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

Dapagliflozin added to metformin reduces perirenal fat layer in type 2 diabetic patients with obesity

Sodium-glucose co-transporters type 2 inhibitors (SLGT2i) are highly effective in controlling type 2 diabetes, but reported beneficial cardiovascular effects suggest broader actions on insulin resistance. Weight loss may be initially explained by glycosuria-induced net caloric output and secondary volumetric reduction, but its maintenance could be due to loss of visceral fat mass. Structured ultrasound (US) imaging of abdominal adipose tissue ("eco-obesity") is a recently described methodology used to measure 5 consecutive layers of abdominal fat, not assessable by DEXA or CT scan: superficial subcutaneous (SS), deep subcutaneous (DS), preperitoneal (PP), omental (Om) and right perirenal (RK). PP, Om and RK are predictors of metabolic syndrome (MS) with defined cut-off points. To assess the effect of SLGT2i on every fat depot we enrolled 29 patients with type 2 Diabetes (HbA1c 6.5-9%) and Obesity (IMC > 30 kg/m2) in an open-label, randomized, phase IV trial (EudraCT: 2019-000979-16): the Omendapa trial. Diabetes was diagnosed < 12 months before randomization and all patients were treatment naïve. 14 patients were treated with metformin alone (cohort A) and 15 were treated with metformin + dapaglifozin (cohort B). Anthropometric measures and laboratory tests for glucose, lipid profile, insulin, HOMA, leptin, ultrasensitive-CRP and microalbuminuria (MAL) were done at baseline, 3rd and 6th months. At 6th month, weight loss was -5.5 ± 5.2 kg (5.7% from initial weight) in cohort A and -8.4 ± 4.4 kg (8.6%) in cohort B. Abdominal circumference showed a -2.7 ± 3.1 cm and -5.4 ± 2.5 cm reduction, respectively (p = 0.011). Both Metformin alone (-19.4 ± 20.1 mm; -21.7%) or combined with Dapaglifozin (-20.5 ± 19.4 mm; -21.8%) induced significant Om fat reduction. 13.3% of cohort A patients and 21.4% of cohort's B reached Om thickness below the cut-off for MS criteria. RK fat loss was significantly greater in cohort B group compared to cohort A, at both kidneys. Only in the Met + Dapa group, we observed correlations between Om fat with leptin/CRP/MAL and RK fat with HOMA-IR. US is a useful clinical tool to assess ectopic fat depots. Both Metformin and Dapaglifozin induce fat loss in layers involved with MS but combined treatment is particularly effective in perirenal fat layer reduction. Perirenal fat should be considered as a potential target for cardiovascular dapaglifozin beneficial effects.

Effect of Liraglutide in Different Abdominal Fat Layers Measured by Ultrasound: The Importance of Perirenal Fat Reduction

INTRODUCTION

Ultrasonography (US) in patients with obesity allows us to measure different layers of abdominal fat (superficial subcutaneous, deep subcutaneous, preperitoneal, omental, and perirenal), not assessable by DEXA or CT scan. Omental and perirenal fat depots are considered predictors of metabolic complications. Liraglutide is particularly effective in reducing weight in patients with insulin-resistance, but its direct impact on each abdominal fat layer is unknown.

METHODS

We measured, at the L4 level, all 5 abdominal fat depots in 860 patients with obesity (72.8% women, mean age 56.6 ± 1.5 years, BMI 34.4 ± 4.7 kg/m2, body fat 47 ± 2%, abdominal circumference 105.8 ± 3 cm), before and after 6 months of liraglutide treatment. Laboratory tests for glucose, insulin, and lipid profile were routinely done. T-student was used to compare intraindividual differences.

RESULTS

Weight loss was 7.5 ± 2.8 kg (7.96% from baseline), with no differences by sex/age/BMI. Greater loss was observed in patients with higher dosages and NAFLD. All US-measured fat layers showed a significant reduction (p < 0.05) at 6th months. Preperitoneal fat showed a -26 ± 5.5% reduction and 46% of the patients went below metabolic syndrome (MS) risk cut-off values. Omental fat was reduced by -17.8 ± 5% (67% of the patients below MS risk) and perirenal fat by -22.4 ± 4.4% (56% of the patients below MS). Both omental and perirenal fat reduction correlated with total and LDL cholesterol. Higher perirenal fat reduction (-28%) was seen among patients with obesity and hypertension. Perirenal fat also correlated with blood pressure reduction.

CONCLUSION

Liraglutide induces greater fat loss in the layers involved with MS. However, the maximal reduction is seen at perirenal fat, which has been recently related with hypertension and could play an important role in modulating kidney's expansion and intraglomerular pressure. US is a reproducible clinical tool to assess pathologic fat depots in patients living with obesity.

Ultrasound-Based Assessment of Preperitoneal Fat as a Surrogate Marker of Cardiovascular Risk: Comparative Study Between People Living with HIV and Controls

Optimal management of cardiovascular disease should start with the identification of subjects at subclinical stages. However, available tools are not always accurate or affordable. We assess the usefulness of ultrasound-guided measurement of abdominal fat layers as a surrogate marker of cardiovascular risk. We performed a cross-sectional, case-control, exploratory, pilot study in 10 people living with HIV (PLWH) and 10 HIV-uninfected subjects (control group) matched for age, sex, and body mass index. All participants were men 45-60 years of age, with no active disease or previous abdominal surgery; the PLWH group had been virologically suppressed for ≥2 years under stable antiretroviral therapy. The thickness of abdominal superficial and deep subcutaneous fat, preperitoneal fat, omental (periaortic) fat, and retroperitoneal (perirenal) fat was compared between both groups. Correlations between fat layers and traditional markers of cardiovascular risk were assessed. The thickness of most layers was always higher among PLWH. The differences were statistically significant for the preperitoneal fat layer (p = .04). The presence of atherosclerotic plaque was correlated with the preperitoneal fat layer in the PLWH group (odds ratio = 1.49, p = .02), and metabolic syndrome was correlated with superficial subcutaneous fat, although this was low (odds ratio = 0.54, p = .02). In the control group, several associations were found between carotid intima media thickness and abdominal fat layers. All abdominal fat layers were thicker in the PLWH group, especially preperitoneal fat, and several associations were found between specific fat layers and traditional cardiovascular risk markers. Our results suggest that the thickness of abdominal fat layers, assessed by ultrasound, could be a marker of cardiovascular risk. However, further studies with larger populations are required to confirm these findings.

Non-Invasive Prediction of Coronary Artery Disease by Multiple Abdominal Fat and Anthropometric Indices: Revisit

Purpose

The aim of this study was to evaluate the efficiency of multiple abdominal fat indices measured by ultrasound and anthropometric indices to predict the presence and severity of coronary artery disease (CAD) assessed by coronary angiography.

Patients and Methods

All participants subjected to clinical and laboratory assessments. Anthropometric measurements were taken followed by an ultrasound examination to measure fat thickness at multiple abdominal areas. Lastly, selective coronary angiography performed by the Judkins technique. Statistical analysis was performed to detect the association between all variables and CAD, followed by regression analysis, and Odds ratio (OR) was used to quantifies the strength of the association between two events.

Results

From the abdominal indices, the posterior right perinephric fat thickness (PRPFT) above the best cutoff value had the highest hazard ratio (HR: 12.3, p = 0.001), followed by visceral adipose tissue volume (VAT) (HR: 10.7, p < 0.001), waist circumference (WC) (HR: 6.7, p = 0.001), visceral fat thickness (VFT) (HR: 5.7, p = 0.002), and body mass index (BMI) (HR: 5.48, p = 0.017). It also showed an independent association between the severity of CAD and WC (HR: 4.28, p = 0.012), VFT (HR: 3.7, p = 0.032), VAT (HR: 3.7, p = 0.034), and waist to height ratio (WHtR) (HR: 3.3, p = 0.033).

Conclusion

Posterior perinephric fat thickness and visceral adipose tissue volume measured by ultrasound are strong noninvasive predictors for coronary artery disease, followed by body mass index, waist circumference and visceral fat thickness.

Ultrasound measures of abdominal fat layers correlate with metabolic syndrome features in patients with obesity

OBJECTIVE

Abdominal fat ultrasound (US) is a simple clinical tool that may allow measures of fat depots not visible using common dual-energy X-ray absorptiometry (DEXA) or computerized tomography (CT) imaging. The aim of this study was to validate the technique, give measures of superficial and profound subcutaneous, preperitoneal, omental and perirenal (retroperitoneal) fat and correlate them with MS markers.

METHODS

Sequential US measures of these five abdominal fat layers were done at 397 adults. Blood pressure (BP), body mass index (BMI), waist, body fat %, HOMA-IR index (homeostatic model assessment of insulin resistance), lipid profile and leptin were recorded. Metabolic syndrome (MS) was defined according to Cholesterol education programme adult treatment panel III (ATPIII) criteria.

RESULTS

Subcutaneous and omental fat were increased among people with obesity, whereas preperitoneal and perirenal fat did not show any difference according to BMI or waist. Women showed thicker subcutaneous fat (both superficial and profound), whereas men had bigger omental fat. Both postmenopausal and diabetic patients had changes in omental fat only, whereas patients with fatty liver showed thicker preperitoneal and perirenal fat, as well. MS patients showed both thicker perirenal and omental fat. A cut-off of 54 mm in male (M)/34 mm in female (F) of omental fat and 22.5 mm (M)/12.5 mm (F) of perirenal fat could be predictive of later MS onset.

CONCLUSIONS

US is a valid method to measure all different abdominal fat depots. Omental and perirenal fat measures may classify patients at risk for MS. Preperitoneal fat depot may also correlate with fatty liver disease.

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.

Evaluation of abdominal fat index by ultrasonography and its relationship with psoriasis and metabolic syndrome

Introduction

Accumulating evidence indicates that psoriasis is associated with obesity and metabolic syndrome. Psoriasis and obesity share similar inflammatory mediators, and obesity may potentiate some inflammatory cytokines seen in psoriasis. Body fat distribution, particularly visceral adipose tissue (VAT), is an important factor in metabolic syndrome and atherosclerotic diseases. An association has been demonstrated between psoriasis and abdominal VAT measured by computed tomography (CT).

Aim

To measure abdominal VAT noninvasively by ultrasonography (USG) in patients with psoriasis and investigated its relation to psoriasis and metabolic syndrome.

Material and methods

The study population consisted of 41 psoriasis patients and 41 control subjects matched for age, sex, and body mass index. The maximal preperitoneal fat thickness (Pmax) at the anterior surface of the liver and the minimal subcutaneous fat thickness (Smin) of the abdomen were measured by USG. The abdominal fat index (AFI = Pmax/Smin ratio) was calculated and the results were compared between groups.

Results

The rate of metabolic syndrome was significantly higher in psoriasis patients (p = 0.0018). The mean AFI was similar in both groups. AFI was not associated with psoriasis in subjects with metabolic syndrome (p = 0.495) or with Psoriasis Area and Severity Index (r = 0.123, p = 0.443).

Conclusions

This is the first study to evaluate abdominal VAT by USG. Computed tomography may be more reliable than USG, but its high cost and radiation exposure are major disadvantages. Further studies are required to determine the relationships between psoriasis and VAT.

Comparative Study of Ultrasonographic and Anthropometric Measurements of Regional Adiposity in Metabolic Syndrome

INTRODUCTION

Metabolic syndrome is complex disorder unifying dyslipidemia, insulin resistance and hyper insulinemia. Rising global epidemic of obesity has tremendous impact on metabolic syndrome. Ultrasound is becoming widely utilized modality for measuring the visceral adiposity.

AIM

To determine the usefulness of ultrasonographic measurements in the estimation of regional adiposity and to compare them with anthropometric measurements and to correlate ultrasonographic measurements of regional adiposity and metabolic syndrome.

MATERIALS AND METHODS

A cross-sectional study was conducted to compare anthropometry and ultrasonography in assessing the regional adiposity in metabolic syndrome. A total of 105 consecutive participants were included in the study after scrutinizing them for various definable factors of metabolic syndrome. Body Mass Index (BMI) of all participants was calculated and their available serological investigations were gathered. Primarily participants were subjected for anthropometric measurements like waist circumference and hip circumference, further waist/hip ratio was calculated. Following which all participants underwent sonological examination and sonographic indices like intraabdominal fat thickness, preperitoneal fat thickness, minimum and maximum subcutaneous fat thicknesses were measured. Abdominal wall fat index was calculated as ratio of maximum preperitoneal fat thickness to minimum subcutaneous fat thickness. Statistical analysis was performed using SPSS (Statistical Package Social Science, version-10.0.5) software. A p-value was calculated and values <0.05 were considered as statistically significant.

RESULTS

Significant correlation was established between the BMI and waist and hip circumferences. Mild positive correlation was obtained between BMI and sonographic indices like IAF, SCF and PPF with Pearson correlation (r) values of 0.324, 0.585 and 0.211 respectively. Anthropometric measurements showed higher r-values (WC- 0.624 and HC- 0.825) than sonographic indices; indicating anthropometry is better in assessing the regional adiposity than the sonography.

CONCLUSION

Sonography can be considered as one of the reliable imaging modality for assessing the regional adiposity but not as better as waist or hip circumferences.

Novel combined index of cardiometabolic risk related to periarterial fat improves the clinical prediction for coronary artery disease complexity

BACKGROUND AND AIMS

Cardiovascular (CV) risk assessment based on conventional risk factors has a limited performance in the prediction of obstructive coronary artery disease (CAD). Therefore, our aim was to provide a complete assessment on the associations between single or combined cardiovascular ultrasound indexes and the complexity of CAD in high and very-high risk patients.

METHODS

Two hundred fifteen patients scheduled for elective coronary angiography were enrolled in the study (F/M: 80/135 pts; age: 61.8 ± 7.9 years). Detailed clinical characteristics, including several obesity parameters, and the following ultrasound indexes were obtained: carotid intima-media thickness (IMT) and extra-media thickness (EMT), epicardial fat thickness (EFT) and intra-abdominal fat thickness (IAT). CAD severity and complexity were assessed based on the well-evidenced SYNTAX score (SS) algorithm.

RESULTS

The study patients (79% with a very high CV risk) had central obesity (77%), and arterial hypertension (81%), one-third (37%) had diabetes and most of the individuals (74%) were current or previous smokers. In the study group, male sex, higher number of CV risk factors, diabetes and increased carotid vascular indexes (IMT or EMT ≥ 900 μm) were associated with significantly higher SS (p < 0.05). Paradoxically, obese patients revealed a significantly lower SS compared to non-obese individuals (3.65 ± 6.66 vs. 5.93 ± 8.8; p < 0.01), which was not explained by the number of CV risk factors or age. All the ultrasound indexes (except for visceral fat - IAT) revealed significant associations with the SS and the highest correlation coefficient was found for PATIMA combined index (r = 0.45; p < 0.01). Hence, none of the obesity-related clinical indexes showed any associations with CAD complexity. Multivariate regression analysis showed that male sex, chronic kidney disease and the PATIMA index were independently associated with the Syntax Score. The ROC analysis showed that the highest sensitivity (71% and 82%) and specificity (77% and 72%) in prediction of either SS > 1 or SS > 7 were found for the combined PATIMA index (negative predictive value = 92% for SS > 7).

CONCLUSIONS

We present the first study showing that a combination of ultrasound indexes related to periarterial fat and vascular wall (PATIMA index) is associated with more complex CAD in high and very-high risk patients. PATIMA index revealed improved predictive value compared to other single ultrasound indexes and clinical risk assessment.

A carotid extra-media thickness, PATIMA combined index and coronary artery disease: Comparison with well-established indexes of carotid artery and fat depots

BACKGROUND

The clinical utility of traditional cardiovascular (CV) risk factors to predict coronary artery disease (CAD) is insufficient and limited. Our aim was to evaluate the association between a novel ultrasound index of periarterial fat and adventitia (carotid extra-media thickness; EMT) and the severity of CAD and to compare this with well-known vascular indexes in patients with high and very high CV risk.

METHODS AND RESULTS

Four hundred twenty two patients scheduled for elective coronary angiography were included in the study (age: 61.3 ± 7.4 years; males 65%). Several clinical parameters of obesity were obtained as well as the following ultrasound indexes: carotid EMT and intima-media thickness (IMT), epicardial and pericardial fat thickness (EFT and PFT), and intra-abdominal fat thickness (IAT). These were then related to CAD severity in all individuals. Our study patients had a very high estimated CV risk (82%), and most (60%) fulfilled the MS criteria. Most individuals (71%) had CAD (≥50% stenosis) with equal rates of one, two, or three-vessel disease, and critical (≥70%) coronary stenosis was found in 40% of patients. Carotid EMT was significantly increased in patients with CAD (812 ± 116 vs 746 ± 131 μm) and patients with critical coronary stenosis (829 ± 119 vs 769 ± 122 μm) compared to the appropriate control groups. Moreover, carotid EMT was significantly associated with the severity of CAD. Carotid IMT and EFT (but not PFT and IAT) also revealed significant relations to the number of diseased vessels. Carotid EMT and the new proposed combined index (PATIMA = EMT/BMIx35 + IMT + EFTx60) were predictive for CAD (AUC: 686 ± 304 and 755 ± 260, sensitivity: 60 and 62%, specificity: 76 and 81% for 772 μm and 2015u).

CONCLUSIONS

We present the first study showing that the new vascular index (carotid EMT) and the proposed combined index PATIMA are associated with the presence and the severity of CAD.

Imaging body fat: techniques and cardiometabolic implications

Obesity is a worldwide epidemic and is associated with multiple comorbidities. The mechanisms underlying the relationship between obesity and adverse health outcomes remain poorly understood. This may be because of several factors including the crude measures used to estimate adiposity, the striking heterogeneity between adipose tissue depots, and the influence of fat accumulation in multiple organs. To advance our understanding of fat stores and associated comorbidities in humans, it will be necessary to image adiposity throughout the body and ultimately also assess its functionality. Large clinical studies are demonstrating the prognostic importance of adipose tissue imaging. Newer techniques capable of imaging fat metabolism and other functions of adipose tissue may provide additional prognostic use and may be useful in guiding therapeutic interventions.

Differential association of visceral adipose tissue with coronary plaque characteristics in patients with and without diabetes mellitus

Background

Excess visceral adipose tissue (VAT) is closely associated with the presence of coronary artery plaques that are vulnerable to rupture. Patients with diabetes mellitus (DM) have more VAT than patients without DM, but the extent to which VAT contributes to the characteristics of coronary plaques before and after the development of DM is not fully understood.

Methods

We retrospectively evaluated 456 patients (60% male, age 64 ± 16 years) who were suspected to have cardiovascular disease and underwent 64-slice computed tomography angiography (CTA). Seventy-one (16%) patients had vulnerable plaques (CT density < 50 Hounsfield Units, positive remodeling index > 1.05, and adjacent spotty areas of calcification).

Results

Patients were divided into tertiles according to the VAT area. There were stepwise increases in noncalcified and vulnerable plaques with increasing tertiles of VAT area in patients without DM, but not in patients with DM. Multivariate analysis showed that a larger VAT area was significantly associated with a higher risk of vulnerable plaque in patients without DM (odds ratio 3.17, 95% confidence interval 1.08–9.31, p = 0.04), but not in patients with DM.

Conclusions

The VAT area is associated with the characteristics of coronary plaques on CTA in patients without DM, but not in patients with DM. VAT may be a significant cardiometabolic risk factor that is associated with plaque vulnerability before the development of DM. CTA findings may help to improve risk stratification in such patients.

Coronary artery calcium score: a review

Context

Coronary artery disease (CAD) is the foremost cause of death in many countries and hence, its early diagnosis is usually concerned as a major healthcare priority. Coronary artery calcium scoring (CACS) using either electron beam computed tomography (EBCT) or multislice computed tomography (MSCT) has been applied for more than 20 years to provide an early CAD diagnosis in clinical routine practice. Moreover, its association with other body organs has been a matter of vast research.

Evidence Acquisition

In this review article, techniques of CACS using EBCT and MSCT scanners as well as clinical and research indications of CACS are searched from PubMed, ISI Web of Science, Google Scholar and Scopus databases in a time period between late 1970s through July 2013 and following appropriate selection, dealt with. Moreover, the previous and ongoing research subjects and their results are discussed.

Results

The CACS is vastly applied in early detection of CAD and in many other research fields.

Conclusions

CACS has remarkably changed the screening techniques to detect CAD earlier than before and is generally accepted as a standard of reference for determination of risk of further cardiac events.