Intra-abdominal Visceral Fat Research Articles

Body fat patterning in lean Asian Indians with diabetes: Case-control study

AimTo perform body fat patterning in Asian-Indian individuals with T2D. MethodsA total of 53 patients with recent-onset diabetes and 106 non-diabetic controls were included from screened 261 individuals. Data was divided into 2 groups; overweight/obese [(BMI ≥23 kg/m2); 45 diabetic, 84 non-diabetic] and lean [(BMI <23 kg/m2); 8 diabetic, 22 non-diabetic]. Anthropometry (weight, height, BMI, waist, hip circumference, waist-hip ratio) and lipids, adiponectin and hsCRP were measured. Body composition (BC) was assessed by bioimpedance analysis (BIA) and Dual Energy X-ray absorptiometry (DEXA). We analyzed the association of visceral adipose tissue (VAT) with anthropometric measures to identify predictors of diabetes. ResultsTotal body fat percentage was comparable between patients with T2D and non-diabetic controls in both, obese [35.0 ± 9.1% vs 36.8 ± 8.4%, p = 0.29 (BIA), 40.1 ± 6.7 vs 46.6 ± 4.1%, p = 0.052 (DEXA) and lean [25.1 ± 5.6% vs 26.0 ± 6.7%, p = 0.74 (BIA), 35.3 ± 4.8% vs 34.1 ± 6.3%, p = 0.72 (DEXA) study group. Individuals of T2D (obese or lean) had significantly higher visceral fat rating (BIA), VAT area, volume, mass and VAT corrected for total body fat percentage (DEXA). Obese T2D had lower muscle mass (57.0 ± 6.4% vs 60.0 ± 5.5%, p = 0.03) than obese controls. Intra-abdominal visceral fat (IAVF) [(VFR, VAT (mass/area/volume) and VAT mass corrected for body fat)] had the best sensitivity (71%) for incident diabetes. ConclusionHigher Intra-abdominal visceral fat and not total body fat is associated with incident diabetes independent of BMI. IAVF estimation by either BIA or DEXA should be performed to predict diabetes especially in lean individuals.

Genome-wide association study of abdominal MRI-measured visceral fat: The multiethnic cohort adiposity phenotype study.

Few studies have explored the genetic underpinnings of intra-abdominal visceral fat deposition, which varies substantially by sex and race/ethnicity. Among 1,787 participants in the Multiethnic Cohort (MEC)-Adiposity Phenotype Study (MEC-APS), we conducted a genome-wide association study (GWAS) of the percent visceral adiposity tissue (VAT) area out of the overall abdominal area, averaged across L1-L5 (%VAT), measured by abdominal magnetic resonance imaging (MRI). A genome-wide significant signal was found on chromosome 2q14.3 in the sex-combined GWAS (lead variant rs79837492: Beta per effect allele = -4.76; P = 2.62 × 10-8) and in the male-only GWAS (lead variant rs2968545: (Beta = -6.50; P = 1.09 × 10-9), and one suggestive variant was found at 13q12.11 in the female-only GWAS (rs79926925: Beta = 6.95; P = 8.15 × 10-8). The negatively associated variants were most common in European Americans (T allele of rs79837492; 5%) and African Americans (C allele of rs2968545; 5%) and not observed in Japanese Americans, whereas the positively associated variant was most common in Japanese Americans (C allele of rs79926925, 5%), which was all consistent with the racial/ethnic %VAT differences. In a validation step among UK Biobank participants (N = 23,699 of mainly British and Irish ancestry) with MRI-based VAT volume, both rs79837492 (Beta = -0.026, P = 0.019) and rs2968545 (Beta = -0.028, P = 0.010) were significantly associated in men only (n = 11,524). In the MEC-APS, the association between rs79926925 and plasma sex hormone binding globulin levels reached statistical significance in females, but not in males, with adjustment for total adiposity (Beta = -0.24; P = 0.028), on the log scale. Rs79837492 and rs2968545 are located in intron 5 of CNTNAP5, and rs79926925, in an intergenic region between GJB6 and CRYL1. These novel findings differing by sex and racial/ethnic group warrant replication in additional diverse studies with direct visceral fat measurements.

Is an Exercise Intervention the only way to Reduce Visceral Fat without Reducing Fat-free Mass in Children and Adolescents?

Objectives: To maintain proper development, it is recommended that children/adolescents focus more on increasing physical activity than dietary restriction when treating obesity. In other words, adults are better able to tolerate the reductions in fat-free body mass that often occur when trying to lose fat mass. In contrast, children and adolescents should avoid losses in fat-free mass in order to ensure proper development. Therefore, when trying to reduce visceral fat in children via a negative energy balance (i.e., exercise with or without calorie restriction), it is necessary to set desirable conditions in order to minimize the loss of fat-free mass. To determine whether this is possible, we reviewed literature discussing the relationship between changes in visceral fat obtained by abdominal imaging and changes in total body fat and fat-free mass after exercise training with and without calorie restriction in children and adolescents.Methods: Literature review.Results and Conclusions: Previous work found no reduction in fat-free mass in the exercise interventions in which there was no dietary-induced calorie restriction. This supports the idea that reducing visceral fat by increasing physical activity is the preferred strategy over dietary restriction in children and adolescents. Although factors such as the type (e.g. aerobic and/or resistance) of exercise and the amount (i.e. energy expenditure) of exercise will likely have an effect on the magnitude of change in intra-abdominal visceral fat, the quantity of each that is needed without reducing fat-free mass is currently unknown.

PNPLA3 rs738409 C>G Variant Influences the Association Between Visceral Fat and Significant Fibrosis in Biopsy-proven Nonalcoholic Fatty Liver Disease.

Background and AimsIntra-abdominal visceral fat accumulation and patatin-like phospholipase domain containing 3 (PNPLA3) rs738409 G/C gene polymorphism confer a greater susceptibility to nonalcoholic fatty liver disease (NAFLD). We examined whether the relationship between visceral fat accumulation and liver disease severity may be influenced by PNPLA3 rs738409 polymorphism.MethodsThe variant of PNPLA3 rs738409 was genotyped within 523 Han individuals with biopsy-confirmed NAFLD. Visceral fat area (VFA) was measured by bioelectrical impedance. Significant liver fibrosis (SF), defined as stage F ≥2 on histology, was the outcome measure of interest.ResultsThe distribution of PNPLA3 genotypes was CC: 27.5%, CG: 48.2%, and GG: 24.3%. Higher VFA was associated with greater risk of having SF (adjusted-odds ratio [OR]: 1.03; 95% confidence interval [CI]: 1.02–1.04, p<0.05), independent of potential confounders. Among subjects with the same VFA level, the risk of SF was greater among carriers of the rs738409 G genotype than among those who did not. Stratified analysis showed that PNPLA3 rs738409 significantly influenced the association between VFA and SF. VFA remained significantly associated with SF only among the rs738409 G-allele carriers (adjusted-OR: 1.05; 95% CI: 1.03–1.08 for the GG group; and adjusted-OR:1.03; 95% CI: 1.01–1.04 for the GC group). There was a significant interaction between VFA and PNPLA3 rs738409 genotype (Pinteraction=0.004).ConclusionsPNPLA3 rs738409 G allele has a moderate effect on the association between VFA and risk of SF in adult individuals with biopsy-proven NAFLD. Existence of the PNPLA3 rs738409 G allele and VFA interact to increase risk of SF.

Evaluation and Comparative Correlation of Abdominal Fat Related Parameters in Obese and Non-obese Groups Using Computed Tomography.

Obesity is a significant risk factor for cardiovascular (CV) disease. Abdominal fat is composed of abdominal subcutaneous fat and intra-abdominal (visceral) fat. Computed tomography (CT) is considered one of the most accurate and reliable methods for assessing abdominal fat. The present study was based on evaluating abdominal fat by computed tomography and the determination of association between CT obtained abdominal fat volumes, anthropometric indices, and lipid profile. The prospective study was carried out on 120 subjects referred to the Radiology department for a CT scan. Non - contrast CT scan was performed with 5 mm slice thickness. Abdominal fat volumes were recorded by using CT attenuation values (- 250 to -50 HU). The section was selected at the level of the umbilicus (L4-L5). Intra-abdominal fat and subcutaneous fat volumes were calculated. Body Mass Index (BMI) and lipid profile were recorded for each subject. A comparative study of the CT values, BMI, and lipid profile was undertaken. In the present study, by comparing the anthropometric parameters, CT findings, and lipid profile and blood parameters of the obese and non-obese groups by sex revealed significant sex differences in all the parameters under study. It was also found that the obese male and female groups showed a high prevalence of diabetes, Non-Alcoholic fatty liver disease (NAFLD), and hypertension than non-obese groups. This finding also adds to the chances of getting cardiovascular diseases, specifically in obese individuals. The results found that in obese males and females the abdominal fat-related parameters Visceral fatty acid (VFA) and subcutaneous fatty acid (SFA) showed highly significant relation to anthropometric parameters like BMI, waist circumference (WC) and waist/hip (W/H) ratio on the other hand blood parameters high-density lipoprotein (HDL), low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL), total cholesterol and triglycerides to some extent have a significant relation to abdominal fat-related parameters. In non-obese groups, by studying the influence of anthropometric parameters on abdominal fat-related parameters, it was revealed that WC was strongly affected by the VFA in both sexes. In obese females, more fat was accumulated in the VFA and SFA and for obese males in SFA and for non-obese males in total fatty acid (TFA). Computed tomography assessed visceral fat area remains the most sensitive independent predictor of cardiovascular risk.

Peritoneal cavity circumference on computed tomography predicts outcomes in acute pancreatitis

ObjectivesWe investigated the role of novel intra-abdominal parameters measured by computed tomography (CT) in the prediction of clinical outcomes in acute pancreatitis (AP). MethodsPatients with AP underwent an abdominal CT scan on admission to define different intra-abdominal parameters (abdominal circumference, peritoneal cavity circumference, intraabdominal visceral fat area, and subcutaneous fat area) at the L2-L3 level using the open-source image analysis software Osirix Lite v.11.0.4 to predict clinical outcomes. ResultsEighty patients with AP were analyzed. Peritoneal cavity circumference (PCC) was the only variable independently associated with outcomes. PCC showed an area under ROC for prediction of severity in AP of 0.830. A PCC ≥ 85 cm increased the risk of severity of AP (RR 15.7), persistent systemic inflammatory response syndrome (RR 9.3), acute peripancreatic fluid collection (RR 6.4), necrotizing pancreatitis (RR 21.50), and mortality (RR 2.4). We found a 4.7-fold increase in the risk of developing severe AP for each 10 cm increase in PCC. ConclusionsPCC measurement at the L2-L3 level using a non-enhanced abdominal CT scan on admission in patients with AP is useful in the early prediction of severity, persistent systemic inflammatory response syndrome, local complications, and mortality.

Range of adiposity and cardiorenal syndrome.

Obesity and obesity-related co-morbidities, diabetes mellitus, and hypertension are among the fastest-growing risk factors of heart failure and kidney disease worldwide. Obesity, which is not a unitary concept, or a static process, ranges from alterations in distribution to the amount of adiposity. Visceral adiposity, which includes intraabdominal visceral fat mass and ectopic fat deposition such as hepatic, cardiac, or renal, was robustly associated with a greater risk for cardiorenal morbidity than subcutaneous adiposity. In addition, morbid obesity has also demonstrated a negative effect on cardiac and renal functioning. The mechanisms by which adipose tissue is linked with the cardiorenal syndrome (CRS) are hemodynamic and mechanical changes, as well neurohumoral pathways such as insulin resistance, endothelial dysfunction, nitric oxide bioavailability, renin-angiotensin-aldosterone, oxidative stress, sympathetic nervous systems, natriuretic peptides, adipokines and inflammation. Adiposity and other associated co-morbidities induce adverse cardiac remodeling and interstitial fibrosis. Heart failure with preserved ejection fraction has been associated with obesity-related functional and structural abnormalities. Obesity might also impair kidney function through hyperfiltration, increased glomerular capillary wall tension, and podocyte dysfunction, which leads to tubulointerstitial fibrosis and loss of nephrons and, finally, chronic kidney disease. The development of new treatments with renal and cardiac effects in the context of type 2 diabetes, which improves mortality outcome, has highlighted the importance of CRS and its prevalence. Increased body fat triggers cellular, neuro-humoral and metabolic pathways, which create a phenotype of the CRS with specific cellular and biochemical biomarkers. Obesity has become a single cardiorenal umbrella or type of cardiorenal metabolic syndrome. This review article provides a clinical overview of the available data on the relationship between a range of adiposity and CRS, the support for obesity as a single cardiorenal umbrella, and the most relevant studies on the recent therapeutic approaches.

Dietary Intake of Carotenoid-Rich Vegetables Reduces Visceral Adiposity in Obese Japanese men-A Randomized, Double-Blind Trial.

Metabolic syndrome, whose main diagnostic component is obesity, is a risk factor for lifestyle-related diseases, type 2 diabetes, and cardiovascular disease. Diet is known to affect the prevalence of metabolic syndrome. However, the effect of diet on metabolic syndrome in Japanese subjects has not been thoroughly explored. In the present study, we investigated the effect of carotenoid-rich vegetables, particularly lycopene- and lutein-rich vegetables, on the metabolic syndrome in obese Japanese men. We conducted an 8-week long randomized, double-blinded, controlled clinical trial in which, 28 middle-aged (40 ≤ age < 65) Japanese men with high body mass index (BMI ≥ 25) were randomized into four dietary groups: high lycopene + high lutein (HLyHLu), high lycopene + low lutein (HLyLLu), low lycopene + high lutein (LLyHLu), and low lycopene + low lutein (LLyLLu). Our results showed that daily beverage-intake increased the plasma levels of carotenoids without adverse effects, and the visceral fat level was significantly decreased in all the groups. The waist circumference was significantly decreased only in the HLyLLu group, whereas the CoQ10 oxidation rate was decreased in all the groups. The gene expression profiles of whole blood samples before and after ingestion differed only in the LLyLLu group, indicating the effect of carotenoids on gene expression profile. In conclusion, our results suggest that dietary uptake of carotenoid-rich vegetables increases their concentration in blood and reduces the intra-abdominal visceral fat.

Relation of visceral fat and haemodynamics in adults with Fontan circulation.

Being overweight is associated with reduced functional capacity in Fontan patients. Increased adiposity leads to accumulation of epicardial and intra-abdominal visceral fat, which produce proinflammatory cytokines and may affect endothelial function. This retrospective study to evaluate the association between visceral fat and Fontan haemodynamics included 23 Fontan patients >18 years old with MRI and catheterization data available. Epicardial fat volume indexed to body surface area was measured by cardiac MRI, and intra-abdominal visceral fat thickness and subcutaneous fat thickness were derived from abdominal MRI. Stepwise regression models were used to determine univariable and multivariable associations between fat measures and haemodynamics. Mean age was 28.2 ± 9.5 years and body mass index was 26 ± 4 kg/m2. Mean central venous pressure was 13 ± 3 mmHg and pulmonary vascular resistance index was 1.23WU·m2 (interquartile range: 0.95-1.56). Epicardial fat volume was associated with age (r2 = 0.37, p = 0.002), weight (r2 = 0.26, p = 0.013), body mass index (r2 = 0.27, p = 0.011), and intra-abdominal visceral fat (r2 = 0.30, p = 0.018). Subcutaneous fat thickness did not relate to these measures. There was modest correlation between epicardial fat volume and pulmonary vascular resistance (r2 = 0.27, p = 0.02) and a trend towards significant correlation between intra-abdominal fat thickness and pulmonary vascular resistance (r2 = 0.21, p = 0.06). Subcutaneous fat thickness was not associated with Fontan haemodynamics. In multivariable analysis, including age and visceral fat measures, epicardial fat was independently correlated with pulmonary vascular resistance (point estimate 0.13 ± 0.05 per 10 ml/m2 increase, p = 0.03). In conclusion, in adults with Fontan circulation, increased visceral fat is associated with higher pulmonary vascular resistance. Excess visceral fat may represent a therapeutic target to improve Fontan haemodynamics.

Diosgenin Supplementation Prevents Lipid Accumulation and Induces Skeletal Muscle-Fiber Hypertrophy in Rats.

Diosgenin (Dio) is a steroid sapogenin found in plants such as Dioscorea species, and is recognized as a phytochemical against various disorders as well as a natural precursor of steroidal drugs. The present study used rats fed high-cholesterol (Chol) diets supplemented with or without 0.5% Dio for 6 wk to investigate the effects of dietary Dio on lipid metabolism. Dio supplementation significantly increased serum high-density lipoprotein Chol concentrations and fecal Chol content, and significantly decreased fecal bile acid content compared rats fed a high-Chol diet alone, showing that dietary Dio may facilitate excretion of Chol rather than bile acids. A reduction in the liver triglyceride content and intra-abdominal visceral fat was observed in Dio-supplemented rats. Interestingly, dietary Dio also significantly increased the skeletal muscle-fiber diameter and area in the thigh muscles of the rats. Mouse myoblast-derived C2C12 cells were used to examine whether Dio directly affected skeletal muscle. Dio promoted fusion of myoblasts into multinucleated cells or myotubes. Furthermore, in myotube C2C12 cells, protein levels of phosphorylated AMP-activated protein kinase (AMPK) increased with Dio treatment in a dose-dependent manner. These results indicate that Dio may not only induce myoblast fusion and enhance skeletal muscle as an energy expenditure organ, but may also activate the catabolic pathway via AMPK in skeletal muscle cells. Thus, these effects of Dio on skeletal muscles may contribute to inhibition of visceral fat accumulation.

Changes in body composition and metabolic disease risk.

As individuals gain weight, they increase the amount of fat that they accrue on their body. This causes adipocytes to enlarge and increases not only subcutaneous fat but also deposits fat in other vulnerable areas of the body. This ectopic fat is deposited in the intra-abdominal visceral fat depot, in muscle, in the liver and in the beta cells. Fat in these locations initiates a dysfunctional state in these insulin-sensitive tissues leading to insulin resistance, the appearance of the Metabolic Syndrome, and an increased risk of developing both type 2 diabetes and cardiovascular disease. A loss of weight and with it a loss of fat decreases this risk.

Angiotensin II‐ mediated vasoconstriction of the visceral adipose tissue vasculature is linked to systemic hypertension in obesity

ObjectivesCentral adiposity, in particular the accumulation of intra‐abdominal visceral fat, has been linked to adipose tissue dysfunction and obesity‐related diseases including hypertension and atherosclerosis, however regulatory mechanisms are poorly understood. We hypothesized that increased micro‐vascular tone specifically in visceral fat may contribute to abnormal peripheral vascular resistance.MethodsIn 30 obese subjects(age 42±10 yr, BMI 42±3 kg/m2) undergoing elective bariatric surgery, we characterized vaso‐contractile responses of isolated subcutaneous (SC) and visceral (VIS) adipose tissue arterioles using videomicroscopy, and examined relevant depot‐specific gene expression using qPCR.ResultsVisceral arterioles exhibited significantly greater angiotensin II‐mediated vasoconstriction by 20% in obese hypertensives (OH, SBP 146±8 mmHg) compared to obese normotensives (O, SBP 118±5 mmHg) (p&lt;0.05). Additionally, VIS arterioles showed greater vasoconstriction in response to angiotensin II compared to SC in OH (by 25%, p&lt;0.05) but not in O. Angiotensin converting enzyme (ACE) mRNA expression was significantly increased in VIS compared to SC (2‐fold, p&lt;0.05) in OH but not O. In contrast, vasopressor responses to other agonists including endothelin‐1 and phenylephrine were not different between fat depots or subjects with or without hypertension.ConclusionThe findings demonstrate differential activation of the renin‐angiotensin system (RAS) in the visceral adipose tissue microvasculature that may contribute to mechanisms of systemic hypertension in obesity. RAS targeting, in particular, may provide incremental clinical benefit in treating obesity‐related hypertension.Support or Funding InformationNIH grants P01HL081587 and RO1 HL1145675

Impact of baseline visceral fat accumulation on prognosis in patients with metastatic renal cell carcinoma treated with systemic therapy.

The aim of this study was to evaluate the clinical significance of visceral fat accumulation as a prognostic factor in patients with metastatic renal cell carcinoma (mRCC) treated with systemic therapies. A total of 114 patients were retrospectively reviewed. All patients received systemic therapy for mRCC at Keio University hospital in Japan. The intra-abdominal visceral fat area was determined by computed tomography at the umbilical level. The visceral fat accumulation was defined as ≥100cm2. The mean visceral fat area was 107.4±62.8cm2. In the whole cohort, the median follow-up was 29months. According to the Memorial Sloan Kettering Cancer Center (MSKCC) classification, 27.2% patients were favorable risk, 53.5% were intermediate risk, and 19.3% were poor risk. Visceral fat accumulation correlated with improved progression-free (P=0.0070) and overall survival (P=0.0001). On multivariate analysis, visceral fat accumulation (P=0.0290) and MSKCC classification (P=0.0085) were independent indices to predict progression-free survival in first-line treatment. In addition, visceral fat accumulation (P=0.0007) and MSKCC classification (P=0.0005) independently predicted overall survival. Prognostic grouping using visceral fat accumulation was identified as an independent prognostic marker in patients with mRCC. The addition of visceral fat accumulation improved the prognostic value of MSKCC classification alone in predicting overall survival in patients treated with systemic therapy for mRCC.

Correlation of Pericoronary Epicardial Adipose Tissue with Coronary Artery Calcification, and Coronary Atherosclerosis in Egyptian Post-Menopausal Women

Background and rationale: Previous data demonstrated that regional fat distribution plays an important role in the development of an unfavorable metabolic and cardiovascular risk profile. Epicardial adipose mass reflects intra-abdominal visceral fat, is related to leftventricular mass and other features of the metabolic syndrome, such as concentrations of LDL cholesterol, fasting insulin and adiponectin, and arterial blood pressure.Aim of the study: To examine the relation of peri-coronary epicardial adipose tissue (EAT) to coronary artery calcification and atherosclerosis in Egyptian post-menopausal women.Patients and methods: The study enrolled 100 post-menopausal women with suspected coronary artery disease. The amount of EAT surrounding the left main and three main coronary arteries was quantified in axial cuts with the most distinct layer of EAT.The amount of calcium in the coronary arteries was quantified with multidetector-row computed tomography (MDCT) using dedicated software for calcium scoring that is based on the Agatston score. Coronary artery disease severity was assessed in terms of numberof vessels affected and severity of coronary stenosis by multiplanner reformation (MPR) technique. Results: Sixty patients had proven coronary artery disease (CAD) of varying severity (Group I), whereas forty patients showed normal coronaries (Group II). The mean ± SD (in millimeters) epicardial adipose tissue thickness (EAT) for the entire study cohort in variouscoronary artery locations were as follows: Left Main (LM-EAT) 12.95 ± 7.86 mm, Left Anterior Descending (LAD-EAT) 8.2 ± 2.3 mm, Left Circumflex (LCX-EAT) 7.4 ± 2; and Right Coronary Artery (RCAEAT) 8.5 ± 1.9. Statistically significant differences were observed between groups I and II with regards to LM-EAT: LAD-EAT; LCXEAT; and RCA-EAT (15.7 ± 8.5 versus 9.11 ± 1.72, p=0.006; 9.1 ± 2 versus 6.88 ± 1.98, p=0.001; 8.27 ± 1.72 versus 6.19 ± 1.79, p=0.004; and 9.23 ± 1.65 versus 7.5 ± 1.9, p=0.005; respectively).Statistically significant differences in LM-EAT: LAD-EAT; LCXEAT; and RCA-EAT values were observed between patients with coronary artery calcium (CAC) scores lower than 400 Hounsfield Units (HU) and those with (CAC) scores equal to or higher than 400 HU (8.99 ± 5.99 versus 13.15 ± 1.94, p=0.001; 8.7 ± 2.1 versus 10.4 ± 2.6, p=0.003, 7.6 ± 1.8 versus 8.9 ± 2.2, p=0.005, and 8.02 ± 1.6 versus 9.48 ± 1.95, p=0.008). Conclusion: The present study demonstrated a significant correlation between peri-coronary epicardial adipose tissue and coronary artery calcification and atherosclerosis.

NASH patients are characterized by increased frequency of Th17 cells not only in hepatic tissue, but also in intra-abdominal visceral fat

NASH patients are characterized by increased frequency of Th17 cells not only in hepatic tissue, but also in intra-abdominal visceral fat

DXA: Technical aspects and application

The key role of dual-energy X-ray absorptiometry (DXA) in the management of metabolic bone diseases is well known. The role of DXA in the study of body composition and in the clinical evaluation of disorders which directly or indirectly involve the whole metabolism as they may induce changes in body mass and fat percentage is less known or less understood. DXA has a range of clinical applications in this field, from assessing associations between adipose or lean mass and the risk of disease to understanding and measuring the effects of pathophysiological processes or therapeutic interventions, in both adult and paediatric human populations as well as in pre-clinical settings. DXA analyses body composition at the molecular level that is basically translated into a clinical model made up of fat mass, non-bone lean mass, and bone mineral content. DXA allows total and regional assessment of the three above-mentioned compartments, usually by a whole-body scan. Since body composition is a hot topic today, manufacturers have steered the development of DXA technology and methodology towards this. New DXA machines have been designed to accommodate heavier and larger patients and to scan wider areas. New strategies, such as half-body assessment, permit accurate body scan and analysis of individuals exceeding scan field limits. Although DXA is a projective imaging technique, new solutions have recently allowed the differential estimate of subcutaneous and intra-abdominal visceral fat. The transition to narrow fan-beam densitometers has led to faster scan times and better resolution; however, inter- or intra-device variation exists depending on several factors. The purposes of this review are: (1) to appreciate the role of DXA in the study of body composition; (2) to understand potential limitations and pitfalls of DXA in the analysis of body composition; (3) to learn about technical elements and methods, and to become familiar with biomarkers in DXA.

Proposed cut-off values of the waist circumference for metabolic syndrome based on visceral fat volume in a Japanese population.

Aim/IntroductionWaist circumference (WC) is the most important parameter for diagnosis of metabolic syndrome. The present study was carried out to obtain optimal WC cut‐off values for diagnosis of metabolic syndrome in a Japanese population based on the measurement of total intra‐abdominal visceral fat volume (VFV), which could be expected to reflect visceral obesity more precisely than visceral fat area.Materials and MethodsA total of 405 Japanese persons undergoing health screening were investigated. visceral fat volume was calculated from the data in 700–800 computed tomography slices from the top of the liver to the floor of the pelvic cavity. Then, receiver operating characteristic analysis was used to determine the cut‐off value of the VFV/height ratio. Subsequently, the corresponding WC value was obtained by linear regression analysis.ResultsThe cut‐off value of the VFV/height ratio was 2,317 cm3/m in men and 1,425 cm3/m in women. The sensitivity and specificity of the ratio were 52.9 and 86.4% in men vs 63.4 and 82.2% in women, respectively. The corresponding cut‐off value of WC was 86.0 cm in men and 80.9 cm in women.ConclusionsThe proposed cut‐off values of WC for metabolic syndrome are 85 cm in Japanese men and 80 cm in Japanese women.

Impact of Visceral Fat Area in Colorectal Surgery.

See Article on Page 20-26 Many studies have demonstrated a close relationship between body fat distribution and the occurrence of metabolic syndrome; an excess of abdominal adipose tissue, especially intra-abdominal visceral fat, leads to obesity-related complications [1]. Visceral obesity is closely related to the development of colorectal cancer, as well as other metabolic complications [2], and the distribution of adipose tissue also seems to be important in the pathogenesis of colorectal cancer [3]. Therefore, analytical morphometric assessment has recently been proposed to improve preoperative risk stratification, and the body mass index (BMI) has been widely used to express the degree of obesity, although it does not always adequately reflect the degree of visceral fat [4]. Accordingly, several other body composition parameters, such as the visceral fat area (VFA), have been assessed by using preoperative staging computed tomography in patients undergoing various surgical procedures [5]. Some cutoff values of the VFA in the Korean population have been reported for use as a diagnostic criterion of abdominal obesity, and the value of the VFA associated with an increased risk of obesity-related disorder in Korea was reported to be 103.8 cm2 [6]. Also, Oka et al. [7] more recently reported cutoff levels of the VFA in the Japanese population, with VFA >130 cm2 in men and VFA >90 cm2 in women indicating obesity. Many reports state that obese patients have unfavorable surgical outcomes, including longer operative time, increased postoperative complication rate, increased conversion rate, prolonged hospital stay [8] and shorter disease-free survival [9] after resection for colorectal cancer. A meta-analysis revealed high BMI to be associated with higher risks of infectious complications, including surgical site infections and pulmonary infection [10]. Recently, however, Yu et al. [11] investigated the distribution of the VFA and general obesity in the Korean population, and they concluded that visceral obesity had no influence on intraoperative difficulties, postoperative complications, and postoperative recovery in patients with sigmoid colon or rectal cancer. They did not clearly state the reason obesity did not influence the operative outcomes in their research, although they presumed the cutoff value of the VFA would affect their results. The associations between obesity and gastrointestinal disease are of variable strength, and the underlying mechanisms are incompletely understood, but obesity and metabolic syndrome clearly have a significant, potentially avoidable, and often underrecognized, impact on the population burden of gastrointestinal disease [12]. No doubt, visceral obesity plays a strong role in the development of metabolic syndrome; however, some controversy still remain and needs to be resolved between the relationship of visceral obesity and postoperative complications. To clarify the correlation between visceral obesity and operative outcome, we need further investigation to identify more accurate predictors, such as BMI, body surface area and VFA/subcutaneous fat area ratio, for the outcomes of colorectal surgery.

Consumption of Japanese Yam Improves Lipid Metabolism in High-Cholesterol Diet-Fed Rats.

We investigated the effects of dietary Japanese yam (Dioscorea japonica Thunb.) on lipid metabolism. Male Wistar rats (6 wk old) were fed a high-cholesterol diet for 6 wk and then supplemented with 26% of Japanese yam or 0.5% of its constituent diosgenin for a further 4 wk of high-cholesterol feeding (C6-J4 and C6-D4 groups, respectively). In the C6-J4 group, body weight gains significantly decreased, but skeletal muscle fiber sizes in quadriceps significantly increased compared with the other groups. Furthermore, Japanese yam supplementation resulted in the reduction of triglyceride contents in their liver, quadriceps, and intra-abdominal visceral fat. Diosgenin supplementation resulted in an increase in the numbers of skeletal muscle fibers and decrease in the fat accumulations in liver and of the lipid contents in quadriceps. Although quadriceps cholesterol contents decreased concomitantly with increased serum HDL-cholesterol in both the groups, fecal bile acid, fecal cholesterol contents, and fecal weight were higher in the C6-J4 group than in the C6-D4 group. Meanwhile, we demonstrated that Japanese yam inhibited micellar cholesterol solubility in vitro in a concentration-dependent manner. These results suggest that Japanese yam is more effective than diosgenin in reducing fat accumulation and improving cholesterol metabolism during chronic consumption of a high-cholesterol diet.

Metformin Loaded Carbopol Gel for lowering the Intra-Abdominal Visceral Fat

The aim of this study was to prove the principle of local delivery of metformin hydrochloride, METHCl, to the abdomen area in order to reduce the intra-badominal visceral fat compared to the METHCL oral tablets. Intraabdominal visceral and subcutaneous fat were highly correlated with body weight of obese people. So, this will be beneficial to assist wight loss in those individuals. Furthermore, oral METHCl tablets (600 mg) might show reduction in weight in diabetic pateints. However, the reqiured high doses is still an issue which put the patients under stress of METHCl side effects. In this preliminary trial, METHCl was formulated in the form of local hydrogel using the carbopol 934 within very small drug dose (6 mg/g). The prepared hydrogel was pharmaceutically evaluated for its pH, viscosity, spreadability, and in vitro release. Furthermore, the abdominal fat lowering activity of METHCl gel was compared to the oral METHCl tablets and control (placebo) groups in human volunteers. The study showed that the prepared METHCl gel significantly (p<0.05, ANOVA/Tukey) decrease the diameter of the abdomen compared to the placebo group and to 50% of participant taking oral METHCl tablets after three weeks treatment. In addition, the group taking METHCl oral tablets failed to decrease the inta-abdominal fat in approximately 50% of participants. In conclusion, METHCl hydrogel could be considered a promising novel formulation which can decrease the accumulated fats in the abdomen reigon with small dose comapred to oral METHCl tablets.