Preoperative Visceral Adiposity and Muscularity Predict Poor Outcomes after Hepatectomy for Hepatocellular Carcinoma

OBJECTIVE

Visceral adiposity, defined as a high visceral-to-subcutaneous adipose tissue area ratio (VSR), has been shown to be associated with poor outcomes in several cancers. However, in the surgical field, the significance of visceral adiposity remains controversial. The present study investigated the impact of visceral adiposity as well as sarcopenic factors (low muscularity) on outcomes in patients undergoing hepatectomy for hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

This retrospective study analyzed data from 606 patients undergoing hepatectomy for HCC at our institution between April 2005 and March 2016. Using preoperative plain computed tomography imaging at the level of the third lumbar vertebra, visceral adiposity, skeletal muscle mass, and muscle quality were evaluated by the VSR, skeletal muscle mass index (SMI), and intramuscular adipose tissue content (IMAC), respectively. The impact of these parameters on outcomes after hepatectomy for HCC was analyzed.

RESULTS

The overall survival rate was significantly lower among patients with a high VSR (p < 0.001) than among patients with a normal VSR. Similarly, the recurrence-free survival rate was significantly lower among patients with a high VSR (p = 0.016). A high VSR, low SMI, and high IMAC contributed to an increased risk of death (p < 0.001) and HCC recurrence (p < 0.001) in an additive manner. Multivariate analysis showed that not only preoperative low muscularity but also visceral adiposity was a significant risk factor for mortality (hazard ratio [HR] = 1.566, p < 0.001) and HCC recurrence (HR = 1.329, p = 0.020) after hepatectomy for HCC.

CONCLUSIONS

Preoperative visceral adiposity, as well as low muscularity, was closely related to poor outcomes after hepatectomy for HCC. It is crucial to establish a new strategy including perioperative nutritional interventions with rehabilitation for better outcomes after hepatectomy for HCC.

Amygdalar activity predicts future incident diabetes independently of adiposity

While it is established that psychosocial stress increases the risk of developing diabetes mellitus (DM), two key knowledge gaps remain: 1) the neurobiological mechanisms that are involved in mediating that risk, and 2) the role, if any, that adiposity plays in that mechanism. We tested the hypotheses that: 1) metabolic activity in the amygdala (AmygA), a key center involved in the neurobiological response to stress, associates with subsequent DM risk, and 2) this association is independent of adiposity. AmygA and adipose tissue volumes were measured, and serial blood assessments for DM were obtained in 232 subjects who underwent combined ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) imaging. Higher baseline AmygA predicted subsequent, new-onset DM, independently of adiposity and other DM risk factors. Furthermore, higher adiposity only increased DM risk in the presence of higher AmygA. In a separate cross-sectional cohort, higher AmygA associated with higher insulin resistance. Accordingly, the current study shows, for the first time, that activity in a stress-responsive neural region predicts the onset of DM. Further, we observed that this neurobiological activity acts independently of, but also synergistically with adiposity to increase DM risk. These findings suggest novel therapeutic targets to help manage and possibly prevent DM.

The discriminatory power of visceral adipose tissue area vs anthropometric measures as a diagnostic marker for metabolic syndrome in South African women

BACKGROUND

A number of studies have shown central adiposity, in particular visceral adipose tissue (VAT) accumulation to be a hallmark of metabolic syndrome (MetS). In clinical practice, waist circumference (WC) is used as a proxy for VAT.

AIM

To compare the ability of dual energy x-ray absorptiometry (DXA)-derived VAT area and anthropometric measures of adiposity for diagnosing MetS in a sample of high risk South African women.

METHODS

MetS was quantified using the Joint Interim Statement (JIS) criteria. Fasting glucose, insulin and lipid profile were measured in 204 post-menopausal women. Anthropometry measures included body mass index (BMI), WC, waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and a body shape index (ABSI). The area under the curve (AUC) was used to assess their performance in detecting any two components of MetS (excluding WC). Optimal WC and VAT area cut-points were derived to compare their performance for diagnosing MetS and to compare to internationally recognised cut-points.

RESULTS

The highest AUC for the prediction of MetS was recorded for VAT, followed by WHtR and WC (AUC, 0.767, 0.747 and 0.738 respectively), but these did not differ significantly (all p ≥ 0.192). In contrast, VAT was significantly better than BMI (p = 0.028), hip (p = 0.0004) and ABSI (p < 0.0001). The optimal WC (94.4 cm) and VAT area (174 cm² based on the Youden's index method and 175.50 cm² based on the CTL approach) cut-points performed similarly in detecting MetS.

CONCLUSION

DXA-derived VAT and WC had the same overall performance in discriminating the presence of any 2 MetS components in high risk South African women. These findings support the current recommendations of using WC rather than VAT for MetS risk screening, as it is cheap, accessible and easy to measure.

Identification of chronic kidney disease risk in relatively lean Southern Chinese: the hypertriglyceridemic waist phenotype vs. anthropometric indexes

PURPOSE

Assessing and comparing the ability of the hypertriglyceridemic waist (HW) phenotype and anthropometric obesity indexes to identify subjects at high risk of chronic kidney disease (CKD) in a relatively lean population in South China.

METHODS

Using data from a community-based, cross-sectional study conducted in Zhuhai City, Southern China, we examined associations between the HW phenotype, anthropometric obesity indexes, and incident CKD risk in a relatively lean population. Multiple logistic regression analyses were used to evaluate the associations.

RESULTS

The HW phenotype associated with CKD significantly in the unadjusted analysis (OR 3.53, 95% CI 1.65-7.52, P = 0.001). Further adjustment for gender, age, and other potential confounding variables had an impact on the odd ratios (OR); the OR decreased but still existed (OR 2.91, 95% 1.23-6.87, P = 0.016). The association of the HW phenotype with CKD remained significant after further adjustment for hypertension and diabetes. No significant association between the anthropometric indexes and incident CKD was found.

CONCLUSION

The HW phenotype, but not the anthropometric indexes, is associated with an elevated risk of CKD in relatively lean subjects. The HW phenotype appears to be a better predictor of CKD than the anthropometric indexes.

LEVEL OF EVIDENCE

Level V, descriptive study.

Relation of plasma ceramides to visceral adiposity, insulin resistance and the development of type 2 diabetes mellitus: the Dallas Heart Study

AIMS/HYPOTHESIS

Ceramides are sphingolipids that contribute to insulin resistance in preclinical studies. We hypothesised that plasma ceramides would be associated with body fat distribution, insulin resistance and incident type 2 diabetes in a multi-ethnic cohort.

METHODS

A total of 1557 participants in the Dallas Heart Study without type 2 diabetes underwent measurements of metabolic biomarkers, fat depots by MRI and plasma ceramides by liquid chromatography-mass spectrometry. Diabetes outcomes were assessed after 7 years. Associations of body fat and insulin resistance with ceramides at baseline and of ceramides with incident diabetes outcomes were analysed.

RESULTS

The cohort had a mean age of 43 years, with 58% women, 45% black participants and a mean BMI of 28 kg/m². Total cholesterol levels were associated with all ceramides, but higher triacylglycerols and lower HDL-cholesterol and adiponectin were associated only with saturated fatty acid chain ceramides (p < 0.0003). After adjusting for clinical characteristics and total body fat, visceral adipose tissue was positively associated with saturated fatty acid ceramides (per SD, β = 0.16 to 0.18) and inversely associated with polyunsaturated fatty acid ceramides (β = -0.14 to -0.16, p < 0.001 for all). Lower-body subcutaneous fat showed an opposite pattern to that for visceral fat. HOMA-IR was positively associated with saturated (β = 0.08 to 0.09, p < 0.001) and inversely with polyunsaturated ceramides (β = -0.06 to -0.07, p < 0.05). Ceramides were not associated with incident type 2 diabetes after adjustment for clinical factors.

CONCLUSIONS/INTERPRETATION

Plasma ceramides demonstrate a biologically complex relationship with metabolic and imaging indicators of dysfunctional adiposity. The role of ceramides in a shared pathway of metabolic dysfunction linking visceral adiposity and insulin resistance requires further investigation.

[Relationship between visceral obesity and atherosclerosis in hemodialysis patients]

Objective: To evaluate the relationship between surrogate markers of visceral obesity[hypertriglyceridemic waist (HW) phenotype, visceral adiposity index (VAL), lipid accumulation product (LAP)]and atherosclerosis in hemodialysis patients. Methods: A multi-center cross-sectional study was carried out. A total of 961 maintenance hemodialysis (MHD) patients from 11 hemodialysis centers of Guizhou province between July 2016 and September 2017 were enrolled in the study. Anthropometric measures were performed in all subjects. Laboratory parameters including triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein-cholesterol were extracted from the medical records by researchers. Pearson correlation analysis was used to investigate the correlation between HW phenotype, VAI, LAP and plasma atherosclerotic index (AIP). Multivariate linear regression analysis was used to evaluate factors affecting AIP. Results: Totally, 585 men and 376 women aged 18-90 years, with a mean age of (56.08±15.42) years were recruited in the study. Pearson correlation analysis showed that VAI (men: r=0.82, women: r=0.84), LAP (men: r=0.73, women: r=0.74) and having HW phenotype (men: r=0.62, women: r=0.63) correlated positively with AIP (all P<0.001). Multivariate linear regression analysis showed that VAI (men: β=0.77, women: β=0.82) and LAP (men: β=0.73, women: β=0.73) were independent associated factors of AIP after adjustment of BMI, age, smoking and history of diabetes and hypertension (all P<0.001). Conclusions: Surrogate markers of visceral obesity such as having HW phenotype, VAI, LAP correlated positively with AIP. VAI, LAP has positive impacts on AIP independent of BMI, age, smoking and other traditional atherosclerosis risk factors.

From inflammation to sexual dysfunctions: a journey through diabetes, obesity, and metabolic syndrome

Metabolic diseases are associated with chronic low-grade inflammation, which has been indicated as a potential mediator of endothelial dysfunction and cardiovascular disease. Visceral adiposity is thought to be the starting condition of the inflammatory state through the release of inflammatory cytokines, including TNF-alpha, CRP, and IL-6, which in turn promote endothelial dysfunction, endothelial expression of chemokines (IL-1) and adhesion molecules (ICAM-1, VCAM-1, and P-selectin), and the inhibition of anti-atherogenic factors (adiponectin). Obesity, metabolic diseases, and diabetes, all conditions characterized by abdominal fat, are well-recognized risk factors for sexual dysfunction in both sexes. Evidence from randomized-controlled trials supports the association between inflammatory milieau and erectile dysfunction in men suffering from metabolic diseases, whereas, in women, this has to be confirmed in further studies. A healthy lifestyle based on dietary pattern with high content of whole grain, fruit, nuts and seeds, and vegetables and low in sodium and saturated fatty acids plus regular physical activity may help to modulate the pro-inflammatory state associated with metabolic diseases and the related burden of sexual dysfunctions.

Design and validation of a novel estimator of visceral adipose tissue area and comparison to existing adiposity surrogates

AIMS

Visceral adiposity measured by computed tomography (CT) as intra-abdominal fat area (IAFA) predicts metabolic diseases. Existing adiposity surrogates have not been systematically compared to a regression-based model derived in individuals of Japanese ancestry. We developed and validated a method to estimate IAFA in individuals of Japanese ancestry and compared it to existing adiposity surrogates.

METHODS

We assessed age, BMI, waist circumference (WC), fasting lipids, glucose, smoking status, grip strength, mid-thigh circumference (MTC), humeral length, leg length, and IAFA by single-slice CT at the umbilicus for 622 Japanese Americans. We used stepwise linear regression to predict IAFA and termed the predicted value the Estimate of Visceral Adipose Tissue Area (EVA). For men, the final model included age, BMI, WC, high-density lipoprotein cholesterol (HDLc), glucose, and MTC; for women, age, BMI, WC, HDLc, low-density lipoprotein cholesterol, glucose, and MTC. We compared goodness-of-fit (R²) from linear regression models and mean-squared errors (MSE) from k-fold cross-validation to compare the ability of EVA to estimate IAFA compared to an estimate by Després et al., waist-to-height ratio, WC, deep abdominal adipose tissue index, BMI, lipid accumulation product, and visceral adiposity index (VAI). We classified low/high IAFA using area under receiver-operating characteristic curves (AUROC) for IAFA dichotomized at the 75th percentile.

RESULTS

EVA gave the least MSE and greatest R² (men: 1244, 0.61; women: 581, 0.72). VAI gave the greatest MSE and smallest R² (mean 2888, 0.08; women 1734, 0.14).

CONCLUSIONS

EVA better predicts IAFA in Japanese-American men and women compared to existing surrogates for adiposity.

Visceral, general, abdominal adiposity and atherogenic index of plasma in relatively lean hemodialysis patients

Background

Obesity is a well-established risk factor for atherosclerosis. However, it is unknown which measure of adiposity best relates to atherosclerosis in relatively lean maintenance hemodialysis (MHD) patients. We aimed to explore and compare the associations between different adiposity indices reflecting general, abdominal, visceral adiposity and arteriosclerosis risk with atherogenic index of plasma(AIP) in relatively lean MHD patients.

Methods

We conducted a multicenter, cross-sectional study in Guizhou Province, Southwest China. General/abdominal adiposity indices like body mass index (BMI), waist circumference(WC), waist-height ratio(WHtR), conicity index (Ci) and visceral obesity indices including visceral adiposity index (VAI), lipid accumulation product (LAP) and the hypertriglyceridemic waist phenotype (HW phenotype) were recorded. Univariate and multivariate linear regression models were used.

Results

All adiposity indices correlated positively with AIP in univariate analysis both in men and women except for Ci. After adjustment for age and traditional atherosclerosis risk factors, BMI, WC, WHtR, VAI and LAP still had associations with AIP both in men (β = 0.265, 0.153, 0.16, 0.788 and 0.74, respectively, all P < 0.001) and women (β = 0.34,0.199, 0.21, 0.83 and 0.74, respectively, all P < 0.001). After further adjustment for BMI, associations between AIP and VAI, LAP remained significant, but associations between WC, WHtR and AIP disappeared.

Conclusions

The HW phenotype, VAI, and LAP, validated and convenient markers of visceral obesity, were superior to classical anthropometric general/ abdominal adiposity indices for atherosclerosis risk assessment, especially in relatively lean MHD patients aged 40 years or older.

Sarcopenic obesity assessed using dual energy X-ray absorptiometry (DXA) can predict cardiovascular disease in patients with type 2 diabetes: a retrospective observational study

Background

Sarcopenic obesity, defined as reduced skeletal muscle mass and power with increased adiposity, was reported to be associated with cardiovascular disease risks in previous cross-sectional studies. Whole body dual-energy X-ray absorptiometry (DXA) can simultaneously evaluate both fat and muscle mass, therefore, whole body DXA may be suitable for the diagnosis of sarcopenic obesity. However, little is known regarding whether sarcopenic obesity determined using whole body DXA could predict incident cardiovascular disease (CVD). The aim of this study was to investigate the impact of sarcopenic obesity on incident CVD in patients with type 2 diabetes.

Methods

A total of 716 Japanese patients (mean age 65 ± 13 years; 47.0% female) were enrolled. Android fat mass (kg), gynoid fat mass (kg), and skeletal muscle index (SMI) calculated as appendicular non-fat mass (kg) divided by height squared (m²), were measured using whole body DXA. Sarcopenic obesity was defined as the coexistence of low SMI and obesity determined by four patterns of obesity as follows: android to gynoid ratio (A/G ratio), android fat mass or percentage of body fat (%BF) was higher than the sex-specific median, or body mass index (BMI) was equal to or greater than 25 kg/m². The study endpoint was the first occurrence or recurrence of CVD.

Results

Over a median follow up of 2.6 years (IQR 2.1–3.2 years), 53 patients reached the endpoint. Sarcopenic obesity was significantly associated with incident CVD even after adjustment for the confounding variables, when using A/G ratio [hazard ratio (HR) 2.63, 95% CI 1.10–6.28, p = 0.030] and android fat mass (HR 2.57, 95% CI 1.01–6.54, p = 0.048) to define obesity, but not %BF (HR 1.67, 95% CI 0.69–4.02, p = 0.252), and BMI (HR 1.55, 95% CI 0.44–5.49, p = 0.496).

Conclusions

The present data suggest that the whole body DXA is valuable in the diagnosis of sarcopenic obesity (high A/G ratio or android fat mass with low SMI) to determine the risk of CVD events in patients with type 2 diabetes. Meanwhile, sarcopenic obesity classified with low SMI, and high %BF or BMI was not associated with incident CVD.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0700-5) contains supplementary material, which is available to authorized users.

Adipose tissue extrinsic factor: Obesity-induced inflammation and the role of the visceral lymph node

Obesity-related adverse health consequences occur predominately in individuals with upper body fat distribution commonly associated with increased central adiposity. Visceral adipose tissue accumulation is described to be the greatest driver of obesity-induced inflammation, however evidence also supports that the intestines fundamentally contribute to the development of obesity-induced metabolic disease. The visceral adipose depot shares the same vasculature and lymph drainage as the small intestine. We hypothesize that the visceral lymph node, which drains adipose tissue and the gastrointestinal tract, is central to the exacerbation of systemic pro-inflammation. Male C57BL/6 mice were fed CHOW or high fat diet (HFD) for 7 weeks. At termination the mesenteric depot, visceral lymph node and ileum, jejunum and Peyer's patches were collected. Cytokine concentration was determined in adipose tissue whereas immune cell populations where investigated in the visceral lymph node and intestinal segments by flow cytometry. Visceral adipose tissue and the gastrointestinal tract mutually influence immune cells enclosed within the visceral lymph node. HFD increased visceral lymph node immune cell number. This likely resulted from 1.) an increase in immune cells migration from the small intestines likely from activated dendritic cells that travel to the lymph node and 2.) cytokine effluent from visceral adipose tissue that promoted expansion, survival and retention of pro-inflammatory immune cells. Overall, the visceral lymph node, the immune nexus of visceral adipose tissue and the small intestines, likely plays a fundamental role in exacerbation of systemic pro-inflammation by HFD-induced obesity. The research of Tim Bartness greatly enhanced the understanding of adipose tissue regulation. Studies from his laboratory significantly contributed to our awareness of extrinsic factors that influence body fatness levels. Specifically, the work he produced eloquently demonstrated that adipose tissue was more complex than an insulating storage center; it was connected to our brains via the sympathetic and sensory nervous system. Mapping studies demonstrated that adipose tissue both receives and sends information to the brain. Further, his lab demonstrated that nervous system connections contributed to lipolysis, thermogenesis and adipocyte proliferation and growth. The work of Tim Bartness will continue to influence adipose tissue research. As such, Tim Bartness directly inspired the following research. Adipose tissue extrinsic factors are not limited to the peripheral nervous system. The lymphatic system is an additional extrinsic factor that cross talks with adipose tissue, however its role in this context is under emphasized. Here we begin to elucidate how the lymphatic system may contribute to the comorbidities associated with visceral adipose tissue accumulation.

Liraglutide Improves Cardiovascular Risk as an Add-on to Metformin and Not to Insulin Secretagogues in Type 2 Diabetic Patients: A Real-life 48-Month Retrospective Study

INTRODUCTION

Although liraglutide is widely recognized to have glycemic and extra-glycemic effects, few studies have compared these effects in relation to hypoglycemic treatment starting from the diagnosis of diabetes. We evaluated the effectiveness of liraglutide in reducing the Framingham risk score (FRS) and visceral adiposity index (VAI) in relation to first-line hypoglycemic treatment from diagnosis of type 2 diabetes, continued without any changes.

METHODS

We selected 105 diabetic outpatients who were treated with liraglutide for at least 48 months as an add-on therapy to metformin alone (group A, n = 52) or insulin secretagogues (group B, n = 53) from diagnosis time.

RESULTS

Although both groups showed a reduction in BMI, waist circumference, blood pressure, HbA1c and triglycerides, only group A showed a significant reduction in FRS (p < 0.001) and VAI (p = 0.012) after 48 months. No significant intergroup difference was found for any parameters at either baseline or 48 months, with the exception of FRS at 48 months, lower in group A (p = 0.002), regardless of duration of disease, improvement in glycemic control and VAI.

CONCLUSION

Our data show that during a 48-month follow-up liraglutide was more efficacious in reducing cardiovascular risk than when it was used as add-on therapy to the first-line therapy from diagnosis with metformin and not with insulin secretagogues.

Visceral adiposity but not subcutaneous fat associated with improved outcome of patients with acute cholecystitis

BACKGROUND

The aim of this study to study the effect of visceral and subcutaneous fat tissue mass on short- and long-term prognosis of patients with acute calculus cholecystitis (ACC).

METHODS

Retrospective analysis of medical records. Included were all patients admitted because of ACC. Computed tomography images at the level of L3 were analyzed for body composition using designated software (Slice-O-matic; TomoVision, Montreal, Quebec, Canada). General linear model was used to analyze the effect of body composition on length of hospital stay, and Cox regression analysis was used to ascertain the effect of the different parameters on 1-y survival.

RESULTS

Included were 159 patients (mean age: 71.7 ± 15.8 y, 54.7% males). Fat was the most abundant tissue (401 ± 175 cm² of the computed tomography slices surface area), and visceral fat was 45.8 ± 14.1% of the fat area measured. Using the general linear model, we found that American Society of Anesthesiologists score, disease severity index, and age were positively associated with higher length of stay, whereas high visceral fat was associated with lower length of stay (estimated marginal means at 7.4 ± 1.4 d compared to 12.7 ± 1.4 d among patients with lower visceral fat surface area, P = 0.010). The Cox regression model showed that 1-y survival risk was significantly reduced by age, the Charlson Comorbidity Index and high muscle mass. High visceral adiposity was associated with improved survival (odds ratio: 0.216, 95% confidence interval: 0.064-0.724, P = 0.013). Subcutaneous adiposity did not affect prognosis.

CONCLUSIONS

Visceral adiposity is associated with shorter length of stay and improved 1-y survival among patients hospitalized with ACC.

Fructose-induced inflammation and increased cortisol: A new mechanism for how sugar induces visceral adiposity

Traditionally, the leading hypothesis regarding the development of obesity involves caloric imbalance, whereby the amount of calories consumed exceeds the amount of calories burned which causes obesity. Another hypothesis for why we get fat has surfaced in the last decade which is the idea that the overconsumption of added sugars and refined carbohydrates induce insulin resistance and high insulin levels causing obesity. While insulin is a fat-storing hormone, this hypothesis does not explain visceral adiposity, or why certain people are found to have fat stored in and around their organs. We propose a new mechanism for body fattening, particular visceral adiposity. This hypothesis involves the overconsumption of fructose, which leads to inflammation in all cells that metabolize it rapidly. When fructose is metabolized in subcutaneous adipocytes, the subsequent inflammation leads to an increase in intracellular cortisol in order to help squelch the inflammation. Unfortunately, the increase in intracellular cortisol leads to an increased flux of fatty acids out of the subcutaneous adipocytes allowing more substrate for fat storage into visceral fat tissue. Moreover fructose-induced inflammation in the liver also leads to increased intracellular cortisol via an upregulation of 11-B hydroxysteroid dehydrogenase type 1 causing increased fat storage in the liver (i.e., fatty liver). In essence, the fructose-induced inflammatory cortisol response causes "thin on the outside, fat on the inside" (TOFI). Furthermore, fructose in the brain, either from fructose uptake via the blood brain barrier or endogenous formation from glucose via the polyol pathway stimulates an increased release of cortisol causing hepatic gluconeogenesis leading to overall insulin resistance and further body fattening. This review paper will discuss in detail the hypothesis that fructose-induced inflammation and cortisol activation causes visceral adiposity.

Visceral and subcutaneous abdominal adiposity and pulmonary function in 30-year-old adults: a cross-sectional analysis nested in a birth cohort

BACKGROUND

Several studies have verified body fat distribution in association with pulmonary function (PF), mainly waist circumference, but few have used measures able to distinguish abdominal fat compartments. The present study aims to verify the association of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) with PF measures.

METHODS

In 1982, all hospital births occurring in Pelotas, Brazil, were identified and those livebirths have been followed. In 2012-13, the cohort participants were evaluated and VAT and SAT measured using ultrasound; forced expiratory volume in the first second (FEV₁) or forced vital capacity (FVC) were patronized in z-scores stratified by sex. The associations were verified using crude and adjusted linear regressions.

RESULTS

The present analyses comprised 3438 individuals (1721 women). VAT was inversely associated with spirometric parameters, in both crude and adjusted models. SAT showed inverse associations in the crude analyzes in males and a positive trend after adjustment, except for SAT and FVC in males. To each centimeter of VAT, mean adjusted FEV₁ z-scores decreased 0.072 (95% CI -0.107; -0.036) in men and 0.127 (95% CI -0.164; -0.090) in women, and FVC z-scores decreased -0.075 (95% CI -0.111; -0.039) and 0.121 (95% CI -0.158; -0.083), in men and women, respectively.

CONCLUSIONS

VAT has a consistent inverse association with FEV₁ and FVC in both sexes. On the other hand, SAT showed inconsistent results with PF parameters.

Effects of endurance training on autophagy and apoptotic signaling in visceral adipose tissue of prolonged high fat diet-fed rats

PURPOSE

Autophagy and apoptosis play critical roles in both development and tissue homeostasis in response to (patho)physiological stimuli, such as high-fat diet (HFD) and endurance training (ET). Therefore, we aimed to investigate how ET modulates autophagy and apoptotic-related signaling in visceral adipose tissue of long-standing HFD-fed rats.

METHODS

The study was conducted over a 17-week period on Sprague-Dawley rats, which were divided into four groups (n = 8/group): standard diet sedentary (STD+SED), high-fat diet sedentary (HFD+SED), standard diet ET (STD+ET) and high-fat diet ET (HFD+ET). After 9 weeks of dietary regimens, ET groups were trained for 8 weeks on treadmill (5 days/week at 25 m/min for 60 min/day), while maintaining dietary regimens. Autophagy and apoptotic-signaling markers in epididymal white adipose tissue (eWAT) were determined using RT-qPCR, Western blot and spectrometry techniques.

RESULTS

ET reduced body weight, visceral fat mass and HOMA-IR in standard and HF diet-fed animals. Moreover, ET reverted the HFD-induced increases in the percentage of larger adipocytes and also reduced the percentage of smaller adipocytes. The HFD decreased pre-adipocyte factor 1 (DLK1/PREF1) and increased the pro-apoptotic markers (Bax protein and caspase 3-like activity), while having no impact on autophagy markers. However, ET increased DLK1/PREF1 and Bcl-2 in both diet types, while decreasing Bax and caspases 9, 8 and 3-like activities in HFD feeding rats. Additionally, Beclin-1 and p62 protein significantly increased in ET groups of both diet types.

CONCLUSIONS

Data demonstrate that 8 weeks of ET was effective in attenuating apoptotic-related signaling in long-standing HFD-fed rats. Moreover, HFD and ET had no impact on VAT autophagy markers.

Metabolic syndrome and its predictors in an urban population in Kenya: A cross sectional study

BACKGROUND

The metabolic syndrome (MetS) is a clustering of interrelated risk factors which doubles the risk of cardio-vascular disease (CVD) in 5-10 years and increases the risk of type 2 diabetes 5 fold. The identification of modifiable CVD risk factors and predictors of MetS in an otherwise healthy population is necessary in order to identify individuals who may benefit from early interventions. We sought to determine the prevalence of MetS as defined by the harmonized criteria and its predictors in subjectively healthy black Africans from various urban centres in Kenya.

METHOD

We used data collected from healthy black Africans in Kenya as part of a global study on establishing reference intervals for common laboratory tests. We determined the prevalence of MetS and its components using the 2009 harmonized criterion. Receiver operator characteristic (ROC) curve analysis was used to determine the area under the curves (AUC) for various predictors of MetS. Youden index was used to determine optimum cut-offs for quantitative measurements such as waist circumference (WC).

RESULTS

A total of 528 participants were included in the analysis. The prevalence of MetS was 25.6% (95% CI: 22.0%-29.5%). Among the surrogate markers of visceral adiposity, lipid accumulation product was the best predictor of MetS with an AUC of 0.880 while triglyceride was the best predictor among the lipid parameters with an AUC of 0.816 for all participants. The optimal WC cut-off for diagnosing MetS was 94 cm and 86 cm respectively for males and females.

CONCLUSIONS

The prevalence of MetS was high for a healthy population highlighting the fact that one can be physically healthy but have metabolic derangements indicative of an increased CVD risk. This is likely to result in an increase in the cases of CVD and type 2 diabetes in Kenya if interventions are not put in place to reverse this trend. We have also demonstrated the inappropriateness of the WC cut-off of 80 cm for black African women in Kenya when defining MetS and recommend adoption of 86 cm.

Investigating the link between drug-naive first episode psychoses (FEPs), weight gain abnormalities and brain structural damages: Relevance and implications for therapy

Evidence suggests that obesity and overweight may be associated with severe brain structural abnormalities and poor cognitive and functional outcomes in the general population. Despite these observations and the high prevalence of weight gain abnormalities in patients with psychosis spectrum disorders (PSDs), no studies have investigated the impact that these metabolic disturbances may have on brain structures and development in the earliest stages of PSDs. In the present review we shed light on the association between weight gain and brain structural abnormalities that may affect the course of illness in drug-naïve FEPs. Given the lack of studies directly investigating this issue, we firstly identified and critically evaluated the literature assessing weight gain abnormalities and gray or white matter (GM, WM) volumes (either globally or in specific regions of interest) in otherwise healthy obese/overweight adolescents and young adults. We then compared the results of this systematic review with those of two recent meta-analysis investigating GM and WM abnormalities in drug-naïve FEPs. Weight gain in otherwise healthy subjects was consistently associated with frontal and temporal GM atrophy and with reduced integrity of WM in the corpus callosum. Of relevance, all these brain regions are affected in drug-naïve FEPs, and their integrity is associated with clinical, cognitive and functional outcomes. The underlying mechanisms that may explain the association between weight gain, adiposity, and brain damage in both healthy subjects and drug-naïve FEPs are widely discussed. On the basis of this knowledge, we tried: a) to deduce an integrative model for the development of obesity in psychosis spectrum disorders; b) to identify the key vulnerability factors underlying the association between weight gain and psychosis; c) to provide information on new potential targets of intervention.

Correlation between pre-pregnancy body mass index and maternal visceral adiposity with fetal biometry during the second trimester

OBJECTIVE

To determine the correlation between pre-pregnancy body mass index (BMI) and maternal visceral adiposity with fetal biometry during the second trimester.

METHODS

A cross-sectional observational study was conducted among pregnant women who received prenatal care at a center in Recife, Brazil, between October 3, 2011, and September 27, 2013. Pre-pregnancy BMI was determined at the first prenatal care visit. Maternal visceral adiposity and fetal biometry were measured at the same ultrasonography session. The associations between maternal and fetal variables were evaluated using the Pearson correlation coefficient (R). The Student t test was used to test the null hypothesis of adjusted correlation coefficients.

RESULTS

Overall, 740 women were included. No correlation was found between pre-pregnancy BMI and any of the fetal biometric variables assessed. By contrast, maternal visceral adiposity positively correlated with fetal abdominal circumference (R=0.529), estimated fetal weight (R=0.524), head circumference (R=0.521), femur length (R=0.521), and biparietal diameter (R=0.524; P<0.001 for all fetal variables). These findings remained statistically significant after controlling for pregnancy length.

CONCLUSION

Maternal visceral adiposity, but not pre-pregnancy BMI, positively correlated with fetal biometry during the second trimester.

The visceral adiposity index is associated with insulin sensitivity and IGF-I levels in adults with growth hormone deficiency

The visceral adiposity index, based on anthropometric and metabolic parameters, has been shown to be related to adipose tissue function and insulin sensitivity. We aimed to evaluate the performance of the visceral adiposity index in adult patients with growth hormone deficiency. We enrolled 52 patients(mean age 51 ± 13 years) with newly diagnosed growth hormone deficiency and 50 matched healthy subjects as controls at baseline. At baseline and after 12 and 24 months of treatment we evaluated anthropometric measures, lipid profile, glucose and insulin during an oral glucose tolerance test, hemoglobin A1c, homeostasis model assessment estimate of insulin resistance, quantitative insulin sensitivity check index, insulin sensitivity index Matsuda, insulin-like growth factor-I and visceral adiposity index. At baseline growth hormone deficiency patients showed higher waist circumference (p < 0.001), low-density lipoprotein cholesterol (p < 0.001) and visceral adiposity index (p = 0.003) with lower insulin sensitivity index (p = 0.007) and high-density lipoprotein cholesterol (p = 0.001) than controls. During growth hormone treatment we observed a significant increase in insulin-like growth factor-I (p < 0.001), high-density lipoprotein (p < 0.001) with a trend toward increase in insulin sensitivity index (p = 0.055) and a significant decrease in total cholesterol (p < 0.001) and visceral adiposity index (p < 0.001), while no significant changes were observed in other clinical and metabolic parameters. The visceral adiposity index was the only parameter that significantly correlated with growth hormone peak at diagnosis (p < 0.001) and with insulin-like growth factor-I and insulin sensitivity index both at diagnosis (p = 0.009 and p < 0.001) and after 12 (p = 0.026 and p = 0.001) and 24 months (p < 0.001 and p = 0.001) of treatment. The visceral adiposity index, which has shown to be associated with both insulin-like growth factor-I and insulin sensitivity, proved to be the most reliable index of metabolic perturbation, among the most common indexes of adiposity assessment and a marker of benefit during treatment in adult growth hormone deficiency patients.

Impact of physical exercise on visceral adipose tissue fatty acid profile and inflammation in response to a high-fat diet regimen

PURPOSE

Studies associate specific fatty-acids (FA) with the pathophysiology of inflammation. We aimed to analyze the impact of exercise on adipose tissue FA profile in response to a high-fat diet (HFD) and to ascertain whether these exercise-induced changes in specific FA have repercussions on obesity-related inflammation.

METHODS

Sprague-Dawley rats were assigned into sedentary, voluntary physical-activity (VPA) and endurance training (ET) groups fed a standard (S, 35kcal% fat) or high-fat (71kcal% fat) diets. VPA-animals had unrestricted access to wheel-running. After 9-wks, ET-animals engaged a running protocol for 8-wks, while maintained dietary treatments. The FA content in epididymal white-adipose tissue (eWAT) triglycerides was analyzed by gas-chromatography and the expression of inflammatory markers was determined using RT-qPCR, Western and slot blotting.

RESULTS

Eight-wks of ET reversed obesity-related anatomical features. HFD increased plasma tumor necrosis factor (TNF)-α content and eWAT monocyte chemoattractant protein (MCP)-1 protein expression. HFD decreased eWAT content of saturated FA and monounsaturated FA, while increased linoleic acid and prostaglandin E2 (PGE2) levels in eWAT. VPA decreased visceral adiposity, adipocyte size and MCP-1 in HFD-fed animals. The VPA and ET interventions diminished palmitoleic acid and increased linoleic acid in HFD-fed groups. Moreover, both interventions increased PGE2 levels in standard diet-fed groups and decreased in HFD. ET increased eWAT fatty acid desaturase 1 (FADS1) and elongase 5 (ELOVL5) protein content in both diet types. ET reduced eWAT inflammatory markers (TNF-α, IL-6), macrophage recruitment (MCP-1 and F4/80) and increased IL-10/TNF-α ratio in plasma and in eWAT in both diet types.

CONCLUSIONS

Exercise induced FA-specific changes independently of dietary FA composition, but only ET attenuated the inflammatory response in VAT of HFD-fed rats. Moreover, the exercise-induced FA changes did not correlate with the inflammatory response in VAT of rats submitted to HFD.

Associations of adipose and muscle tissue parameters at colorectal cancer diagnosis with long-term health-related quality of life

Purpose

Increased visceral adiposity (visceral obesity) and muscle wasting (sarcopenia) at colorectal cancer (CRC) diagnosis, quantified by computed tomography (CT) image analysis, have been unfavorably associated with short-term clinical outcomes and survival, but associations with long-term health-related quality of life (HRQoL) have not been investigated. We studied associations of visceral adiposity, muscle fat infiltration, muscle mass, and sarcopenia at CRC diagnosis with HRQoL 2–10 years post-diagnosis.

Methods

A cross-sectional study was conducted in 104 stage I‒III CRC survivors, diagnosed at Maastricht University Medical Center+, the Netherlands (2002–2010). Diagnostic CT images at the level of the third lumbar vertebra were analyzed to retrospectively determine visceral adipose tissue area (cm²); intermuscular adipose tissue area (cm²) and mean muscle attenuation (Hounsfield units) as measures of muscle fat infiltration; and skeletal muscle index (SMI, cm²/m²) as measure of muscle mass and for determining sarcopenia.

Results

Participants showed a large variation in body composition parameters at CRC diagnosis with a mean visceral adipose tissue area of 136.1 cm² (standard deviation: 93.4) and SMI of 47.8 cm²/m² (7.2); 47% was classified as being viscerally obese, and 32% as sarcopenic. In multivariable linear regression models, associations of the body composition parameters with long-term global quality of life, physical, role and social functioning, disability, fatigue, and distress were not significant, and observed mean differences were below predefined minimal important differences.

Conclusions

Although visceral obesity and sarcopenia are relatively common at CRC diagnosis, we found no significant associations of these parameters with long-term HRQoL in stage I–III CRC survivors.

Electronic supplementary material

The online version of this article (doi:10.1007/s11136-017-1539-z) contains supplementary material, which is available to authorized users.

Pituitary growth hormone (GH) secretion is partially rescued in HIV-infected patients with GH deficiency (GHD) compared to hypopituitary patients

Biochemical growth hormone deficiency is prevalent among human immunodeficiency virus-infected patients, but if this condition is clinically relevant remains challenging. The aim is to prospectively compare the growth hormone deficiency/insulin-like growth factor-1 status of 71 human immunodeficiency virus-infected patients with impaired growth hormone response to growth hormone releasing hormone + Arginine with that of 65 hypopituitary patients affected by a true growth hormone deficiency secondary to pituitary disease. The main outcomes were: basal serum growth hormone, insulin-like growth factor-1, insulin-like growth factor binding protein 3, growth hormone peak and area under the curve after growth hormone response to growth hormone releasing hormone + Arginine test, body mass index, waist and hip circumference, and body composition by dual energy X-ray absorptiometry. Insulin-like growth factor-1 binding protein 3, basal growth hormone (p < 0.005), growth hormone peak and area under the curve after growth hormone response to growth hormone releasing hormone + Arginine, waist to hip ratio, insulin-like growth factor-1, fasting glucose, insulin, and triglycerides (p < 0.0001) were lower in hypopituitary than human immunodeficiency virus-infected patients. Total and trunk fat mass by dual energy X-ray absorptiometry were higher in hypopituitary than in human immunodeficiency virus-infected patients (p < 0.0001). In all the patients total body fat was associated with both growth hormone peak and area under the curve at stepwise linear regression analysis. The degree of growth hormone deficiency is more severe in hypopituitary than in human immunodeficiency virus-infected patients, suggesting that the function of growth hormone/insulin-like growth factor-1 axis is partially rescued in the latter thanks to a preserved pituitary secretory reserve. Data from the current study suggest that human immunodeficiency virus-infected patients with peak growth hormone < 9 mg/L may have partial growth hormone deficiency and clinicians should be cautious before prescribing recombinant human growth hormone replacement treatment to patients living with human immunodeficiency virus.

Dietary soy protein improves adipose tissue dysfunction by modulating parameters related with oxidative stress in dyslipidemic insulin-resistant rats

The present study investigates the benefits of the dietary intake of soy protein on adipose tissue dysfunction in a rat model that mimics several aspects of the human metabolic syndrome. Wistar rats were fed a sucrose-rich diet (SRD) for 4 months. After that, half of the animals continued with SRD until month 8 while in the other half, casein protein was replaced by isolated soy protein for 4 months (SRD-S). A reference group consumed a control diet all the time. In adipose tissue we determined: i) the activities of antioxidant enzymes, gene expression of Mn-superoxide dismutase (SOD) and glutathione peroxidase (GPx), and glutathione redox state ii) the activity of xanthine oxidase (XO), ROS levels and the gene expression of NAD(P)H oxidase iii) the expression of the nuclear factor erythroid-2 related factor-2 (Nrf2). Besides, adiposity visceral index, insulin sensitivity, and tumor necrosis factor-α (TNF-α) in plasma were determined. Compared with the SRD-fed rats, the animals fed a SRD-S showed: activity normalization of SOD and glutathione reductase, improvement of mRNA SOD and normalization of mRNA GPx without changes in the expression of the Nrf2, and improvement of glutathione redox state. These results were accompanied by a normalization of XO activity and improvement of both the ROS production as well as TNF-α levels in plasma. Besides, adipocyte size distribution, adiposity visceral index and insulin sensitivity improved. The results suggest that soy protein can be a complementary nutrient for treating some signs of the metabolic syndrome.

Place of sodium-glucose cotransporter-2 inhibitors in East Asian subjects with type 2 diabetes mellitus: Insights into the management of Asian phenotype

The burden of type 2 diabetes (T2DM) in East Asia is alarming. Rapid modernization and urbanization have led to major lifestyle changes and a tremendous increase in the prevalence of obesity, metabolic syndrome, and diabetes mellitus. The development of T2DM at a younger age, with lower body mass index, higher visceral adiposity, and more significant pancreatic beta-cell dysfunction compared to Caucasians are factors responsible for the increased prevalence of T2DM in East Asians. Sodium-glucose Cotransporter-2 (SGLT2) inhibitors (canagliflozin, dapaglifozin, empagliflozin, etc.) reduce renal glucose reabsorption, leading to favorable effects on glycemic, blood pressure, and weight control. The insulin-independent mechanism enables their use as monotherapy or combination therapy with insulin and other oral antidiabetic agents. The role of SGLT2 inhibitors in the management of T2DM among East Asians is an interesting area of research, given that East Asians have been proven to be uniquely different from Caucasians. This review provides comprehensive coverage of the available literature not only on the efficacy and safety, but also on the recent cardiovascular and renal outcomes of SGLT2 inhibitors, focusing among East Asians.

Preeclampsia and Preterm Birth Associated With Visceral Adiposity in Early Pregnancy

OBJECTIVE

To determine if an increasing amount of visceral adipose tissue, measured by ultrasound in early pregnancy, is associated with a higher risk of preeclampsia and preterm birth (PTB).

METHODS

We completed a prospective cohort study of 463 pregnant women. Maternal visceral adiposity tissue (VAT) depth was measured by ultrasound at 11 to 14 weeks' gestation. Relative risks (RR) were adjusted for age, parity, chronic hypertension, pre-pregnancy BMI, and use of acetylsalicylic acid.

RESULTS

The rate of preeclampsia was much higher at quintile (Q) 5 of VAT depth (9.8%) than at Q1 to Q4 (1.6%) but not significantly so in the adjusted model (RR 3.39, 95% CI 0.86 to 13.39). The adjusted RR of PTB was significantly elevated at Q5 VAT depth (6.53, 95% CI 1.47 to 6.53), as was preeclampsia with PTB (16.91, 95% CI 1.24 to 231.07).

CONCLUSION

Higher amounts of VAT in pregnancy may play a direct role in the pathogenesis of preeclampsia, including early onset preeclampsia necessitating preterm delivery.

Computed Tomography Morphometrics and Pulmonary Intolerance in Endometrial Cancer Robotic Surgery

STUDY OBJECTIVES

To identify morphometric characteristics of obese patients that best predict pulmonary intolerance to robotic pelvic surgery using a novel method for quantifying adipose distribution.

DESIGN

Retrospective study (Canadian Task Force classification II-2).

SETTING

University hospital.

PATIENTS

Fifty-nine patients with endometrial cancer who underwent robotic hysterectomy and lymphadenectomy between April 2008 and May 2014 and also underwent perioperative computed tomography (CT) imaging within 1 year.

INTERVENTION

Visceral fat volume (VFV) and subcutaneous fat volume (SFV) were quantified through waist circumference measurements along with average volume estimation of slices taken at 3 levels: mid-waist, L2-L3, and L4-L5. Mean and maximum values were obtained for intraoperative physiological data.

MEASUREMENTS AND MAIN RESULTS

The patients' mean body mass index (BMI) was 34 (range, 20-59). Along with waist circumference, VFV and SFV quantified by CT at the mid-waist, L2-L3, and L4-L5 levels were all significant independent predictors for peak airway pressure (PAP; average and maximum) and plateau airway pressure (Pplat; average and maximum) on multivariate regression analysis after adjustment for age, ethnicity, diabetes, hypertension, pulmonary disease, smoking, obstructive sleep apnea, American Society of Anesthesiologists classification, and duration of anesthesia. Compared with the other CT parameters, L2-L3 VFV was the best predictor of average PAP (β = 0.398; p = .002), maximum PAP (β = 0.493; p < .001), average Pplat (β = 0.536; p < .001), and maximum Pplat (β = 0.573; p < .001).

CONCLUSION

These novel CT morphometric measurements represent valid predictors of pulmonary intolerance to robotic surgery in obese patients. Of the measures analyzed, VFV at L2-L3 best predicts pulmonary tolerance in obese patients.

Visceral to subcutaneous fat ratio predicts acuity of diverticulitis

INTRODUCTION

There is an association between obesity and more complicated diverticular disease. We hypothesize that this link may be due to an increased level of visceral fat rather than an elevated body mass index alone. Adipose tissue secretes inflammatory cytokines, and chronic inflammation may account for the link between obesity and a more severe presentation of diverticular disease. We have applied a quantitative measure of visceral fat content in a series of patients admitted with diverticulitis, comparing those who required emergent versus elective surgical procedures for diverticulitis.

METHODS

We performed a retrospective review of all adult patients who underwent emergent or elective surgery at our institution for diverticulitis from 2010 to 2014. Data were collected on demographics, comorbidities, operative findings, complications, and length of stay. Radiologic measurements of adiposity were obtained from preoperative CT scans. Visceral fat areas and subcutaneous fat areas were measured, and the V/S ratio was calculated.

RESULTS

Thirty-four patients underwent emergent and 32 patients underwent elective surgery. The mean age was 66.3 years for the emergent and 57.11 for the elective group (p = 0.04178). The perinephric, visceral, subcutaneous fat, and V/S ratio for the emergent group were 1.71, 185.22, 338.22, and 0.56 and were 1.11, 127.18, 295.28, and 0.46 for the elective group. The difference between the V/S ratio for each group was significant (p = 0.0238). The emergent group had an average LOS of 16.11 days compared to 5.15 for the elective group (p = <0.00001). The complication rate was significantly higher (p = 0.024) in the emergent group (n = 12, 35.2 %) compared to the elective group (n = 4, 12.5 %).

CONCLUSION

Our study demonstrates a clinically significant link between visceral fat and severity of presentation of diverticulitis. Patients with higher V/S fat ratios were more likely to require emergency surgery and have more complications and a longer LOS.

The relationship between visfatin and serum concentrations of C-reactive protein, interleukin 6 in patients with metabolic syndrome

AIM

To evaluate the relationship between inflammatory and pro inflammatory markers, with obesity and visceral adiposity in male subjects with or without metabolic syndrome (MS).

SUBJECTS AND METHODS

A total of 37 patients with MS and 37 age matched controls were included (mean age 46.35 ± 1.6 years). MS was defined by the criteria of the international diabetes federation 2005. Anthropometric and biochemical profiles, including high-sensitivity C-reactive protein (Hs-CRP), visfatin and interleukin 6 (IL-6), were measured. Data were compared between groups by using t test. Pearson's correlation was used to evaluate the relationship between variables. P values less than 0.05 were considered as statistically significant.

RESULTS

In patients with MS, CRP and IL-6 were significantly correlated with body mass index, waist circumference and waist to hip ratio. Visfatin levels were significantly lower in patients with MS compared to controls (log visfatin: 1.74 ± 0.27 vs. 1.86 ± 0.13 ng/ml, MS vs. control group respectively). We cannot find any significant correlation between visfatin, CRP and IL-6. Also there were no correlation between visfatin levels and any anthropometric parameters in patients with MS or control groups.

CONCLUSION

Serum visfatin was lower in patients with MS. Therefore it seems that visfatin could not be considered as a pro inflammatory adipocytokine in MS. The positive associations of obesity and visceral adiposity with elevated CRP and IL-6 levels suggest the importance of reducing visceral adiposity to prevent the risk of coronary disease.

Cardiovascular Risk in Growth Hormone Deficiency: Beneficial Effects of Growth Hormone Replacement Therapy

Growth hormone deficiency (GHD) in adulthood is associated with an increased risk of developing adverse cardiovascular events and with reduced life expectancy. Cardiovascular and metabolic abnormalities have so far been evaluated only in a small number of children with GHD and adolescents. In this article we review these abnormalities and their underlying mechanisms and discuss the beneficial effect of growth hormone treatment in subjects with GHD.

Novel Approaches to Targeting Visceral and Hepatic Adiposities in HIV-Associated Lipodystrophy

Visceral and hepatic adiposities have been associated with both cardiovascular and liver disease and are of concern in HIV-infected persons in the modern era of combination antiretroviral therapy (ART). The development of therapeutic targets to reduce visceral and hepatic adiposities in HIV-infected persons has been slow, because of early reports that attributed the excess adiposity to specific antiretroviral drugs. Visceral adiposity was initially thought to occur as part of a protease inhibitor-induced "HIV-associated lipodystrophy syndrome." Subsequent studies show that visceral adiposity is likely a result of effective ART, recovery of health, and the normal aging process. Visceral adiposity is an established risk factor for hepatic adiposity. Identifying drug targets for non-alcoholic fatty liver disease is under active investigation. The present review summarizes the recent literature on the pathogenesis of visceral and hepatic adiposities in HIV-infected persons, current therapeutic strategies, and novel interventions in HIV-infected and uninfected persons.

Clinical relevance of dual-energy X-ray absorptiometry (DXA) as a simultaneous evaluation of fatty liver disease and atherosclerosis in patients with type 2 diabetes

Background

Whole body dual-energy X-ray absorptiometry (DXA) can simultaneously measure both regional fat and non-fat mass. Android-to-gynoid (A/G) ratio measured by DXA has been reported to be associated with cardiovascular risks and visceral adiposity; however, little is known regarding its relationship with fatty liver disease and atherosclerosis among patients with diabetes. This study was designed to investigate the association of android and gynoid fat mass measured by DXA with fatty liver disease and atherosclerosis in patients with type 2 diabetes.

Methods

This is a cross-sectional study of 259 patients with type 2 diabetes (mean age 64 ± 13 years; 40.2 % female). Android and gynoid fat mass (kg) were measured by DXA. Skeletal muscle index (SMI) was calculated as appendicular non-fat mass (kg) divided by height (m²). Visceral fat area (VFA, cm²), subcutaneous fat area (SFA, cm²), and liver attenuation index (LAI) were assessed by abdominal computed tomography. Intima media thickness (IMT, mm) in common carotid arteries was determined by carotid ultrasonography.

Results

A/G ratio was significantly correlated with VFA (r = 0.72, p < 0.001), SFA (r = 0.32, p < 0.001) and LAI (r = −0.26, p < 0.001). A/G ratio (standardized β −0.223, p = 0.002) as well as VFA (standardized β −0.226, p = 0.001) were significantly associated with LAI in the univariate model. A/G ratio remained to be significantly associated with LAI (standardized β −0.224, p = 0.005) after adjusting for covariates including body mass index and transaminases. Among patients with low SMI (SMI < 7.0 in male and < 5.4 in female), A/G ratio was significantly associated with carotid IMT in the multivariate model (standardized β 0.408, p = 0.014).

Conclusions

DXA can be used to simultaneously estimate the risks for both fatty liver disease and atherosclerosis in patients with type 2 diabetes.

The effect of visceral obesity on clinicopathological features in patients with endometrial cancer: a retrospective analysis of 200 Chinese patients

Background

To assess the effect of visceral adiposity on clinical and pathological characteristics in patients with endometrial cancer.

Methods

A retrospective review of medical documentation was performed in surgically treated endometrial cancer patients from January to November 2015 in our institution. The visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were measured at the level of umbilicus on single-slice computerized tomography. Visceral adiposity (VAT%) was calculated as VAT/(VAT + SAT).

Results

A total of 200 cases were included in the study. Median age at diagnosis was 54 years old. Most patients presented with early-stage tumor (86.0 % for I + II) and endometrioid histology (90.5 %). Positive lymph node occurred in 11.0 % (22/200) of the patients with the median number of retrieved nodes as 25 (range, 4–56). The entire population had a median body mass index (BMI) of 24.7 kg/m² and median VAT% of 31.89 %. BMI correlated with total adipose tissue (correlation coefficient = 0.667, P < 0.001), but not with VAT% (P = 0.495). Viscerally obese patients tended to be old and post-menopausal (P < 0.001; P = 0.003). Nodal metastasis and extrauterine disease were more commonly reported in patients with high VAT% (6.0 % vs. 16.0 %, P = 0.024; 9.0 % vs. 19.0 %, P = 0.042, respectively). Univariate and multivariate logistic regressions were performed to discern the contribution of variable factors on the lymph node metastasis. Grade (HR = 15.41, 95 % CI = 1.60–148.76; P = 0.018), lympho-vascular invasion (HR = 449.61, 95 % CI = 31.27–6463.93; P < 0.001) and high VAT% (HR = 6.37, 95 % CI = 1.42–28.69; P = 0.016) retained statistical significance for predicting lymph node metastasis.

Conclusions

Viscerally obese patients were more likely to be old and have positive lymph node as well as extrauterine disease. Grade, lympho-vascular invasion presence and visceral adiposity were predictors of nodal disease.

Vegetarianism and cardiometabolic disease risk factors: Differences between South Asian and US adults

OBJECTIVES

Cardiometabolic diseases are increasing disproportionately in South Asia compared with other regions of the world despite high levels of vegetarianism. This unexpected discordance may be explained by differences in the healthfulness of vegetarian and non-vegetarian diets in South Asia compared with the United States. The aim of this study was to compare the food group intake of vegetarians with non-vegetarians in South Asia and the United States and to evaluate associations between vegetarianism and cardiometabolic disease risk factors (overweight/obesity, central obesity, diabetes, hypertension, high triacylglycerols, high low-density lipoprotein, low high-density lipoprotein, and high Framingham Heart Score).

METHODS

Using cross-sectional data from adults (age 20-69 y) in South Asia (Centre for Cardiometabolic Risk Reduction in South-Asia [CARRS] 2010-2011; N = 15 665) and the United States (National Health and Nutrition Examination Survey 2003-2006; N = 2159), adherence to a vegetarian diet was assessed using food propensity questionnaires. Multivariable logistic regression was used to estimate odds ratios and predicted margins (e.g., adjusted prevalence of the outcomes).

RESULTS

One-third (33%; n = 4968) of adults in the South Asian sample were vegetarian compared with only 2.4% (n = 59) in the US sample. Among South Asians, vegetarians more frequently ate dairy, legumes, vegetables, fruit, desserts, and fried foods than non-vegitarians (all P < 0.05). Among Americans, vegetarians more frequently ate legumes, fruit, and whole grains, and less frequently ate refined cereals, desserts, fried foods, fruit juice, and soft drinks than non-vegetarians (all P < 0.05). After adjustment for confounders (age, sex, education, tobacco, alcohol, and also city in CARRS), South Asian vegetarians were slightly less frequently overweight/obese compared with non-vegetarians: 49% (95% confidence interval [CI], 45%-53%) versus 53% (95% CI, 51%-56%), respectively; whereas US vegetarians were considerably less frequently overweight/obese compared with non-vegetarians: 48% (95% CI, 32%-63%) versus 68% (95% CI, 65%-70%), respectively. Furthermore, US vegetarians were less likely to exhibit central obesity than non-vegetarians: 62% (95% CI, 43%-78%) versus 78% (95% CI, 76%-80%), respectively.

CONCLUSIONS

There is greater divergence between vegetarian and non-vegetarian diets in the United States than in South Asia, and US vegetarians have more consistently healthier food group intakes than South Asian vegetarians. Vegetarians in both populations have a lower probability of overweight/obesity compared with non-vegetarians. The strength of this association may be stronger for US vegetarian diets, which were also protective against central obesity.

Associations between plasma branched-chain amino acids, β-aminoisobutyric acid and body composition

Plasma branched-chain amino acids (BCAA) are elevated in obesity and associated with increased cardiometabolic risk. β-Aminoisobutyric acid (B-AIBA), a recently identified small molecule metabolite, is associated with decreased cardiometabolic risk. Therefore, we investigated the association of BCAA and B-AIBA with each other and with detailed body composition parameters, including abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). A cross-sectional study was carried out with lean (n 15) and obese (n 33) men and women. Detailed metabolic evaluations, including measures of body composition, insulin sensitivity and plasma metabolomics were completed. Plasma BCAA were higher (1·6 (se 0·08) (×10⁷) v. 1·3 (se 0·06) (×10⁷) arbitrary units; P = 0·005) in obese v. lean subjects. BCAA were positively associated with VAT (R 0·49; P = 0·0006) and trended to an association with SAT (R 0·29; P = 0·052). The association between BCAA and VAT, but not SAT, remained significant after controlling for age, sex and race on multivariate modelling (P < 0·05). BCAA were also associated with parameters of insulin sensitivity (Matsuda index: R −0·50, P = 0·0004; glucose AUC: R 0·53, P < 0·001). BCAA were not associated with B-AIBA (R −0·04; P = 0·79). B-AIBA was negatively associated with SAT (R −0·37; P = 0·01) but only trended to an association with VAT (R 0·27; P = 0·07). However, neither relationship remained significant after multivariate modelling (P > 0·05). Plasma B-AIBA was associated with parameters of insulin sensitivity (Matsuda index R 0·36, P = 0·01; glucose AUC: R −0·30, P = 0·04). Plasma BCAA levels were positively correlated with VAT and markers of insulin resistance. The results suggest a possible complex role of adipose tissue in BCAA homeostasis and insulin resistance.

Increased visceral adiposity with normal weight is associated with the prevalence of non-alcoholic fatty liver disease in Japanese patients with type 2 diabetes

AIMS/INTRODUCTION

To investigate the impact of increased visceral adiposity with normal weight (OB[-]VA[+]) on the prevalence of non-alcoholic fatty liver disease in patients with type 2 diabetes.

MATERIALS AND METHODS

This was a cross-sectional study of 140 Japanese patients with type 2 diabetes (mean age 65 ± 11 year; 44.6% women). Visceral fat area (VFA; cm(2) ) and liver attenuation index (LAI) were assessed by abdominal computed tomography. The patients were divided into four groups by VFA and body mass index (BMI; kg/m(2) ) as follows: BMI <25 kg/m(2) and VFA <100 cm(2) (OB[-]VA[-]), BMI ≥25 kg/m(2) and VFA <100 cm(2) (OB[+]VA[-]), BMI <25 kg/m(2) and VFA ≥100 cm(2) (OB[-]VA[+]), and BMI ≥25 kg/m(2) and VFA ≥100 cm(2) (OB[+]VA[+]). Multivariate linear regression and logistic regression analysis were carried out to determine the impact of OB(-)VA(+) on LAI.

RESULTS

In the present study, 25.0% were OB(-)VA(+) patients, where the LAI levels were lower (1.09 ± 0.22) than those in OB(-)VA(-) patients (1.23 ± 0.15), and were equivalent to those in OB(+)VA(+) patients (1.03 ± 0.26). In multivariate linear regression analysis, OB(-)VA(+) was independently associated with LAI (standardized β-0.212, P = 0.014). In multivariate logistic regression analysis, OB(-)VA(+) was a significant predictor of LAI <0.9 (odds ratio 5.88, 95% confidence interval 1.03-33.52, P = 0.046).

CONCLUSIONS

The present study provides evidence that increased visceral adiposity with normal weight is a strong predictor for the prevalence of non-alcoholic fatty liver disease in Japanese patients with type 2 diabetes.

A visceral adiposity index-related dietary pattern and the cardiometabolic profiles in women with polycystic ovary syndrome

BACKGROUND & AIMS

Visceral adiposity index (VAI), an indicator of visceral adiposity, has been found to be associated with cardiometabolic disturbances in women with polycystic ovary syndrome (PCOS). The association of dietary intakes with VAI, and subsequently cardiometabolic variables is still unclear. The aims of this study were to identify a dietary pattern associated with VAI and to investigate whether this pattern is associated with cardiometabolic variables in PCOS women.

METHODS

The study was conducted on 53 PCOS women, aged 18-45 years, diagnosed according to National Institutes of Health (NIH) criteria, and 167 age-matched normo-ovulatory women who were recruited from the Tehran Lipid and Glucose Study. Reduced rank regression was applied to determine a dietary pattern that explains the maximum variation of the VAI. Associations between the dietary pattern and cardiometabolic profiles were investigated using linear and logistic regression, adjusted for age and BMI.

RESULTS

A VAI dietary pattern was identified characterized by high consumption of fried vegetables, vegetable oils (except olive oil), salty snacks, legumes, eggs, fast foods and low consumption of traditional sweets, high and low fat dairy, cruciferous vegetables, sugars and honey. A one standard deviation (SD) increase in dietary pattern score was significantly associated with higher triglycerides (TGs) (βcontrol = 0.22, p = 0.003; βcase = 0.48, p = 0.001) and TGs/HDL-C ratio (βcontrol = 0.23, p = 0.002; βcase = 0.52, p = 0.001) in both groups. After adjusting for age and BMI, a 1-SD increase in dietary pattern score was associated with increased risk of VAD in PCOS (OR 2.77; 95% CI 1.15, 6.66) and control groups (OR 2.41; 95% CI 1.41-4.12). In the control group, the risk of hypercholesterolemia, hypertriglyceridemia, high LDL-C, low HDL-C, hyperglycemia and IGT + IFG increased significantly per 1-SD increase in dietary pattern score, which all remained significant after adjusting for age and BMI, except for the risk of high LDL-C. Among the cardiometabolic abnormalities, only the risk of hypertriglyceridemia was significantly associated with dietary pattern score in women with PCOS, which lost its significance after adjusting for age and BMI.

CONCLUSION

The VAI dietary pattern affects most cardiometabolic variables in controls, but to a lesser extent in PCOS women. Our study suggests that relationships between diet and cardiometabolic risk profiles may be modified by PCOS status.

Visceral adiposity and left ventricular remodeling: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

Visceral fat (VF) is a source of pro-inflammatory adipokines implicated in cardiac remodeling. We sought to determine the impact of visceral fat and subcutaneous fat (SQ) depots on left ventricular (LV) structure, function, and geometry in the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS AND RESULTS

We performed a post-hoc analysis on 1151 participants from MESA with cardiac magnetic resonance quantification of LV mass and LV mass-to-volume ratio (LVMV, an index of concentricity) and computed tomographic-derived SQ and VF area. Multivariable regression models to estimate association between height-indexed SQ and VF area (per cm(2)/m) with height-indexed LV mass (per height(2.7)) and LVMV were constructed, adjusted for clinical, biochemical, and demographic covariates. We found that both VF and SQ area were associated with height-indexed LV mass (ρ = 0.36 and 0.12, P < 0.0001, respectively), while only VF area was associated with LVMV (ρ = 0.28, P < 0.0001). Individuals with above-median VF had lower LV ejection fraction, greater indexed LV volumes and mass, and higher LVMV (all P < 0.001). In multivariable models adjusted for weight, VF (but not SQ) area was associated with LV concentricity and LV mass index, across both sexes.

CONCLUSION

Visceral adiposity is independently associated with LV concentricity, a precursor to heart failure. Further study into the role of VF in LV remodeling as a potential therapeutic target is warranted.

Higher visceral adiposity is associated with an enhanced early thermogenic response to carbohydrate-rich food

BACKGROUND

Studies examining the dynamics of the thermic effect of feeding (TEF) of specific food items and the relationship of TEF to visceral adiposity are limited.

METHODS

We measured resting energy expenditure (REE) and early-TEF (40-min postprandial, e-TEF) after 8-h fast by indirect calorimetry in 40 obese men, and imaged abdominal fat tissues by magnetic resonance imaging. Each participant was examined on two occasions, 3-weeks apart. At each examination we measured fasting REE and then postprandial REE following the isocaloric [∼380 kcal] consumption of either 56 gr walnuts [(8% carbohydrates; 84% fat, of which 72% polyunsaturated fat)], or 5-slices (150gr) of whole-grain bread (48% carbohydrates; 32% fat). e-TEF was calculated as the area under the curve between the fasting and postprandial tests.

RESULTS

Participants had a mean age of 45 ± 8 years, body-mass-index (BMI) = 31.1 ± 3.8 kg/m(2), total abdominal fat area = 901.4 ± 240 cm(2), visceral fat area (VAT) = 260 ± 102.9 cm(2), fasting REE = 1854 ± 205 kcal, REE/kg = 19.39 ± 1.73 kcal/kg, and respiratory quotient (RQ, CO2 eliminated/O2 consumed) = 0.82 ± 0.04. Individuals who exhibited increased e-TEF (top ΔAUC median) to bread had higher VAT (299 cm(2) vs. 223 cm(2); p = 0.024) and higher BMI (32.4 kg/m(2) vs. 30.0 kg/m(2); p = 0.013), compared to their peers with the lower e-TEF response (ΔAUC below median). As expected, postprandial e-TEF was higher after whole-grain bread consumption [ΔAUC = +14 kcal/40min] compared to walnuts [ΔAUC = -2 kcal/40 min; p < 0.001].

CONCLUSIONS

Higher early thermic effect of high-carbohydrate food, likely reflecting digestion, early absorption and/or sympathetic tone (rather than metabolic utilization (oxidation)), associates with visceral adiposity. Future studies are required to determine if this association represents an added causality between early carbohydrate processing and visceral fat accumulation.

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.

Visceral adiposity and skeletal muscle mass are independently and synergistically associated with left ventricular structure and function: the Korean Genome and Epidemiology Study

BACKGROUND

Obesity and low muscle mass may coexist as age-related changes in body composition. We aimed to investigate the effect of visceral adiposity and skeletal muscle mass on left ventricular (LV) structure and function in the general population.

METHODS

A total of 1941 participants without known cardiovascular disease were enrolled from the Korean Genome and Epidemiology Study. Visceral fat area (VFA) was assessed by computed tomography. Appendicular skeletal muscle mass (ASM) was estimated by dual-energy X-ray absorptiometry and was used as a percentage of body weight (ASM/Wt). LV structure and function were assessed by tissue Doppler imaging (TDI) echocardiography.

RESULTS

Across VFA tertiles, ASM increased, but ASM/Wt decreased (all P<0.001). In multivariate models adjusted for conventional cardiovascular risk factors, LV mass index and LV diastolic parameters, such as left atrial dimension, TDI Ea velocity, and E/Ea ratio, were significantly impaired as VFA increased. On the other hand, an increase in ASM/Wt was associated with a decrease in LV mass index and improvement of LV diastolic parameters. With regard to LV mass index and TDI Ea velocity, VFA and ASM/Wt showed synergistic effects (all P interaction<0.05). When both VFA and ASM/Wt were simultaneously included in the same model, both remained independent predictors of LV mass index and TDI Ea velocity.

CONCLUSIONS

More visceral fat and less muscle mass are independently and synergistically associated with an increase in LV mass index and impairment of LV diastolic parameters. Further research is needed to explore the complex mechanisms underlying these associations.

Abdominal obesity is an independent predictor of serum 25-hydroxyvitamin D deficiency in adults with cerebral palsy

Background

Individuals with cerebral palsy (CP) are at risk for nutritional insufficiency. The purpose of the study was to examine the vitamin D status of adults with CP, and to evaluate the association between vitamin D and functional level, age, race, and anthropometric indicators of adiposity.

Methods

Serum vitamin D levels, BMI, waist circumference (WC), and functional level (measured by Gross Motor Function Classification System (GMFCS)) were examined in 112 adults with CP. Vitamin D status was assessed by serum 25-hydroxyvitamin D level (25(OH)D). The influence of motor impairment and adiposity on 25(OH)D were assessed using general linear modeling and logistic regression, with age, sex, race, and season as covariates.

Results

Mean vitamin D was 28.1 ± 16.0 ng/ml. Only 45% of subjects had optimal levels of 25(OH)D, 21% were insufficient and 34% were deficient. Overweight or obesity was prevalent (52%), as was abdominal obesity in men (23.5% at 102 cm cutoff) and women (31.1% at 88 cm cutoff). There was a robust association between the indicator of visceral adiposity (WC) and 25(OH)D level (p <0.001), even after controlling for age, sex, race, season, and GMFCS. According to sex-specific WC cutoffs, the odds of being deficient in vitamin D increase by a factor of 3.5 (95% CI 1.12-11.0) for abdominal obesity. GMFCS was not associated with 25(OH)D.

Conclusions

Adults with CP are at risk for low vitamin D levels and overweight/obesity. Waist circumference is a strong independent predictor for low vitamin D levels.

Stop feeding cancer: pro-inflammatory role of visceral adiposity in liver cancer

Liver cancer is the fifth most common cancer in the world with an estimated over half a million new cases diagnosed every year. Due to the difficulty in early diagnosis and lack of treatment options, the prevalence of liver cancer continues to climb with a 5-year survival rate of between 6% and 11%. Coinciding with the rise of liver cancer, the prevalence of obesity has rapidly increased over the past two decades. Evidence from epidemiological studies demonstrates a higher risk of hepatocellular carcinoma (HCC) in obese individuals. Obesity is recognised as a low-grade inflammatory disease, this is of particular relevance as inflammation has been proposed as the seventh hallmark of cancer development with abdominal visceral adiposity considered as an important source of pro-inflammatory stimuli. Emerging evidence points towards the direct role of visceral adipose tissue rather than generalised body fat in carcinogenesis. Cytokines such as IL-6 and TNF-α secreted from visceral adipose tissue have been demonstrated to induce a chronic inflammatory condition predisposing the liver to a protumourigenic milieu. This review focuses on excess visceral adiposity rather than simple obesity; particularly adipokines and their implications for chronic inflammation, lipid accumulation, insulin resistance, Endoplasmic Reticulum (ER) stress and angiogenesis. Evidence of molecular signalling pathways that may give rise to the onset and progression of HCC in this context are depicted. Delineation of the pro-inflammatory role of visceral adiposity in liver cancer and its targeting will provide better rational and therapeutic approaches for HCC prevention and elimination. The concept of a central role for metabolism in cancer is the culmination of an effort that began with one of the 20th century's leading biochemists and Nobel laureate of 1931, Otto Warburg.

Visceral adiposity and risk of coronary heart disease in relatively lean Chinese adults

BACKGROUND

The hypertriglyceridemic waist phenotype (defined using both elevated waist circumference and triglycerides) and visceral adiposity index (VAI, defined using waist circumference, body mass index, triglycerides, and high-density lipoprotein cholesterol) have been suggested to be inexpensive yet effective markers of visceral (intra-abdominal) obesity and related dysmetabolic state. These markers may be particularly useful to Asian populations who generally have a low body weight but are prone to visceral adiposity.

METHODS

We examined associations of the hypertriglyceridemic waist phenotype and VAI with risk of coronary heart disease (CHD) in a nested case-control study conducted within two prospective cohort studies of Chinese adults. We identified 355 incident cases of CHD and 697 controls matched for sex, age, and date and time of baseline sample collection. Anthropometric and lipid measurements were performed and used to define the hypertriglyceridemic waist phenotype and VAI according to published methods. Conditional logistic regression was used to evaluate the associations.

RESULTS

Cases had a higher prevalence of the hypertriglyceridemic waist phenotype and higher VAI score than controls in both sexes. Adjusted odds ratios of CHD associated with hypertriglyceridemic waist were 5.18 (95% CI, 2.46-10.9) and 4.63 (2.03-10.5) for women and men, respectively. Adjusted odds ratios of CHD comparing the highest vs. lowest quartile of VAI were 4.44 (95% CI, 2.24-8.82) and 4.23 (1.99-9.00) for women and men, respectively.

CONCLUSION

Our study demonstrates, for the first time, that the hypertriglyceridemic waist phenotype and high VAI score are associated with substantially elevated risk of CHD in Chinese men and women.

Treatment with heme arginate alleviates adipose tissue inflammation and improves insulin sensitivity and glucose metabolism in a rat model of Human primary aldosteronism

Visceral adiposity and insulin resistance are common pathophysiological denominators in patients with primary aldosteronism. Although we recently reported the antidiabetic effects of heme oxygenase (HO), no study has examined the effects of upregulating HO on visceral adiposity in uninephrectomized (UnX) deoxycorticosterone acetate (DOCA-salt) hypertensive rats, a model of human primary aldosteronism characterized by elevated endothelin (ET-1) and oxidative/inflammatory events. Here, we report the effects of the HO inducer heme arginate and the HO blocker chromium mesoporphyrin (CrMP) on visceral adipose tissue obtained from retroperitoneal fat pads of UnX DOCA-salt rats. UnX DOCA-salt rats were hypertensive but normoglycemic. Heme arginate reduced visceral adiposity and enhanced HO activity and cGMP in the adipose tissue, but suppressed ET-1, nuclear-factor κB (NF-κB), activating-protein (AP-1), c-Jun-NH2-terminal kinase (JNK), macrophage chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), and 8-isoprostane. These were associated with reduced glycemia, increased insulin, and the insulin-sensitizing protein adiponectin, with corresponding reduction in insulin resistance. In contrast, the HO inhibitor, CrMP, abolished the effects of heme arginate, aggravating insulin resistance, suggesting a role for the HO system in insulin signaling. Importantly, the effects of the HO system on ET-1, NF-κB, AP-1, JNK, MCP-1, and ICAM-1 in visceral or retroperitoneal adiposity in UnX-DOCA-salt rats have not been reported. Because 8-isoprostane stimulates ET-1 to enhance oxidative insults, and increased oxidative events deplete adiponectin and insulin levels, the suppression of oxidative/inflammatory mediators such as 8-isoprostane, NF-κB, AP-1, MCP-1, ICAM-1, and JNK, an inhibitor of insulin biosynthesis, may account for the potentiation of insulin signaling/glucose metabolism by heme arginate. These data indicate that although UnX DOCA-salt rats were normoglycemic, insulin signaling was impaired, suggesting that dysfunctional insulin signaling may be a forerunner to overt diabetes in primary aldosteronism.