Comparison of visceral fat and liver fat as risk factors of metabolic syndrome

Liver Fat Storage Is a Better Predictor of Coronary Artery Disease than Visceral Fat

Fatty liver is one aspect of metabolic syndrome. The roles and contributions of fatty liver and visceral fat storage to coronary artery disease (CAD) are not clear. This study measured associations among visceral fat storage, fatty liver, insulin resistance, atherosclerosis, and CAD. Patients were divided into three groups: excess visceral fat (visceral fat area >330 ± 99 cm2), non-alcoholic fatty liver disease (NAFLD), and a control group. The definition of fatty liver is liver minus spleen density greater than or equal to -10. We defined early atherosclerosis as intima-media thickness of the common carotid artery >7 mm in men and >0.65 mm in women, measured with Doppler ultrasound. Visceral fat area was defined using CT (>330 ± 99 cm2). Insulin-resistance biomarkers (HOMA), CRP, and oxidant-antioxidant status (MDA-Paraoxonase) were also measured. Patients with high liver or visceral fat showed higher coronary plaque prevalence (50% (p < 0.001), 38% (p < 0.01), respectively vs. 25% in the control group), higher prevalence of coronary stenosis (30% (p < 0.001), 22% (p < 0.01) vs. 11% in the control group), higher intimal thickening (0.98 ± 0.3 (p< 0.01), 0.86 ± 0.1 (p < 0.01) vs. 0.83 ± 0.1 in the control group), higher HOMA (4.0 ± 3.0 (p < 0.005), 3.0 ± 1.0 (p < 0.001) vs. 1.5 ± 1.2 in the control group), and higher triglyceride levels (196.8 ± 103 (p < 0.005), 182.6 ± 90.87 (p < 0.005) vs. 145 ± 60 in the control group). Multiple logistic regression analysis showed that fatty liver predicted CAD (OR 2.7, 95% CI 2.3-4.9, p < 0.001) independently of visceral fat storage (OR 2.01, 95% CI 1.2-2.8, p < 0.001). Liver fat storage is a strong independent risk factor for CAD and carotid atherosclerosis and contributes more than visceral fat storage.

Comparison of Sodium-Glucose Cotransporter-2 Inhibitors and Thiazolidinediones for Management of Non-Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

BACKGROUND

The pharmacologic treatment of non-alcoholic fatty liver disease (NAFLD) remains unclear.

METHODS

Two reviewers searched PubMed, SCOPUS, Cochrane Central and clinicaltrials.gov for randomized controlled trials (RCTs) of patients with NAFLD with or without type 2 diabetes mellitus (T2DM) receiving TZDs vs SGLT2 inhibitors. The primary outcomes were change in alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT) and improvement in steatosis and fibrosis. The secondary outcomes were changes in lipid profile, body weight and glycated hemoglobin (HbA1c). Random effects models with continuous outcomes as weighted mean differences (WMD) with 95% confidence intervals (CI) were used.

RESULTS

Five studies (n= 311 NAFLD patients) were included. Patients treated with SGLT2 inhibitors (n= 156) showed significant decrease in visceral fat area (VFA; WMD 23.45, p<0.00001) and body weight (WMD 4.22, p<0.00001) as compared to those treated with TZDs (n= 155). Patients from both groups showed improvement in AST (WMD 1.21, p= 0.40), ALT (WMD -0.46, p= 0.81), GGT (WMD -0.47, p= 0.84), hepatic fibrosis (WMD 0.11, p= 0.52), LDL (WMD 2.19, p= 0.35), HbA1c (WMD -0.16%, p= 0.20), HOMA-IR (WMD: -0.04, p= 0.91) and FPG (WMD -7.37, p= 0.28) which was equivalent and non-significant.

CONCLUSION

The improvement in liver enzymes, steatosis and fibrosis caused by SGLT2 inhibitors and TZDs was similar. SGLT2 inhibitors, however, resulted in a significant decrease in VFA and body weight. As weight loss is found to have a positive effect on the resolution of steatosis and fibrosis in NAFLD patients, SGLT2 inhibitors may have the potential to be considered for long-term management, however, further research needs to be conducted to determine the utility of SGLT2 inhibitor class of antidiabetic drugs for effectively treating NAFLD.

The relationship between renal sinus lipomatosis detected at abdominal computed tomography and abdominal visceral and subcutaneous fat accumulation and metabolic risk factors

Purpose

To investigate the relationship between renal sinus lipomatosis (RSL) and abdominal visceral and subcutaneous fat accumulation and metabolic risk factors.

Material and methods

A total 73 subjects were included in the study. The study group consisted of 35 cases with RSL and 38 control cases matched for age and sex. Total, visceral, and subcutaneous abdominal fat areas were measured by abdominal computed tomography (CT). The relationship between RSL and visceral abdominal fat, subcutaneous abdominal fat, total abdominal fat, high total cholesterol level, high low-density lipoprotein (LDL) cholesterol level, high very low-density lipoprotein (VLDL) cholesterol level, high triglyceride level, low high-density lipoprotein (HDL) cholesterol level, impaired fasting glucose level, type 2 diabetes mellitus, hypertension (HT), and metabolic syndrome (MS) were investigated.

Results

RSL existence was observed at significantly higher levels statistically in cases with low HDL cholesterol level, high LDL cholesterol level, high VLDL cholesterol level, high triglyceride level, high total cholesterol level, and high glucose levels. In the presence of MS, DM, and HT, the presence of RSL was at a significantly higher level according to the statistics. Logistic regression analysis was performed to examine the factors affecting RSL presence together. It was observed that the model formed as the result of the evaluation using the backward method is statistically significant. Furthermore, the variables of age, high total cholesterol level, high glucose level, and abdominal subcutaneous fat were included in the obtained model.

Conclusions

Our study demonstrated an association between the presence of RSL and age, high total cholesterol level, high glucose level, and subcutaneous fat.

Hepatic and Skeletal Muscle Adiposity Are Associated with Diabetes Independent of Visceral Adiposity in Nonobese African-Caribbean Men

Background: Adipose tissue (AT) around and within non-AT organs (i.e., ectopic adiposity) is emerging as a strong risk factor for type 2 diabetes (T2D). Not known is whether major ectopic adiposity depots, such as hepatic, skeletal muscle, and pericardial adiposity (PAT), are associated with T2D independent of visceral adiposity (VAT). More data are particularly needed among high-risk nonobese minority populations, as the race/ethnic gap in T2D risk is greatest among nonobese. Methods: Thus, we measured several ectopic adiposity depots by computed tomography in 718 (mean age = 64 years) African-Caribbean men on the Island of Tobago overall, and stratified by obesity (obese N = 187 and nonobese N = 532). Results: In age, lifestyle risk factors, health status, lipid-lowering medication intake, body mass index and all other adiposity-adjusted regression analyses, and hepatic and skeletal muscle adiposity were associated with T2D among nonobese men only (all P < 0.05), despite no association between VAT and PAT and T2D. Conclusions: Our results support the "ectopic fat syndrome" theory in the pathogenesis of T2D among nonobese African-Caribbean men. Longitudinal studies are needed to clarify the independent role of ectopic adiposity in T2D, and to identify possible biological mechanisms underlying this relationship, particularly in high-risk African ancestry and other nonwhite populations.

Fat Accumulation, Liver Fibrosis, and Metabolic Abnormalities in Chinese Patients With Moderate/Severe Versus Mild Hepatic Steatosis

Several drugs in development for nonalcoholic fatty liver disease (NAFLD) aim to decrease the amount of fat in the liver. We compared quantity and quality of fat in subcutaneous, visceral and muscle compartments, liver fibrosis, and prevalence of metabolic abnormalities between Chinese patients with moderate/severe hepatic steatosis versus those with mild hepatic steatosis. NAFLD patients were prospectively recruited from Peking University People's Hospital in Beijing, China. All patients had baseline body composition measurements using computed tomography and analytic morphomics, clinical evaluation, labs and Fibroscan® controlled attenuation parameter and liver stiffness measurement. Moderate/severe hepatic steatosis was defined as computed tomography liver attenuation of 40 Hounsfield units or less. Calorie intake and physical activity were based on self-report. A total of 160 NAFLD patients were included (46% men, median age 47 years): 50% had normal body mass index (BMI), 24% were diabetic, and 56% had metabolic syndrome (MS). Fifty-three (33%) had moderate/severe steatosis, of whom 19 (35.8%) had normal BMI, and the rest had mild steatosis. Patients who had moderate/severe steatosis had significantly higher BMI, waist circumference, aminotransferases, controlled attenuation parameter, liver stiffness measurement, and prevalence of MS compared to those with mild steatosis. They also had larger visceral fat area, subcutaneous fat area, and low density dorsal muscle area. In addition, their calorie intake was higher and time spent on recreation activities was shorter. Conclusion: NAFLD patients with moderate/severe steatosis, including those with normal BMI, had higher prevalence of MS and more fat in visceral, subcutaneous, and muscle compartments than those with mild steatosis. They also had more advanced liver disease. Strategies to decrease hepatic fat may benefit both liver and metabolic diseases.

Ethnic distinctions in the pathophysiology of type 2 diabetes: a focus on black African-Caribbean populations

Type 2 diabetes (T2D) is a global public health priority, particularly for populations of black African-Caribbean ethnicity, who suffer disproportionately high rates of the disease. While the mechanisms underlying the development of T2D are well documented, there is growing evidence describing distinctions among black African-Caribbean populations. In the present paper, we review the evidence describing the impact of black African-Caribbean ethnicity on T2D pathophysiology. Ethnic differences were first recognised through evidence that metabolic syndrome diagnostic criteria fail to detect T2D risk in black populations due to less central obesity and dyslipidaemia. Subsequently more detailed investigations have recognised other mechanistic differences, particularly lower visceral and hepatic fat accumulation and a distinctly hyperinsulinaemic response to glucose stimulation. While epidemiological studies have reported exaggerated insulin resistance in black populations, more detailed and direct measures of insulin sensitivity have provided evidence that insulin sensitivity is not markedly different to other ethnic groups and does not explain the hyperinsulinaemia that is exhibited. These findings lead us to hypothesise that ectopic fat does not play a pivotal role in driving insulin resistance in black populations. Furthermore, we hypothesise that hyperinsulinaemia is driven by lower rates of hepatic insulin clearance rather than heightened insulin resistance and is a primary defect rather than occurring in compensation for insulin resistance. These hypotheses are being investigated in our ongoing South London Diabetes and Ethnicity Phenotyping study, which will enable a more detailed understanding of ethnic distinctions in the pathophysiology of T2D between men of black African and white European ethnicity.

Visceral adipose tissue tracks more closely with metabolic dysfunction than intrahepatic triglyceride in lean Asians without diabetes

Increased visceral adipose tissue (VAT) and intrahepatic triglyceride (IHTG) are important risk factors for the development of type 2 diabetes in subjects with obesity. The relative contribution of these ectopic fat depots to cardiometabolic risk differs between populations, depends on the degree of obesity and the level of cardiorespiratory fitness, and is difficult to dissect because VAT and IHTG typically covary. The aim of this study was to evaluate the effect of an isolated increase in VAT or IHTG on insulin sensitivity and insulin secretion in apparently healthy normal-weight Asian subjects. Total body fat (dual X-ray absorptiometry), VAT and IHTG (magnetic resonance), insulin sensitivity (4-h hyperinsulinemic-euglycemic clamp), beta cell responsivity and insulin secretion rate (3-h mixed meal with mathematical modeling), and cardiorespiratory fitness (maximal oxygen consumption [V̇o2max]) were evaluated in groups of lean subjects with low or high VAT (687 ± 94 vs. 1,279 ± 197 ml, matched for IHTG; n = 13 each) and low or high IHTG (1.7 ± 0.3 vs. 6.7 ± 2.0%, matched for VAT; n = 15 each). All groups were matched for age, sex, total body fat, and V̇o2max. High-VAT subjects had ~25% lower insulin sensitivity, ~20%–40% greater beta cell responsivity and insulin secretion rate, ~35% greater fasting triglyceride concentration, and ~40% lower adiponectin concentration than low-VAT subjects (all P < 0.05). No differences were observed between low-IHTG and high-IHTG subjects. Accumulation of excess fat in the intra-abdominal area is more strongly associated with metabolic dysfunction than accumulation of liver fat in lean Asians without diabetes.

NEW & NOTEWORTHY It is not known whether metabolic abnormalities in Asians without obesity track more closely with visceral or liver fat. We found an isolated increase in visceral fat was associated with reduced insulin sensitivity, greater insulin secretion, greater triglyceride, and lower adiponectin concentrations; no differences were observed with an isolated increase in liver fat. These results suggest that visceral fat is a better correlate of metabolic dysfunction than liver fat in Asians without obesity.

Anthropometry and body composition of adolescents in cracow, poland

Background and Objective

The aim of the present study was to determine the level of adiposity and obesity in Polish adolescents and compare the results with earlier studies conducted in this population as well as those carried out in other populations.

Methods

The study group consisted of 456 boys and 514 girls aged 14-18 years living in Cracow chosen from randomly selected secondary schools. Weight, height, waist, and hip circumference (WC, HC) as well as triceps, biceps, subscapular, and suprailiac skinfold thickness (SFT) were measured. Body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), subscapular/triceps skinfold ratio (STR), and percentage body fat were computed. The prevalence of overweight and obesity based on Polish children growth reference were calculated and age-dependent and gender-specific smoothed percentile curves for BMI and ROC curves were generated.

Results

Weight, height, WC, HC (up 16yr), WHtR (up 15yr), and WHR were considerably higher in males than females. Weight, height, and HC increased with age; WHtR remained the same. The prevalence of overweight and obesity were 10.2% (boys 10.3%; girls 10.1%) and 4.2% (boys 5.3%; girls 3.3%). ROC analysis revealed that WHtR was the best tool for detection of obesity (AUC of 0.982±0.007) in males, whereas the sum of four SFTs (AUC: 0.968±0.011) and WHtR (AUC: 0.963±0.012) were the best predictors of obesity in females.

Conclusions

The level of adiposity in Cracow adolescents increased during the last decade. However, it is still lower than in other well-developed societies struggling with obesity epidemics.

Beyond central adiposity: liver fat and visceral fat area are associated with metabolic syndrome in morbidly obese patients

BACKGROUND

Despite its widespread clinical use, both body mass index (BMI) and waist circumference have been reported as inaccurate methods to measure abdominal obesity. The main objective of this study was to determine the relation between visceral fat area and fatty liver infiltration with the expression of metabolic syndrome (MS) in morbidly obese patients.

METHODS

We recruited a random selection of 100 morbidly obese patients on pre-operative evaluation for bariatric surgery. A pre-operative CT slice at L4-L5 level, was performed to measure visceral fat and at T12 level to measure hepatic attenuation.

RESULTS

Patients with MS had lower hepatic attenuation values (median 49.9 vs 55.5HU; p = .018) and had more VAT (242 vs 172 cm(2);p = .001). Conventional measures (BMI: p = .729 and waist circumference: p = .356), were not useful in discriminating morbidly obese patients with MS. By multivariable logistic regression, fatty liver infiltration (OR = 5.3; p = .03) and age (OR = 1.08; p = .04) were the only factors independently related to the presence of MS. MS prevalence was 100%, 71% and 55%, respectively for patients with both fatty liver and visceral adiposity; one; or none of this findings (AUC - .715; p = .016).

CONCLUSION

CT scan seems to measure 2 important markers of MS: visceral adiposity and hepatic fatty infiltration. In morbidly obese patients, both visceral adiposity and hepatic fatty infiltration increase the risk for the presence of MS.

Gender differences in the association between serum γ-glutamyltransferase and blood pressure change: a prospective community-based cohort study

We evaluated the gender differences in the relation of baseline serum γ-glutamyltransferase (GGT) levels to blood pressure (BP) change during 4 yr. 4,025 normotensive subjects (1,945 men and 2,080 women) who aged 40-69 yr at baseline participated in the Ansung-Ansan cohort of the Korean Genome Epidemiology Study were included. The associations of GGT with baseline BP or 4-yr change of BP were evaluated. GGT levels were associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) at baseline after adjusting for age, body mass index (BMI), HDL-cholesterol, triglyceride, C-reactive protein (CRP), current smoking status and alcohol intake (SBP, β=1.28, P<0.001; DBP, β=1.41, P<0.001). GGT levels were also associated with 4-yr change in BP after adjusting for age, BMI, HDL-cholesterol, triglyceride, CRP, current smoking status, alcohol intake and SBP (SBP, β=1.08, P=0.001; DBP, β=0.64, P=0.003). This association was statistically significant in men (SBP, β=1.82, P<0.001; DBP, β=1.05, P=0.001), but not in women (SBP, β=0.38, P=0.466; DBP, β=-0.37, P=0.304). Remarkably, this association between GGT and BP was significant in men at 40-49 yr of age. In summary, we found positive associations between GGT levels at baseline and the change of BP. The relation of GGT level and the change of BP was only significant in men, not in women, which warrants further studies to elucidate the biologic mechanisms.

Bariatric endocrinology: principles of medical practice

Obesity, is a chronic, biological, preventable, and treatable disease. The accumulation of fat mass causes physical changes (adiposity), metabolic and hormonal changes due to adipose tissue dysfunction (adiposopathy), and psychological changes. Bariatric endocrinology was conceived from the need to address the neuro-endocrinological derangements that are associated with adiposopathy, and from the need to broaden the scope of the management of its complications. In addition to the well-established metabolic complications of overweight and obesity, adiposopathy leads to hyperinsulinemia, hyperleptinemia, hypoadiponectinemia, dysregulation of gut peptides including GLP-1 and ghrelin, the development of an inflammatory milieu, and the strong risk of vascular disease. Therapy for adiposopathy hinges on effectively lowering the ratio of orexigenic to anorexigenic signals reaching the the hypothalamus and other relevant brain regions, favoring a lower caloric intake. Adiposopathy, overweight and obesity should be treated indefinitely with the specific aims to reduce fat mass for the adiposity complications, and to normalize adipose tissue function for the adiposopathic complications. This paper defines the principles of medical practice in bariatric endocrinology-the treatment of overweight and obesity as means to treat adiposopathy and its accompanying metabolic and hormonal derangements.

Hepatic steatosis is associated with surgical-site infection after hepatic and colorectal surgery

BACKGROUND

Obesity and increased visceral fat deposits are important risk factors for surgical-site infection (SSI). Interestingly, a potential role of hepatic steatosis on complications after extrahepatic surgery remains unknown. The aim of the present study was to investigate the impact of hepatic steatosis on SSI in patients that underwent open abdominal surgery.

METHODS

A total of 231 patients that underwent either liver (n = 116) or colorectal (n = 115) resection and received preoperative contrast-enhanced computed tomography scans were retrospectively investigated. Signal attenuation of the liver parenchyma was measured on computed tomography scans to assess hepatic steatosis.

RESULTS

More SSIs (including types 1, 2, and 3) were found in the group with hepatic steatosis (56/118 [47.5%]) compared with the control group (30/113 [26.6%]; P = .001). Patients with hepatic steatosis showed greater median body mass index than patients without hepatic steatosis (26.6 kg/m(2) [range 16.8-47.0 kg/m(2)] vs 23.2 kg/m(2) [15.9-32.7 kg/m(2)]; P < .001). Patients with hepatic steatosis experienced longer median operation times (297 minutes [52-708 minutes] vs 240 minutes [80-600 minutes]; P = .003). In a multivariate analysis, hepatic steatosis was identified as an independent risk factor for SSI in patients undergoing hepatic (odds ratio 10.33 [95% confidence interval 1.19-89.76]; P = .03) or colorectal (odds ratio 6.67 [95% confidence interval 1.12-39.33]; P = .04) operation.

CONCLUSION

Hepatic steatosis is associated with SSI after hepatic and colorectal operation.

Association of weight-adjusted body fat and fat distribution with bone mineral density in middle-aged chinese adults: a cross-sectional study

Background

Although it is well established that a higher body weight is protective against osteoporosis, the effects of body fat and fat distribution on bone mineral density (BMD) after adjustment for body weight remains uncertain.

Objective

To examine the relationship between body fat and fat distribution and BMD beyond its weight-bearing effect in middle-aged Chinese adults.

Method

The study had a community-based cross-sectional design and involved 1,767 women and 698 men aged 50–75 years. The BMD of the lumbar spine, total hip, and whole body, and the fat mass (FM) and percentage fat mass (%FM) of the total body and segments of the body were measured by dual-energy X-ray absorptiometry. General information on the participants was collected using structured questionnaire interviews.

Result

After adjusting for potential confounders, an analysis of covariance showed the weight-adjusted (WA-) total FM (or %FM) to be negatively associated with BMD in all of the studied sites (P<0.05) in both women and men. The unfavorable effects of WA-total FM were generally more substantial in men than in women, and the whole body was the most sensitive site related to FM, followed by the total hip and the lumbar spine, in both genders. The mean BMD of the lumbar spine, total hip, and whole body was 3.93%, 3.01%, and 3.65% (in women) and 5.02%, 5.57%, 6.03% (in men) lower in the highest quartile (vs. lowest quartile) according to the WA-total FM (all p<0.05). Similar results were noted among the groups for WA-total FM%. In women, abdominal fat had the most unfavorable association with BMD, whereas in men it was limb fat.

Conclusion

FM (or %FM) is inversely associated with BMD beyond its weight-bearing effect. Abdominal fat in women and limb fat in men seems to have the greatest effect on BMD.

Body fat percentile curves for Korean children and adolescents: a data from the Korea National Health and Nutrition Examination Survey 2009-2010

A valid assessment of obesity in children and adolescents is important due to significant change in body composition during growth. This study aimed to develop percentile curves of body fat and fat free mass using the Lambda, Mu, and Sigma method, and to examine the relationship among body mass index (BMI), fat mass and fat free mass in Korean children and adolescents, using the Korea National Health and Nutrition Examination Survey (KNHANES) 2009-2010. The study subjects were 834 for boys and 745 for girls aged between 10 and 18 yr. Fat mass and fat free mass were measured by dual-energy x-ray absorptiometry. The patterns of development in body fat percentage, fat mass and fat free mass differed for boys and girls, showing a decreased fat mass with an increased fat free mass in boys but gradual increases with age in girls. The considerable proportion of boys and girls with relatively normal fat mass appeared to be misclassified to be at risk of overweight based on the BMI criteria. Therefore, the information on the percentiles of body fat and fat free mass with their patterns would be helpful to complement assessment of overweight and obesity based on BMI for Korean children and adolescents.

What is the role of adiponectin in obesity related non-alcoholic fatty liver disease?

Non-alcoholic fatty liver disease (NAFLD) is recognized as the most common type of chronic liver disease in Western countries. Insulin resistance is a key factor in the pathogenesis of NAFLD, the latter being considered as the hepatic component of insulin resistance or obesity. Adiponectin is the most abundant adipose-specific adipokine. There is evidence that adiponectin decreases hepatic and systematic insulin resistance, and attenuates liver inflammation and fibrosis. Adiponectin generally predicts steatosis grade and the severity of NAFLD; however, to what extent this is a direct effect or related to the presence of more severe insulin resistance or obesity remains to be addressed. Although there is no proven pharmacotherapy for the treatment of NAFLD, recent therapeutic strategies have focused on the indirect upregulation of adiponectin through the administration of various therapeutic agents and/or lifestyle modifications. In this adiponectin-focused review, the pathogenetic role and the potential therapeutic benefits of adiponectin in NAFLD are analyzed systematically.