Contribution of visceral fat accumulation to the development of coronary artery disease in non-obese men

Factors Associated with Visceral Fat Loss in Response to a Multifaceted Weight Loss Intervention

Background

Visceral adipose tissue is more metabolically active than other fat depots and is more closely associated with obesity-related diseases, such as cardiovascular disease and type 2 diabetes, than indicators of obesity, such as body mass index. Across various strategies to promote weight loss, including energy-reduced diet and exercise, variable effects on VAT compared to loss of total body fat have been reported.

Methods

To examine the effect of a behavioral weight loss intervention using portion-controlled prepackaged entrées on VAT, we examined data and measurements from overweight/obese men and women (N=183) who were assigned to a weight loss intervention and prescribed a reduced-energy diet with either portion-controlled prepackaged entrées or self-selected meals in a randomized clinical trial. VAT was estimated with dual-energy X-ray absorptiometry at baseline and study end (12 weeks).

Results

VAT loss was greater for the prepackaged entrees group (p=0.02), with an average loss of 29% compared to an average loss of 19% among participants consuming self-selected meals. VAT (mean [SEM]) was 1651 (71) g and 1546 (157) g at baseline and 1234 (59) g and 1278 (118) g at study end in the prepackaged entrees and self-selected meal groups, respectively. Greater VAT loss was associated with higher baseline weight and VAT, and greater weight loss, but not associated with age or physical activity.

Conclusion

Prescribing portion-controlled prepackaged entrees in a behavioral weight loss intervention promotes a reduction in VAT, which should promote improved metabolic profile and reduced cardiovascular disease risk.

Testosterone increases CCL-2 expression in visceral adipose tissue from obese women of reproductive age

CONTEXT

Hyperandrogenic states and obesity in women are associated with insulin-resistance. Androgens reduce glucose uptake in adipose cells and increase TNFα production in peripheral monocytes. Inflammatory cytokines have a known detrimental effect on insulin resistance. The aim of the present study was to explore the role of testosterone in local cytokine production in visceral adipose tissue from women of reproductive age.

DESIGN

Twenty-four women 18-40 years old, undergoing elective abdominal surgery for benign and non-inflammatory conditions, were recruited for the study. Women with clinical hyperandrogenism, diabetes, hepatic or renal dysfunction, hypothyroidism, BMI> 40 or drugs known to interfere with hormonal levels or fat metabolism were excluded. Women were classified into two groups according to BMI, non-obese (NO; BMI < 30) and obese (O; BMI 30-40). A basal blood sample was drawn at the time of surgery for the measurement of glucose, insulin, total testosterone, lipid profile and circulating CCL-2, IL-6 and total adiponectin. Omental fat tissue (10 g) was obtained in all women. Samples of 300 mg of minced adipose tissue were incubated with vehicle (CTL) or testosterone (T) 10^-9 M to 10^-6 M for 24, 48 or 72 h. CCL-2, IL-6, TNFα, androgen Receptor (AR) mRNA levels were measured by Real Time quantitative polymerase chain reaction (qPCR) and normalized to GAPDH expression. Secretion of CCL-2 and IL-6 was measured in conditioned media by ELISA.

RESULTS

Expression of CCL-2 and IL-6 at 24 h in CTLs was significantly higher in the obese group compared to the non-obese group (2.81 ± 0.43 fold for CCL-2; p = 0.005 and 3.26 ± 0.73 fold for IL-6; p = 0.03). At 48 and 72 h there were no differences between both groups in any of the markers. In the total group without T stimulation (CTL) there were significant correlations between: TNFα expression at 24 h and BMI (r = 0.708; p = 0.005), TGC levels (r = 0.904; p = 0.004), total Cholesterol (r = 0.904; p = 0.0046) and IL-6 expression at 24 h (r = 0.642; p = 0.015). CCL-2 expression at 24 h was correlated with BMI (r = 0.637; p = 0.007) and TGC levels (r = 0.700; p = 0.02). Stimulation with T 10^-6 M for 72 h produced an increase in CCL-2 expression, which was significantly larger in the obese group compared to the non-obese group (2.04 ± 0.44 in obese vs 0.82 ± 0.11 in non-obese; p = 0.015). Moreover, in the whole group there was a positive correlation between CCL-2 expression in T-treated tissues (10^-6 M 72 h) and BMI (r = 0.514; p = 0.017). Cytokine determinations followed the same pattern as mRNA but without significant differences.

CONCLUSIONS

Testosterone increases CCL-2 expression in visceral adipose tissue from obese women of reproductive age. This response is associated to BMI. These results show new possible mechanisms connecting androgens to insulin resistance and chronic inflammation.

Alpha Linolenic Acid-enriched Diacylglycerol Consumption Enhances Dietary Fat Oxidation in Healthy Subjects: A Randomized Double-blind Controlled Trial

Consumption of alpha linolenic acid-enriched diacylglycerol (ALA-DAG) reduces visceral fat area. In this study, we performed a randomized, placebo-controlled, double-blind, crossover intervention trial to investigate the effect of ALA-DAG on dietary fat oxidation in comparison with control triacylglycerol (TAG). Each subject (n=16) consumed either 2.5 g/d of ALA-DAG or TAG for 14-d, separated by a 21-d washout period. At the end of each consumption period, we assessed dietary fat oxidation. ALA-DAG consumption significantly enhanced dietary fat utilization as energy compared to TAG consumption.

Validation of a semi-automated technique to accurately measure abdominal fat distribution using CT and MRI for clinical risk stratification

OBJECTIVE

A valid method for accurate quantification of abdominal fat distribution (AFD) using both CT and MRI is described. This method will be primarily useful in the prospective risk stratification of patients undergoing reconstructive breast surgery. Secondary applications in many other clinical specialities are foreseen.

METHODS

15 sequential patients who had undergone breast reconstruction following both CT and MRI (30 scans) were retrospectively identified at our single centre. The AFD was quantified at the level of the L3 vertebra. Image analysis was performed by at least two independent operators using free software. Intra- and interobserver differences were assessed using Bland-Altman plots. Data were validated between imaging modalities by Pearson's correlation. Linear regression analyses were used to mathematically normalize results between imaging modalities.

RESULTS

The method was statistically independent of rater bias (intra: Pearson's R-0.954-1.00; inter: 0.799-0.999). Strong relationships between imaging modalities were demonstrated and are independent of time between imaging (Pearson's R 0.625-0.903). Interchangeable mathematical models to normalize between imaging modality are shown.

CONCLUSION

The method described is highly reproducible and independent of rater bias. A strong interchangeable relationship exists between calculations of AFD on retrospective CT and MRI. Advances in knowledge: This is the first technique to be applicable to scans that are not performed sequentially or in a research setting. Analysis is semi-automated and results can be compared directly, regardless of imaging modality or patient position. This method has clinical utility in prospective risk stratification and will be applicable to many clinical specialities.

High-intensity interval training: a review of its impact on glucose control and cardiometabolic health

Exercise plays a central role in the management and treatment of common metabolic diseases, but modern society presents many barriers to exercise. Over the past decade there has been considerable interest surrounding high-intensity interval training (HIIT), with advocates claiming it can induce health benefits of similar, if not superior magnitude to moderate-intensity continuous exercise, despite reduced time commitment. As the safety of HIIT becomes clearer, focus has shifted away from using HIIT in healthy individuals towards using this form of training in clinical populations. The continued growth of metabolic disease and reduced physical activity presents a global health challenge and effective therapies are urgently required. The aim of this review is to explore whether the acclaim surrounding HIIT is justified by examining the effect of HIIT on glucose control, its ability to affect cardiovascular function and the underlying mechanisms of the changes observed in those with common metabolic diseases. It also explores translation of the research into clinical practice.

Visceral Fat: Higher Responsiveness of Fat Mass and Gene Expression to Calorie Restriction than Subcutaneous Fat

Visceral fat accumulation is accompanied by several metabolic disorders. Here, we investigate the improvement of visceral fat accumulation in the early phase of diet. Hyperlipidemic obese patients received a low-calorie diet (1000 kcal/day) for 14 days. Visceral and subcutaneous fat accumulation was analyzed using ultrasonography. After 14 days of the diet, the average visceral fat of obese patients obviously decreased (P < 0.05), as well as the visceral fat-related secreted proteins, whereas subcutaneous fat did not decrease in these patients. These results show that visceral fat is reduced significantly in the early phase of diet therapy in humans. Therefore, to clarify its mechanism, we analyzed the expression of lipid metabolism-related genes in visceral and subcutaneous fat using obese rats. The Long-Evans Tokushima Otsuka (LETO) rats, as an obese model, were divided into two groups: fasting and non-fasting. The gene expressions in visceral and subcutaneous fat were measured by reverse transcriptase-polymerase chain reaction (RT-PCR). The expression of beta(3)-adrenergic receptor (AR), hormone sensitive lipase (HSL), peroxisome proliferator-activated receptor (PPAR)-gamma, and uncoupling protein (UCP)-2 genes increased by 3.2-, 2.3-, 2.2-, and 2-fold in visceral fat (P < 0.01), but remained almost unchanged in subcutaneous fat. Taken together, the responsiveness of lipid metabolism-related genes to fasting is more sensitive in visceral fat than in subcutaneous fat in rats, suggesting that the different responsiveness to calorie restriction in fat tissues is due to the different induction of metabolism-related gene expression.

Adipose tissue regulates insulin sensitivity: role of adipogenesis, de novo lipogenesis and novel lipids

Obesity, the major cause of the current global epidemic of type 2 diabetes (T2D), induces insulin resistance in peripheral insulin target tissues. Several mechanisms have been identified related to cross-talk between adipose tissue, skeletal muscle and liver. These mechanisms involve both increased free fatty acid release and altered secretion of adipokines from adipose tissue. A major determinant of metabolic health is the ability of subcutaneous adipose tissue (SAT) to store excess fat rather than allowing it to accumulate in ectopic depots including liver (i.e. in nonalcoholic fatty liver disease), muscle and heart, or in epicardial/pericardial and visceral fat depots which promote the metabolic complications of obesity. The ability to recruit and differentiate precursor cells into adipose cells (adipogenesis) in SAT is under genetic regulation and is reduced in high-risk individuals who have first-degree relatives with T2D. Early recruitment of new adipose cells is dependent on the cross-talk between canonical WNT and BMP4 signalling; WNT enhances their undifferentiated and proliferative state whereas BMP4 induces their commitment to the adipogenic lineage. Dysregulation of these signalling pathways is associated with impaired adipogenesis and impaired ability to respond to the need to store excess lipids in SAT. This leads to hypertrophic, dysfunctional and insulin-resistant adipose cells with a reduced content of GLUT4, the major insulin-regulated glucose transporter, which in turn reduces adipose tissue glucose uptake and de novo lipogenesis. We recently identified that reduced GLUT4 and lipogenesis in adipocytes impairs the synthesis of a novel family of lipids secreted by adipose tissue (and potentially other tissues), branched fatty acid esters of hydroxy fatty acids (FAHFAs). FAHFAs have beneficial metabolic effects, including enhancing insulin-stimulated glucose transport and glucose-stimulated GLP1 and insulin secretion, as well as powerful anti-inflammatory effects. FAHFA levels are reduced in subcutaneous adipose tissue in insulin-resistant individuals, and this novel family of lipids may become of future therapeutic use.

Uric acid, carotid intima-media thickness and body composition in prepubertal children

BACKGROUND

Increased uric acid is an independent biomarker for cardiovascular disease in obese adolescents and adults.

OBJECTIVE

We investigated whether uric acid relates to carotid intima-media thickness (cIMT) in prepubertal children, and whether body mass index (BMI) and preperitoneal fat modulate this association.

METHODS

359 asymptomatic prepubertal Caucasian children were stratified according to BMI categories (171 with BMI-SDS < 0; 188 with BMI-SDS ≥ 0) and according to preperitoneal fat levels (180 with preperitoneal fat <50th centile; 179 with preperitoneal fat >50th centile). Uric acid levels, insulin resistance (homeostasis model assessment insulin resistance; HOMA-IR), C-reactive protein (CRP), triacylglycerol (TG), systolic blood pressure (SBP), abdominal fat and cIMT (both by ultrasound) were assessed.

RESULTS

Uric acid was associated with several cardiovascular risk factors, namely higher HOMA-IR, CRP, TG, BMI, waist, SBP, preperitoneal fat and cIMT (all P < 0.001 to P < 0.0001). Significant BMI and preperitoneal fat interactions were documented in the relationship between uric acid and cIMT (both P < 0.05), as uric acid was preferentially related to cIMT in heavier children (β = 0.247, P < 0.001, r(2)  = 9.1%) and in children with more preperitoneal fat (β = 0.263, P < 0.0001, r(2)  = 11.9%).

CONCLUSIONS

Serum uric acid is associated with cIMT in asymptomatic prepubertal children. Both higher BMI and preperitoneal fat aggravate the potential risk of atherosclerotic disease imposed by higher concentrations of uric acid.

Higher visceral to subcutaneous fat ratio is associated with small intestinal bacterial overgrowth

BACKGROUND AND AIMS

There is a lack of studies evaluating the association between small intestinal bacterial overgrowth (SIBO) and abdominal fat. The aim of this study was to evaluate whether visceral fat area (VFA), subcutaneous fat area (SFA) or visceral to subcutaneous fat ratio (VFA/SFA ratio) were associated with SIBO.

METHODS AND RESULTS

In this case-control study, 152 eligible patients submitted to glucose hydrogen/methane breath test who also had computed tomography (CT) of the abdomen performed were included. Clinical and demographic information was obtained. VFA and SFA were measured using Image J software at lumbar 3 level on CT cross-sectional image of the 152 patients included in this study, 68 patients (44.7%) tested positive for SIBO. In the univariate analysis, the presence of SIBO was associated with older age (65.2 ± 1.5 vs. 59.3 ± 1.5, p = 0.007); type 2 diabetes mellitus (33.8% vs. 17.9%; p = 0.019); hypertension (63.2% vs. 39.3%; p = 0.003); metabolic syndrome (85.3% vs. 64.3%; p = 0.003); and higher VFA/SFA ratio (1.0 ± 0.1 vs. 0.7 ± 0.1; p < 0.001). In multivariate analysis, metabolic syndrome (odds ratio [OR]: 2.5; 95% confidence interval [CI]: 1.1-5.7; p = 0.035) and higher VFA/SFA ratio (OR: 3.3; 95% CI: 1.6-7.2; p = 0.002) remained independently associated with SIBO.

CONCLUSION

The presence of SIBO was found to be associated with high VFA/SFA ratio measured from cross-sectional CT image.

Longitudinal Body Composition Changes in Diffuse Large B-cell Lymphoma Survivors: A Retrospective Cohort Study of United States Veterans

BACKGROUND

Body composition parameters are associated with long-term health outcomes. We assessed longitudinal body composition changes in diffuse large B-cell lymphoma (DLBCL) survivors and identified clinical variables associated with the long-term development of sarcopenia and visceral obesity.

METHODS

A retrospective cohort of United States veterans with DLBCL treated with cyclophosphamide, doxorubicin, vincristine, and prednisone, with or without rituximab, was assembled. Muscle, subcutaneous fat, and visceral fat areas were measured with computed tomography analysis. Data were analyzed with repeated-measures analysis of variance and logistic regression. All statistical tests were two-sided.

RESULTS

Three hundred forty-two patients were included. Muscle area initially decreased during treatment, then returned to baseline by 24 months after treatment. Subcutaneous fat area increased from baseline by 6.5% (95% confidence interval [CI] = 2.6% to 10.5%) during treatment and by 21.4% (95% CI = 15.7% to 27.2%) by 24 months after treatment. Visceral fat area increased from baseline by 4.5% (95% CI = -0.9% to 9.9%) during treatment and by 21.6% (95% CI = 14.8% to 28.4%) by 24 months after treatment. Variables associated with long-term development of sarcopenia included: baseline sarcopenia (adjusted odds ratio [aOR] = 17.21, 95% CI = 8.48 to 34.94), older than age 60 years (aOR = 2.93, 95% CI = 1.46 to 5.88), and weight loss greater than 5% during treatment (aOR = 2.40, 95% CI = 1.12 to 5.14). Variables associated with long-term visceral fat gain included: weight gain greater than 5% during treatment (aOR = 4.60, 95% CI = 2.42 to 8.74).

CONCLUSIONS

DLBCL survivors undergo unfavorable long-term body composition changes. Patients at risk for the long-term development of sarcopenia or visceral obesity can be identified based on clinical risk factors and targeted for lifestyle interventions.

Differential association of cardiorespiratory fitness and central adiposity among US adolescents and adults: A quantile regression approach

Previous studies assessing the association between cardiorespiratory fitness (CRF) and waist circumference (WC) have often restricted their evaluation to the association of CRF on average WC. Consequently, the assessment of important variations in the relationship of CRF across the WC distribution was precluded. The purpose of this study was to comprehensively evaluate the association between CRF and the distribution of WC using quantile regression. Secondary data analysis was conducted using data from the 1999-2004 NHANES. Participants (n=8260) aged 12-49years with complete data on estimated maximal oxygen consumption and WC were included. Quantile regression models were performed to assess the association between CRF and the 10th, 25th, 50th, 75th and 90th WC percentiles and were adjusted for age and race/ethnicity. For male and female adolescents with high CRF compared to low-fit counterparts, significant negative estimates (2.8 to 20.2cm and 2.3 to 11.2cm, respectively) were observed across most WC percentiles. Similarly, among male and female adults, high CRF was associated with significant reductions in WC across all percentiles (9.5 to 12.0cm and 3.7 to 9.2cm, respectively). For both populations, an increasing trend in the magnitude of the association of high CRF across the WC percentiles was observed. CRF appears to have a differential relationship across the WC distribution with the largest reductions in WC were found among high-fit individuals with the greatest amount of central adiposity (WC≥90th percentile). Additionally, this differential association highlights the significant limitations of statistical techniques used in previous analyses which focused on the center of the distribution.

The usefulness of mesenterium thickness as an index of visceral fat accumulation

Visceral fat syndrome, which includes visceral fat accumulation, glucose intolerance, hyperlipidemia, and hypertension, refers to a highly atherogenic state with a cluster of risk factors secondary to visceral fat accumulation. Although X-ray computed tomography (CT) is used commonly in diagnosis of visceral fat accumulation, it is expensive and exposes the patient to radiation. Some indices obtained using ultrasonography, which is fast and easy to use, have been reported. The ratio of the maximum thickness of preperitoneal fat (P) to the minimum thickness of subcutaneous fat (S), the abdominal wall fat index (P/S), is widely used in ultrasonographic diagnosis, however, this ratio tends to vary largely according to examiners. To establish a more reliable ultrasonographic index of visceral fat accumulation, we measured the thickness of the mesenterium, and tried to examine the relation between its thickness and maximum thickness of preperitoneal fat, minimum thickness of subcutaneous fat, and abdominal wall fat index, as well as body mass index, systolic and diastolic blood pressure, and levels of serum triglyceride, high-density lipoprotein cholesterol, total cholesterol, and blood sugar. The subjects were 131 individuals, 98 males and 33 females, averaging 47.0±7.9 years, with a mean body mass index of 24.1±2.6. The mesenterium was measured with a 3.5 or 3.75 MHz convex probe by longitudinal scanning on the left side of the umbilicus of the patient in the supine position. The thickness of the mesenterium correlated positively with maximum thickness of the preperitoneal fat, abdominal wall fat index, body mass index, and levels of serum triglyceride, total cholesterol, and blood sugar, and negatively with levels of high-density lipoprotein cholesterol. When the subjects were divided into a high-M group and a normal-M group, body mass index, triglyceride level, and blood sugar levels in the high-M group were significantly higher and level of high-density lipoprotein cholesterol was significantly lower than in the normal-M group. These results suggest that the thickness of mesenteium measured by ultrasonography may be useful in the diagnosis of accumulation of visceral fat.

Serum Chemerin Levels Are Associated with Abdominal Visceral Fat in Type 2 Diabetes

Chemerin is a recently identified adipokine suggested to play a role in obesity and its metabolic complications. The relationship between visceral obesity and serum chemerin levels in type 2 diabetes (T2DM) is unknown and may differ from that of subjects without diabetes. Therefore, we evaluated whether serum chemerin was associated with visceral abdominal obesity in patients with T2DM. A total of 218 Korean patients with T2DM were enrolled and metabolic parameters, abdominal visceral and subcutaneous fat areas, and serum chemerin levels were measured. Serum chemerin level showed positive correlation with fasting insulin, HOMA-IR, serum triglyceride, serum creatinine, urine albumin/creatinine ratio, high-sensitivity C-reactive protein (hsCRP), fibrinogen, abdominal visceral fat area, visceral to subcutaneous fat area ratio, and negatively correlation with high density lipoprotein cholesterol and creatinine clearance (CCr) after adjusting for age, gender and body mass index. Multiple linear stepwise regression analysis showed that abdominal visceral fat area (β = 0.001, P < 0.001), serum triglyceride (β = 0.001, P < 0.001), CCr (β = -0.003, P = 0.001), hsCRP (β = 0.157, P = 0.001), fibrinogen (β = 0.001, P < 0.001) and BMI (β = 0.02, P = 0.008) independently affected log transformed serum chemerin levels. Higher serum chemerin level was associated with higher level of abdominal visceral fat area, serum triglyceride, hsCRP and fibrinogen and lower level of CCr in patients with T2DM. Serum chemerin may be used as a biomarker of visceral adiposity and chemerin may play a role in inflammation, decreased renal function, and increased cardiovascular risk in T2DM.

(-)-Hydroxycitric Acid Nourishes Protein Synthesis via Altering Metabolic Directions of Amino Acids in Male Rats

(-)-Hydroxycitric acid (HCA), a major active ingredient of Garcinia Cambogia extracts, had shown to suppress body weight gain and fat accumulation in animals and humans. While, the underlying mechanism of (-)-HCA has not fully understood. Thus, this study was aimed to investigate the effects of long-term supplement with (-)-HCA on body weight gain and variances of amino acid content in rats. Results showed that (-)-HCA treatment reduced body weight gain and increased feed conversion ratio in rats. The content of hepatic glycogen, muscle glycogen, and serum T4 , T3 , insulin, and Leptin were increased in (-)-HCA treatment groups. Protein content in liver and muscle were significantly increased in (-)-HCA treatment groups. Amino acid profile analysis indicated that most of amino acid contents in serum and liver, especially aromatic amino acid and branched amino acid, were higher in (-)-HCA treatment groups. However, most of the amino acid contents in muscle, especially aromatic amino acid and branched amino acid, were reduced in (-)-HCA treatment groups. These results indicated that (-)-HCA treatment could reduce body weight gain through promoting energy expenditure via regulation of thyroid hormone levels. In addition, (-)-HCA treatment could promote protein synthesis by altering the metabolic directions of amino acids. Copyright © 2016 John Wiley & Sons, Ltd.

Nonalcoholic fatty liver disease as a multi-systemic disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. NAFLD includes a wide spectrum of liver conditions ranging from simple steatosis to nonalcoholic steatohepatitis and advanced hepatic fibrosis. NAFLD has been recognized as a hepatic manifestation of metabolic syndrome linked with insulin resistance. NAFLD should be considered not only a liver specific disease but also an early mediator of systemic diseases. Therefore, NAFLD is usually associated with cardiovascular disease, chronic kidney disease, type 2 diabetes, obesity, and dyslipidemia. NAFLD is highly prevalent in the general population and is associated with increased cardiovascular morbidity and mortality. The underlying mechanisms and pathogenesis of NAFLD with regard to other medical disorders are not yet fully understood. This review focuses on pathogenesis of NAFLD and its relation with other systemic diseases.

Epicardial fat thickness regression with continuous positive airway pressure therapy in patients with obstructive sleep apnea: assessment by two-dimensional echocardiography

BACKGROUND

Obstructive sleep apnea (OSA) is a common syndrome in patients with metabolic syndrome (MetS). Epicardial fat thickness (EFT), an indicator of visceral adiposity, is a novel parameter for studying patients with OSA. Our aim was to investigate the effects of continuous positive airway pressure therapy (CPAP) therapy on EFT.

METHODS

A total of 162 subjects (68 women and 94 men) were included and divided into three groups: Group I: Apnea-hypopnea index (AHI) < 5 (n  = 45), Group II: AHI 5-15 (n  = 22), and Group III: AHI > 15 (n  = 95). All participants underwent full-night polysomnography and transthoracic echocardiography. There were 28 symptomatic patients with AHI > 15 who received compliant CPAP therapy for 24 weeks.

RESULTS

MetS was more frequent, and systolic blood pressure (SBP), diastolic blood pressure (DBP), blood glucose were higher in Group III compared with I (p  < 0.05). High-density lipoprotein (HDL) levels were lower in Group III compared with I (p < 0.05). Triglyceride levels and waist circumference were higher in Group III compared with I and II (p  < 0.05). EFT was higher in Group III compared with I and higher in Group II compared with I (p < 0.05). EFT was predicted by MetS and AHI. After CPAP therapy high-sensitive C-reactive protein (hsCRP) and EFT were reduced (p < 0.05).

CONCLUSION

EFT was significantly higher in patients with AHI > 15 and predicted by MetS and AHI. CPAP therapy reduced hsCRP levels and EFT.

Obesity-associated cancer: an immunological perspective

Epidemiological studies have established an association between obesity, insulin resistance, type 2 diabetes and a number of cancer types. Research has focused predominantly on altered endocrine factors, growth factors and signalling pathways, with little known in man about the immune involvement in the relevant pathophysiological processes. Moreover, in an era of exciting new breakthroughs in cancer immunotherapy, there is also a need to study the safety and efficacy of immunotherapeutics in the complex setting of inflammatory-driven obesity-associated cancer. This review addresses key immune cell subsets underpinning obesity-associated inflammation and describes how such immune compartments might be targeted to prevent and treat obesity-associated cancer. We propose that the modulation, metabolism, migration and abundance of pro- and anti-inflammatory cells and tumour-specific T cells might be therapeutically altered to both restore immune balance, alleviating pathological inflammation, and to improve anti-tumour immune responses in obesity-associated cancer.

Plasma leptin level is associated with cardiac autonomic dysfunction in patients with type 2 diabetes: HSCAA study

Background

It has been shown that visceral fat accumulation is associated with autonomic dysfunction, though the precise mechanism remains unclear. A recent basic study found that leptin can directly modulate autonomic function through the dorsomedial hypothalamus in relation to obesity. Here, we investigated the mutual relationships among plasma leptin, visceral fat accumulation, and cardiac autonomic dysfunction in patients with type 2 diabetes.

Methods

This cross-sectional study included 100 diabetic patients, and 100 age- and gender-matched non-diabetic patients with cardiovascular risk factors. Plasma leptin and soluble leptin receptor levels, visceral fat area (VFA), and heart rate variability (HRV) were determined in addition to classical cardiovascular risk factors.

Results

In the type 2 diabetic patients, VFA was significantly (p < 0.05) and inversely associated with HRV parameters (SDNN: r = −0.243; SDANN5: r = −0.238), while the plasma level of leptin, but not soluble leptin receptor, was also significantly (p < 0.05) and inversely associated with HRV parameters (SDNN: r = −0.243; SDANN5: r = −0.231). Multiple regression analysis showed that plasma leptin was significantly associated with SDNN and SDANN5 independent of other factors, including age, gender, presence of hypertension and dyslipidemia, duration of diabetes, HbA1c, and eGFR. Furthermore, the relationship of leptin with SDNN and SDANN5 (β = −0.279 and −0.254, respectively) remained significant (p < 0.05) after adjustment for VFA. In patients without diabetes, no significant associations were observed between leptin and any of the HRV parameters.

Conclusions

Hyperleptinemia may be involved in cardiac autonomic dysfunction in patients with type 2 diabetes and visceral obesity.

Visceral adiposity in persons with chronic spinal cord injury determined by dual energy X-ray absorptiometry

OBJECTIVE

To determine visceral adipose tissue (VAT) volume (VATvol) by dual energy X-ray absorptiometry (DXA) in spinal cord injured (SCI) and able-bodied (AB) participants and to explore the relationships between VATvol and routine anthropometric measures.

METHODS

Sixty-three subjects with SCI and 126 healthy male AB controls were stratified as low risk [LR: waist circumference (WC) < 102 cm] and moderate to high risk (MHR: WC ≥ 102 cm) for identification of risk for cardiometabolic disease: AB-LR, SCI-LR, AB-MHR, and SCI-MHR. Anthropometrics and standard body composition measurements by DXA with analysis to derive VATvol were performed.

RESULTS

Comparison of the four subgroups demonstrated the highest subcutaneous adipose tissue volume (SATvol) in the AB-MHR group (P < 0.01), and the highest VATvol in the SCI-MHR group (P < 0.01). Furthermore, when compared to the AB group, participants with SCI had a 27% increase in VATvol for every centimeter increase in WC and a 20% increase in VATvol for every unit increase in BMI.

CONCLUSIONS

Because cutoff values for the routine surrogate measures of adiposity underestimate visceral adiposity in persons with SCI, the risk of adverse metabolic consequences would also be underestimated, which necessitates adjustment of the these cutoff values or, preferably, to perform its direct measurement.

Epicardial adipose tissue and coronary artery calcium predict incident myocardial infarction and death in HIV-infected patients

BACKGROUND

Epicardial adipose tissue (EAT) and coronary artery calcium (CAC) have been associated with incident coronary artery disease (CAD) and all-cause mortality in the general population. Their prognostic impact in HIV is unknown.

METHODS

Observational study of 843 consecutive HIV-infected patients receiving antiretroviral therapy for at least 6 months. Risk stratification was performed with coronary artery calcium (CAC) scoring and EAT screening. Patients were followed for CAD and all-cause mortality for a median of 2.8 years accounting for a total of 2572 patient-year follow-up.

RESULTS

Mean patient age was 50 ± 8 years and 69% were men. At baseline EAT was associated with male gender, age, waist circumference, visceral adipose tissue, and lipodystrophy, while CAC score ≥ 100 was associated with male gender, age and total cholesterol. During follow-up 33 patients suffered an event (15 incident myocardial infarctions and 18 deaths); the EAT volume was larger and the CAC score was higher in patients with events (p = 0.038 and p = 0.001 respectively). Multivariable regression analyses demonstrated that the upper tertile of EAT (≥ 93 cc; OR 2.15, 95% CI 1.06 - 4.39, p = 0.034), and CAC score ≥ 100 (OR 3.37, 95% CI 1.49 - 7.60, p = 0.003) were independent predictors of events after adjusting for age and sex.

CONCLUSIONS

In this observational cohort of HIV patients, EAT and CAC were independent predictors of hard outcomes after a median follow-up of approximately 3 years.

Effect of aerobic exercise training dose on liver fat and visceral adiposity

BACKGROUND & AIMS

Aerobic exercise reduces liver fat and visceral adipose tissue (VAT). However, there is limited data from randomized trials to inform exercise programming recommendations. This study examined the efficacy of commonly prescribed exercise doses for reducing liver fat and VAT using a randomized placebo-controlled design.

METHODS

Inactive and overweight/obese adults received 8 weeks of either; i) low to moderate intensity, high volume aerobic exercise (LO:HI, 50% VO 2peak, 60 min, 4d/week); ii) high intensity, low volume aerobic exercise (HI:LO, 70% VO 2peak, 45 min, 3d/week); iii) low to moderate intensity, low volume aerobic exercise (LO:LO, 50% VO 2peak, 45 min, 3d/week); or iv) placebo (PLA). Liver fat (spectroscopy) and VAT (magnetic resonance imaging) were measured before and after intervention.

RESULTS

Forty-seven of the 48 (n = 12 in each group) participants completed the trial. There were no serious adverse events. There was a significant change in group × time interaction in liver fat, which reduced in HI:LO by 2.38 ± 0.73%, in LO:HI by 2.62 ± 1.00%, and in LO:LO by 0.84 ± 0.47% but not in PLA (increase of 1.10 ± 0.62%) (p = 0.04). There was a significant reduction in VAT in HI:LO (-258.38 ± 87.78 cm(3)), in LO:HI (-386.80 ± 119.5 cm(3)), and in LO:LO (-212.96 ± 105.54 cm(3)), but not in PLA (92.64 ± 83.46 cm(3)) (p = 0.03). There were no significant differences between the dose or intensity of the exercise regimen and reductions in liver fat or VAT (p > 0.05).

CONCLUSION

The study found no difference in efficacy of liver fat reduction by either aerobic exercise dose or intensity. All of the aerobic exercise regimens employed reduced liver fat and VAT by a small amount without clinically significant weight loss.

Four-Year Changes in Visceral Fat Mass and the Risk of Developing Proteinuria in the General Population

Background

Previous cross-sectional studies demonstrated the close relationship between visceral obesity and the increased prevalence of proteinuria. But, little is known about the role of changes in visceral fat mass (∆VFM) over several years in the development of proteinuria. In this longitudinal cohort study with the general population, the changes in ∆VFM as well as baseline VFM on proteinuria development were evaluated.

Methods

Healthy individuals (n = 2393) who participated in two health screening exams were analyzed. Subjects were divided into three groups based on gender-specific tertiles of baseline VFM and ∆VFM. Each patient was tested for proteinuria using a dipstick, and proteinuria was defined as 1+ or greater.

Results

The mean age was 51.9±7.7 years, and the incidence of proteinuria was 3.9% (n = 93). During the 4 years, 52.5% of the subjects experienced a decline in ∆VFM. However, subjects who developed proteinuria exhibited a significant increase in ∆VFM. Even after adjustment for age, smoking, systolic and diastolic BP, serum creatinine, and hs-CRP levels, the highest tertiles for baseline VFM [men, odds ratio (OR) 3.43, 95% confidence interval (CI) 1.22–9.67; women, OR 2.01, 95% CI 1.05–4.15] and ∆VFM (men, OR 2.92, 95% CI 1.22–6.99; women, OR 3.16, 95% CI 1.56–6.39) were independent predictors of proteinuria development. Following adjustment of both parameters, subjects in the highest baseline VFM and ∆VFM tertiles exhibited the greatest risk of proteinuria development, which suggested the additive harmful effects of the two factors.

Conclusions

Baseline VFM and greater increase in ∆VFM were both important risk factors for developing proteinuria in the general population. Appropriate education and interventions to prevent accumulation of VFM should be the major focus of preemptive strategies.

Visceral adipose tissue measured by DXA correlates with measurement by CT and is associated with cardiometabolic risk factors in children

BACKGROUND

Visceral adipose tissue (VAT) generally demonstrates a stronger relationship with cardiometabolic risk factors than total body fat or subcutaneous adipose tissue.

OBJECTIVES

The purpose of this study was to compare VAT estimated in children by total volume dual-energy X-ray absorptiometry (DXA) with a gold standard measurement, single slice (L4-L5) computed tomography (CT).

METHODS

A total of 329 (152 females, 177 males) children ages 6-18 years (mean age 12.3 ± 3.6) and with average body mass index percentile of 54.9% (3-99%) had their VAT estimated by both CT and DXA. Linear association between methods was measured using Pearson's correlation. Multiple linear regressions compared the associations between cardiometabolic risk factors and both CT-VAT and DXA-VAT, respectively.

RESULTS

In children, DXA-VAT was correlated significantly with CT-VAT, with a stronger relationship in overweight and obese children. Multiple regression analysis showed that both estimates of VAT were significantly associated with lipids and insulin sensitivity, measured by euglycaemic-hyperinsulinaemic clamp. Additionally, DXA-VAT was associated with diastolic blood pressure, homeostasis model of insulin resistance and fasting insulin, but CT-VAT was not.

CONCLUSION

In children, total volume DXA-VAT and single slice CT-VAT are significantly correlated and each demonstrates similar associations with cardiometabolic risk factors. This suggests that DXA is a useful and valid method for estimation of VAT in children.

Serum interleukin-1β in subjects with abdominal obesity and periodontitis

BACKGROUND & OBJECTIVE

Abdominal obesity and periodontal diseases are believed to share close relation through commonality of chronic inflammation. Both inflammatory periodontal disease and excess abdominal fat modulate their systemic influences through several inflammatory mediators. The present study was carried out to evaluate and compare serum interleukin-1β levels in subjects with abdominal obesity and periodontal disease.

METHODS

Sixty non-diabetic and non-smoking subjects (aged 25-49 years; 28 females and 32 males) were assessed for abdominal obesity by waist to hip ratio. Full-mouth clinical periodontal measurements were recorded for determination of periodontal status. Serum samples were obtained and interleukin-1β was assessed using commercially available ELISA kit. Obtained data were analyzed statistically.

RESULTS

Measures of abdominal obesity and periodontal disease were found to significantly influence the serum interleukin-1β. Abdominally obese subjects had significantly higher serum interleukin-1β in healthy (p=0.006), gingivitis (p<0.001) and periodontitis (p<0.001) groups. There was a significant difference in serum interleukin-1β levels among subjects with different periodontal status in both non obese (F(2,27)=18.17, p<0.0001) and obese groups (F(2,27)=15.70, p<0.0001). Serum interleukin-1β was significantly correlated with PI, GI, BOP%, PD and CAL non obese and obese groups. A significant correlation was also seen with WC, HC and WHR only in obese group.

CONCLUSION

Significant changes in serum interleukin-1β are influenced by abdominal obesity and periodontal status independently even in the absence of diabetes mellitus and smoking. Serum interleukin-1β was significantly higher in patients with abdominal obesity and periodontitis.

Identification of sex-specific thresholds for accumulation of visceral adipose tissue in adults

OBJECTIVE

The purpose of this study was to measure the linearity of visceral adipose tissue (VAT) accumulation with measures of total body adiposity to determine whether a threshold exists and to explore the association with cardiometabolic risk factors in adults.

METHODS

Using a cross-sectional design, data were obtained from 723 adults (324 females) age 19-47 years. Body mass index ranged from 15 to 52 kg/m(2) . Segmented linear regression was used to identify sex-specific percent body fat thresholds at which VAT slope changes. Linear regression measured the association of VAT mass, total fat mass, and subcutaneous fat with cardiometabolic risk factors above and below each threshold.

RESULTS

Adiposity thresholds were identified at 23.4% body fat in males and 38.3% body fat in females beyond which the slope of VAT per unit of percent body fat increased to strongly positive. Males and females above these adiposity thresholds had significant dyslipidemia (P<0.001), increased insulin resistance (P<0.001), and higher fat mass across all depots.

CONCLUSIONS

From these cross-sectional data, the following were inferred: the accumulation of VAT mass is not linear with increasing adiposity; increases in visceral accumulation above threshold are associated with decreased insulin sensitivity and cardiovascular risk in males and females independent of total body fat.

Factors affecting high-sensitivity cardiac troponin T elevation in Japanese metabolic syndrome patients

PURPOSE

The blood concentration of cardiac troponin T (ie, high-sensitivity cardiac troponin T [hs-cTnT]), measured using a highly sensitive assay, represents a useful biomarker for evaluating the pathogenesis of heart failure or predicting cardiovascular events. However, little is known about the clinical significance of hs-cTnT in metabolic syndrome. The aim of this study was to examine the factors affecting hs-cTnT elevation in Japanese metabolic syndrome patients.

PATIENTS AND METHODS

We enrolled 258 metabolic syndrome patients who were middle-aged males without a history of cardiovascular events. We examined relationships between hs-cTnT and various clinical parameters, including diagnostic parameters of metabolic syndrome.

RESULTS

There were no significant correlations between hs-cTnT and diagnostic parameters of metabolic syndrome. However, hs-cTnT was significantly correlated with age (P<0.01), blood concentrations of brain natriuretic peptide (P<0.01), reactive oxygen metabolites (markers of oxidative stress, P<0.001), and the cardio-ankle vascular index (marker of arterial function, P<0.01). Furthermore, multiple regression analysis revealed that these factors were independent variables for hs-cTnT as a subordinate factor.

CONCLUSION

The findings of this study indicate that in vivo oxidative stress and abnormality of arterial function are closely associated with an increase in hs-cTnT concentrations in Japanese metabolic syndrome patients.

Metabolic syndrome and lifestyle modification

A clustering of metabolic abnormalities such as dyslipidemia, hypertension, and diabetes mellitus, all of which are major risk factors for cardiovascular disease (CVD), occurs more often than by chance. Numerous epidemiological studies, as well as basic researches, have revealed that visceral fat accumulation is closely involved in this risk clustering. This morbid condition is now well recognized as the metabolic syndrome. The concept of the metabolic syndrome, i.e., the involvement of visceral adiposity in the clustering of CVD risk factors, implies that an effective CVD risk reduction will be accomplished by an intervention to reduce visceral fat deposits. The primary strategy of the intervention is lifestyle modification, which can be put into practice in healthcare fields, without necessity of medical treatment. Now that CVD is a leading global health burden, the metabolic syndrome attracts increasing attention in the world. To take global action against the syndrome, several working groups developed its internationally unified diagnostic criteria. Most recently, the International Diabetes Federation (IDF) and the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) jointly proposed the criteria, although some cautions will be needed in their practical use. In this review, we mainly focus on the findings observed in clinical and epidemiological studies, to discuss a practical strategy of the management of the metabolic syndrome in healthcare fields.

Associations of physical activity and sedentary behavior with regional fat deposition

INTRODUCTION

Increased sedentary behavior predicts greater cardiovascular morbidity and mortality and does so independently of physical activity (PA). This association is only partially explained by body mass index (BMI) and overall body fat, suggesting mechanisms besides general increased adiposity. The purpose of this study was to explore associations of self-reported leisure PA and sitting time with regional fat depositions and abdominal muscle among community-dwelling older adults.

METHODS

Participants were 539 diverse adults (mean age = 65 yr) who completed a study visit in 2001-2002. Areas of pericardial, intrathoracic, subcutaneous, visceral, and intermuscular fat, as well as abdominal muscle, were measured using computed tomography. Leisure PA and sitting hours were entered simultaneously into multivariate regression models to determine associations with muscle and fat areas.

RESULTS

After adjusting for demographics, smoking, diabetes, hypertension, triglycerides, and cholesterol, greater PA was associated with less intrathoracic, visceral, subcutaneous, and intermuscular fat (for all P < 0.05), while greater sedentary time was associated with greater pericardial and intrathoracic fat (for both P < 0.05). After further adjusting for BMI, each hour of weekly PA was associated with 1.85 cm less visceral fat (P < 0.01) but was not associated with other fat depositions. Conversely, each hour of daily sitting was associated with 2.39 cm more pericardial fat (P < 0.05) but was not associated with any other fat depositions. There were no associations with abdominal muscle area. Adjusting for common inflammatory markers had little effect. Associations between fat and PA were stronger for men.

CONCLUSIONS

Sitting and PA have distinct associations with regional fat deposition in older adults. The association between sitting and pericardial fat could partially explain the link between sitting and coronary heart disease.

Adiposity measures, lean body mass, physical activity and mortality: NHANES 1999-2004

Background

Obesity and physical inactivity are major public health problems. We studied the associations between measures of adiposity, lean body mass, leisure time physical activity (LTPA), and death in those with and without chronic kidney disease (CKD).

Methods

Associations between body mass index (BMI), waist circumference (WC), percent body fat, lean body mass (assessed with Dual-Energy X-ray Absorptiometry[DEXA]), leisure time physical activity (LTPA) and death were examined using the National Health and Nutrition Examination Surveys (NHANES 1999–2004). All-cause mortality was ascertained by linkage of NHANES files with the National Death Index.

Results

9,433 non-CKD participants and 2,153 CKD participants who had fat mass measured using DEXA, BMI, WC, LTPA and mortality data were included. After adjusting for demographics, comorbid conditions, kidney function measures, C-Reactive Protein (CRP), and sodium intake there was no significant risk for death noted with higher WC, fat mass and BMI in those with and without CKD. When examining normal, overweight, and obese groups based on BMI criteria, being overweight (BMI 25–29.9 kg/m²) was associated with lower risk of death in those without CKD (Hazard ratio 0.62, 95% CI 0.40, 0.95). Higher lean body mass was associated with lower risk for death in those without kidney disease but not in the CKD population. There was a significantly higher risk for death among those who did not meet the minimum LTPA goals compared to those who met or exceeded the recommended activity levels (>450 MET/min/week) in those with and without CKD (CKD Hazard ratio: 1.36, 95% CI 1.003, 1.85; non-CKD HR 1.65, 95% CI 1.21, 2.26).

Conclusions

In a representative sample of the US population, higher LTPA levels and lean body mass were associated with lower mortality in those without kidney disease. In CKD, higher LTPA was associated with lower risk of death. There was no association between adiposity measures and death in those with and without CKD except for lower mortality associated with overweight among those without CKD. The data suggests the need to develop programs to facilitate an increase in physical activity in people with and without kidney disease.

Exercise and dietary-mediated reductions in postprandial lipemia

Postprandial hyperlipemia produces long-term derangements in lipid/lipoprotein metabolism, vascular endothelial dysfunction, hypercoagulability, and sympathetic hyperactivity which are strongly linked to atherogenesis. The purpose of this review is to (1) provide a qualitative analysis of the available literature examining the dysregulation of postprandial lipid metabolism in the presence of obesity, (2) inspect the role of adiposity distribution and sex on postprandial lipid metabolism, and (3) examine the role of energy deficit (exercise- and/or energy restriction-mediated), isoenergetic low-carbohydrate diets, and omega-3 (n-3) fatty acid supplementation on postprandial lipid metabolism. We conclude from the literature that central adiposity primarily accounts for sex-related differences in postprandial lipemia and that aerobic exercise attenuates this response in obese or lean men and women to a similar extent through potentially unique mechanisms. In contrast, energy restriction produces only mild reductions in postprandial lipemia suggesting that exercise may be superior to energy restriction alone as a strategy for lowering postprandial lipemia. However, isoenergetic very low-carbohydrate diets and n-3 fatty acid supplementation reduce postprandial lipemia indicating that macronutrient manipulations reduce postprandial lipemia in the absence of energy restriction. Therefore, interactions between exercise/energy restriction and alterations in macronutrient content remain top priorities for the field to identify optimal behavioral treatments to reduce postprandial lipemia.

Effects of garcinia cambogia (Hydroxycitric Acid) on visceral fat accumulation: a double-blind, randomized, placebo-controlled trial

BACKGROUND

(-)-Hydroxycitric acid (HCA) is an active ingredient extracted from the rind of the Indian fruit Garcinia cambogia. It inhibits adenosine triphosphate citrate lyase and has been used in the treatment of obesity.

OBJECTIVE

The primary end point of this study was the effects of 12 weeks of G cambogia extract administration on visceral fat accumulation. The secondary end points were body indices (including height, body weight, body mass index [BMI], waist and hip circumference, and waist-hip ratio) and laboratory values (including total cholesterol, triacylglycerol, and free fatty acid).

METHODS

This study was performed according to a double-blind, randomized, placebo-controlled, parallel-group design. Subjects aged 20 to 65 years with a visceral fat area >90 cm(2) were enrolled. Subjects were randomly assigned to receive treatment for 12 weeks with G cambogia (containing 1000 mg of HCA per day) or placebo. At the end of the treatment period, both groups were administered placebo for 4 weeks to assess any rebound effect. Each subject underwent a computed tomography scan at the umbilical level at -2, 0, 12, and 16 weeks.

RESULTS

Forty-four subjects were randomized at baseline, and 39 completed the study (G cambogia group, n = 18; placebo group, n = 21). At 16 weeks, the G cambogia group had significantly reduced visceral, subcutaneous, and total fat areas compared with the placebo group (all indices P<0.001). No severe adverse effect was observed at any time in the test period. There were no significant differences in BMI or body weight at week 12, but there were slight numeric decreases in body weight and BMI in men. There were no signs of a rebound effect from week 12 to week 16.

CONCLUSION

G cambogia reduced abdominal fat accumulation in subjects, regardless of sex, who had the visceral fat accumulation type of obesity. No rebound effect was observed. It is therefore expected that G cambogia may be useful for the prevention and reduction of accumulation of visceral fat.

Regulation of the Body Fat Percentage in Developmental-Stage Rats by Methylxanthine Derivatives in a High-Fat Diet

We investigated the regulatory effects of structural differences among methylxanthine derivatives on the elevation of body fat percentage in developmental-stage rats. Caffeine, theophylline and theobromine were used as the methylxanthines. High-fat diets (20% lard) containing each methylxanthine (0.025%) were administered to male Sprague-Dawley rats for 12 weeks, with the result that the body fat percentage was generally reduced in each methylxanthine-fed group. The abdominal adipose tissue weight in the caffeine group was also significantly lower than that in the control group, the serum cholesterol and triglyceride levels in the caffeine group also being significantly lower than the levels in the control group. The study results suggest that caffeine could contribute most to preventing arteriosclerotic diseases.

Visceral fat level is an independent risk factor for cardiovascular mortality in hemodialysis patients

BACKGROUND

Obesity is an independent risk factor for morbidity and mortality in cardiovascular diseases not only in the general population, but also in hemodialysis (HD) patients. We previously reported that an increased visceral fat area (VFA) determined using computed tomography (CT) scans was associated with atherosclerosis in HD patients. However, whether a high VFA is associated with increased cardiovascular mortality in HD patients remains unknown. Therefore, we investigated the relationship between VFA and prognosis in HD patients.

METHODS

VFA was estimated in 126 patients on maintenance HD using CT scans. These patients were followed for 60 months.

RESULTS

Kaplan-Meier analysis revealed that the cardiovascular survival rate was significantly lower in the high-VFA group, with a VFA of 71.5 cm(2) or greater, than in the low-VFA group, with a VFA of less than 71.5cm(2). In univariate Cox proportional hazards analyses, age, albumin, low-density lipoprotein cholesterol, cardio-thoracic ratio and VFA above 71.5 cm(2) were significantly correlated with cardiovascular deaths. In multivariate analyses testing these factors as dependent variables, VFA above 71.5 cm(2) was estimated to be an independent predictor of cardiovascular deaths.

CONCLUSION

These results suggest that an increased VFA is a stronger risk factor for cardiovascular deaths in HD patients. Measuring VFA may be recommended for predicting the risk of cardiovascular diseases in HD patients.

Visceral adipose tissue as a source of inflammation and promoter of atherosclerosis

The current epidemic of obesity with the associated increasing incidence of insulin resistance, diabetes mellitus and atherosclerosis affecting a large proportion of the North American and Western populations, has generated a strong interest in the potential role of visceral adipose tissue in the development of atherosclerosis and its complications. The intra-abdominal and epicardial space are two compartments that contain visceral adipose tissue with a similar embryological origin. These visceral fats are highly inflamed in obese patients, patients with the metabolic syndrome and in those with established coronary artery disease; additionally they are capable of secreting large quantities of pro-inflammatory cytokines and free fatty acids. There is accumulating evidence to support a direct involvement of these regional adipose tissue deposits in the development of atherosclerosis and its complicating events, as will be reviewed in this article.

Fat accumulation and obesity-related cardiovascular risk factors in middle-aged Japanese men and women

OBJECTIVE

A cluster of multiple risk factors has been noted to constitute the background of cardiovascular disease. The purpose of this study was to evaluate the relationship between the visceral fat area (VFA) or subcutaneous fat area (SFA) and a cluster of obesity-related cardiovascular risk factors, including hyperglycemia, dyslipidemia and elevated blood pressure, in middle-aged Japanese men and women.

METHODS

A total of 571 subjects (m=434; f=137; age: 53 ± 9 years) who underwent health examinations with evaluations of body fat distribution using computed tomography scans and assessments of 75-g oral glucose tolerance tests were enrolled in this study.

RESULTS

The VFA and SFA were linearly correlated with the number of risk factors in both men and women. The area under the receiver-operating characteristic curve of VFA (m=0.741, f=0.763) was significantly higher than that of SFA (m=0.636, f=0.689) with respect to the clustering of risk factors (one or more). The men exhibited larger VFA values and smaller SFA values than the women in similar body mass index (BMI) categories. Men with a VFA of ≥100 cm(2) irrespective of BMI and women with a VFA of ≥100 cm(2) and a BMI of ≥25 kg/m(2) demonstrated a high prevalence of diabetes mellitus and impaired glucose tolerance. Men and women with a VFA of ≥100 cm(2) irrespective of BMI demonstrated a high prevalence of type IIb dyslipidemia.

CONCLUSION

These results suggest that the absolute value of VFA rather than SFA is more closely associated with a cluster of risk factors irrespective of sex and is a good marker for selecting subjects to whom weight reduction should be recommended in order to prevent cardiovascular disease in the general population.

Aerobic exercise attenuates the loss of skeletal muscle during energy restriction in adults with visceral adiposity

OBJECTIVE

To evaluate the effects of energy restriction with or without aerobic exercise on thigh muscle mass and quality in adults with visceral adiposity.

METHODS

75 males and females were randomly assigned to the groups 'diet only' (DO; n = 42) or 'diet plus aerobic exercise' (D/Ex; n = 33) for 12 weeks. The target energy intake in both groups was 25 kcal/kg of ideal body weight. Subjects in the D/Ex group were instructed to exercise for ≥300 min/week at lactate threshold. Computed tomography was used to measure thigh muscle cross-sectional area (CSA), normal-density muscle area (NDMA), and visceral fat area.

RESULTS

Total body weight (DO: -6.6 ± 3.6%; D/Ex: -7.3 ± 4.6%) and visceral fat (DO: -16.0 ± 13.8%; D/Ex: -23.1 ± 14.7%) decreased significantly in both groups; however, the changes were not significantly different between the two groups. The decrease in muscle CSA was significantly greater in the DO group (-5.1 ± 4.5%) compared with the D/Ex group (-2.5 ± 5.0%). NDMA decreased significantly in the DO (-4.9 ± 4.9%) but not in the D/Ex group (-1.4 ± 5.0%).

CONCLUSION

Aerobic exercise attenuated the loss of skeletal muscle during energy restriction in adults with visceral adiposity.

Adiponectin and the cardiometabolic syndrome: an epidemiological perspective

Adiponectin is an adipocyte-derived plasma protein with cardio-vasculo-protective and anti-diabetic properties. Plasma adiponectin levels are low in patients with the cardiometabolic syndrome (a cluster of multiple risk factors based on visceral fat accumulation). Routine measurement of plasma adiponectin may be useful to encourage life-style changes.

Continuous exercise but not high intensity interval training improves fat distribution in overweight adults

OBJECTIVE

The purpose of this study was to assess the effect of high intensity interval training (HIIT) versus continuous aerobic exercise training (CONT) or placebo (PLA) on body composition by randomized controlled design.

METHODS

Work capacity and body composition (dual-energy X-ray absorptiometry) were measured before and after 12 weeks of intervention in 38 previously inactive overweight adults.

RESULTS

There was a significant group × time interaction for change in work capacity (P < 0.001), which increased significantly in CONT (23.8 ± 3.0%) and HIIT (22.3 ± 3.5%) but not PLA (3.1 ± 5.0%). There was a near-significant main effect for percentage trunk fat, with trunk fat reducing in CONT by 3.1 ± 1.6% and in PLA by 1.1 ± 0.4%, but not in HIIT (increase of 0.7 ± 1.0%) (P = 0.07). There was a significant reduction in android fat percentage in CONT (2.7 ± 1.3%) and PLA (1.4 ± 0.8%) but not HIIT (increase of 0.8 ± 0.7%) (P = 0.04).

CONCLUSION

These data suggest that HIIT may be advocated as a time-efficient strategy for eliciting comparable fitness benefits to traditional continuous exercise in inactive, overweight adults. However, in this population HIIT does not confer the same benefit to body fat levels as continuous exercise training.

Overweight dynamics in Chinese children and adults

China has experienced a transition from a history of undernutrition to a rapid increase in obesity. The China Health and Nutrition Survey, an ongoing longitudinal, household-based survey of urban and rural residents of nine provinces, documents these changes using measured height and weight across 53,298 observations from 18,059 participants collected from 1991 to 2011. Adult overweight (body mass index [BMI] ≥ 25 kg/m(2)) prevalence nearly tripled from 1991 (11.7%) to 2009 (29.2%), with significant cohort and age-related effects (stronger in males). Among youth, quantile regression reveals changes across the BMI distribution. By 2009, approximately 12% of children and adolescents were overweight, and 3% of 7-11-year-olds and 1% of 12-17-year-olds were obese (International Obesity Taskforce BMI 25 and 30 kg/m(2) equivalents, respectively). In 1991-2000, urbanicity was strongly and positively associated with BMI, but in 2000-2011, trends were similar across rural and urban areas. Among women, the burden has shifted to lower educated women (the reverse is true for males, as overweight was higher in men of higher education). Our findings highlight the importance of preventive measures early in the life cycle to reduce weight gain.

Relationship between dual-energy X-ray absorptiometry volumetric assessment and X-ray computed tomography-derived single-slice measurement of visceral fat

To reduce radiation exposure and cost, visceral adipose tissue (VAT) measurement on X-ray computed tomography (CT) has been limited to a single slice. Recently, the US Food and Drug Administration has approved a dual-energy X-ray absorptiometry (DXA) application validated against CT to measure VAT volume. The purpose of this study was to develop an algorithm to compute single-slice area values on DXA at 2 common landmarks, L2/3 and L4/5, from an automated volumetrically derived measurement of VAT. Volumetric CT and total body DXA were measured in 55 males (age: 21-77 yr; body mass index [BMI]: 21.1-37.9) and 60 females (age: 21-85 yr; BMI: 20.0-39.7). Equations were developed by applying the relationship of CT single-slice area and volume measurements of VAT to the DXA VAT volume measure as well as validating these against the CT single-slice measurements. Correlation coefficients between DXA estimate of single-slice area and CT were 0.94 for L2/3 and 0.96 for L4/5. The mean difference between DXA estimate of single-slice area and CT was 5 cm(2) at L2/3 and 3.8 cm(2) at L4/5. Bland-Altman analysis showed a fairly constant difference across the single-slice range in this study, and the 95% limits of agreement for the 2 methods were -44.6 to +54.6 cm(2) for L2/3 and -47.3 to +54.9 cm(2) for L4/5. In conclusion, a volumetric measurement of VAT by DXA can be used to estimate single-slice measurements at the L2/3 and the L4/5 landmarks.

Measurement of visceral fat by abdominal bioelectrical impedance analysis is beneficial in medical checkup

SUMMARY

OBJECTIVE

In addition to the waist circumference (WC) measurement, an accurate measurement of visceral fat is very important in terms of the pathology associated with the metabolic syndrome. The only method available for an accurate measurement of a visceral fat area (VFA) is abdominal computed tomography (CT). To overcome this limitation, we estimated VFA using abdominal bioelectrical impedance analysis (BIA) with accuracy comparable to that of abdominal CT, and investigated the relationship between VFA and risk factors of the metabolic syndrome. Because abdominal BIA detects excess visceral fat accumulation that cannot be detected by a measurement of WC, the characteristics of the subjects who were identified as having excessive visceral fat using BIA, but not WC, were examined.

METHODS

Abdominal BIA was used to estimate VFA in male subjects (n = 1803) (age: 48 ± 10 years, body mass index: 23.9 ± 3.0 kg/m(2)) who provided informed consent.

RESULTS

The prevalence of the metabolic syndrome diagnosed based on the diagnostic criteria established by the Japanese Society of Internal Medicine was 18%. Among the risk factors of the metabolic syndrome, WC was significantly correlated with triglycerides (TG), but estimated VFA was correlated with blood pressure and HDL-cholesterol (HDL-C), in addition to TG. Abdominal BIA detected excess visceral fat accumulation in 3% of subjects for whom WC had detected none. Elevated blood pressure, TG, and fasting plasma glucose and decreased HDL-C were also noted in these subjects, and the values of these risk factors were comparable to those of subjects in whom visceral fat accumulation was detected using WC.

CONCLUSION

Abdominal BIA is a simple and safe method that is superior to WC for the detection of excessive visceral fat accumulation. Therefore, abdominal BIA will likely be used clinically to detect excessive accumulation of visceral fat, which is an important predictor of the metabolic syndrome.

The effects of obesity on fall efficacy in elderly people

[Purpose] The aim of this study was to identify the effects of obesity on falls as a practical verification of the importance of obesity-targeting interventions as part of future fall prevention programs. [Subjects and Methods] The study involved 351 elderly people (172 men, 179 women) living in rural areas. The dependent variable, fall efficacy, was measured using the Falls Efficacy Scale, while the independent variables, body mass index (BMI) and visceral fat, were measured using the InBody 720. The Faces Pain Scale was used to measure pain. Mobility was measured using the Timed Up and Go Test, and balance ability was measured according to the duration subjects could stand on one foot with their eyes closed. Hierarchical multiple regression analysis was performed for the final data analysis. [Results] Investigation of the correlations between the variables revealed a negative correlation between fall efficacy and the other variables. Ultimatley, investigation of the causality of fall efficacy revealed that the BMI, pain, and mobility were influential factors. In other words, fall efficacy tends to be lower when there are higher degrees of obesity, increased pain, and decreased mobility. [Conclusion] To improve the fall efficacy of elderly people living in rural areas, pain management and the maintenance of physical functionality are required. The present study confirms that the elderly need continuous obesity management to lead healthy lives.