Metabolic Complications Of Obesity Research Articles

The evolutionary conserved miR-137/325 tandem mediates obesity-induced hypogonadism and metabolic comorbidities by repressing hypothalamic kisspeptin

BackgroundObesity-induced hypogonadism (OIH) is a prevalent, but often neglected condition in men, which aggravates the metabolic complications of overweight. While hypothalamic suppression of Kiss1-encoded kisspeptin has been suggested to contribute to OIH, the molecular mechanisms for such repression in obesity, and the therapeutic implications thereof, remain unknown. MethodsA combination of bioinformatic, expression and functional analyses was implemented, assessing the role of the evolutionary-conserved miRNAs, miR-137 and miR-325, in mediating obesity-induced suppression of hypothalamic kisspeptin, as putative mechanism of central hypogonadism and metabolic comorbidities. The implications of such miR-137/325-kisspeptin interplay for therapeutic intervention in obesity were also explored using preclinical OIH models. ResultsMiR-137/325 repressed human KISS1 3’-UTR in-vitro and inhibited hypothalamic kisspeptin content in male rats, while miR-137/325 expression was up-regulated, and Kiss1/kisspeptin decreased, in the medio-basal hypothalamus of obese rats. Selective over-expression of miR-137 in Kiss1 neurons reduced Kiss1/ kisspeptin and partially replicated reproductive and metabolic alterations of OIH in lean mice. Conversely, interference of the repressive actions of miR-137/325 selectively on Kiss1 3’-UTR in vivo, using target-site blockers (TSB), enhanced kisspeptin content and reversed central hypogonadism in obese rats, together with improvement of glucose intolerance, insulin resistance and cardiovascular and inflammatory markers, despite persistent exposure to obesogenic diet. Reversal of OIH by TSB miR-137/325 was more effective than chronic kisspeptin or testosterone treatments in obese rats. ConclusionsOur data disclose that the miR-137/325-Kisspeptin repressive interaction is a major player in the pathogenesis of obesity-induced hypogonadism and a putative druggable target for improved management of this condition and its metabolic comorbidities in men suffering obesity. Significance statementUp to half of the men suffering obesity display also central hypogonadism, an often neglected complication of overweight that can aggravate the clinical course of obesity and its complications. The mechanisms for such obesity-induced hypogonadism remain poorly defined. We show here that the evolutionary conserved miR137/miR325 tandem centrally mediates obesity-induced hypogonadism via repression of the reproductive-stimulatory signal, kisspeptin; this may represent an amenable druggable target for improved management of hypogonadism and other metabolic complications of obesity.

Fat-associated lymphoid clusters: Supporting visceral adipose tissue B cell function in immunity and metabolism.

It is now widely understood that visceral adipose tissue (VAT) is a highly active and dynamic organ, with many functions beyond lipid accumulation and storage. In this review, we discuss the immunological role of this tissue, underpinned by the presence of fat-associated lymphoid clusters (FALCs). FALC's distinctive structure and stromal cell composition support a very different immune cell mix to that found in classical secondary lymphoid organs, which underlies their unique functions of filtration, surveillance, innate-like immune responses, and adaptive immunity within the serous cavities. FALCs are important B cell hubs providing B1 cell-mediated frontline protection against infection and supporting B2 cell-adaptative immune responses. Beyond these beneficial immune responses orchestrated by FALCs, immune cells within VAT play important homeostatic role. Dysregulation of immune cells during obesity and aging leads to chronic pathological "metabolic inflammation", which contributes to the development of cardiometabolic diseases. Here, we examine the emerging and complex functions of B cells in VAT homeostasis and the metabolic complications of obesity, highlighting the potential role that FALCs play and emphasize the areas where further research is needed.

Predictive factors of Cardiovascular and metabolic complications of obesity:About 502 cases

Predictive factors of Cardiovascular and metabolic complications of obesity:About 502 cases

Adipomyokines in children with obesity

Adipomyokines are synthesized and secreted into the bloodstream by cells of both muscle and adipose tissue. They can have both a negative metabolic effect, acting as pro-inflammatory adipokines in obesity, and a positive one, increasing in response to physical exertion in the form of myokines. To study the features of adipocytokine secretion in children with constitutionally exogenous obesity. The study included 80 patients: 60 adolescents aged 15 [13; 16] years with constitutionally exogenous obesity SDS BMI: 3.0 [2.6; 3.3] and 20 control group children aged 16 [15; 17] years without excess weight SDS BMI: -0.3 [-1.25; 0.33]. Commercial enzyme immunoassay kits were used to determine the level of adipomyokines. The compositional composition of the body was evaluated by bioimpedance analysis (InBody 770 analyzer, South Korea) in the morning, on an empty stomach. Statistical processing was carried out using STATISTICA v.12.0 (StatSoft Inc., USA). The results are presented in the form of median (Me) and quartiles (Q1; Q3) corresponding to 25 and 75 percentiles. The critical significance level (p) was assumed to be <0.05. Levels of IL-6 and irisin are statistically significantly higher in obese adolescents compared to the control group: 0.55 [0.226; 1.35] pg/ml vs 0.202 [0.128; 0.652] pg/ml (p=0.041) and 11.16 [6.6; 22.76] mcg/ml vs 7.36 [6.48; 9.68] mcg/ml (p=0.043), respectively. Concentrations of IL-6, myostatin and decorin increase with an increase in the degree of obesity: grade I vs III: 0.226 [0.224; 0.398] vs 0.80 [0.36; 1.81] pg/ml (p=0,0197), 25,85 [21,53; 28,23] vs 31.41 [24.36; 35.06] ng/ml (p=0.03), 4065.3 [3244.9; 5245.5] vs 5322.5 [4199.8; 7702.4] pg/ml (p=0.0376), respectively. In obese children, IL-6 levels positively correlate with BMI, SDS BMI and the amount of adipose tissue, and myostatin - with BMI and SDS BMI. The concentration of irisin in the blood serum is significantly higher in obese girls than in obese boys and healthy girls. Obese patients, compared with lean peers, are characterized by a statistically significantly higher content of both fat and lean mass. With the progression of obesity, there is a statistically significant increase in the ratio of fat to lean mass (I degree - 0.66 [0.56; 0.7], III - 0.78 [0.68; 0.98] (p=0.0073). Patients with obesity and normal body weight have different levels of adipomyokines. An increase in the level of IL-6 with the progression of obesity is directly related to an increase in the content of adipose tissue. Further study of the features of adipocytokine secretion, their relationship with the features of the body composition and metabolic complications in obesity is required.

Sex-specific association between adipose tissue inflammation and vascular and metabolic complications of obesity.

Adipose tissue (AT) inflammation predisposes to insulin resistance and metabolic syndrome in obesity. To investigate the association between adipocyte size, AT inflammation, systemic inflammation, and metabolic and atherosclerotic complications of obesity in a sex-specific manner. Cross-sectional cohort study. University hospital in the Netherlands. 302 adult subjects with a BMI ≥ 27 kg/m2. We obtained subcutaneous abdominal fat biopsies and systematically assessed, in a sex-specific manner, associations of several parameters of AT inflammation (including adipocyte size, macrophage content, crown like structures (CLS), and gene expression) to biomarkers of systemic inflammation, leukocyte number and function, and to the presence of metabolic syndrome, insulin resistance, and carotid atherosclerotic plaques, assessed with ultrasound. Adipocyte size was associated with metabolic syndrome and AT macrophage content with insulin resistance. In contrast, none of the AT parameters were associated with carotid atherosclerosis, although mRNA expression of the anti-inflammatory IL-37 was associated with a lower intima-media thickness. We revealed profound sex-specific differences, with an association between BMI and adipocyte size, and between adipocyte size and metabolic syndrome only in men. Also, only men showed an association between adipocyte size, AT expression of leptin and MCP-1, and AT macrophage numbers), and between AT inflammation (CLS number) and several circulating inflammatory proteins, including hsCRP, and IL-6. Inflammation in abdominal subcutaneous adipose tissue is more related to the metabolic than the atherosclerotic complications of obesity, and there are profound sex-specific differences in the association between BMI, adipocyte size, AT inflammation, and systemic inflammation, which are much stronger in men than women.

Omega-3 to omega-6 fatty acid oxidation ratio as a novel inflammation resolution marker for metabolic complications in obesity

Background and aimsThe oxidative metabolism of polyunsaturated fatty acids (PUFAs) leads to bioactive isoprostanoids. The aim was to establish the associations of a complete urinary isoprostanoid profiling in a cohort study of carefully phenotyped obese subjects to determine possible potential differential implications for omega-6 PUFA- and omega-3 PUFA-derived isoprostanoids for obesity, metabolic indicators, and inflammation. Methods and resultsPUFA peroxidation compounds were determined in urine samples from obese human subjects (n = 46) by liquid chromatography coupled to tandem mass spectrometry. Increased omega-6 arachidonic acid (AA) oxidation, mainly represented by 5-F2c isoprostane (5-F2c-IsoP) and metabolites of 15-F2t-IsoP, was associated with body mass index, glycated hemoglobin (HbA1c) and mean arterial blood pressure. In addition, we identified the omega-3 PUFA-derived urinary metabolites 14-F4t-NeuroP from docosahexaenoic acid (DHA) and 5-F3t-IsoP from eicosapentaenoic acid (EPA), which declined with age. The omega-3 to omega-6 oxidation ratio was a significant predictor of inflammation in obesity. ConclusionThe findings point to full urinary isoprostanoid profiling as a more sensitive measure of PUFA oxidative stress in obesity-induced metabolic complications compared with individual isoprostanoid measures. Furthermore, the results suggest the balance between the omega-3 and omega-6 PUFA oxidation as determinative for the consequences of oxidative stress on inflammation in obesity.

Gene Expression Profiling of Peripheral Blood Mononuclear Cells in Type 2 Diabetes: An Exploratory Study.

Background and Objectives: Visceral obesity is associated with chronic low-grade inflammation that predisposes to metabolic syndrome. Indeed, infiltration of adipose tissue with immune-inflammatory cells, including 'classical' inflammatory M1 and anti-inflammatory 'alternative' M2 macrophages, causes the release of a variety of bioactive molecules, resulting in the metabolic complications of obesity. This study examined the relative expression of macrophage phenotypic surface markers, cholesterol efflux proteins, scavenger receptors, and adenosine receptors in human circulating peripheral blood mononuclear cells (PBMCs), isolated from patients with type 2 diabetes mellitus (T2DM), with the aim to phenotypically characterize and identify biomarkers for these ill-defined cells. Materials and Methodology: PBMCs were isolated from four groups of adults: Normal-weight non-diabetic, obese non-diabetic, newly diagnosed with T2DM, and T2DM on metformin. The mRNA expression levels of macrophage phenotypic surface markers (interleukin-12 (IL-12), C-X-C motif chemokine ligand 10 (CXCL10), C-C motif chemokine ligand 17 (CCL17), and C-C motif receptor 7 (CCR7)), cholesterol efflux proteins (ATP-binding cassette transporter-1 (ABCA1), ATP binding cassette subfamily G member 1 (ABCG1), and sterol 27-hydroxylase (CYP27A)), scavenger receptors (scavenger receptor-A (SR-A), C-X-C motif ligand 16 (CXCL16), and lectin-like oxidized LDL receptor-1 (LOX-1)), and adenosine receptors (adenosine A2A receptor (A2AR) and adenosine A3 receptor (A3R)) were measured using qRT-PCR. Results: In PBMCs from T2DM patients, the expression of IL-12, CCR7, ABCA1, and SR-A1 was increased, whereas the expression of CXCL10, CCL17, ABCG1,27-hydroxylase, LOX-1, A2AR and A3R was decreased. On the other hand, treatment with the antidiabetic drug, metformin, reduced the expression of IL-12 and increased the expression of 27-hydroxylase, LOX-1, CXCL16 and A2AR. Conclusions: PBMCs in the circulation of patients with T2DM express phenotypic markers that are different from those typically present in adipose tissue M1 and M2 macrophages and could be representative of metabolically activated macrophages (MMe)-like cells. Our findings suggest that metformin alters phenotypic markers of MMe-like cells in circulation.

Novel plasma exosome biomarkers for prostate cancer progression in co-morbid metabolic disease

Comorbid Type 2 diabetes (T2D), a metabolic complication of obesity, associates with worse cancer outcomes for prostate, breast, head and neck, colorectal and several other solid tumors. However, the molecular mechanisms remain poorly understood. Emerging evidence shows that exosomes carry miRNAs in blood that encode the metabolic status of originating tissues and deliver their cargo to target tissues to modulate expression of critical genes. Exosomal communication potentially connects abnormal metabolism to cancer progression. Here, we hypothesized that T2D plasma exosomes induce epithelial-mesenchymal transition (EMT) and immune checkpoints in prostate cancer cells. We demonstrate that plasma exosomes from subjects with T2D induce EMT features in prostate cancer cells and upregulate the checkpoint genes CD274 and CD155. We demonstrate that specific exosomal miRNAs that are differentially abundant in plasma of T2D adults compared to nondiabetic controls (miR374a-5p, miR-93-5p and let-7b-3p) are delivered to cancer cells, thereby regulating critical target genes. We build on our previous reports showing BRD4 controls migration and dissemination of castration-resistant prostate cancer, and transcription of key EMT genes, to show that T2D exosomes require BRD4 to drive EMT and immune ligand expression. We validate our findings with gene set enrichment analysis of human prostate tumor tissue in TGCA genomic data. These results suggest novel, non-invasive approaches to evaluate and potentially block progression of prostate and other cancers in patients with comorbid T2D.

1393-P: Cardiac and Skeletal Muscles Exhibit Discordant Flux Adaptations as a Result of Western Diet–Induced Obesity

The metabolic complications of obesity are distributed throughout the body, yet studies assessing its impact on metabolic fluxes have primarily focused on single tissues. Here we use a 13C tracer approach to simultaneously quantify metabolic flux dysregulation in the liver, skeletal muscle, and heart induced by Western diet (WD) feeding in a mouse model of obesity. Male wildtype (WT) and Mc4r-/- mice (KO) were fed chow until 8wks of age, when ∼50% of the KO cohort transitioned to WD (KO+WD) for 8wks. KO and KO+WD had increased adiposity, hepatic steatosis, HOMA-IR, and reduced glucose tolerance relative to WT by 16wks of age; however, only KO+WD had extensive liver fibrosis. Stable- and radio-labeled isotopes were infused and blood was sampled from fasted, conscious, and unrestrained mice (n ≥ 6 per group) through jugular vein and carotid artery catheters, respectively. Metabolic fluxes were estimated by fitting an integrated mathematical model of liver, skeletal muscle, and cardiac metabolism to 13C enrichment measurements of plasma and tissue metabolites taken at the end of the infusion. Endogenous glucose production was elevated in both KO cohorts, with WD further increasing hepatic gluconeogenic and citric acid cycle (CAC) fluxes. Glycolytic, anaplerotic, and CAC fluxes were lower in the skeletal muscle of KO and KO+WD compared to WT, which coincided with a decrease and increase in gene expression of glycolytic and β-oxidation enzymes, respectively. In the heart, however, WD feeding increased glycolytic and CAC fluxes as well as the gene expression of glycolytic and β-oxidation enzymes. Thus, cardiac and skeletal muscles exhibit discordant flux adaptations in obese, WD-fed mice, as WD accelerates aerobic glycolysis and terminal oxidation in the heart but not skeletal muscle. We expect the multi-organ fluxomics platform described here to broadly benefit research to understand systemic metabolism in health and disease. Disclosure C.M.Hasenour: Employee; Eli Lilly and Company. M.Rahim: None. T.Bednarski: None. D.R.Banerjee: None. J.Young: Consultant; Pfizer Inc., Research Support; Merck & Co., Inc., Stock/Shareholder; Metalytics, Inc. Funding National Institutes of Health (R01DK106348, U01CA235508, T32DK101003)

Τhe effects of weight loss on the metabolic complications of obesity

Τhe effects of weight loss on the metabolic complications of obesity

Ocular manifestations of Obesity: Beyond what meets the eye.

Obesity has reached pandemic proportions across the globe. Though much literature is available on the metabolic complications of obesity, their ocular associations are underreported. Visual impairment further contributes to the poor health related quality of life in individuals living with obesity. In this manuscript, the authors have highlighted the key ocular manifestations that have been associated with obesity, the evidence that supports their association and the impact of weight loss on these co-morbidities. Obesity has often been negatively associated with visual acuity. Premature cataract, glaucoma and age-related maculopathy have also been shown to have a strong association with obesity. Furthermore, presence of associated cardiometabolic disorders linked with metabolic syndrome may also have an indirect impact on the eye. Conditions like diabetic and hypertensive retinopathy, have commonly been described in people living with obesity. Given the huge public health impact of obesity, this manuscript highlights the unmet need of comprehensive research on the association of eye disorders and obesity in the South Asian region.

Wogonin Ameliorates Neuronal Injury Induced by Obesity Via Inactivation of the Mitogen Activated Protein Kinase Pathway

Metabolic syndromes and type 2 diabetes mellitus are major metabolic complications of obesity. These metabolic complications are implicated in the pathogenesis of Alzheimer’s disease, vascular dementia, and mild cognitive impairment. Wogonin protects against ischemia-induced neurodegeneration, exerts neuroprotective effect against amyloid betainduced toxicity, and ameliorates cognitive dysfunction. However, the role of wogonin in obesity associated neuronal injury and a cognitive change has not yet been examined. To this end, using a high fat diet induced obese mouse model, we have examined the effect of wogonin on cognitive function, neuronal apoptosis, markers of inflammation, and mitogen activated protein kinase pathway. High fat diet induced obesity impaired spatial recognition memory, upregulated expression of proinflammatory cytokines, and neuronal apoptosis through downregulation of B-cell lymphoma 2 protein and upregulation of Bcl-2-associated X protein, cleaved caspase-3, and cleaved caspase-9. These obesity-associated changes were ameliorated by wogonin treatment. Lastly, the high fat diet upregulated expression of phospho-extracellular signal-regulated kinase 1/2, phospho-stress stimulated kinase, and phospho-c-Jun NH2-terminal kinase was reversed by wogonin administration. In conclusion, wogonin exerts antiapoptotic and anti-inflammatory effects against high fat diet induced cognitive impairment through inactivation of the mitogen activated protein kinase pathway.

Nocturnal non-dipping on 24-h Ambulatory Blood Pressure Monitoring in children and adolescents with obesity is associated with higher total cholesterol levels

ABSTRACT Background Few studies indicate the occurrence of abnormal nocturnal dipping of blood pressure (BP) in 35–50% of children and adolescents with obesity. The relation between that phenomenon and metabolic complications of obesity remains unclear. To evaluate the association between disorders of glucose and lipid metabolism, and nocturnal non-dipping in pediatric patients with obesity. Methods In 207 children (53.14% girls, mean age 14 (range 2–17), mean BMI Z-SCORE 4.38, range 2.07–10.74) standard 24-h Ambulatory Blood Pressure Monitoring was performed. Normal dipping was defined as a ≥ 10% decline in BP during the night. Results There were 106 (51.21%) cases of non-dippers. The mean 24-h nocturnal systolic BP (SBP) reduction (%) was 9.9 ± 5.5. The mean 24-h nocturnal diastolic BP (DBP) reduction (%) was 15.8 ± 8.5. There was a significant correlation between BMI Z-SCORE and mean day-time SBP (r = 0.14 P = .042). There are positive correlations between 24-h heart rate (beats/min) and BMI Z-SCORE (r = 0.15, P = .027), between fasting glucose and systolic BP Z-SCORE (r = 0.17, P = .03) and between mean diastolic BP and LDL cholesterol (r = 0.23, P = .004). Total cholesterol level was significantly higher in non-dippers (4.34 vs. 3.99 mmol/L, P = .034). There were no significant differences between non-dippers and dippers regarding fasting glucose (4.6 vs. 4.8 mmol/L), 120ʹpost load glucose (5.7 vs. 5.9 mmol/L), insulin (19 vs. 20.2 µIU/mL), HOMA-IR (2.36 vs. 2.44), LDL cholesterol (2.64 vs. 2.51 mmol/L), HDL cholesterol (1.06 vs. 1.03 mmol/L) or triglycerides (1.36 vs. 1.34 mmol/L) levels. Conclusion Nocturnal non-dipping is frequent in pediatric patients with obesity. It is associated with higher total cholesterol levels.

Mild intermittent hypoxia exposure induces metabolic and molecular adaptations in men with obesity

ObjectiveRecent studies suggest that hypoxia exposure may improve glucose homeostasis, but well-controlled human studies are lacking. We hypothesized that mild intermittent hypoxia (MIH) exposure decreases tissue oxygen partial pressure (pO2) and induces metabolic improvements in people who are overweight/obese. MethodsIn a randomized, controlled, single-blind crossover study, 12 men who were overweight/obese were exposed to MIH (15 % O2, 3 × 2 h/day) or normoxia (21 % O2) for 7 consecutive days. Adipose tissue (AT) and skeletal muscle (SM) pO2, fasting/postprandial substrate metabolism, tissue-specific insulin sensitivity, SM oxidative capacity, and AT and SM gene/protein expression were determined. Furthermore, primary human myotubes and adipocytes were exposed to oxygen levels mimicking the hypoxic and normoxic AT and SM microenvironments. ResultsMIH decreased systemic oxygen saturation (92.0 ± 0.5 % vs 97.1 ± 0.3, p < 0.001, respectively), AT pO2 (21.0 ± 2.3 vs 36.5 ± 1.5 mmHg, p < 0.001, respectively), and SM pO2 (9.5 ± 2.2 vs 15.4 ± 2.4 mmHg, p = 0.002, respectively) compared to normoxia. In addition, MIH increased glycolytic metabolism compared to normoxia, reflected by enhanced fasting and postprandial carbohydrate oxidation (pAUC = 0.002) and elevated plasma lactate concentrations (pAUC = 0.005). Mechanistically, hypoxia exposure increased insulin-independent glucose uptake compared to standard laboratory conditions (~50 %, p < 0.001) and physiological normoxia (~25 %, p = 0.019) through AMP-activated protein kinase in primary human myotubes but not in primary human adipocytes. MIH upregulated inflammatory/metabolic pathways and downregulated extracellular matrix-related pathways in AT but did not alter systemic inflammatory markers and SM oxidative capacity. MIH exposure did not induce significant alterations in AT (p = 0.120), hepatic (p = 0.132) and SM (p = 0.722) insulin sensitivity. ConclusionsOur findings demonstrate for the first time that 7-day MIH reduces AT and SM pO2, evokes a shift toward glycolytic metabolism, and induces adaptations in AT and SM but does not induce alterations in tissue-specific insulin sensitivity in men who are overweight/obese. Future studies are needed to investigate further whether oxygen signaling is a promising target to mitigate metabolic complications in obesity. Clinical trial registrationThis study is registered at the Netherlands Trial Register (NL7120/NTR7325).

Normalizing glucose levels reconfigures the mammary tumor immune and metabolic microenvironment and decreases metastatic seeding.

Obesity and diabetes cumulatively create a distinct systemic metabolic pathophysiological syndrome that predisposes patients to several diseases including breast cancer. Moreover, diabetic and obese women with breast cancer show a significant increase in mortality compared to non-obese and/or non-diabetic women. We hypothesized that these metabolic conditions incite an aggressive tumor phenotype by way of impacting tumor cell-autonomous and tumor cell non-autonomous events. In this study, we established a type 2 diabetic mouse model of triple-negative mammary carcinoma and investigated the effect of a glucose lowering therapy, metformin, on the overall tumor characteristics and immune/metabolic microenvironment. Diabetic mice exhibited larger mammary tumors that had increased adiposity with high levels of O-GlcNAc protein post-translational modification. These tumors also presented with a distinct stromal profile characterized by altered collagen architecture, increased infiltration by tumor-permissive M2 macrophages, and early metastatic seeding compared to non-diabetic/lean mice. Metformin treatment of the diabetic/obese mice effectively normalized glucose levels, reconfigured the mammary tumor milieu, and decreased metastatic seeding. Our results highlight the impact of two metabolic complications of obesity and diabetes on tumor cell attributes and showcase metformin's ability to revert tumor cell and stromal changes induced by an obese and diabetic host environment.

The 24-hour average concentration of cortisol is elevated in obese African-American youth with type 2 diabetes.

24-h average (IC) plasma concentrations of cortisol and growth hormone are lower in obese youth and adults without Type 2 diabetes (T2D) compared to lean subjects. Here we examined IC-cortisol and IC-growth hormone levels in obese youth with and without T2D. We pooled ½-hourly samples from 20 to 24-hour sampling to create an IC for cortisol, cortisone, C-peptide, insulin, growth hormone and cortisol-binding-globulin in obese African-American youth with (n = 8) and without T2D (N = 9). Analytes were assayed by standard methods. The groups were similar in age and sex, all participants had BMI% ≥94. T2D patients had slightly lower BMI z-score (2.25 ± 0.36 versus 2.58 ± 0.16, p = 0.0429). IC-cortisol (5.70 ± 1.8 μg/dl vs 4.18 ± 1.07 μg/dl, p = 0.0481) was higher and IC-C-peptide (2.33 ± 0.89 ng/ml vs 4.36 ± 1.12 ng/ml, p = 0.001) lower in T2D. There were no differences in cortisone/cortisol or for other analytes between groups. IC-cortisol was correlated with IC-cortisone (r = 0.46, p = 0.0471) but not with ICs of insulin, C-peptide, cortisol-binding-globulin, or growth hormone. IC-cortisol levels are higher and IC-C-peptide lower in obese African-American youth with T2D. Higher levels of IC-cortisol in obese youth with T2D may indicate a change in hypothalamic-pituitary-adrenal regulation which may exacerbate hyperglycemia and other metabolic complications of obesity.

Differences in the vascular and metabolic profiles between metabolically healthy and unhealthy obesity

Individuals suffering from severe obesity but not presenting the typical metabolic alterations, are included in a subclass of obesity defined Metabolically Healthy Obesity (MHO). The physiological factors underlying what seems a protective and favourable metabolic profile remain unclear. MHO individuals are more insulin-sensitive, have relatively lower visceral/ectopic fat accumulation and reduced levels of chronic low-grade inflammation, compared to obese subjects with co-morbidities. The study of MHO subjects represents a great opportunity for the recognition of the mechanisms that lead to the vascular and metabolic complications in obesity. Finding the differences among the metabolic profile of visceral adipose tissue between metabolically healthy and unhealthy obesity may lead to future personalized and stratified therapies.This review article summarizes the pathomechanisms and metabolic changes in MHO and metabolically unhealthy obesity (MUO), reviews clinical studies on the subject, and discusses preventive and therapeutic options.

Milk thistle seed cold press oil attenuates markers of the metabolic syndrome in a mouse model of dietary-induced obesity.

Milk thistle cold press oil (MTO) is an herbal remedy derived from Silybum marianum which contains a low level of silymarin and mixture of polyphenols and flavonoids. The effect of MTO on the cardiovascular and metabolic complications of obesity was studied in mice that were fed a high-fat diet (HFD) for 20weeks and treated with MTO for the final 8weeks of the diet. MTO treatment attenuated HFD-induced obesity, fasting hyperglycemia, hypertension, and induced markers of mitochondrial fusion and browning of white adipose. Markers of inflammation were also attenuated in both adipose and the liver of MTO-treated mice. In addition, MTO resulted in the improvement of liver fibrosis. These results demonstrate that MTO has beneficial actions to attenuate dietary obesity-induced weight gain, hyperglycemia, hypertension, inflammation, and suggest that MTO supplementation may prove beneficial to patients exhibiting symptoms of metabolic syndrome. PRACTICAL APPLICATIONS: Natural supplements are increasingly being considered as potential therapies for many chronic cardiovascular and metabolic diseases. Milk thistle cold press oil (MTO) is derived from Silybum marianum which is used as a dietary supplement in different parts of the world. The results of the present study demonstrate that MTO supplementation normalizes several metabolic and cardiovascular complications arising from dietary-induced obesity. MTO supplementation also had anti-inflammatory actions in the adipose as well as the liver. These results suggest that supplementation of MTO into the diet of obese individuals may afford protection against the worsening of cardiovascular and metabolic disease and improve inflammation and liver fibrosis.

Brown Adipose Expansion and Remission of Glycemic Dysfunction in Obese SM/J Mice

SUMMARYWe leverage the SM/J mouse to understand glycemic control in obesity. High-fat-fed SM/J mice initially develop poor glucose homeostasis relative to controls. Strikingly, their glycemic dysfunction resolves by 30 weeks of age despite persistent obesity. The mice dramatically expand their brown adipose depots as they resolve glycemic dysfunction. This occurs naturally and spontaneously on a high-fat diet, with no temperature or genetic manipulation. Removal of the brown adipose depot impairs insulin sensitivity, indicating that the expanded tissue is functioning as an insulin-stimulated glucose sink. We describe morphological, physiological, and transcriptomic changes that occur during the brown adipose expansion and remission of glycemic dysfunction, and focus on Sfrp1 (secreted frizzled-related protein 1) as a compelling candidate that may underlie this phenomenon. Understanding how the expanded brown adipose contributes to glycemic control in SM/J mice will open the door for innovative therapies aimed at improving metabolic complications in obesity.

MORPHOLOGY OF HUMAN ADIPOSE TISSUE

The risk of developing metabolic complications in obesity depends on the topography of excess adipose tissue. Adipose tissue is the main source of energy and also performs an endocrine function secreting substances that affect the sensitivity of tissues to insulin. The article describes the characteristics of histological preparations of adipose tissue samples taken from the omentum of middle-aged human cadavers with no confirmed diseases of the digestive system and of subcutaneous adipose tissue samples from interscapular region in the human dead foetuses. Microscopy of sections of adipose tissue from the omentum and subcutaneous adipose tissue from the interscapular region of the foetus revealed that it consisted of lobes and microvessels. Lobes of adipose tissue of a human large omentum consist of polygonal white adipocytes containing in their cytoplasm a nucleus displaced to the periphery and a fat drop. The subcutaneous adipose tissue taken from the interscapular region of the foetus consists of brown adipocytes with a nucleus located in the centre of the cytoplasm and surrounded by numerous fat droplets. Brown adipocytes when compared with white adipocyted are smaller and rounded in shape. Brown adipose tissue predominates in women than in men. Brown adipose tissue is not active all the time, but only at low ambient temperatures. In women, brown adipocytes are more saturated with mitochondria than in men. Adipose tissue of a human omentum can be a source of graft implant for restoring abdominal organ defects during extensive surgical operations.