scholarly journals The Role of Adipose Tissue in Insulin Resistance in Women of African Ancestry

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Julia H. Goedecke ◽  
Naomi S. Levitt ◽  
Juliet Evans ◽  
Nicole Ellman ◽  
David John Hume ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
White Women ◽  
African Ancestry ◽  
Fat Distribution ◽  
Future Research ◽  
Industrialized Countries ◽  
Tissue Biology ◽  
Ectopic Fat Deposition

Women of African ancestry, particularly those living in industrialized countries, experience a disproportionately higher prevalence of type 2 diabetes (T2D) compared to their white counterparts. Similarly, obesity and insulin resistance, which are major risk factors for T2D, are greater in black compared to white women. The exact mechanisms underlying these phenomena are not known. This paper will focus on the role of adipose tissue biology. Firstly, the characteristic body fat distribution of women of African ancestry will be discussed, followed by the depot-specific associations with insulin resistance. Factors involved in adipose tissue biology and their relation to insulin sensitivity will then be explored, including the role of sex hormones, glucocorticoid metabolism, lipolysis and adipogenesis, and their consequent effects on adipose tissue hypoxia, oxidative stress, and inflammation. Finally the role of ectopic fat deposition will be discussed. The paper proposes directions for future research, in particular highlighting the need for longitudinal and/or intervention studies to better understand the mechanisms underlying the high prevalence of insulin resistance and T2D in women of African ancestry.

scholarly journals The potential role of the adipokine HMGB1 in obesity and insulin resistance. Novel effects on adipose tissue biology

2021 ◽  
pp. 111417
Author(s):  
R. Guzmán-Ruiz ◽  
Tercero-Alcázar C. López-Alcalá J ◽  
J. Sánchez-Ceinos ◽  
Malagón Mm ◽  
Gordon A
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Potential Role ◽  
Tissue Biology

scholarly journals Contribution of Adipose Tissue Oxidative Stress to Obesity-Associated Diabetes Risk and Ethnic Differences: Focus on Women of African Ancestry

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 622
Author(s):  
Pamela A. Nono Nankam ◽  
Télesphore B. Nguelefack ◽  
Julia H. Goedecke ◽  
Matthias Blüher
Keyword(s):  
Oxidative Stress ◽  
Adipose Tissue ◽  
Metabolic Diseases ◽  
African Ancestry ◽  
Fat Distribution ◽  
African Women ◽  
European Ancestry ◽  
Whole Body ◽  
Redox Equilibrium ◽  
Systemic Oxidative Stress

Adipose tissue (AT) storage capacity is central in the maintenance of whole-body homeostasis, especially in obesity states. However, sustained nutrients overflow may dysregulate this function resulting in adipocytes hypertrophy, AT hypoxia, inflammation and oxidative stress. Systemic inflammation may also contribute to the disruption of AT redox equilibrium. AT and systemic oxidative stress have been involved in the development of obesity-associated insulin resistance (IR) and type 2 diabetes (T2D) through several mechanisms. Interestingly, fat accumulation, body fat distribution and the degree of how adiposity translates into cardio-metabolic diseases differ between ethnicities. Populations of African ancestry have a higher prevalence of obesity and higher T2D risk than populations of European ancestry, mainly driven by higher rates among African women. Considering the reported ethnic-specific differences in AT distribution and function and higher levels of systemic oxidative stress markers, oxidative stress is a potential contributor to the higher susceptibility for metabolic diseases in African women. This review summarizes existing evidence supporting this hypothesis while acknowledging a lack of data on AT oxidative stress in relation to IR in Africans, and the potential influence of other ethnicity-related modulators (e.g., genetic-environment interplay, socioeconomic factors) for consideration in future studies with different ethnicities.

scholarly journals Chemotactic cytokines, obesity and type 2 diabetes:in vivoandin vitroevidence for a possible causal correlation?

2009 ◽  
Vol 68 (4) ◽  
pp. 378-384 ◽  
Author(s):  
Henrike Sell ◽  
Jürgen Eckel
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Low Grade ◽  
Obese Patients ◽  
Tissue Mass ◽  
Tissue Biology ◽  
Wide Range ◽  
Adipose Tissue Mass

A strong causal link between increased adipose tissue mass and insulin resistance in tissues such as liver and skeletal muscle exists in obesity-related disorders such as type 2 diabetes. Increased adipose tissue mass in obese patients and patients with diabetes is associated with altered secretion of adipokines, which also includes chemotactic proteins. Adipose tissue releases a wide range of chemotactic proteins including many chemokines and chemerin, which are interesting targets for adipose tissue biology and for biomedical research in obesity and obesity-related diseases. This class of adipokines may be directly linked to a chronic state of low-grade inflammation and macrophage infiltration in adipose tissue, a concept intensively studied in adipose tissue biology in recent years. The inflammatory state of adipose tissue in obese patients may be the most important factor linking increased adipose tissue mass to insulin resistance. Furthermore, chemoattractant adipokines may play an important role in this situation, as many of these proteins possess biological activity beyond the recruitment of immune cells including effects on adipogenesis and glucose homeostasis in insulin-sensitive tissues. The present review provides a summary of experimental evidence of the role of adipose tissue-derived chemotactic cytokines and their function in insulin resistancein vivoandin vitro.

scholarly journals Adipose tissue inflammation and metabolic dysfunction: a clinical perspective

2013 ◽  
Vol 15 (1) ◽  
Author(s):  
Charmaine S. Tam ◽  
Leanne M. Redman
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Low Grade ◽  
Metabolic Dysfunction ◽  
Adipose Tissue Inflammation ◽  
Tissue Inflammation ◽  
Proinflammatory Mediators ◽  
Low Grade Inflammation

AbstractObesity is characterized by a state of chronic low-grade inflammation due to increased immune cells, specifically infiltrated macrophages into adipose tissue, which in turn secrete a range of proinflammatory mediators. This nonselective low-grade inflammation of adipose tissue is systemic in nature and can impair insulin signaling pathways, thus, increasing the risk of developing insulin resistance and type 2 diabetes. The aim of this review is to provide an update on clinical studies examining the role of adipose tissue in the development of obesity-associated complications in humans. We will discuss adipose tissue inflammation during different scenarios of energy imbalance and metabolic dysfunction including obesity and overfeeding, weight loss by calorie restriction or bariatric surgery, and conditions of insulin resistance (diabetes, polycystic ovarian syndrome).

Abstract 461: Role of Physical Training Intensity in Metabolic and Cardiovascular Dysfunctions in a Fructose Overload Model

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Jacqueline F Machi ◽  
Nathalia Bernardes ◽  
Danielle S Dias ◽  
Cristiano Mostarda ◽  
Edson Moreira ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Adipose Tissue ◽  
Maximum Speed ◽  
Normal Range ◽  
Maximal Exercise Test ◽  
Baroreceptor Sensitivity ◽  
Chronic Effects ◽  
Male Wistar Rats

This study evaluated the chronic effects of the run and walk in the metabolic and cardiovascular parameters of a metabolic syndrome experimental model. Male Wistar rats were divided into 4 groups(n=8): Control (C),Sedentary Fructose (SF), Fructose Run (FR) and Fructose Walk (FW, n= 8). Metabolic syndrome (MS) induction was performed with D-fructose in drinking water for 18 weeks. The exercise training was initiated after the nineth week of treatment with fructose and was held for 8 weeks (60 minutes/day, 5 times / week). The FW and FR were performed on a treadmill (1 h/day; 5 days/wk for 8 wk), with ∼20% and 60% intensities respectively of the maximum speed in a maximal exercise test. Plasma glucose, triglycerides, insulin resistance, adipose tissue, blood pressure, heart rate, baroreceptor sensitivity and sympathetic and parasympathetic tone, were evaluated at the end of protocol. The results showed that run and walking decreased the adipose tissue (FR: 2.97±0.2; FW: 4.26±0.9; SF: 6.49±0.6; C: 3.23±0.2 g). The glycemia values remained within the normal range,(FR: 86.7±2.3; WF: 91.0±1.4; SF: 70.2±1.9; C: 84±2.3 mg/dl), however only the FR group decreased the triglycerides levels (FR: 133±8.8; FW: 159±10.2; SF: 220±6.3; C: 96± 4.2 mg/dl), and the insulin resistance (FR: 4.37±0.1; FW: 3.55±0.2; SF: 2.79±0.3; C: 4.86±0.3 %/min). The FR group showed a reduction in mean arterial pressure (FR: 111±4.5, FW: 125±4.1; SF: 137±2.6, C: 113±1.5 mmHg) and increased of bradycardic (FR 1.76±0.08; FW 1.31±0.10; SF 1.37±0.10; C 1.72±0.14 bpm/mmHg) and tachycardic response to BP changes (FR 4.02±0.32; FW 2.56±0.16; SF 1.97±0.15; C (and C 3.25±0.37 bpm/mmHg). Finally we observed that only the FR group showed an increase of the vagal tone (FR: 72.3±8.1, FW: 47.3±6.7; FS: 40.3±4.6, C: 60.7±6.5 bpm). In conclusion, our results suggest that training walk (FW), a practice widely recommended, is especially effective for the treatment of metabolic disorders, whereas controlled exercise (FR) seems to encompass hemodynamic and metabolic aspects. This application is easy and within reach of the majority of the population, indicating that this practice should be encouraged and may be effective in managing cardiovascular risk in MS as start therapeutic. Sources of Funding:FAPESP.

scholarly journals Gormony zhirovoy tkani i funktsional'nayaaktivnost' shchitovidnoy zhelezy

2010 ◽  
Vol 7 (4) ◽  
pp. 8-11 ◽  
Author(s):  
N A Petunina ◽  
N E Al'tshuler ◽  
N G Rakova ◽  
L V Trukhina
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Lipid Metabolism ◽  
Subclinical Hypothyroidism ◽  
Thyroid Dysfunction ◽  
The Impact ◽  
The Relationship ◽  
Tissue Hormones

The review presents a recent data from the literature on the physiologic and pathophysiologic role of adipose tissue hormones (adiponectin, resistin, leptin). The article details the role of adipocytokines in atherogenesis. It also presents the results of studies depicting the relationship between subclinical hypothyroidism, lipid metabolism and insulin resistance as well as the impact of thyroid dysfunction upon the secretion of adipocytokines.

scholarly journals Protocatechuic acids protects against high glucose- induced insulin resistance in human visceral adipose tissue

2016 ◽  
Vol 62 (5) ◽  
pp. 45-46
Author(s):  
Paulina Ormazabal ◽  
Beatrice Scazzocchio ◽  
Rosaria Varì ◽  
Annunziata Iacovelli ◽  
Roberta Masella
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Visceral Adipose Tissue ◽  
High Glucose ◽  
Protective Role ◽  
Insulin Sensitizer ◽  
20 Nm ◽  
Visceral Adipose

Adipocytes exposed to high glucose concentrations exhibit impaired insulin signaling. Binding of insulin to its membrane receptor activates insulin metabolic pathway leading to IRS-1 and AKT phosphorylations. The accumulation of visceral adipose tissue (VAT) correlates with insulin resistance and metabolic syndrome. Anthocyanins (ACN) are bioactive food compounds of great nutritional interest. We have shown that protocatechuic acid (PCA), a major metabolite of ACN, might exert insulin-sensitizer activities in human visceral adipose tissue. The aim of this work was to define the protective role of PCA against insulin-resistance induced by high glucose in VAT.Methodology: VAT obtained from control subject (BMI≤25) were separated in four experimental groups: i) PCA: samples treated for 24 h with 100 μM PCA, ii) GLU: VAT treated with 30 mM glucose for 24 h, iii) PCA+GLU: 1 hour incubation with 100 μM PCA before adding glucose (30 mM, 24 h), iv) CTR: vehicle. After treatment, VAT groups were (or not) acutely stimulated with insulin (20 nM, 20 min). Tyr-IRS-1 and Ser-Akt phosphorylations were assessed by Western blotting (WB) in basal or insulin stimulated tissues in all experimental groups. Samples were assessed for IRS-1, IR, Akt and GLUT4 protein content by WB. Results: No differences in protein contents between experimental groups were found. GLU tissues showed a lower increment in insulin-stimulated phosphorylation of IRS-1 and Akt compared to CTR and PCA samples. This impaired activation was completely reversed by the pretreatment with PCA.Conclusion: An in-vitro insulin-resistance condition induced by high glucose was established in biopsies of VAT. PCA restores the ability of GLU-tissues to fully respond to insulin by increasing IRS-1 and Akt phosphorylations. These results confirm the insulin-sensitizer effect of PCA on VAT previously reported by our group. An anthocyanin rich diet might help to protect against insulin-resistance in VAT.

scholarly journals Osteopontin Expression in Human and Murine Obesity: Extensive Local Up-Regulation in Adipose Tissue but Minimal Systemic Alterations

Endocrinology ◽  
2007 ◽  
Vol 149 (3) ◽  
pp. 1350-1357 ◽  
Author(s):  
Florian W. Kiefer ◽  
Maximilian Zeyda ◽  
Jelena Todoric ◽  
Joakim Huber ◽  
René Geyeregger ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Plasma Concentrations ◽  
Morbidly Obese ◽  
Low Grade ◽  
Obese Patients ◽  
Multifunctional Protein ◽  
Inflammatory Processes ◽  
Low Grade Inflammation

Obesity is associated with a chronic low-grade inflammation characterized by macrophage infiltration of adipose tissue (AT) that may underlie the development of insulin resistance and type 2 diabetes. Osteopontin (OPN) is a multifunctional protein involved in various inflammatory processes, cell migration, and tissue remodeling. Because these processes occur in the AT of obese patients, we studied in detail the regulation of OPN expression in human and murine obesity. The study included 20 morbidly obese patients and 20 age- and sex-matched control subjects, as well as two models (diet-induced and genetic) of murine obesity. In high-fat diet-induced and genetically obese mice, OPN expression was drastically up-regulated in AT (40 and 80-fold, respectively) but remained largely unaltered in liver (<2-fold). Moreover, OPN plasma concentrations remained unchanged in both murine models of obesity, suggesting a particular local but not systemic importance for OPN. OPN expression was strongly elevated also in the AT of obese patients compared with lean subjects in both omental and sc AT. In addition, we detected three OPN isoforms to be expressed in human AT and, strikingly, an obesity induced alteration of the OPN isoform expression pattern. Analysis of AT cellular fractions revealed that OPN is exceptionally highly expressed in AT macrophages in humans and mice. Moreover, OPN expression in AT macrophages was strongly up-regulated by obesity. In conclusion, our data point toward a specific local role of OPN in obese AT. Therefore, OPN could be a critical regulator in obesity induced AT inflammation and insulin resistance.

Waisted: The Biology of Body Fat

2021 ◽  
Author(s):  
Nathan Denton
Keyword(s):  
Adipose Tissue ◽  
Body Fat ◽  
Fat Distribution ◽  
Passive Layer ◽  
Evidence Based ◽  
Physical And Mental Health ◽  
Tissue Biology ◽  
Adipose Tissue Dysfunction ◽  
Social Meanings ◽  
Practical Implications

Waisted outlines the fascinating and misunderstood biology of fat (i.e., adipose tissue). This controversial, much-maligned organ plays a crucial yet curiously overlooked role in the global obesity crisis currently wreaking havoc on the world’s healthcare systems and economies. Attaining a better appreciation of the biology of fat, its social meanings, and how these intersect is essential for improving the world’s physical and mental health. Far from being a passive layer of blubber under the skin, fat plays a highly dynamic role in energy metabolism, reproductive health, and immunity, with these links having ancient origins in the evolution of modern humanity. Waisted provides a comprehensive, evidence-based perspective on the biology of fat and its crucial role in human evolution, health, disease, and society. Waisted draws upon biomedical, epidemiological, and evolutionary research to understand adipose tissue biology and the striking relationship between body fat distribution and health outcomes. Waisted demonstrates the practical implications of key conceptual points through relatable real-world cases and highlights how seemingly disparate common and rare diseases may be underpinned by adipose tissue dysfunction. Overall, Waisted covers a wide breadth of material that challenges and reframes the generally negative perspective of fat to highlight the underappreciated importance of adipose tissue biology in humans.

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