Change in abdominal, but not femoral subcutaneous fat CT-radiodensity is associated with improved metabolic profile after bariatric surgery.

BACKGROUND AND AIMS: Computed tomography (CT)-derived adipose tissue radiodensity represents a potential noninvasive surrogate marker for lipid deposition and obesity-related metabolic disease risk. We studied the effects of bariatric surgery on CT-derived adipose radiodensities in abdominal and femoral areas and their relationships to circulating metabolites in morbidly obese patients. METHODS AND RESULTS: We examined 23 morbidly obese women who underwent CT imaging before and 6 months after bariatric surgery. Fifteen healthy non-obese women served as controls. Radiodensities of the abdominal subcutaneous (SAT) and visceral adipose tissue (VAT), and the femoral SAT, adipose tissue masses were measured in all participants. Circulating metabolites were measured by NMR. At baseline, radiodensities of abdominal fat depots were lower in the obese patients as compared to the controls. Surprisingly, radiodensity of femoral SAT was higher in the obese as compared to the controls. In the abdominal SAT depot, radiodensity strongly correlated with SAT mass (r = -0.72, p < 0.001). After surgery, the radiodensities of abdominal fat increased significantly (both p < 0.01), while femoral SAT radiodensity remained unchanged. Circulating ApoB/ApoA-I, leucine, valine, and GlycA decreased, while glycine levels significantly increased as compared to pre-surgical values (all p < 0.05). The increase in abdominal fat radiodensity correlated negatively with the decreased levels of ApoB/ApoA-I ratio, leucine and GlycA (all p < 0.05). The increase in abdominal SAT density was significantly correlated with the decrease in the fat depot mass (r = -0.66, p = 0.002). CONCLUSION: Higher lipid content in abdominal fat depots, and lower content in femoral subcutaneous fat, constitute prominent pathophysiological features in morbid obesity. Further studies are needed to clarify the role of non-abdominal subcutaneous fat in the pathogenesis of obesity. CLINICAL TRIAL REGISTRATION NUMBER: NCT01373892.

The role of insulin resistance in the relation of visceral, abdominal subcutaneous and total body fat to cardiovascular function.

BACKGROUND AND AIMS: The separate cardiovascular effects of type 2 diabetes and adiposity remain to be examined. This study aimed to investigate the role of insulin resistance in the relations of visceral (VAT), abdominal subcutaneous (aSAT) adipose tissue and total body fat (TBF) to cardiovascular remodeling. METHODS AND RESULTS: In this cross-sectional analysis of the population-based Netherlands Epidemiology of Obesity study, 914 middle-aged individuals (46% men) were included. Participants underwent magnetic resonance imaging. Standardized linear regression coefficients (95%CI) were calculated, adjusted for potential confounding factors. All fat depots and insulin resistance (HOMA-IR), separate from VAT and TBF, were associated with lower mitral early and late peak filling rate ratios (E/A): -0.04 (-0.09;0.01) per SD (54 cm2) VAT; -0.05 (-0.10;0.00) per SD (94 cm2) aSAT; -0.09 (-0.16;-0.02) per SD (8%) TBF; -0.11 (-0.17;-0.05) per 10-fold increase in HOMA-IR, whereas VAT and TBF were differently associated with left ventricular (LV) end-diastolic volume: -8.9 (-11.7;-6.1) mL per SD VAT; +5.4 (1.1;9.7) mL per SD TBF. After adding HOMA-IR to the model to evaluate the mediating role of insulin resistance, change in E/A was -0.02 (-0.07;0.04) per SD VAT; -0.03 (-0.08;0.02) per SD aSAT; -0.06 (-0.13;0.01) per SD TBF, and change in LV end-diastolic volume was -7.0 (-9.7;-4.3) mL per SD VAT. In women, adiposity but not HOMA-IR was related to higher aortic arch pulse wave velocity. CONCLUSION: Insulin resistance was associated with reduced diastolic function, separately from VAT and TBF, and partly mediated the associations between adiposity depots and lower diastolic function.

The Transcriptomic Evidence on the Role of Abdominal Visceral vs. Subcutaneous Adipose Tissue in the Pathophysiology of Diabetes in Asian Indians Indicates the Involvement of Both.

The roles of abdominal visceral (VAT) and subcutaneous adipose tissue (SAT) in the molecular pathogenesis type-2 diabetics (T2D) among Asian Indians showing a "thin fat" phenotype largely remains obscure. In this study, we generated transcription profiles in biopsies of these adipose depots obtained during surgery in 19 diabetics (M: F ratio, 8:11) and 16 (M: F ratio 5:11) age- and BMI-matched non-diabetics. Gene set enrichment analysis (GSEA) was used for comparing transcription profile and showed that 19 gene sets, enriching inflammation and immune system-related pathways, were upregulated in diabetics with F.D.R. <25% and >25%, respectively, in VAT and SAT. Moreover, 13 out of the 19 significantly enriched pathways in VAT were among the top 20 pathways in SAT. On comparison of VAT vs. SAT among diabetics, none of the gene sets were found significant at F.D.R. <25%. The Weighted Gene Correlation Analysis (WGCNA) analysis of the correlation between measures of average gene expression and overall connectivity between VAT and SAT was significantly positive. Several modules of co-expressed genes in both the depots showed a bidirectional correlation with various diabetes-related intermediate phenotypic traits. They enriched several diabetes pathogenicity marker pathways, such as inflammation, adipogenesis, etc. It is concluded that, in Asian Indians, diabetes pathology inflicts similar molecular alternations in VAT and SAT, which are more intense in the former. Both adipose depots possibly play a role in the pathophysiology of T2D, and whether it is protective or pathogenic also depends on the nature of modules of co-expressed genes contained in them.

Visceral-to-Subcutaneous Abdominal Fat Ratio Is Associated with Nonalcoholic Fatty Liver Disease and Liver Fibrosis.

BACKGROUND: We evaluated the association of visceral-to-subcutaneous fat ratio (VSR) with nonalcoholic fatty liver disease (NAFLD) and advanced fibrosis degree based on noninvasive serum fibrosis markers in the general population with NAFLD. METHODS: This is a cross-sectional study, in 7,465 Korean adults who underwent health screening examinations. NAFLD was defined as fatty liver detected on ultrasonography, and visceral and subcutaneous abdominal fat was measured using computed tomography. We predicted fibrosis based on the fibrosis-4 (FIB-4) score and aspartate aminotransferase-to-platelet ratio index (APRI) and categorized the risk for advanced fibrosis as low, indeterminate, or high. RESULTS: The multivariable-adjusted prevalence ratios for indeterminate to high risk of advanced fibrosis based on FIB-4, determined by comparing the second, third, and fourth quartiles with the first quartile of VSR, were 3.38 (95% confidence interval [CI], 0.64 to 17.97), 9.41 (95% CI, 1.97 to 45.01), and 19.34 (95% CI, 4.06 to 92.18), respectively. The multivariable-adjusted prevalence ratios for intermediate to high degree of fibrosis according to APRI also increased across VSR quartiles (5.04 [95% CI, 2.65 to 9.59], 7.51 [95% CI, 3.91 to 14.42], and 19.55 [95% CI, 9.97 to 38.34], respectively). High VSR was more strongly associated with the prevalence of NAFLD in nonobese subjects than in obese subjects, and the associations between VSR and intermediate to high probability of advanced fibrosis in NAFLD were stronger in obese subjects than in nonobese subjects. CONCLUSION: High VSR values predicted increased NAFLD risk and advanced fibrosis risk with NAFLD, and the predictive value of VSR for indeterminate to high risk of advanced fibrosis was higher in obese subjects than in nonobese subjects.

Fat metabolism and acute resistance exercise in trained women.

This study investigated the effect of acute full-body resistance exercise [RE; one set of 10 repetitions at 40% 1 repetition maximum (1RM) and three sets of 10 repetitions at 65% 1RM] on subcutaneous abdominal adipose tissue (SCAAT) lipolysis and whole body substrate oxidation in young (age: 22 ± 1 yr), normal-weight and body fatness (body mass index: 20 ± 1 kg/m2; %body fat: 28.7 ± 1.4%), resistance-trained women. Microdialysis was used to measure SCAAT lipolysis at baseline, mid-RE, post-RE, and 30 min post-RE, and indirect calorimetry was used to measure whole body substrate oxidation at baseline and immediately post-RE in 13 women. Plasma concentrations of glucose, insulin, nonesterified fatty acids (NEFA), glycerol, growth hormone (GH), epinephrine (Epi), and norepinephrine (NE) were measured at baseline, mid-RE, and post-RE. Lipolysis (dialysate glycerol concentration) was elevated post-RE (baseline: 596.7 ± 82.8, post-RE: 961.4 ± 116.3 µM, P = 0.01). Energy expenditure (baseline: 1,560 ± 49; post-RE: 1,756 ± 68 kcal/day; P = 0.02) and fat oxidation (baseline: 5.64 ± 0.24; post-RE: 7.57 ± 0.41 g/h; P = 0.0003) were elevated post-RE. GH (baseline: 513.1 ± 147.4; mid-RE: 1,288.3 ± 83.9; post-RE: 1,522.8 ± 51.1 pg/ml, P = 0.000), Epi (baseline: 23.2 ± 2.7; mid-RE: 92.5 ± 16.6; post-RE: 84.5 ± 21.4 pg/ml, P = 0.000), and NE (baseline: 139.2 ± 13.6; mid-RE: 850.9 ± 155.3; post-RE: 695.3 ± 93.5 pg/ml, P = 0.000) were higher at mid-RE and post-RE. Therefore, one of the potential mechanisms behind RE-induced fat mass changes in resistance-trained women may be in part due to the accumulated effect of transient increases in SCAAT lipolysis, fat oxidation, and energy expenditure, mediated by GH, Epi, and NE release.

Comparative thermographic analysis at pre- and postcryolipolysis treatment: Clinical case report.

INTRODUCTION: Although the exact cryolipolysis mechanisms on adipose tissue remain unknown, the current literature indicates that it may occur a crystallization followed by an ischemic reaction which generates an inflammatory process. OBJECTIVE: To evaluate thermographically, the tissue's circulatory pattern of a patient submitted to the cryolipolysis technique and the beginning of the inflammatory process, through variations of temperature gradients and the evaluation of the pains degree of the patient in these same moments. METHODS: A descriptive study, of an interventional case report, performed in an 18-year-old patient who had clearly visible fat in the lower abdomen area, with a skin fold greater than 2 centimeters and body mass index ≤ 30 kg/m2 . RESULTS: Comparing the maximum temperatures showed on the last thermography with the pre-application image, an increase of 0.4°C was observed, which is suggestive of abnormality. Regarding the minimum temperatures verified, there was a significative decrease in the temperature with the procedure, which was observed on the last 5 minutes (ΔT = 9.8°C). However, in 48 hour, the minimum temperature began to recover (ΔT = 0.3°C). CONCLUSION: The observed data indicate that there was a significant decrease in the temperature during the cooling phase, whereas in the recovery phase, the inverse was found.

Correlations between serum concentration of three bone-derived factors and obesity and visceral fat accumulation in a cohort of middle aged men and women.

BACKGROUND: The aim of this study was to investigate the interrelationships between three bone-derived factors [serum osteocalcin (OCN), fibroblast growth factor (FGF) 23, and neutrophil gelatinase-associated lipocalin (NGAL) levels] and body fat content and distribution, in order to reveal the potential endocrine function of bone in the development of obesity. METHODS: We recruited 1179 people (aged 59.5 ± 6.2 years) from communities in Shanghai. Serum OCN levels were determined using an electrochemiluminescence immunoassay. Serum FGF23 and NGAL levels were determined using a sandwich enzyme-linked immunosorbent assay. The abdominal fat distribution, including visceral fat area (VFA), was assessed by magnetic resonance imaging. Visceral obesity was defined as a VFA ≥ 80 cm2. RESULTS: Serum OCN levels were inversely correlated with body fat parameters, while FGF23 and NGAL were positively correlated (P < 0.05). After adjusting for confounders, waist circumference (W) and VFA had a closer relationship with serum OCN, FGF23, and NGAL levels than body mass index (BMI) and body fat percentage (fat%, all P < 0.05). The risk of visceral obesity significantly increased with higher FGF23 and/or NGAL levels, as well as with reduced OCN levels (all P < 0.05). In addition, serum OCN, FGF23, and NGAL levels were independently associated with visceral obesity (all P < 0.01). The relationships persisted among subjects with normal glucose tolerance or subjects with hyperglycaemia (both P < 0.05). CONCLUSIONS: Compared to the indicators of overall adiposity such as BMI or fat%, visceral adiposity indicators (W or VFA) were more closely related to serum OCN, FGF23 and NGAL levels. There was no interaction among the relationship of three bone-derived factors with visceral obesity, which revealed the independent relationship of endocrine function of skeleton with body fat.

Endogenous secretory RAGE increases with improvements in body composition and is associated with markers of adipocyte health.

BACKGROUND AND AIMS: The receptor for advanced glycation end products (RAGE) is implicated in obesogenesis. Conversely, soluble RAGE (sRAGE) competitively inhibits RAGE. Our aim was to determine the effects of weight-loss via alternate day fasting (ADF) on sRAGE isoforms and evaluate potential relationships with body composition. METHODS AND RESULTS: 42 obese participants were randomized to control (CON) or ADF. For 24 weeks, the ADF group consumed 25% or 125% of their caloric requirements on alternating days while the CON group did not change their diet. Body fat was measured via DXA, visceral fat (VAT) via MRI and subcutaneous fat (SAT) was derived by subtracting VAT from total fat. sRAGE isoforms were measured via ELISAs. After 24 weeks, ADF -6.8 (-9.5, -3.5)kg (Median, IQR) lost more weight than CON -0.3 (-1.9, 1.0)kg (p < 0.05). The change in endogenous secretory RAGE (esRAGE) was different between ADF 15 (-30, 78)pg/mL and CON -21 (-72, 16)pg/mL after 24 weeks (p < 0.05). To examine the effect of changes in body composition, the cohort was stratified by median weight-, fat-, SAT-, and VAT-loss. The changes in all sRAGE isoforms were different between those above and below median weight-loss (p < 0.05) with sRAGE isoforms tending to decrease in individuals below the median. Changes in total sRAGE and esRAGE were different between individuals above compared to below median fat- and SAT-loss (p < 0.05). Those above median fat-loss increased esRAGE by 29 (-5, 66)pg/mL (p < 0.05). CONCLUSION: Improvements in body composition are related to increased sRAGE isoforms, implicating sRAGE as a potential target for the treatment of obesity. CLINICAL TRIAL REGISTRATION: NCT00960505.

Creeping fat in patients with ileo-colonic Crohn's disease correlates with disease activity and severity of inflammation: A preliminary study using energy spectral computed tomography.

OBJECTIVE: To investigate the relationship between creeping fat and inflammatory activity as well as the prognosis of ileo-colonic Crohn's disease (CD), based on a quantitative analysis of energy spectral computed tomography (CT). METHODS: A total of 40 patients with CD and 40 with other gastrointestinal diseases who underwent an energy spectral CT scanning between March 2014 and March 2015 were retrospectively enrolled. The endoscopic severity of CD was evaluated by the simple endoscopic score for Crohn's disease (SES-CD). The slope of the Hounsfield unit (HU) curve (λHU ) was measured and calculated on energy spectral CT images. Visceral and subcutaneous fat areas were also measured. The relationship between the quantitative data of creeping fat as well as the fat area and CD inflammation were analyzed. RESULTS: The λHU of creeping fat in patients with CD increased with the severity of intestinal inflammation (moderate/severe vs mild: -0.17 ± -0.68 vs -0.49 ± -0.61, P < 0.01). Moreover, the λHU of creeping fat around the intestinal segments without lesions in CD was significantly larger than that in the controls (-1.19 ± -0.56 vs - 1.42 ± -0.45, P < 0.01). The λHU was more accurate for detecting inflammatory lesions in CD than for calculating visceral fat. It was significantly correlated with SES-CD (r = 0.66, P < 0.01) and moderately correlated with the Harvey-Bradshaw index (r = 0.414, P < 0.01). CONCLUSION: The quantitative analysis of creeping fat using energy spectral CT is an effective method in inflammatory evaluation in patients with CD.

Differences in Upper and Lower Body Adipose Tissue Oxygen Tension Contribute to the Adipose Tissue Phenotype in Humans.

Context and Objectives: Upper and lower body adipose tissue (AT) exhibits opposing associations with obesity-related cardiometabolic diseases. Recent studies have suggested that altered AT oxygen tension (pO2) may contribute to AT dysfunction. Here, we compared in vivo abdominal (ABD) and femoral (FEM) subcutaneous AT pO2 in women who are overweight and have obesity, and investigated the effects of physiological AT pO2 on human adipocyte function. Design: ABD and FEM subcutaneous AT pO2 and AT blood flow (ATBF) were assessed in eight [BMI (body mass index) 34.4 ± 1.6 kg/m2] postmenopausal women who were overweight with obesity and impaired glucose metabolism. ABD and FEM AT biopsy specimens were collected to determine adipocyte morphology and AT gene expression. Moreover, the effects of prolonged exposure (14 days) to physiological AT pO2 on adipokine expression/secretion, mitochondrial respiration, and glucose uptake were investigated in differentiated human multipotent adipose-derived stem cells. Results: AT pO2 was higher in ABD than FEM AT (62.7 ± 6.6 vs 50.0 ± 4.5 mm Hg, P = 0.013), whereas ATBF was comparable between depots. Maximal uncoupled oxygen consumption rates were substantially lower in ABD than FEM adipocytes for all pO2 conditions. Low physiological pO2 (5% O2) decreased proinflammatory gene expression, increased basal glucose uptake, and altered adipokine secretion in ABD and FEM adipocytes. Conclusions: We demonstrated for the first time, to our knowledge, that AT pO2 is higher in ABD than FEM subcutaneous AT in women who are overweight/with obesity, partly due to a lower oxygen consumption rate in ABD adipocytes. Moreover, low physiological pO2 decreased proinflammatory gene expression and improved the metabolic phenotype in differentiated human adipocytes, whereas more heterogeneous effects on adipokine secretion were found.

Abdominal subcutaneous adipose tissue: a favorable adipose depot for diabetes?

BACKGROUND: Previous studies have documented that visceral adipose tissue is positively associated with the risk of diabetes. However, the association of subcutaneous adipose tissue with diabetes risk is still in dispute. We aimed to assess the associations between different adipose distributions and the risk of newly diagnosed diabetes in Chinese adults. METHODS: The Shanghai Nicheng Cohort Study was conducted among Chinese adults aged 45-70 years. The baseline data of 12,137 participants were analyzed. Subcutaneous and visceral fat area (SFA and VFA) were measured by magnetic resonance imaging. Diabetes was newly diagnosed using a 75 g oral glucose tolerance test. RESULTS: The multivariable-adjusted odds ratios (OR) and 95% confidence intervals (CI) of newly diagnosed diabetes per 1-standard deviation increase in SFA and VFA were 1.29 (1.19-1.39) and 1.61 (1.49-1.74) in men, and 1.10 (1.03-1.18) and 1.56 (1.45-1.67) in women, respectively. However, the association between SFA and newly diagnosed diabetes disappeared in men and was reversed in women (OR 0.86 [95% CI, 0.78-0.94]) after additional adjustment for body mass index (BMI) and VFA. The positive association between VFA and newly diagnosed diabetes remained significant in both sexes after further adjustment for BMI and SFA. Areas under the receiver operating characteristic curve of newly diagnosed diabetes predicted by VFA (0.679 [95% CI, 0.659-0.699] for men and 0.707 [95% CI, 0.690-0.723] for women) were significantly larger than by the other adiposity indicators. CONCLUSIONS: SFA was beneficial for lower risk of newly diagnosed diabetes in women but was not associated with newly diagnosed diabetes in men after taking general obesity and visceral obesity into account. VFA, however, was associated with likelihood of newly diagnosed diabetes in both Chinese men and women.

Ultrasound elastography reliably identifies altered mechanical properties of burned soft tissues.

Although burn injury to the skin and subcutaneous tissues is common in both civilian and military scenarios, a significant knowledge gap exists in quantifying changes in tissue properties as a result of burns. In this study, we present a noninvasive technique based on ultrasound elastography which can reliably assess altered nonlinear mechanical properties of a burned tissue. In particular, ex vivo porcine skin tissues have been exposed to four different burn conditions: (i) 200°F for 10s, (ii) 200°F for 30s, (iii) 450°F for 10s, and (iv) 450°F for 30s. A custom-developed instrument including a robotically controlled ultrasound probe and force sensors has been used to compress the tissue samples to compute two parameters (C10 and C20) of a reduced second-order polynomial hyperelastic material model. The results indicate that while the linear model parameter (C10) does not show a statistically significant difference between the test conditions, the nonlinear model parameter (C20) reliably identifies three (ii-iv) of the four cases (p<0.05) when comparing burned with unburned tissues with a classification accuracy of 60-87%. Additionally, softening of the tissue is observed because of the change in structure of the collagen fibers. The ultrasound elastography-based technique has potential for application under in vivo conditions, which is left for future work.

Associations of Abdominal Subcutaneous and Visceral Fat with Insulin Resistance and Secretion Differ Between Men and Women: The Netherlands Epidemiology of Obesity Study.

BACKGROUND: Abdominal obesity is a well-established risk factor for the development of type 2 diabetes. However, sex differences may exist. We aimed to investigate the associations of abdominal subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) with insulin resistance and insulin secretion in men and women. METHODS: In this cross-sectional analysis of the Netherlands Epidemiology of Obesity study, fasting and postprandial concentrations of glucose and insulin were measured and abdominal fat depots were assessed using magnetic resonance imaging in 2253 participants (53% women). With linear regression analysis, we examined associations of abdominal SAT and VAT with measures of insulin resistance and insulin secretion in men and women, while adjusting for age, ethnicity, education, smoking habits, alcohol consumption, menopausal state and hormone use in women, and models with VAT additionally for total body fat. RESULTS: Participants had a mean [standard deviation (SD)] age of 56 (6) years, body mass index: 25.9 (3.9) kg/m2, VAT: 89 (55) cm2, and SAT: 235 (95) cm2. In the multivariate models in men, per SD of VAT the homeostatic model assessment of insulin resistance (HOMA-IR) was 20% (95% CI: 14-26) higher, and per SD SAT 21% (15-27) higher. In women, per SD of VAT the HOMA-IR was 40% (29-52) higher, and per SD SAT 12% (6-19) higher. Associations with measures of insulin secretion were weaker than with insulin resistance. CONCLUSIONS: In men, abdominal SAT and VAT were associated with insulin resistance to a similar extent, whereas in women particularly VAT was associated with insulin resistance and insulin secretion. Future studies need to unravel the mechanisms underlying the metabolic effects of visceral fat in women. Simple and less expensive measures that can distinct abdominal subcutaneous and visceral fat are needed for an improved metabolic risk stratification.

Interferon-gamma released from omental adipose tissue of insulin-resistant humans alters adipocyte phenotype and impairs response to insulin and adiponectin release.

BACKGROUND: Inflammatory factors derived from adipose tissue have been implicated in mediating insulin resistance in obesity. We sought to identify these using explanted human adipose tissue exposed to innate and adaptive immune stimuli. METHODS: Subcutaneous and omental adipose tissue from obese, insulin-resistant donors was cultured in the presence of macrophage and T-cell stimuli, and the conditioned medium tested for its ability to inhibit insulin-stimulated glucose uptake into human Simpson-Golabi-Behmel Syndrome (SGBS) adipocytes. The nature of the inhibitory factor in conditioned medium was characterized physicochemically, inferred by gene microarray analysis and confirmed by antibody neutralization. RESULTS: Conditioned medium from omental adipose tissue exposed to a combination of macrophage- and T-cell stimuli inhibited insulin action and adiponectin secretion in SGBS adipocytes. This effect was associated with a pronounced change in adipocyte morphology, characterized by a decreased number of lipid droplets of increased size. The bioactivity of conditioned medium was abolished by trypsin treatment and had a molecular weight of 46 kDa by gel filtration. SGBS adipocytes exposed to a bioactive medium expressed multiple gene transcripts regulated by interferon-gamma (IFN-γ). Recombinant human IFN-γ recapitulated the effects of the bioactive medium and neutralizing antibody against IFN-γ but not other candidate factors abrogated medium bioactivity. CONCLUSIONS: IFN-γ released from inflamed omental adipose tissue may contribute to the metabolic abnormalities seen in human obesity.

Intra-abdominal and subcutaneous abdominal fat as predictors of cardiometabolic risk in a sample of Mexican children.

BACKGROUND/OBJECTIVE: Few studies in Latin American paediatric populations have differentiated fat deposits in specific areas, such as intra-abdominal fat (IAF) and subcutaneous abdominal fat (SAF). Research in diverse populations is needed, as patterns of fat accumulation vary by ethnicity. The aim of this study was to determine whether IAF and/or SAF are related to cardiometabolic risk factors, independent of total body fat (TBF), in a group of Mexican schoolchildren. SUBJECTS/METHODS: A cross-sectional study was conducted in Mexico City with 94 children aged between 5 and 11 years. IAF and SAF were assessed by magnetic resonance using two different estimation methods: (a) at the midpoint of lumbar vertebras 4 and 5 (L4-L5) and (b) the sum of the areas of four slices (L1-L2, L2-L3, L3-L4 and L4-L5, which will be referred to as 'total' IAF and SAF). TBF was measured by dual-energy X-ray absorptiometry. The following cardiometabolic risk factors were assessed: total cholesterol, low-density lipoprotein-cholesterol, triglycerides, glucose, insulin, high-density lipoprotein-cholesterol, blood pressure, insulin resistance, number of risk factors and metabolic syndrome score. RESULTS: After adjusting for sex, age and TBF, total SAF was related to the number of cardiometabolic risk factors and metabolic syndrome score. Although IAF at L4-L5 was also related to the number of cardiometabolic risk factors, there was evidence of collinearity with TBF. CONCLUSIONS: In this sample of Mexican schoolchildren, TBF and SAF, but not IAF, were associated with higher cardiometabolic risk.

Adolescent Obesity and Insulin Resistance: Roles of Ectopic Fat Accumulation and Adipose Inflammation.

As a consequence of the global rise in the prevalence of adolescent obesity, an unprecedented phenomenon of type 2 diabetes has emerged in pediatrics. At the heart of the development of type 2 diabetes lies a key metabolic derangement: insulin resistance (IR). Despite the widespread occurrence of IR affecting an unmeasurable number of youths worldwide, its pathogenesis remains elusive. IR in obese youth is a complex phenomenon that defies explanation by a single pathway. In this review we first describe recent data on the prevalence, severity, and racial/ethnic differences in pediatric obesity. We follow by elucidating the initiating events associated with the onset of IR, and describe a distinct "endophenotype" in obese adolescents characterized by a thin superficial layer of abdominal subcutaneous adipose tissue, increased visceral adipose tissue, marked IR, dyslipidemia, and fatty liver. Further, we provide evidence for the cellular and molecular mechanisms associated with this peculiar endophenotype and its relations to IR in the obese adolescent.

[Intraabdominal fat redistribution in long-term continuous positive airway pressure treatment in obstructive sleep apnea patients]. / Redistribución de grasa intraabdominal en el tratamiento a largo plazo con presión positiva continua de la vía aérea en los pacientes con síndrome de apnea-hipopnea durante el sueño.

BACKGROUND AND OBJECTIVE: Obesity is the main risk factor for obstructive sleep apnoea (OSA). The aim was to evaluate the long-term effect of continuous positive airway pressure (CPAP) on intraabdominal fat distribution in OSA patients. PATIENTS AND METHODS: Fifty OSA patients with and 35 without CPAP treatment criteria were followed-up for 2 years. Visceral and subcutaneous adipose tissue (VAT and SAT) and preaortic intraabdominal fat (PIF) were assessed by sonography. RESULTS: In the non CPAP treated group, SAT and VAT mean values didn't change, while a significantly PIF growth was observed (55.19 [23.44] vs. 63.45 [23.94] mm, P=.021). In the CPAP treated group, VAT and PIF mean were not changed, while SAT decreased significantly (11.29 [5.69] vs. 10.47 [5.71] mm, P=.012). CONCLUSIONS: Long-term CPAP treatment produces intraabdominal fat redistribution and is associated with an anthropometric profile of lower cardiovascular risk in OSA patients.

Serum CETP concentration is not associated with measures of body fat: The NEO study.

INTRODUCTION: Adipose tissue has been postulated to contribute substantially to the serum cholesteryl ester transfer protein (CETP) pool. However, in a recent large cohort study waist circumference was not associated with plasma CETP. The aim of the present study was to further examine associations of accurate measures of body fat and body fat distribution with serum CETP concentration. METHODS: In this cross-sectional analysis of the Netherlands Epidemiology of Obesity study, we examined in 6606 participants (aged 45-65 years) the associations of total body fat, body mass index (BMI), waist circumference, waist-to-hip ratio (WHR), abdominal subcutaneous (aSAT) and visceral adipose tissue (VAT) assessed with magnetic resonance imaging (n = 2547) and total and trunk fat mass assessed with dual-energy X-ray absorptiometry (n = 909) with serum CETP concentration. Regression models were adjusted for age, ethnicity, sex, dietary intake of fat and cholesterol, physical activity, smoking and menopausal status. RESULTS: Mean (SD) age was 56 (6) years and BMI 26.3 (4.4) kg/m(2), 56% were women. Mean serum CETP concentration was 2.47 µg/mL. The difference in serum CETP was 0.02 µg/mL (95%CI: -0.01, 0.05) per SD total body fat (8.7%), and 0.02 µg/mL (0.00, 0.04) per SD BMI (4.4 kg/m(2)). Similar associations around the null were observed for waist circumference, WHR, aSAT, VAT, total and trunk fat mass. CONCLUSION: In this population-based study, there was no evidence for clinically relevant associations between several measures of body fat and serum CETP concentration. This finding implies that adipose tissue does not contribute to the CETP pool in serum.

Investigation of relation between visceral and subcutaneous abdominal fat volumes and calcified aortic plaques via multislice computed tomography.

OBJECTIVE: The present study investigated effect of subcutaneous fat volume and abdominal visceral fat volume on aortic atherosclerosis via multislice computed tomography. MATERIALS AND METHODS: The present study comprised 424 subjects who underwent non-contrast-enhanced abdominal CT in our clinic between June 2012 and June 2013. Using dedicated software visceral fat volume was calculated for each individual and then subcutaneous fat volume was calculated by subtracting visceral fat volume from total fat volume. By dividing visceral fat volume/subcutaneous fat volume participants were assigned to three groups according to their mean visceral fat volume/subcutaneous fat volume: Group 1 consisted of subjects with visceral fat volume/subcutaneous fat volume lower than 0.48 (Group 1 < 0.48); Group 2 consisted of subjects with visceral fat volume/subcutaneous fat volume equal to or higher than 0.48 and lower than 0.69 (0.48 ≤ Group 2 < 0.69); and Group 3 consisted of subjects with visceral fat volume/subcutaneous fat volume equal to or higher than 0.69 (Group 3 ≥ 0.69). RESULTS: The mean abdominal aortic calcium scores according to Agatston scoring (au) were 136.8 ± 418.7 au in Group 1, 179.9 ± 463 au in Group 2 and 212.2 ± 486.9 in Group 3, respectively. CONCLUSIONS: We have demonstrated a significant correlation between visceral fat volume and abdominal aorta atherosclerosis, while there was absence of significant correlation between subcutaneous fat volume and abdominal atherosclerosis.