Obesity, hypertension and insulin resistance

Revista da Associação Médica Brasileira, 2015

Objectives: the conditions of obesity and overweight pose a major risk for a number of comorbidities, including clinical syndromes resulting from atherosclerotic disease. Recent studies strongly indicate that adipose tissue is an active endocrine organ that secretes bioactive factors such as adipokines. Adiponectin appears to have a regulatory role in the mechanism of insulin resistance and in the development of atherosclerosis. This systematic review aims to evaluate the anti-atherogenic effects of adiponectin and its properties to improve and mimic metabolic and vascular actions of insulin and its influence on endothelial function. Methods: a qualitative, exploratory and literature review was performed in the PubMed, Portal Capes and Scielo databases using as key-words "adiponectin", "obesity", "insulin resistance", "anti-inflammatory", "therapeutic strategies" and "future prospects". Results: evidence suggests that adipo...

Clinica Chimica Acta, 2013

Adipose tissue is a major source of energy for the human body. It is also a source of major adipocytokines 23 adiponectin and leptin. Insulin resistance is a condition in which insulin action is impaired in adipose tissue 24 and is more strongly linked to intra-abdominal fat than to fat in other depots. The expression of adiponectin 25 decreases with increase in the adiposity. Adiponectin mediates insulin-sensitizing effect through binding to 26 its receptors AdipoR1 and AdipoR2, leading to activation of adenosine monophosphate dependent kinase 27 (AMPK), PPAR-α, and presumably other yet-unknown signalling pathways. Weight loss significantly elevates 28 plasma adiponectin levels. Reduction of adiponectin has been associated with insulin resistance, 29 dyslipidemia, and atherosclerosis in humans. The other major adipokine is leptin. Leptin levels increase in 30 obesity and subcutaneous fat has been a major determinant of circulating leptin levels. The leptin signal is 31 transmitted by the Janus kinase, signal transducer and activator of transcription ((JAK-STAT) pathway. The 32 net action of leptin is to inhibit appetite, stimulate thermogenesis, enhance fatty acid oxidation, decrease glu-33 cose, and reduce body weight and fat.

Nutrients

Obesity, which is a worldwide epidemic, confers increased risk for multiple serious conditions including type 2 diabetes, nonalcoholic fatty liver disease, and cardiovascular diseases. Adipose tissue is considered one of the largest endocrine organs in the body as well as an active tissue for cellular reactions and metabolic homeostasis rather than an inert tissue only for energy storage. The functional pleiotropism of adipose tissue relies on its ability to synthesize and release a large number of hormones, cytokines, extracellular matrix proteins, and growth and vasoactive factors, which are collectively called adipokines known to influence a variety of physiological and pathophysiological processes. In the obese state, excessive visceral fat accumulation causes adipose tissue dysfunctionality that strongly contributes to the onset of obesity-related comorbidities. The mechanisms underlying adipose tissue dysfunction include adipocyte hypertrophy and hyperplasia, increased inflamm...

Current Atherosclerosis Reports, 2006

Journal of Human Hypertension, 2008

Low plasma adiponectin levels are related to a higher risk of development of metabolic and cardiovascular disorders, including hypertension (HT). To date, there have been no studies supporting the relationship between epicardial adipose tissue (EAT) expression of adiponectin and HT. We collected samples of EAT from 116 patients undergoing elective cardiac surgery, mostly for coronary artery bypass grafting (n ¼ 54), valve surgery (n ¼ 49) or both (n ¼ 12). Samples of subcutaneous adipose tissue (SAT) were harvested from 85 patients. After RNA isolation, the expression of adiponectin was analysed by real-time retrotranscriptase (RT)-PCR. Baseline clinical data were obtained from medical records. The diagnosis of HT was established mostly by the patients' general physicians following current guidelines. We included 84 hypertensive and 32 non-hypertensive patients. Mean (± s.d.) age was 70.3±7.9 years. EAT expression levels of adiponectin were lower in hypertensives (14.0 ± 3.6 vs 15.3 ± 3.6 arbitrary units (a.u.), P ¼ 0.06). This difference was statistically significant (odds ratio (OR) 0.828 per a.u., P ¼ 0.020) after adjustment for age, gender, body mass index, diabetes mellitus, heart failure, coronary artery disease (CAD), total cholesterol and triglyceride levels. However, SAT adiponectin mRNA levels were similar in hypertensive and non-hypertensive patients (15.3 ± 4.2 vs 15.3 ± 5.0 a.u., P40.99). Adjustment for potential confounding factors hardly altered this result. Our findings indicate that EAT expression of adiponectin may be associated with HT status independently of CAD or other comorbidities, whereas SAT expression does not. These results support the hypothesis that EAT is actively implicated in global cardiovascular risk, describing its association with HT.

Acta Pharmacologica Sinica, 2010

Insulin plays an important role in the stimulation of vascular nitric oxide production, with both short term (vasomotility and antithrombotic effects) and long term (smooth muscle cell growth and migration inhibition) benefits. Impaired vasodilatory response to insulin, the hallmark of vascular insulin resistance (IR), has important implications for circulatory pathophysiology. An association between adipokines and IR has been observed in both diabetic and nondiabetic states. Adiponectin (APN) is an insulin-sensitizing adipokine known to stimulate skeletal muscle fatty acid (FA) oxidation and reduce lipid accumulation. Recent demonstrations of potential cross-talk between APN and insulin in vascular function regulation are particularly interesting. The lipid accumulation observed after chronic high-fat (HF) diets and in the obese state may reduce vascular response to APN, a pathologic state termed as APN resistance. This review highlights the importance of insulin sensitivity and APN activity in the maintenance of endothelial function. It explores the relationships between vascular IR and APN resistance in the hyperlipidemic pathological condition, representative of the metabolic syndrome. The investigation of vascular insulin and APN resistance provides not only better understanding of vascular pathophysiology, but also an opportunity for therapeutic targeting in individuals affected by the metabolic syndrome.

International journal of drug delivery technology, 2024

These metabolic and clinical risk factors, which include obesity, dyslipidemia, hypertension, and type 2 diabetes mellitus, are together referred to as the "metabolic syndrome", or "Met. S". 1 Met. S has a major independent effect on the onset of coronary heart disease and type 2 diabetes. 2 Globalization raises the possibility of developing metabolic syndrome by increasing the prevalence of central obesity, particularly in developing countries. It implies that insulin resistance and metabolic syndrome are significantly influenced by central obesity. The mechanism by which adipocytes produce specific cytokines known as

European Heart Journal, 2008

The classical perception of adipose tissue as a storage place of fatty acids has been replaced over the last years by the notion that adipose tissue has a central role in lipid and glucose metabolism and produces a large number of hormones and cytokines, e.g. tumour necrosis factor-a, interleukin-6, adiponectin, leptin, and plasminogen activator inhibitor-1.

Many studies have profoundly changed the concept of adipose tissue from being an energy depot to an active endocrine organ. Adipose tissue secretes bioactive peptides, termed as 'adipokines'.They act through autocrine, paracrine and endocrine pathways. In obesity, increased production of most adipokines affects multiple functions such as appetite and energy balance, immunity, insulin sensitivity, angiogenesis, blood pressure, lipid metabolism and haemostasis. Increased activity of the tumor necrosis factor and interleukin 6 are involved in the development of obesityrelated insulin resistance. Angiotensinogen has been implicated in hypertension and plasminogen activating inhibitor-1 in impaired fibrinolysis. Decreased levels of adiponectin indicate adipose tissue dysfunction in obesity. Thus increased adipose tissue mass plays a key role in the development of obesity-associated diseases and the development of obesity alters adipocyte-derived hormones or cytokines expression. This provides a link between obesity, impaired insulin sensitivity and metabolic defects in other tissues. The present review will focus on effect of obesity on adipose tissue endocrine function.

2021

Adipose tissue secretes many adipokines that regulate important physiological functions. Growing studies have highlighted that these bioactive molecules may contribute to the development of metabolic and cardiovascular diseases. Adipokines exert systemic metabolic effects and independent activity on numerous cells of the cardiovascular system, including cardiomyocytes and vascular cell walls. Adiponectin shows anti-inflammatory and anti-atherosclerotic activity on blood vessels. Conversely, resistin is endowed with pro-inflammatory effects and stimulates the proliferation of smooth muscle cells, thus promoting the development of atherosclerotic plaque. Leptin plays an important role in cardiac remodeling and blood pressure regulation through the activation of the sympathetic system. Obesity is a pathological condition associated with hypertrophy of white adipose tissue, which stimulates the production of pro-inflammatory adipokines while, it reduces the production of anti-inflammato...