Adipose Tissue and Insulin Resistance

AdipocytesFor a long time, adipocytes were considered as a relatively inert and static energy depot. However, in recent years, adipose tissue is recognized as an active endocrine and paracrine organ. It was discovered that adipocytes secrete hormones and cytokines that produce both central effect on the regulation of energy metabolism and peripheral effects on insulin sensitivity or insulin resistance. Among these substances are leptin, resistin, adiponectin, and the protein that stimulates the acetylation. In addition, adipocytes respond to the incoming neural hormonal signals via the adrenergic receptors and signals of the circulating hormones. In this way adipocytes are involved in lipogenesis, lipolysis and thermogenesis. There are several different hormones, which stimulate lipolysis, but the main stimulator of lipogenesis is insulin. In adipocytes, insulin increases the expression of the carrier Glut 4 and the activity of acetyl-CoA carboxylase, fatty acid synthase and lipoprotein lipase. Therefore, the net effect of insulin on adipocytes is rapid clearance from the circulation and depositing of glucose and lipids. The list of biologically active metabolites of adipose tissue is rather long and includes leptin, adiponectin, resistin, tumor necrosis factor, interleukin-6, free fatty acids, protein that stimulates acetylation, inhibitor of plasminogen activator-1, transforming growth factor B, angiotensinogen, lipoprotein lipase, hormone sensitive lipase, and protein that transfers cholesterol esters.How insulin resistance developsObesity and insulin resistance often go together. To determine the level of obesity, it is recommended to use BMI calc showing Body Mass Index and weight categories. Pathogenesis of insulin resistance in obesity is heterogeneous in nature and is determined by the interaction of genetic, hormonal, age-related, and environmental factors. The excessive consumption of saturated fats, duration and type of obesity are essential factors in the development of insulin resistance. These factors contribute to the development of diabetes, the formation of cardiovascular risks such as hypertension and dyslipidemia, the development of vascular pathology of large and small blood vessels. Doctors affirm that the upsurge of the number of patients suffering from diabetes, cardiovascular disease, and atherosclerosis is directly related to the prevalence of obesity and insulin resistance. Thus, the correction of the severity of visceral obesity and the restoration of the sensitivity of peripheral tissues to insulin may be the deciding factors in the treatment and prevention of the diseases associated with obesity.How to improve the conditionScientists have convincingly proven that the weight loss significantly reduces the blood pressure, improves lipid profile, and reduces the risk of diabetes development. It is difficult to overestimate the role of lifestyle changes for the correction of metabolic and hemodynamic disorders in patients with obesity. To date, the recommendations on lifestyle modifications include several components. First of all, these are nutritional modifications with moderate reduction of daily calorie intake in the frames of balanced diet, fractional food intake, reducing the amount of saturated fat and easily digestible carbohydrates. Important is also physical, preferentially aerobic, activity, which must be of low or moderate intensity, regular, and should last about an hour. Scientists have clearly demonstrated the effectiveness of healthy lifestyle for the reduction of body weight, prevention of the development of diabetes even in case of impaired carbohydrate tolerance, as well as the positive impact of healthy way of life on the wide range of lipid disorders and hypertension.