic predisposition to HH was analyzed in a case-control study.

SETTING

The study was conducted at University Hospital Lipid Clinic.

PARTICIPANTS

We studied two groups: 1) the HTG group, composed of 208 patients; and 2) the control group, composed of 215 normolipemic subjects and 161 familial hypercholesterolemia patients.

INTERVENTION

Two HFE mutations (C282Y and H63D) were analyzed.

MAIN OUTCOME MEASURE

We measured HH genetic predisposition difference between groups.

RESULTS

HH genetic predisposition was 5.9 and 4.4 times higher in the HTG group than in the normolipemic (P = 0.02) and FH (P = 0.05) subjects, respectively. There were 35 cases (16.8%) of iron overload in the primary HTG group, 14 (6.5%) and nine (5.6%) in the normolipidemic and FH groups, respectively. A higher HH genetic predisposition and a different prevalence of iron overload in subjects with HH genetic predisposition among groups contributed to this higher prevalence. None of the four cases with the HFE genotype associated with high risk of HH in the control groups presented iron overload; however, in eight of 11 subjects (72.7%) with primary HTG and HH genetic predisposition, the iron overload was present.

CONCLUSION

Mutations in HFE gene, favoring iron overload and causing HH, could play an important role in the development of several phenotypes of primary HTG.

Sonographic assessment of abdominal fat distribution in infancy

There is growing evidence that not only the total amount of fat, but also the distribution of body fat determines risks for metabolic and cardiovascular disease. Developmental studies on factors influencing body fat distribution have been hampered by a lack of appropriate techniques for measuring intraabdominal fat in early life. Sonography, which is an established method for assessing abdominal fat distribution in adults, has not yet been evaluated in infants. To adapt the sonographic measurement of abdominal fat distribution to infants and study its reliability. The Generation R study, a population-based prospective cohort study. We included 212 one- and 227 two-year old Dutch infants in the present analysis. Sixty-two infants underwent replicate measurements to assess reproducibility. We developed a standardized protocol to measure the thickness of (1) subcutaneous and (2) preperitoneal fat in the upper abdomen of infants. To this end we defined infancy specific measurement areas to quantify fat thickness. Reproducibility of fat measurements was good to excellent with intraclass correlation coefficients of 0.93–0.97 for intra-observer agreement and of 0.89–0.95 for inter-observer agreement. We observed a pronounced increase in preperitoneal fat thickness in the second year of life while subcutaneous fat thickness increased only slightly, resulting in an altered body fat distribution. Gender did not significantly influence fat distribution in the first two years of life. Our age specific protocol for the sonographic measurement of central subcutaneous and preperitoneal fat is a reproducible method that can be instrumental for investigating fat distribution in early life.

Young adult obese subjects with and without insulin resistance: what is the role of chronic inflammation and how to weigh it non-invasively?

BACKGROUND

Obesity is a leading risk factor for metabolic syndrome whose further expression is non-alcoholic fatty liver disease. Metabolic syndrome is associated with a proinflammatory state that contributes to insulin resistance. Finally, a "metabolically benign obesity" that is not accompanied by insulin resistance has recently been postulated to exist.

AIM

To find whether any inflammation markers were independently associated with the presence of insulin resistance, evaluating specific anthropometric, ultrasonographic and laboratory parameters in a population of young adult obese subjects.

METHODS

Of forty two young individuals, divided into two groups (with or without insulin resistance), were studied serum C-reactive protein and fibrinogen as indexes of chronic pro-inflammatory status. Body mass index, waist circumference and metabolic syndrome presence were assessed as part of the metabolic evaluation. Ultrasonography weighted visceral and subcutaneous abdominal fat thickness, spleen size as longitudinal diameter and liver hyperechogenicity.

RESULTS AND DISCUSSION

Serum C-reactive protein and fibrinogen as well as spleen longitudinal diameter were significantly increased in the obese young with insulin resistance compared to non-insulin resistance group. Insulin resistance was significantly associated with hepatic steatosis score at sonography (r = 0.33, P = 0.03), spleen longitudinal diameter (r = 0.35, P = 0.02) and C-reactive protein (r = 0.38, P = 0.01), but not with body mass index, visceral or subcutaneous abdominal adipose tissue, waist circumference and fibrinogen (P = 0.18, 0.46, 0.33, 0.37 and 0.4, respectively). Steatosis score at sonography was well associated with spleen volume (rho = 0.40, P = 0.01) and C-reactive protein levels (rho = 0.49, P = 0.002). Metabolic syndrome was much more frequent in obese patients with insulin resistance. These findings show that in young adults the only abdominal adiposity without insulin resistance, plays a scarce role in determining hepatic steatosis as well as metabolic syndrome.

CONCLUSION

Increases in spleen size and CRP levels represent a reliable tool in diagnosing insulin resistance.

[Sensitivity and specificity of metabolic syndrome criteria for insulin resistance diagnosis in Spanish population]

BACKGROUND AND OBJECTIVE

Metabolic syndrome (MS) is an abdominal obesity and insulin resistance (IR)-related syndrome associated with a high cardiovascular risk. Recently, the International Diabetes Federation (IDF) has proposed a modification of the Adult Treatment Panel III (ATP III) diagnostic criteria. However, the sensitivity of these new criteria has not been established. The aim of the present study was to define the sensitivity and specificity of the different criteria used for the diagnosis of the MS in our population.

SUBJECTS AND METHOD

We studied in 177 healthy subjects, 68 men and 109 women, the body mass index, waist circumference (WC), blood pressure, glucose, insulin, lipids and apolipoproteins A1 and B. The HOMA index was used as an IR indicator. IR was considered with an HOMA index > or = 3.8.

RESULTS

Subjects with IR showed higher age, systolic blood pressure, triglycerides and apo B, and lower HDL cholesterol. A WC > or = 102 cm in men and > or = 88 cm in women (ATP III criteria) had a low sensitivity for IR (29.4% and 44.7% respectively), with high specificity (81% and 90%). A WC > or = 94 cm in men and > or = 80 cm in women (IDF criteria) showed good sensitivity (73.5% and 73.7% respectively) but less specificity (57.1% and 53.3%). The IDF criteria showed better sensitivity than ATP III, without substantial change in the specificity for the different HOMA cut-off points.

CONCLUSIONS

ATP III criteria had low sensitivity in our population. The new criteria (WC > or = 94 cm in men and > or = 80 cm in women, and blood glucose > or = 100 mg/dL) improve three-fold the diagnostic sensitivity and, therefore, seems to be more useful for detecting IR in our country.