Visceral fat and metabolic inflammation: the portal theory revisited

Baicalin suppresses macrophage JNK-mediated adipose tissue inflammation to mitigate insulin resistance in obesity

ETHNOPHARMACOLOGICAL RELEVANCE

Radix scutellariae (the root of Scutellaria baicalensis Georgi) is a traditional Chinese medicine (TCM) used to treat a wide range of inflammation-related diseases, such as obesity, diabetes, diabetic kidney disease, and COVID-19-associated inflammatory states in the lung and kidney. Baicalin is the major anti-inflammatory component of Radix scutellariae and has shown the potential to inhibit inflammation in metabolic disorders. In this study, we explored the ability and underlying mechanisms of baicalin to modulate the macrophage to mitigate insulin resistance in obesity.

MATERIALS AND METHODS

Obese mice were administered baicalin (50 mg/kg/day) intraperitoneally for 3 weeks. RAW264.7 and BMDM cells were stimulated with LPS and treated with baicalin for 24 h, while 3T3-L1 and primary white adipocytes were treated with the supernatants from baicalin-treated RAW264.7 cells for 24 h.

RESULTS

The results showed that baicalin significantly improved glucose and insulin tolerance as well as decreased fat and adipose tissue macrophage levels in obese mice. Besides, baicalin significantly reduced serum and adipose tissue IL-1β, TNF-α and IL-6 levels in obese mice, as well as suppressed LPS-induced IL-1β, TNF-α and IL-6 expression and release in macrophages. Furthermore, treatment with the supernatant from baicalin-treated RAW264.7 cells increased the levels of PGC-1α, SIRT1, p-IRS-1 and p-AKT in adipocytes. Moreover, baicalin treatment dramatically downregulated macrophage p-p38, p-JNK, and Ac-p65Lys310 levels while increasing SIRT1 both in vivo and in vitro. Importantly, JNK inhibitor SP600125 blocked most of the effects of baicalin on SIRT1, Ac-p65Lys310 and pro-inflammatory factors in macrophages.

CONCLUSION

Therefore, these results demonstrated for the first time that baicalin exerts its anti-inflammatory effects in obese adipose tissue macrophages mainly through suppressing JNK/SIRT1/p65 signaling. These findings amplified the mechanisms of baicalin and its potential to attenuate insulin resistance.

Mature adipocytes inhibit differentiation of myogenic cells but stimulate proliferation of fibro-adipogenic precursors derived from trout muscle in vitro

Interactions between tissues and cell types, mediated by cytokines or direct cell-cell exchanges, regulate growth. To determine whether mature adipocytes influence the in vitro growth of trout mononucleated muscle cells, we developed an indirect coculture system, and showed that adipocytes (5 × 106 cells/well) derived from perivisceral adipose tissue increased the proliferation (BrdU-positive cells) of the mononucleated muscle cells (26% vs. 39%; p < 0.001) while inhibiting myogenic differentiation (myosin+) (25% vs. 15%; p < 0.001). Similar effects were obtained with subcutaneous adipose tissue-derived adipocytes, although requiring more adipocytes (3 × 107 cells/well vs. 5 × 106 cells/well). Conditioned media recapitulated these effects, stimulating proliferation (31% vs. 39%; p < 0.001) and inhibiting myogenic differentiation (32 vs. 23%; p < 0.001). Adipocytes began to reduce differentiation after 24 h, whereas proliferation stimulation was observed after 48 h. While adipocytes did not change pax7+ and myoD1/2+ percentages, they reduced myogenin+ cells showing inhibition from early differentiation stage. Finally, adipocytes increased BrdU+ cells in the Pdgfrα+ population but not in the myoD+ one. Collectively, our results demonstrate that trout adipocytes promote fibro-adipocyte precursor proliferation while inhibiting myogenic cells differentiation in vitro, suggesting the key role of adipose tissue in regulating fish muscle growth.

Altered proteome profiles related to visceral adiposity may mediate the favorable effect of green Mediterranean diet: the DIRECT-PLUS trial

OBJECTIVE

The objective of this study was to explore the effects of a green Mediterranean (green-MED) diet, which is high in dietary polyphenols and green plant-based protein and low in red/processed meat, on cardiovascular disease and inflammation-related circulating proteins and their associations with cardiometabolic risk parameters.

METHODS

In the 18-month weight loss trial Dietary Intervention Randomized Controlled Trial Polyphenols Unprocessed Study (DIRECT-PLUS), 294 participants with abdominal obesity were randomized to basic healthy dietary guidelines, Mediterranean (MED), or green-MED diets. Both isocaloric MED diet groups consumed walnuts (28 g/day), and the green-MED diet group also consumed green tea (3-4 cups/day) and green shakes (Mankai plant shake, 500 mL/day) and avoided red/processed meat. Proteome panels were measured at three time points using Olink CVDII.

RESULTS

At baseline, a dominant protein cluster was significantly related to higher phenotypic cardiometabolic risk parameters, with the strongest associations attributed to magnetic resonance imaging-assessed visceral adiposity (false discovery rate of 5%). Overall, after 6 months of intervention, both the MED and green-MED diets induced improvements in cardiovascular disease and proinflammatory risk proteins (p < 0.05, vs. healthy dietary guidelines), with the green-MED diet leading to more pronounced beneficial changes, largely driven by dominant proinflammatory proteins (IL-1 receptor antagonist protein, IL-16, IL-18, thrombospondin-2, leptin, prostasin, galectin-9, and fibroblast growth factor 21; adjusted for age, sex, and weight loss; p < 0.05). After 18 months, proteomics cluster changes presented the strongest correlations with visceral adiposity reduction.

CONCLUSIONS

Proteomics clusters may enhance our understanding of the favorable effect of a green-MED diet that is enriched with polyphenols and low in red/processed meat on visceral adiposity and cardiometabolic risk.

The Influence of Visceral Adiposity on Overall Survival: Exploring "Obesity Paradox" Among Hepatocellular Carcinoma Patients Who Receiving Immunotherapy

Purpose

The impact of visceral adiposity on overall survival (OS) in hepatocellular carcinoma (HCC) receiving immunotherapy was unclear. We aimed to determine how visceral adiposity affected OS and explore the interrelationships between visceral adiposity, body mass index (BMI), and other body compositions.

Patients and Methods

Data from three centers were retrospectively analyzed. Skeletal muscle index (SMI), skeletal muscle density (SMD), visceral adipose tissue index (VATI), and subcutaneous adipose tissue index (SATI) were used to define each body composition. The BMI subgroups included the underweight, the normal weight, and the obesity. The Log rank test compared survival curves calculated by the Kaplan-Meier method. The relationships between body compositions and BMI with OS were examined using Cox proportional risk regression models.

Results

A total of 305 patients who met the criteria were included. Patients with low VATI had significantly worse OS (P = 0.001). The protections of VATI (P = 0.011) on OS were independent of covariates. However, after additional adjustment of SMI, the effect of VATI on OS disappeared (P = 0.146), but the effect of SMD on OS did not (P = 0.021). BMI has a significant U-shaped relationship with OS, and the effect of BMI on OS equally disappeared after additional adjustment by SMI.

Conclusion

This study first demonstrated that high VATI and mid-level BMI were protective for the survival of patients with HCC receiving immunotherapy. Skeletal muscle status (including SMI and SMD) may be the better predictor for outcomes of patients with HCC receiving immunotherapy.

Molecular Pathways Governing the Termination of Liver Regeneration

The liver has the unique capacity to regenerate, and up to 70% of the liver can be removed without detrimental consequences to the organism. Liver regeneration is a complex process involving multiple signaling networks and organs. Liver regeneration proceeds through three phases: the initiation phase, the growth phase, and the termination phase. Termination of liver regeneration occurs when the liver reaches a liver-to-body weight that is required for homeostasis, the so-called "hepatostat." The initiation and growth phases have been the subject of many studies. The molecular pathways that govern the termination phase, however, remain to be fully elucidated. This review summarizes the pathways and molecules that signal the cessation of liver regrowth after partial hepatectomy and answers the question, "What factors drive the hepatostat?" SIGNIFICANCE STATEMENT: Unraveling the pathways underlying the cessation of liver regeneration enables the identification of druggable targets that will allow us to gain pharmacological control over liver regeneration. For these purposes, it would be useful to understand why the regenerative capacity of the liver is hampered under certain pathological circumstances so as to artificially modulate the regenerative processes (e.g., by blocking the cessation pathways) to improve clinical outcomes and safeguard the patient's life.

The Different Shades of Thermogenic Adipose Tissue

PURPOSE OF REVIEW

By providing a concise overview of adipose tissue types, elucidating the regulation of adipose thermogenic capacity in both physiological contexts and chronic wasting diseases (a protracted hypermetabolic state that precipitates sustained catabolism and consequent progressive corporeal atrophy), and most importantly, delving into the ongoing discourse regarding the role of adipose tissue thermogenic activation in chronic wasting diseases, this review aims to provide researchers with a comprehensive understanding of the field.

RECENT FINDINGS

Adipose tissue, traditionally classified as white, brown, and beige (brite) based on its thermogenic activity and potential, is intricately regulated by complex mechanisms in response to exercise or cold exposure. This regulation is adipose depot-specific and dependent on the duration of exposure. Excessive thermogenic activation of adipose tissue has been observed in chronic wasting diseases and has been considered a pathological factor that accelerates disease progression. However, this conclusion may be confounded by the detrimental effects of excessive lipolysis. Recent research also suggests that such activation may play a beneficial role in the early stages of chronic wasting disease and provide potential therapeutic effects. A more comprehensive understanding of the changes in adipose tissue thermogenesis under physiological and pathological conditions, as well as the underlying regulatory mechanisms, is essential for the development of novel interventions to improve health and prevent disease.

Beta cell lipotoxicity in the development of type 2 diabetes: the need for species-specific understanding

The propensity to develop type 2 diabetes (T2D) is known to have both environmental and hereditary components. In those with a genetic predisposition to T2D, it is widely believed that elevated concentrations of circulatory long-chain fatty acids (LC-FFA) significantly contribute towards the demise of insulin-producing pancreatic β-cells - the fundamental feature of the development of T2D. Over 25 years of research support that LC-FFA are deleterious to β-cells, through a process termed lipotoxicity. However, the work underpinning the theory of β-cell lipotoxicity is mostly based on rodent studies. Doubts have been raised as to whether lipotoxicity also occurs in humans. In this review, we examine the evidence, both in vivo and in vitro, for the pathogenic effects of LC-FFA on β-cell viability and function in humans, highlighting key species differences. In this way, we aim to uncover the role of lipotoxicity in the human pathogenesis of T2D and motivate the need for species-specific understanding.

A fully convolutional neural network for comprehensive compartmentalization of abdominal adipose tissue compartments in MRI

BACKGROUND

Existing literature has highlighted structural, physiological, and pathological disparities among abdominal adipose tissue (AAT) sub-depots. Accurate separation and quantification of these sub-depots are crucial for advancing our understanding of obesity and its comorbidities. However, the absence of clear boundaries between the sub-depots in medical imaging data has challenged their separation, particularly for internal adipose tissue (IAT) sub-depots. To date, the quantification of AAT sub-depots remains challenging, marked by a time-consuming, costly, and complex process.

PURPOSE

To implement and evaluate a convolutional neural network to enable granular assessment of AAT by compartmentalization of subcutaneous adipose tissue (SAT) into superficial subcutaneous (SSAT) and deep subcutaneous (DSAT) adipose tissue, and IAT into intraperitoneal (IPAT), retroperitoneal (RPAT), and paraspinal (PSAT) adipose tissue.

MATERIAL AND METHODS

MRI datasets were retrospectively collected from Singapore Preconception Study for Long-Term Maternal and Child Outcomes (S-PRESTO: 389 women aged 31.4 ± 3.9 years) and Singapore Adult Metabolism Study (SAMS: 50 men aged 28.7 ± 5.7 years). For all datasets, ground truth segmentation masks were created through manual segmentation. A Res-Net based 3D-UNet was trained and evaluated via 5-fold cross-validation on S-PRESTO data (N = 300). The model's final performance was assessed on a hold-out (N = 89) and an external test set (N = 50, SAMS).

RESULTS

The proposed method enabled reliable segmentation of individual AAT sub-depots in 3D MRI volumes with high mean Dice similarity scores of 98.3%, 97.2%, 96.5%, 96.3%, and 95.9% for SSAT, DSAT, IPAT, RPAT, and PSAT respectively.

CONCLUSION

Convolutional neural networks can accurately sub-divide abdominal SAT into SSAT and DSAT, and abdominal IAT into IPAT, RPAT, and PSAT with high accuracy. The presented method has the potential to significantly contribute to advancements in the field of obesity imaging and precision medicine.

Interplay between Vitamin D and Adipose Tissue: Implications for Adipogenesis and Adipose Tissue Function

Adipose tissue encompasses various types, including White Adipose Tissue (WAT), Brown Adipose Tissue (BAT), and beige adipose tissue, each having distinct roles in energy storage and thermogenesis. Vitamin D (VD), a fat-soluble vitamin, maintains a complex interplay with adipose tissue, exerting significant effects through its receptor (VDR) on the normal development and functioning of adipocytes. The VDR and associated metabolic enzymes are widely expressed in the adipocytes of both rodents and humans, and they partake in the regulation of fat metabolism and functionality through various pathways. These encompass adipocyte differentiation, adipogenesis, inflammatory responses, and adipokine synthesis and secretion. This review primarily appraises the role and mechanisms of VD in different adipocyte differentiation, lipid formation, and inflammatory responses, concentrating on the pivotal role of the VD/VDR pathway in adipogenesis. This insight furnishes new perspectives for the development of micronutrient-related intervention strategies in the prevention and treatment of obesity.

Meeting at the Crossroad between Obesity and Hepatic Carcinogenesis: Unique Pathophysiological Pathways Raise Expectations for Innovative Therapeutic Approaches

The escalating global prevalence of obesity and its intricate association with the development of hepatocellular carcinoma (HCC) pose a substantial challenge to public health. Obesity, acknowledged as a pervasive epidemic, is linked to an array of chronic diseases, including HCC, catalyzing the need for a comprehensive understanding of its molecular underpinnings. Notably, HCC has emerged as a leading malignancy with rising incidence and mortality. The transition from viral etiologies to the prominence of metabolic dysfunction-associated fatty liver disease (MAFLD)-related HCC underscores the urgent need to explore the intricate molecular pathways linking obesity and hepatic carcinogenesis. This review delves into the interwoven landscape of molecular carcinogenesis in the context of obesity-driven HCC while also navigating using the current therapeutic strategies and future prospects for combating obesity-related HCC. We underscore the pivotal role of obesity as a risk factor and propose an integrated approach encompassing lifestyle interventions, pharmacotherapy, and the exploration of emerging targeted therapies. As the obesity-HCC nexus continues to challenge healthcare systems globally, a comprehensive understanding of the intricate molecular mechanisms and innovative therapeutic strategies is imperative to alleviate the rising burden of this dual menace.

Association of waist-calf circumference ratio, waist circumference, calf circumference, and body mass index with all-cause and cause-specific mortality in older adults: a cohort study

BACKGROUND

Waist circumference (WC), calf circumference (CC), and body mass index (BMI) have been independently linked to mortality. However, it's not yet clear how the waist-calf circumference ratio (WCR) relates to mortality. This study aims to investigate the relationship between WCR, WC, CC, and BMI with all-cause and cause-specific mortality in older adults.

METHODS

In the 2014 Chinese Longitudinal Healthy Longevity Survey, 4627 participants aged 65 years and older were included, and they were subsequently followed up in 2018. Cox proportional hazards models were utilized to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality, based on WCR, WC, CC, and BMI.

RESULTS

During a median follow-up of 3.4 years, 1671 deaths (36.1%) occurred. Compared to the second quartile of WCR, the highest quartile had a higher risk of mortality from all causes (HR 1.42, 95%CI 1.24-1.64), cardiovascular disease (CVD) (HR 1.88, 95%CI 1.38-2.56), and other causes (HR 1.37, 95%CI 1.15-1.63). The first and fourth quartiles of WC had HRs of 2.19 (1.00-4.79) and 2.69 (1.23-5.89), respectively, for cancer mortality. The highest quartile of CC was associated with a lower risk of all-cause and other-cause mortality, whereas the lowest quartile was associated with a higher risk of all-cause, CVD, and other-cause mortality compared to the second CC quartile. Additionally, the lowest quartile of BMI was associated with a higher risk of all-cause and respiratory disease mortality. Interaction analyses showed that the effects of CC on all-cause and CVD mortality were more pronounced in adults aged ≥ 80 years (P-interaction < .05).

CONCLUSIONS

Higher WCR and lower CC increased the risk of all-cause, CVD, and other-cause mortality. Lower BMI was associated with higher all-cause and respiratory disease mortality risk, while WC only predicted cancer mortality.

Adipose Tissue and Metabolic Health

In this review, we provide a brief synopsis of the connections between adipose tissue and metabolic health and highlight some recent developments in understanding and exploiting adipocyte biology. Adipose tissue plays critical roles in the regulation of systemic glucose and lipid metabolism and secretes bioactive molecules possessing endocrine, paracrine, and autocrine functions. Dysfunctional adipose tissue has a detrimental impact on metabolic health and is intimately involved in key aspects of metabolic diseases such as insulin resistance, lipid overload, inflammation, and organelle stress. Differences in the distribution of fat depots and adipose characteristics relate to divergent degrees of metabolic dysfunction found in metabolically healthy and unhealthy obese individuals. Thermogenic adipocytes increase energy expenditure via mitochondrial uncoupling or adenosine triphosphate-consuming futile substrate cycles, while functioning as a metabolic sink and participating in crosstalk with other metabolic organs. Manipulation of adipose tissue provides a wealth of opportunities to intervene and combat the progression of associated metabolic diseases. We discuss current treatment modalities for obesity including incretin hormone analogs and touch upon emerging strategies with therapeutic potential including exosome-based therapy, pharmacological activation of brown and beige adipocyte thermogenesis, and administration or inhibition of adipocyte-derived factors.

The Transcriptomic Landscape of Age-Induced Changes in Human Visceral Fat and the Predicted Omentum-Liver Connectome in Males

Aging causes alterations in body composition. Specifically, visceral fat mass increases with age and is associated with age-related diseases. The pathogenic potential of visceral fat accumulation has been associated with its anatomical location and metabolic activity. Visceral fat may control systemic metabolism by secreting molecules that act in distal tissues, mainly the liver, through the portal vein. Currently, little is known about age-related changes in visceral fat in humans. Aiming to identify molecular and cellular changes occurring with aging in the visceral fat of humans, we analyzed publicly available transcriptomic data of 355 omentum samples from the Genotype-Tissue Expression portal (GTEx) of 20-79-year-old males and females. We identified the functional enrichment of genes associated with aging, inferred age-related changes in visceral fat cellularity by deconvolution analysis, profiled the senescence-associated secretory phenotype of visceral adipose tissue, and predicted the connectivity of the age-induced visceral fat secretome with the liver. We demonstrate that age induces alterations in visceral fat cellularity, synchronous to changes in metabolic pathways and a shift toward a pro-inflammatory secretory phenotype. Furthermore, our approach identified candidates such as ADIPOQ-ADIPOR1/ADIPOR2, FCN2-LPR1, and TF-TFR2 to mediate visceral fat-liver crosstalk in the context of aging. These findings cast light on how alterations in visceral fat with aging contribute to liver dysfunction and age-related disease etiology.

Adipose Tissue Remodeling in Obesity: An Overview of the Actions of Thyroid Hormones and Their Derivatives

Metabolic syndrome and obesity have become important health issues of epidemic proportions and are often the cause of related pathologies such as type 2 diabetes (T2DM), hypertension, and cardiovascular disease. Adipose tissues (ATs) are dynamic tissues that play crucial physiological roles in maintaining health and homeostasis. An ample body of evidence indicates that in some pathophysiological conditions, the aberrant remodeling of adipose tissue may provoke dysregulation in the production of various adipocytokines and metabolites, thus leading to disorders in metabolic organs. Thyroid hormones (THs) and some of their derivatives, such as 3,5-diiodo-l-thyronine (T2), exert numerous functions in a variety of tissues, including adipose tissues. It is known that they can improve serum lipid profiles and reduce fat accumulation. The thyroid hormone acts on the brown and/or white adipose tissues to induce uncoupled respiration through the induction of the uncoupling protein 1 (UCP1) to generate heat. Multitudinous investigations suggest that 3,3',5-triiodothyronine (T3) induces the recruitment of brown adipocytes in white adipose depots, causing the activation of a process known as "browning". Moreover, in vivo studies on adipose tissues show that T2, in addition to activating brown adipose tissue (BAT) thermogenesis, may further promote the browning of white adipose tissue (WAT), and affect adipocyte morphology, tissue vascularization, and the adipose inflammatory state in rats receiving a high-fat diet (HFD). In this review, we summarize the mechanism by which THs and thyroid hormone derivatives mediate adipose tissue activity and remodeling, thus providing noteworthy perspectives on their efficacy as therapeutic agents to counteract such morbidities as obesity, hypercholesterolemia, hypertriglyceridemia, and insulin resistance.

The Role of Olfactomedin 2 in the Adipose Tissue–Liver Axis and Its Implication in Obesity-Associated Nonalcoholic Fatty Liver Disease

This study’s objective was to assess the involvement of olfactomedin 2 (OLFM2), a secreted glycoprotein related to lipid metabolism regulation, in nonalcoholic fatty liver disease (NAFLD) mediated by the adipose-tissue–liver axis. OLFM2 mRNA expression was analyzed in subcutaneous (SAT) and visceral (VAT) adipose tissue by RT–qPCR. The cohort included women with normal weight (n = 16) or morbid obesity (MO, n = 60) who were subclassified into normal liver (n = 20), simple steatosis (n = 21), and nonalcoholic steatohepatitis (NASH, n = 19) groups. The results showed that OLFM2 expression in SAT was enhanced in MO individuals and in the presence of NAFLD. Specifically, OLFM2 expression in SAT was increased in mild and moderate degrees of steatosis in comparison to the absence of it. Moreover, OLFM2 expression in SAT was negatively correlated with interleukin-6 levels. On the other hand, OLFM2 expression in VAT decreased in the presence of NASH and exhibited a positive correlation with adiponectin levels. In conclusion, OLFM2 in SAT seems to be implicated in hepatic lipid accumulation. Additionally, since we previously suggested the possible implication of hepatic OLFM2 in NAFLD progression, now we propose a possible interaction between the liver and SAT, reinforcing the potential implication of this tissue in NAFLD development.

Taste Function in Adult Humans from Lean Condition to Stage II Obesity: Interactions with Biochemical Regulators, Dietary Habits, and Clinical Aspects

Differences in gustatory sensitivity, nutritional habits, circulating levels of modulators, anthropometric measures, and metabolic assays may be involved in overweight (OW) development. The present study aimed at evaluating the differences in these aspects between 39 OW (19 female; mean age = 53.51 ± 11.17), 18 stage I (11 female; mean age = 54.3 ± 13.1 years), and 20 II (10 female; mean age = 54.5 ± 11.9) obesity participants when compared with 60 lean subjects (LS; 29 female; mean age = 54.04 ± 10.27). Participants were evaluated based on taste function scores, nutritional habits, levels of modulators (leptin, insulin, ghrelin, and glucose), and bioelectrical impedance analysis measurements. Significant reductions in total and subtests taste scores were found between LS and stage I and II obesity participants. Significant reductions in total and all subtests taste scores were found between OW and stage II obesity participants. Together with the progressive increase in plasmatic leptin levels, insulin, and serum glucose, decrease in plasmatic ghrelin levels, and changes in anthropometric measures and nutritional habits along with body mass index, these data for the first time demonstrated that taste sensitivity, biochemical regulators, and food habits play a parallel, concurring role along the stages evolving to obesity.

Visceral adipose tissue-directed human kallistatin gene therapy improves adipose tissue remodeling and metabolic health in obese mice

OBJECTIVE

Adipose tissue remodeling is a dynamic process that is pathologically expedited in the obese state and is closely related to obesity-associated disease progression. This study aimed to explore the effects of human kallistatin (HKS) on adipose tissue remodeling and obesity-related metabolic disorders in mice fed with a high-fat diet (HFD).

METHODS

Adenovirus-mediated HKS cDNA (Ad.HKS) and a blank adenovirus (Ad.Null) were constructed and injected into the epididymal white adipose tissue (eWAT) of 8-weeks-old male C57B/L mice. The mice were fed normal or HFD for 28 days. The body weight and circulating lipids levels were assessed. Intraperitoneal glucose tolerance test (IGTT) and insulin tolerance test (ITT) were also performed. Oil-red O staining was used to assess the extent of lipid deposition in the liver. Immunohistochemistry and HE staining were used to measure HKS expression, adipose tissue morphology, and macrophage infiltration. Western blot and qRT-PCR were used to evaluate the expression of adipose function-related factors.

RESULTS

At the end of the experiment, the expression of HKS in the serum and eWAT of the Ad.HKS group was higher than in the Ad.Null group. Furthermore, Ad.HKS mice had lower body weight and decreased serum and liver lipid levels after four weeks of HFD feeding. IGTT and ITT showed that HKS treatment maintained balanced glucose homeostasis. Additionally, inguinal white adipose tissue (iWAT) and eWAT in Ad.HKS mice had a higher number of smaller-size adipocytes and had less macrophage infiltration than Ad.Null group. HKS significantly increased the mRNA levels of adiponectin, vaspin, and eNOS. In contrast, HKS decreased RBP4 and TNFα levels in the adipose tissues. Western blot results showed that local injection of HKS significantly upregulated the protein expressions of SIRT1, p-AMPK, IRS1, p-AKT, and GLUT4 in eWAT.

CONCLUSIONS

HKS injection in eWAT improves HFD-induced adipose tissue remodeling and function, thus significantly improving weight gain and dysregulation of glucose and lipid homeostasis in mice.

Loss of Visceral Fat is Associated with a Reduction in Inflammatory Status in Patients with Metabolic Syndrome

SCOPE

Excessive visceral adipose tissue (VAT) is associated with higher secretion of pro-inflammatory molecules, contributing to systemic inflammation and obesity-related metabolic disturbances.

METHODS AND RESULTS

This prospective analysis includes 117 overweight/obese adults (55-75 years) from the PREDIMED-Plus study. Fourteen inflammatory markers and adipokines are measured using a Bio-Plex assay with multiplex technology: insulin, glucagon, IL-6, visfatin, ghrelin, GLP-1, TNF-α, MCP-1, PAI-1, resistin, C-peptide, leptin, adipsin, and adiponectin. Participants are categorized into tertiles according to changes in VAT after 1-year of follow-up, determined by dual-energy X-Ray absorptiometry. Participants allocate in tertile 3, which represent an increase of VAT content after 1-year of follow-up compared to tertile 1, show significant differences in insulin (T3 vs T1, fully adjusted model: p = 0.037, p for trend 0.042), PAI-1 (fully adjusted model: p = 0.05, p for trend 0.06), c-peptide (fully adjusted model: p = 0.037, p for trend 0.042), and TNF-α (fully adjusted model p = 0.037, p for trend 0.042).

CONCLUSION

The results evidence that a reduction in VAT is associated with clinical improvements in several inflammatory and adiposity markers, mainly in insulin, c-peptide, and PAI-1 levels, and these improvements may contribute to a reduction in cardiometabolic disturbances observe in obesity.

Predictive and prognostic effect of computed tomography-derived body composition analysis during neoadjuvant chemotherapy for operable and locally advanced breast cancer

OBJECTIVES

Excess adiposity is associated with several factors involved in carcinogenesis and breast cancer progression. Evidence supporting the role of body composition in breast cancer treatment is promising, but still scanty and mainly focused on adjuvant treatment. The aim of this study was to evaluate the changes in body composition during neoadjuvant chemotherapy and its association with pathologic complete response and survival outcome in patients treated for operable/locally advanced breast cancer.

METHODS

A retrospective review of patients with breast cancer treated with neoadjuvant chemotherapy was performed in the Oncology Section of the Department of Medicine, University of Verona between 2014 and 2019. Body composition was evaluated from clinically acquired computed tomography scans at diagnosis and after neoadjuvant chemotherapy. Descriptive statistic was adopted. The associations of body composition measures with pathologic complete response and disease-free survival were analyzed. Kaplan-Meier curves were compared with log-rank analysis.

RESULTS

Data from 93 patients were collected. After neoadjuvant chemotherapy, the adipose compound changed significantly across all body mass index categories. Body composition parameters had no significant effect on pathologic complete response. Survival analysis showed that a high gain of visceral adipose tissue during neoadjuvant chemotherapy was associated with shorter disease-free survival (hazard ratio, 10.2; P = 0.026). In particular, disease-free survival was significantly worse in patients who gained ≥10% of visceral adipose tissue compared with patients who gained <10% of visceral adipose tissue (5-y disease-free survival 71.4 versus 96.3, P = 0.009, respectively).

CONCLUSIONS

Our results indicated that neoadjuvant chemotherapy significantly affects body composition, which seems to have an effect on survival outcome of breast cancer, highlighting the relevance of the body composition assessment when estimating treatment outcomes.

SARS-CoV-2 infects adipose tissue in a fat depot- and viral lineage-dependent manner

Visceral adiposity is a risk factor for severe COVID-19, and a link between adipose tissue infection and disease progression has been proposed. Here we demonstrate that SARS-CoV-2 infects human adipose tissue and undergoes productive infection in fat cells. However, susceptibility to infection and the cellular response depends on the anatomical origin of the cells and the viral lineage. Visceral fat cells express more ACE2 and are more susceptible to SARS-CoV-2 infection than their subcutaneous counterparts. SARS-CoV-2 infection leads to inhibition of lipolysis in subcutaneous fat cells, while in visceral fat cells, it results in higher expression of pro-inflammatory cytokines. Viral load and cellular response are attenuated when visceral fat cells are infected with the SARS-CoV-2 gamma variant. A similar degree of cell death occurs 4-days after SARS-CoV-2 infection, regardless of the cell origin or viral lineage. Hence, SARS-CoV-2 infects human fat cells, replicating and altering cell function and viability in a depot- and viral lineage-dependent fashion.

Visceral adiposity is a risk factor for severe COVID-19, and infection of adipose tissue by SARS-CoV-2 has been reported. Here the authors confirm that human adipose tissue is a possible site for SARS-CoV-2 infection, but the degree of adipose tissue infection and the way adipocytes respond to the virus depend on the adipose tissue depot and the viral strain.

In-depth investigation of the hypoglycemic mechanism of Morchella importuna polysaccharide via metabonomics combined with 16S rRNA sequencing

Increasing evidence indicates that type 2 diabetes mellitus (T2DM) is closely related to intestinal bacteria disorders and abnormal hepatic metabolism. Morchella importuna polysaccharide (MIP) shows excellent hypoglycemic activity in vitro. However, the hypoglycemic effect and mechanism of MIP in vivo have yet to be investigated. In this study, the blood glucose, blood lipid and insulin resistance of diabetic mice after MIP intervention were measured to evaluate its hypoglycemic effect. Then, the microbiome and metabolomics were combined to explore the hypoglycemic mechanism of MIP. Results indicated that high dose MIP (400 mg/kg) had significant hypoglycemic effect. Furthermore, MIP could reverse diabetes-induced intestinal disorder by increasing the abundance of Akkermansia, Blautia, Dubosiella, and Lachnospiraceae, as well as decreasing the abundance of Helicobacteraceae. Besides, the hepatic metabolites and complex network systems formed by multiple metabolic pathways were regulated after MIP treatment. Notably, a new biomarker of diabetes (N-P-coumaroyl spermidine) was discovered in this study. Moreover, the significant association between intestinal bacteria and hepatic metabolites was determined by correlations analysis, which in turn confirmed MIP alleviated T2DM via the gut-liver axis. Therefore, these findings elucidated in-depth hypoglycemic mechanisms of MIP and provided a new biomarker for the prevention of diabetes.

Weight change and the risk of hip fractures in patients with type 2 diabetes: a nationwide cohort study

Both weight gain and weight loss in type 2 diabetic population were associated with increased risk of hip fracture, while maintaining weight lowered the risk of hip fracture. Regarding the risk of hip fracture, we can propose active monitoring to maintain the weight of type 2 diabetes patients.

INTRODUCTION

In type 2 diabetes, patients are often asked to control their weight in order to reduce their diabetic morbidity. The American Diabetes Association recommends that diabetic patients conduct high-intensity interventions for regulating diet, physical activity, and behavior to reduce weight, followed by long-term comprehensive weight maintenance programs. Although such weight control attempts are required in diabetic patients, there are few studies on the effect of weight change on hip fracture in this population. We aim to investigate the association between body weight change and the incidence of hip fracture in subjects with type 2 diabetes using large-scale, nationwide cohort data on the Korean population.

MATERIALS AND METHODS

A total of 1,447,579 subjects (894,204 men and 553,375 women) > 40 years of age, who were diagnosed with type 2 diabetes, were enrolled in this study. Weight change within 2 years was divided into five categories: from weight loss ≥ 10% to weight gain ≥ 10%. The hazard ratios (HRs) and 95% confidence intervals for the incidence of hip fracture were analyzed, compared with the reference of the stable weight group (weight change < 5%).

RESULTS

Among 5 weight change groups, more than 10% weight loss showed the highest HR (HR, 1.605; 95% CI, 1.493 to 1.725), followed by more than 10% weight gain (HR, 1.457; 95% CI, 1.318 to 1.612). The effect of weight change on hip fracture risk was greater in males than in females, and those under 65 years of age were greater than those over 65 years of age. Baseline BMI did not play a role of weight change affecting the risk of hip fracture. The HR for hip fracture of subjects with regular exercise was lower than those without regular exercise.

CONCLUSIONS

In the type 2 diabetes population, both weight gain and weight loss were significantly associated with a higher risk of hip fracture, whereas maintaining body weight reduced the risk of hip fracture the most.

Noninvasive NMR/MRS Metabolic Parameters to Evaluate Metabolic Syndrome in Rats

(1) Background: Ectopic fat deposition and its effects, metabolic syndrome, have been significantly correlated to lifestyle and caloric consumption. There is no specific noninvasive evaluation tool being used in order to establish clinical markers for tracing the metabolic pathway implicated in obesity-related abnormalities that occur in the body as a result of a high-fat diet (HFD). The purpose of this work is to investigate in vivo ectopic fat distribution and in vitro metabolite profiles given by HFDs, as well as how they are inter-related, in order to find surrogate metabolic biomarkers in the development of metabolic syndrome utilizing noninvasive approaches. (2) Methods: Male Wistar rats were divided into a standard normal chow diet, ND group, and HFD group. After 16 weeks of different diet administration, blood samples were collected for proton nuclear magnetic resonance (¹H NMR) and biochemical analysis. Magnetic resonance imaging/proton magnetic resonance spectroscopy (MRI/¹H MRS) was performed on the abdomen, liver, and psoas muscle of the rats. (3) Results: Visceral fat showed the strongest relationship with blood cholesterol. Although liver fat content (LFC) was not associated with any biophysical profiles, it had the highest correlation with metabolites such as (-CH₂)_n very-low-density lipoprotein/low-density lipoprotein (VLDL/LDL), lactate, and N-acetyl glycoprotein of serum ¹H NMR. HFD showed no obvious influence on muscle fat accumulation. Acetoacetate, N-acetyl glycoprotein, lactate, (-CH₂)_n VLDL/LDL, and valine were the five possible metabolic biomarkers used to differentiate HFD from ND in the present study. (4) Conclusions: Our study has validated the influence of long-term HFD-induced ectopic fat on body metabolism as well as the metabolic profile deterioration both in vivo and in vitro.

Non-alcoholic fatty liver disease: a multi-system disease influenced by ageing and sex, and affected by adipose tissue and intestinal function

In recent years, a wealth of factors are associated with increased risk of developing non-alcoholic fatty liver disease (NAFLD) and NAFLD is now thought to increase the risk of multiple extra-hepatic diseases. The aim of this review is first to focus on the role of ageing and sex as key, poorly understood risk factors in the development and progression of NAFLD. Secondly, we aim to discuss the roles of white adipose tissue (WAT) and intestinal dysfunction, as producers of extra-hepatic factors known to further contribute to the pathogenesis of NAFLD. Finally, we aim to summarise the role of NAFLD as a multi-system disease affecting other organ systems beyond the liver. Both increased age and male sex increase the risk of NAFLD and this may be partly driven by alterations in the distribution and function of WAT. Similarly, changes in gut microbiota composition and intestinal function with ageing and chronic overnutrition are likely to contribute to the development of NAFLD both directly (i.e. by affecting hepatic function) and indirectly via exacerbating WAT dysfunction. Consequently, the presence of NAFLD significantly increases the risk of various extra-hepatic diseases including CVD, type 2 diabetes mellitus, chronic kidney disease and certain extra-hepatic cancers. Thus changes in WAT and intestinal function with ageing and chronic overnutrition contribute to the development of NAFLD – a multi-system disease that subsequently contributes to the development of other chronic cardiometabolic diseases.

Adipose tissue aging: mechanisms and therapeutic implications

Adipose tissue, which is the crucial energy reservoir and endocrine organ for the maintenance of systemic glucose, lipid, and energy homeostasis, undergoes significant changes during aging. These changes cause physiological declines and age-related disease in the elderly population. Here, we review the age-related changes in adipose tissue at multiple levels and highlight the underlying mechanisms regulating the aging process. We also discuss the pathogenic pathways of age-related fat dysfunctions and their systemic negative consequences, such as dyslipidemia, chronic general inflammation, insulin resistance, and type 2 diabetes (T2D). Age-related changes in adipose tissue involve redistribution of deposits and composition, in parallel with the functional decline of adipocyte progenitors and accumulation of senescent cells. Multiple pathogenic pathways induce defective adipogenesis, inflammation, aberrant adipocytokine production, and insulin resistance, leading to adipose tissue dysfunction. Changes in gene expression and extracellular signaling molecules regulate the aging process of adipose tissue through various pathways. In addition, adipose tissue aging impacts other organs that are infiltrated by lipids, which leads to systemic inflammation, metabolic system disruption, and aging process acceleration. Moreover, studies have indicated that adipose aging is an early onset event in aging and a potential target to extend lifespan. Together, we suggest that adipose tissue plays a key role in the aging process and is a therapeutic target for the treatment of age-related disease, which deserves further study to advance relevant knowledge.

Amentoflavone-Enriched Selaginella rossii Warb. Suppresses Body Weight and Hyperglycemia by Inhibiting Intestinal Lipid Absorption in Mice Fed a High-Fat Diet

Many Selaginellaceae species are used as traditional medicines in Asia. This study is the first to investigate the anti-obesity and anti-diabetic effects of Selaginella rossii (SR) in high-fat diet (HFD)–fed C57BL/6J mice. Seven-day oral administration of ethanol extract (100 mg/kg/day) or ethyl acetate (EtOAc) extract (50 mg/kg/day) from SR improved oral fat tolerance by inhibiting intestinal lipid absorption; 10-week long-term administration of the EtOAc extract markedly reduced HFD-induced body weight gain and hyperglycemia by reducing adipocyte hypertrophy, glucose levels, HbA1c, and plasma insulin levels. Treatment with SR extracts reduced the expression of intestinal lipid absorption-related genes, including Cd36, fatty acid-binding protein 6, ATP-binding cassette subfamily G member 8, NPC1 like intracellular cholesterol transporter 1, and ATP-binding cassette subfamily A member 1. In addition, the EtOAc extract increased the expression of protein absorption–related solute carrier family genes, including Slc15a1, Slc8a2, and Slc6a9. SR extracts reduced HFD-induced hepatic steatosis by suppressing fatty acid transport to hepatocytes and hepatic lipid accumulation. Furthermore, amentoflavone (AMF), the primary compound in SR extracts, reduced intestinal lipid absorption by inhibiting fatty acid transport in HFD-fed mice. AMF-enriched SR extracts effectively protected against HFD-induced body weight gain and hyperglycemia by inhibiting intestinal lipid absorption.

Role of age, gender and ethnicity in the association between visceral adiposity index and non-alcoholic fatty liver disease among US adults (NHANES 2003-2018): cross-sectional study

OBJECTIVES

The association between visceral adiposity index (VAI) and the prevalence of non-alcoholic fatty liver disease (NAFLD) has not been fully determined. Here, we aimed to explore the association between VAI and NAFLD in the general US population, and further investigate whether the association involves population differences.

DESIGN

Cross-sectional population-based study.

SETTING

The National Health and Nutrition Examination Survey (2003-2018).

PARTICIPANTS

A total of 7522 participants aged 20 years or older who have complete information for NAFLD assessment test were included in this study.

PRIMARY AND SECONDARY OUTCOME MEASURES

NAFLD was assessed by the modified fatty liver index for the US population (USFLI) using a cut-off point of 30. Correlation between VAI and NAFLD prediction scores was calculated using the partial correlation analysis. Logistic regression models were further used to estimate ORs and 95% CIs.

RESULTS

Insulin resistance (IR), inflammation and waist circumference-adjusted partial correlation analysis indicated that VAI scores were positively correlated with USFLI (r=0.404 for men, and r=0.395 for women; p<0.001). In a comparison of the highest versus the lowest quartiles of VAI, multivariable logistic regression analysis demonstrated a positive association between VAI and NAFLD (OR (95% CI)=1.97 (1.12 to 3.47) for men, OR (95% CI)=4.03 (1.98 to 8.20) for women). The stratified analyses revealed that the positive association involves age/gender-specific and ethnic differences. As for the impact of metabolic disorders, our results revealed that the association was independent of IR and diabetes, but it would be confounded by other metabolic disorders. However, no significant association was found between VAI and hepatic fibrosis.

CONCLUSION

VAI is positively associated with the prevalence of NAFLD, but not hepatic fibrosis among US adults, and the association involves age/gender-specific and ethnic differences. The results reported here have important public health implications in NAFLD screening in the future.

Adipose-tissue plasticity in health and disease

Adipose tissue, colloquially known as "fat," is an extraordinarily flexible and heterogeneous organ. While historically viewed as a passive site for energy storage, we now appreciate that adipose tissue regulates many aspects of whole-body physiology, including food intake, maintenance of energy levels, insulin sensitivity, body temperature, and immune responses. A crucial property of adipose tissue is its high degree of plasticity. Physiologic stimuli induce dramatic alterations in adipose-tissue metabolism, structure, and phenotype to meet the needs of the organism. Limitations to this plasticity cause diminished or aberrant responses to physiologic cues and drive the progression of cardiometabolic disease along with other pathological consequences of obesity.

Low level of adiponectin predicts the development of Nonalcoholic fatty liver disease: is it irrespective to visceral adiposity index, visceral adipose tissue thickness and other obesity indices?

We aimed to study the correlation of adiponectin level with insulin resistance (IR), carotid intima-media thickness (cIMT), and various obesity indices especially visceral adipose tissue (VAT) thickness, and visceral adiposity index (VAI), in patients with NAFLD (n = 41), T2D (n = 22), NAFLD + T2D (n = 41), and healthy subjects (n = 20). Results showed the median level of adiponectin in patients with NAFLD (2.97 μg/mL) and ones with NAFLD + T2D (3.21 μg/mL) is significantly lower rather than in controls (4.39 μg/mL). Moreover, VAI is the only predictor for adiponectin concentration in the combination of patient groups and also in all participants independent of IR and other obesity indices. Adiponectin level had also a positive correlation with cIMT and IR in NAFLD patients. Interestingly, lower level of adiponectin was associated with the presence of T2D, NAFLD, and NAFLD + T2D independent of IR and obesity indices. Collectively, it seems that VAI reflecting visceral adipose tissue function is a possible predictor of adiponectin level.

Genomic Analysis of Visceral Fat Accumulation in Holstein Cows

Visceral fat is related to important metabolic processes, including insulin sensitivity and lipid mobilization. The goal of this study was to identify individual genes, pathways, and molecular processes implicated in visceral fat deposition in dairy cows. Data from 172 genotyped Holstein cows classified at slaughterhouse as having low (n = 77; omental fold <5 mm in thickness and minimum fat deposition in omentum) or high (n = 95; omental fold ≥20 mm in thickness and marked fat deposition in omentum) omental fat were analyzed. The identification of regions with significant additive and non-additive genetic effects was performed using a two-step mixed model-based approach. Genomic scans were followed by gene-set analyses in order to reveal the genetic mechanisms controlling abdominal obesity. The association mapping revealed four regions located on BTA19, BTA20 and BTA24 with significant additive effects. These regions harbor genes, such as SMAD7, ANKRD55, and the HOXB family, that are implicated in lipolysis and insulin tolerance. Three regions located on BTA1, BTA13, and BTA24 showed marked non-additive effects. These regions harbor genes MRAP, MIS18A, PRNP and TSHZ1, that are directly implicated in adipocyte differentiation, lipid metabolism, and insulin sensitivity. The gene-set analysis revealed functional terms related to cell arrangement, cell metabolism, cell proliferation, cell signaling, immune response, lipid metabolism, and membrane permeability, among other functions. We further evaluated the genetic link between visceral fat and two metabolic disorders, ketosis, and displaced abomasum. For this, we analyzed 28k records of incidence of metabolic disorders from 14k cows across lactations using a single-step genomic BLUP approach. Notably, the region on BTA20 significantly associated with visceral fat deposition was also associated with the incidence of displaced abomasum. Overall, our findings suggest that visceral fat deposition in dairy cows is controlled by both additive and non-additive effects. We detected at least one region with marked pleiotropic effects affecting both visceral fat accumulation and displaced abomasum.

Repercussions of absolute and time-rated BMI "yo-yo" fluctuations on cardiovascular stress-related morbidities within the vascular-metabolic CUN cohort

AIMS

The association between body mass index (BMI) fluctuation and BMI fluctuation rate with cardiovascular stress morbidities in a Caucasian European cohort was evaluated to ascertain the impact of weight cycling.

METHODS

A total of 4,312 patients of the Vascular-Metabolic CUN cohort (VMCUN cohort) were examined and followed up during 9.35 years ( ± 4.39). Cox proportional hazard ratio analyses were performed to assess the risk of developing cardiovascular stress-related diseases (CVDs) across quartiles of BMI fluctuation, measured as the average successive variability (ASV) (ASV = |BMIt0 - BMIt1| + |BMIt1 - BMIt2| + |BMIt2-BMIt3| +…+ |BMItn - 1 - BMItn|/n - 1), and quartiles of BMI fluctuation rate (ASV/year).

RESULTS

There were 436 incident cases of CVD-associated events involving 40,323.32 person-years of follow-up. A progressively increased risk of CVD in subjects with greater ASV levels was found. Also, a higher level of ASV/year was significantly associated with an increased risk of developing CVD stress independent of confounding factors with a value of 3.71 (95% CI: 2.71-5.07) for those in the highest quartile and 1.82 (95% CI: 1.33-2.50) for those in the third quartile.

CONCLUSIONS

The BMI fluctuation rate seems to be a better predictor than BMI fluctuation of the potential development of cardiovascular stress morbidities. The time-rated weight fluctuations are apparently more determinant in increasing the risk of a CVD than the weight fluctuation itself, which is remarkable in subjects under "yo-yo" weight patterns for precision medicine.

Indian Phenotype Characteristics Among Patients with Type 2 Diabetes Mellitus: Insights from a Non-interventional Nationwide Registry in India

Background: Indian patients with type 2 diabetes mellitus (T2D) constitute one-sixth of affected adults globally. Here, we evaluate the association of body mass index (BMI) with body fat percentage (BF%) and glycated haemoglobin (HbA1c) levels among patients with T2D in India. Method: This was a cross-sectional Indian registry study across 845 geographically diverse zones between December 2017 and August 2019. Results: Of 37,927 patients, 55.6% were men, with a mean ± standard deviation age of 54.2 ± 11.5 years and HbA1c of 8.3 ± 1.71%. Mean ± standard deviation BMI and BF% were 27.0 ± 4.6 kg/m2 and 32.0 ± 8.0%, respectively. Overall, 15.4% of patients were overweight, and 25.0% were obese. Despite fewer males (20.7%) having BMI-based obesity than females (31.2%), around three-quarters of both sexes had BF%-defined obesity (males 77.2%; females 71.2%). One-third of males (34.6%) and 41.9% of females had BF%-defined obesity despite normal BMI. The association was substantiated by a moderately significant correlation (r=0.51) between BMI and BF% in the overall population (p<0.0001). Conclusion: This pan-India registry presents a real-world reflection of the Asian Indian phenotype: high BF% despite lower BMI in people with T2D. This highlights the importance of primordial and primary prevention, and may guide decisions on the choice of agents for glycaemic control, with a preference for drugs that promote weight loss or are weight neutral.

Mendelian randomization prioritizes abdominal adiposity as an independent causal factor for liver fat accumulation and cardiometabolic diseases

Background

Observational studies have linked adiposity and especially abdominal adiposity to liver fat accumulation and non-alcoholic fatty liver disease. These traits are also associated with type 2 diabetes and coronary artery disease but the causal factor(s) underlying these associations remain unexplored.

Methods

We used a multivariable Mendelian randomization study design to determine whether body mass index and waist circumference were causally associated with non-alcoholic fatty liver disease using publicly available genome-wide association study summary statistics of the UK Biobank (n = 461,460) and of non-alcoholic fatty liver disease (8434 cases and 770,180 control). A multivariable Mendelian randomization study design was also used to determine the respective causal contributions of waist circumference and liver fat (n = 32,858) to type 2 diabetes and coronary artery disease.

Results

Using multivariable Mendelian randomization we show that waist circumference increase non-alcoholic fatty liver disease risk even when accounting for body mass index (odd ratio per 1-standard deviation increase = 2.35 95% CI = 1.31-4.22, p = 4.2e-03), but body mass index does not increase non-alcoholic fatty liver disease risk when accounting for waist circumference (0.86 95% CI = 0.54-1.38, p = 5.4e-01). In multivariable Mendelian randomization analyses accounting for liver fat, waist circumference remains strongly associated with both type 2 diabetes (3.27 95% CI = 2.89-3.69, p = 3.8e-80) and coronary artery disease (1.66 95% CI = 1.54-1.8, p = 3.4e-37).

Conclusions

These results identify waist circumference as a strong, independent, and causal contributor to non-alcoholic fatty liver disease, type 2 diabetes and coronary artery disease, thereby highlighting the importance of assessing body fat distribution for the prediction and prevention of cardiometabolic diseases.

The Perirenal Fat Thickness Was Associated with Nonalcoholic Fatty Liver Disease in Patients with Type 2 Diabetes Mellitus

PURPOSE

Obesity is an important risk factor for nonalcoholic fatty liver disease (NAFLD). Perirenal fat and paranephric fat were seldom studied in NAFLD. We aimed to explore the relationship between perirenal fat thickness (PrFT) and paranephric fat thickness (PnFT) and NAFLD in patients with type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

A total of 493 diabetic patients including 231 NAFLD patients were enrolled in our study from September 2019 to December 2020. Patients with NAFLD were categorized into three subgroups according to the severity and fibrosis risk of NAFLD. Anthropometric indices and clinical characteristics were collected from clinical records. PrFT and PnFT were measured via ultrasound. Multivariate logistic regression analysis was used to assess the association between PrFT, PnFT and presence, severity and advanced fibrosis risk of NAFLD.

RESULTS

Compared with non-NAFLD patients, those with NAFLD had significantly higher PrFT and PnFT. The PrFT and PnFT were independently associated with presence of NAFLD and the PrFT was independently associated with the advanced fibrosis risk of NAFLD after adjusting confounding factors.

CONCLUSION

The PrFT was independently associated with the presence and advanced fibrosis risk of NAFLD in patients with T2DM.

A Distinctive NAFLD Signature in Adipose Tissue from Women with Severe Obesity

Development and severity of nonalcoholic fatty liver disease (NAFLD) have been linked to obesity and white adipose tissue (WAT) dysfunction plays a key role in this relation. We compared the main features of subcutaneous (SAT) and visceral WAT (VAT) tissue dysfunction in 48 obese women without (Ob) and with NAFLD (Ob-NAFLD) undergoing bariatric surgery and matched for age, BMI and T2D status. Fat cell area, adipocyte size distribution, the degree of histological fibrosis and the mRNA expression of adipokines and genes implicated in inflammation, adipogenesis, angiogenesis, metabolism and extracellular matrix remodeling were measured by RT-qPCR in both fat depots. Ob-NAFLD group showed higher TG and lower HDL circulating levels, increased VAT fat cell area and similar WAT fibrosis in comparison with Ob group. A sPLS-DA was performed in order to identify the set of genes that better characterize the presence of NAFLD. Finally, we build a multinomial logistic model including seven genes that explained 100% of the variance in NAFLD and correctly predicted 100% of cases. Our data support the existence of distinctive NAFLD signatures in WAT from women with severe obesity. A better understanding of these pathways may help in future strategies for the prevention and treatment of NAFLD.

Superficial vs Deep Subcutaneous Adipose Tissue: Sex-Specific Associations With Hepatic Steatosis and Metabolic Traits

CONTEXT

Subcutaneous adipose tissue (SAT) is not homogeneous, as the fascia scarpa separates the deep SAT (dSAT) from the superficial SAT (sSAT).

OBJECTIVE

The aim of this study is to evaluate the sex-specific associations of sSAT and dSAT with hepatic steatosis and metabolic syndrome in overweight individuals.

METHODS

We recruited 285 individuals with a body mass index (BMI) greater than or equal to 27 and aged 55 to 81 years. Abdominal magnetic resonance imaging was performed around level L4 to L5 to measure visceral adipose tissue (VAT), dSAT, and sSAT volumes. The amount of hepatic fat was quantified by MR spectroscopy.

RESULTS

Men had significantly higher volumes of VAT (122.6 cm3 vs 98.7 cm3, P < .001) and had only half the volume of sSAT compared to women adjusted for BMI (50.3 cm3 in men vs 97.0 cm3 in women, P < .001). dSAT correlated significantly with hepatic fat content in univariate analysis (standardized β = .190, P < .05), while VAT correlated significantly with hepatic steatosis in a multivariate model, adjusted for age, alcohol use, and other abdominal fat compartments (standardized β = .184, P = .037). Moreover, dSAT in men correlated negatively with HDL cholesterol (standardized β = -0.165, P = .038) in multivariate analyses. In women with a BMI between 30 and 40, in a multivariate model adjusted for age, alcohol use, and other abdominal fat compartments, VAT correlated positively (standardized β = -.404, P = .003), and sSAT negatively (standardized β = -.300, P = .04) with hepatic fat content.

CONCLUSION

In men, dSAT is associated with hepatic steatosis and adverse metabolic traits, such as lower HDL cholesterol levels, whereas in women with obesity sSAT shows a beneficial relation with respect to hepatic fat content.

Pre-transplant morphometry by computed tomography scan and post-transplant dialysis risk in overweight or obese kidney transplant recipients

PURPOSE

Adipose distribution and sarcopenia could better assess kidney transplantation outcomes than body mass index (BMI) and have been poorly evaluated among obese and overweight recipients. We aimed to evaluate morphometric radiologic markers to predict post-operative dialysis within this population.

METHODS

We conducted a retrospective study including patients with a BMI > 25 kg/m² undergoing kidney transplantation during 5 years. Subcutaneous adipose tissue surface (SAT), visceral adipose tissue surface (VAT), and psoas surface were measured on CT scans sections. A model predictive of post-transplantation dialysis was elaborated through a multivariable logistic regression and was compared to a model including only BMI.

RESULTS

Overall, 248 patients were included whom mean (SD) BMI and age were, respectively, 29.7 kg/m2 (3.6) and 56 years (12.7). Of them, 83 (33.5%) needed dialysis: 14 (5.7%) for primary kidney failure and 69 (27.8%) for delayed kidney function. On multivariable analysis, SAT, VAT and deceased donor were significantly associated with post-operative dialysis (respectively, OR [95%CI]:1.6 [1.1-2.6], 1.6[1.1-2.6], and 7.5 [1.6-56]). The area under the curve of this predictive model was 0.70 versus 0.64 for a BMI-based model.

CONCLUSION

High VAT and SAT were associated with post-transplantation dialysis. A predictive model based on these morphometrics could provide a better appreciation of graft recovery after transplantation among obese and overweight recipients. External validation is needed.

Effects of Fasting and Feeding on Transcriptional and Posttranscriptional Regulation of Insulin-Degrading Enzyme in Mice

Insulin-degrading enzyme (IDE) is a highly conserved and ubiquitously expressed Zn²⁺-metallopeptidase that regulates hepatic insulin sensitivity, albeit its regulation in response to the fasting-to-postprandial transition is poorly understood. In this work, we studied the regulation of IDE mRNA and protein levels as well as its proteolytic activity in the liver, skeletal muscle, and kidneys under fasting (18 h) and refeeding (30 min and 3 h) conditions, in mice fed a standard (SD) or high-fat (HFD) diets. In the liver of mice fed an HFD, fasting reduced IDE protein levels (~30%); whereas refeeding increased its activity (~45%) in both mice fed an SD and HFD. Likewise, IDE protein levels were reduced in the skeletal muscle (~30%) of mice fed an HFD during the fasting state. Circulating lactate concentrations directly correlated with hepatic IDE activity and protein levels. Of note, L-lactate in liver lysates augmented IDE activity in a dose-dependent manner. Additionally, IDE protein levels in liver and muscle tissues, but not its activity, inversely correlated (R² = 0.3734 and 0.2951, respectively; p < 0.01) with a surrogate marker of insulin resistance (HOMA index). Finally, a multivariate analysis suggests that circulating insulin, glucose, non-esterified fatty acids, and lactate levels might be important in regulating IDE in liver and muscle tissues. Our results highlight that the nutritional regulation of IDE in liver and skeletal muscle is more complex than previously expected in mice, and that fasting/refeeding does not strongly influence the regulation of renal IDE.

White adipose tissue dysfunction in obesity and aging

Both obesity and aging are associated with the development of metabolic diseases such as type 2 diabetes and cardiovascular disease. Chronic low-grade inflammation of adipose tissue is one of the mechanisms implicated in the progression of these diseases. Obesity and aging trigger adipose tissue alterations that ultimately lead to a pro-inflammatory phenotype of the adipose tissue-resident immune cells. Obesity and aging also share other features such as a higher visceral vs. subcutaneous adipose tissue ratio and a decreased lifespan. Here, we review the common characteristics of obesity and aging and the alterations in white adipose tissue and resident immune cells. We focus on the adipose tissue metabolic derangements in obesity and aging such as inflammation and adipose tissue remodeling.

Liver-spleen axis in nonalcoholic fatty liver disease

Introduction: NAFLD is often under-diagnosed, even though rates of its co-morbidities such as obesity and type2 diabetes mellitus, prominent statuses of inflammation, are significantly high. The spleen-liver axis is gaining much credit in the last years like other well-known organ axes.Areas covered: PubMed/MEDLINE was searched for relevant articles related to concomitant occurrence of NAFLD and spleen. Areas covered in this review include: (1) updated findings of spleen dimensions at ultrasonography, (2) discussion of current data on pathophysiological connections between obesity-related NAFLD and increased volume of the spleen, and (3) analysis of current immune-mediated mechanisms characterizing the so.called chronic low-grade inflammation leading to insulin resistance.Expert opinion: The advances in explaining mechanisms underlying the spleen involvement in immune regulation, coupled with research about the role of spleen in NAFLD, could impact real world outcomes through establishing better tools for a precocious diagnosis. Using both liver and spleen ultrasonography, technique largely dealt with in this review, could expand the possibility to cover an adequate diagnostic path toward NAFLD, reaching a good sensibility and specificity.

Aging adipose: Depot location dictates age-associated expansion and dysfunction

Adipose tissue has a variety of diverse functions that maintain energy homeostasis. In conditions of excess energy availability, adipose tissue increases its lipid storage and communicates the nutritional abundance to various organs in the body. In conditions of energy depletion, such as fasting, cold exposure, or prolonged exercise, triglycerides stored in adipose tissue are released as free fatty acids to support the shift to catabolic metabolism. These diverse functions of storage, communication, and energy homeostasis are shared between numerous adipose depots including subcutaneous, visceral, brown, beige, intramuscular, marrow, and dermal adipose tissue. As organisms age, the cellular composition of these depots shifts to facilitate increased inflammatory cell infiltration, decreased vasculature, and increased adipocyte quantity and lipid droplet size. The purpose of this review is to give a comprehensive overview of the molecular and cellular changes that occur in various aged adipose depots and discuss their impact on physiology. The molecular signature of aged adipose leads to higher prevalence of metabolic disease in aged populations including type 2 diabetes, cardiovascular disease, Alzheimer's disease, and certain types of cancer.

100th anniversary of the discovery of insulin perspective: insulin and adipose tissue fatty acid metabolism

Insulin inhibits systemic nonesterified fatty acid (NEFA) flux to a greater degree than glucose or any other metabolite. This remarkable effect is mainly due to insulin-mediated inhibition of intracellular triglyceride (TG) lipolysis in adipose tissues and is essential to prevent diabetic ketoacidosis, but also to limit the potential lipotoxic effects of NEFA in lean tissues that contribute to the development of diabetes complications. Insulin also regulates adipose tissue fatty acid esterification, glycerol and TG synthesis, lipogenesis, and possibly oxidation, contributing to the trapping of dietary fatty acids in the postprandial state. Excess NEFA flux at a given insulin level has been used to define in vivo adipose tissue insulin resistance. Adipose tissue insulin resistance defined in this fashion has been associated with several dysmetabolic features and complications of diabetes, but the mechanistic significance of this concept is not fully understood. This review focusses on the in vivo regulation of adipose tissue fatty acid metabolism by insulin and the mechanistic significance of the current definition of adipose tissue insulin resistance. One hundred years after the discovery of insulin and despite decades of investigations, much is still to be understood about the multifaceted in vivo actions of this hormone on adipose tissue fatty acid metabolism.

Visceral Obesity, Metabolic Syndrome, and Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC) represents an exemplar of obesity-associated carcinogenesis, with a progressive increase in EAC risk with increased body mass index. In this context, there is increased focus on visceral adipose tissue and associated metabolic dysfunction, including hypertension, diabetes mellitus and hyperlipidemia, or combinations of these in the metabolic syndrome. Visceral obesity (VO) may promote EAC via both directly impacting on gastro-esophageal reflux disease and Barrett's esophagus, as well as via reflux-independent effects, involving adipokines, growth factors, insulin resistance, and the microbiome. In this review these pathways are explored, including the impact of VO on the tumor microenvironment, and on cancer outcomes. The current evidence-based literature regarding the role of dietary, lifestyle, pharmacologic and surgical interventions to modulate the risk of EAC is explored.

Anthropometric variables as mediators of the association of changes in diet and physical activity with inflammatory profile

BACKGROUND

Mechanisms underlying the associations of high levels of physical activity (PA) and adherence to the Mediterranean Diet (MedDiet) with a better inflammatory profile remain unclear. Our objective was to assess the mediating role of changes in body mass index (BMI) and waist circumference (WC), as markers of body fat in the association of changes in PA and adherence to the MedDiet, with changes in the inflammatory profile.

METHODS

This study included 489 adults, aged 55 to 75 years, from the PREDIMED-Plus multi-centre lifestyle intervention trial. An inflammatory score was calculated, based on 8 blood biomarkers: high-sensitivity C-reactive protein, interleukin 6, interleukin 8, interleukin 18, monocyte chemo-attractant protein-1, C-peptide, leptin, and regulated on activation, normal T-cell expressed and secreted chemokine (RANTES). Biomarkers, levels of PA, score of MedDiet adherence, BMI and WC were measured at baseline and at one-year follow-up. Linear regression models were fitted according to the Baron and Kenny framework for mediation analysis.

RESULTS

Changes in BMI and WC mediated the association of both changes in PA and changes in the MedDiet adherence with the inflammatory score. BMI mediated 26% of the association of changes in total PA with the inflammatory profile, and 27% of the association of changes in the MedDiet, while WC mediated 13% and 12% of these associations, respectively.

CONCLUSION

In older adults at high cardiovascular risk, increasing PA levels and adherence to a MedDiet during 1 year were associated with a lower inflammatory score, which was partly mediated by a reduction in body fat.

The Prognostic Impact of Body Composition for Locally Advanced Breast Cancer Patients Who Received Neoadjuvant Chemotherapy

Simple Summary

We aimed to determine the prognostic role of body composition in patients with breast cancer who received neoadjuvant chemotherapy. Previous studies suggested that body composition is a better indicator of breast cancer treatment outcome than body mass index. A comprehensive body composition analysis found that a low ratio of total visceral adipose tissue to subcutaneous adipose tissue was associated with shorter overall survival. This finding will lead to further investigation of the role of body composition in outcomes for patients with locally advanced breast cancer.

Abstract

Our previous study indicated that a high amount of visceral adipose tissue was associated with poor survival outcomes in patients with early breast cancer who received neoadjuvant chemotherapy. However, inconsistency was observed in the prognostic role of body composition in breast cancer treatment outcomes. In the present study, we aimed to validate our previous research by performing a comprehensive body composition analysis in patients with a standardized clinical background. We included 198 patients with stage III breast cancer who underwent neoadjuvant chemotherapy between January 2007 and June 2015. The impact of body composition on pathologic complete response and survival outcomes was determined. Body composition measurements had no significant effect on pathologic complete response. Survival analysis showed a low ratio of total visceral adipose tissue to subcutaneous adipose tissue (V/S ratio ≤ 34) was associated with shorter overall survival. A changepoint method determined that a V/S ratio cutoff of 34 maximized the difference in overall survival. Our study indicated the prognostic effect of body composition measurements in patients with locally advanced breast cancer compared to those with early breast cancer. Further investigation will be needed to clarify the biological mechanism underlying the association of V/S ratio with prognosis in locally advanced breast cancer.

Modulation of Insulin Sensitivity by Insulin-Degrading Enzyme

Insulin-degrading enzyme (IDE) is a highly conserved and ubiquitously expressed metalloprotease that degrades insulin and several other intermediate-size peptides. For many decades, IDE had been assumed to be involved primarily in hepatic insulin clearance, a key process that regulates availability of circulating insulin levels for peripheral tissues. Emerging evidence, however, suggests that IDE has several other important physiological functions relevant to glucose and insulin homeostasis, including the regulation of insulin secretion from pancreatic β-cells. Investigation of mice with tissue-specific genetic deletion of Ide in the liver and pancreatic β-cells (L-IDE-KO and B-IDE-KO mice, respectively) has revealed additional roles for IDE in the regulation of hepatic insulin action and sensitivity. In this review, we discuss current knowledge about IDE’s function as a regulator of insulin secretion and hepatic insulin sensitivity, both evaluating the classical view of IDE as an insulin protease and also exploring evidence for several non-proteolytic functions. Insulin proteostasis and insulin sensitivity have both been highlighted as targets controlling blood sugar levels in type 2 diabetes, so a clearer understanding the physiological functions of IDE in pancreas and liver could led to the development of novel therapeutics for the treatment of this disease.

Correlation of Waist to Calf Circumference Ratio and Carotid Intima-Media Thickness in Diabetes Mellitus

INTRODUCTION

Diabetes mellitus is a well-known risk factor for cardiovascular disease because of the accelerated process of atherosclerosis. Obesity is an established risk factor and has gained immense importance in recent studies as an important risk factor for clinical cardiovascular disease, yet the fundamental component stays unclear. Calf circumference is another form for lean mass and peripheral subcutaneous fat and is inversely associated with the occurrence of carotid plaques (CP). Multiplicative and opposite effects of both Calf Circumference (CC) and Waist Circumference (WC) in the event of CP suggest that the two measures should be taken into account commonly while assessing vascular risk profile.

AIMS & OBJECTIVES

To ascertain if waist to calf circumference ratio (WCR) is a marker of carotid atherosclerosis in patients with type 2 diabetes mellitus, and the correlation between waist to calf circumference ratio and carotid intima-media thickness (CIMT ) in patients with Type 2 diabetes.

MATERIALS AND METHODS

A cross-sectional study at Hospital affiliated to Kasturba Medical college Mangalore from Sept 2016 to Sept 2018. Patients with type 2 DM as per ADA criteria, age >18years, are recruited for the study.

RESULTS AND DISCUSSION

In our study, with 150 population, 25 patients had carotid atherosclerosis and 20 patients had CIMT>1.1. The waist circumference in patients with CA is in the range of 93.07, and 99.85 & the CC in patients with CA is in the range of 29.49 to 31.25. The WCR in patients with CA is in the range of 3.12 to 3.26. The difference was statistically significant with a p-value of <0.05. In our study, it was found that WC and WCR correlated well with carotid atherosclerosis, and surprisingly, calf circumference also correlated with carotid atherosclerosis but not as significant as both WC and WCR.

CONCLUSION

To conclude, in our population-based study of 150 subjects, we found that carotid atherosclerosis is significantly more in people with increased waist calf circumference ratio. WCR may be a new, useful, and practical anthropometric index that facilitates the early identification of diabetic subjects with high risk for cardiovascular disease. Validation of this finding in individual populations is required. Future studies should test the association of calf circumference with carotid intima-media thickness and carotid plaques using better measures than ultrasound, such as magnetic resonance imaging. Further research focusing on underlying mechanisms in the role of lean mass and peripheral fat mass is required.