Abdominal obesity

Abdominal obesity, also known as central obesity, occurs when excessive abdominal fat around the stomach and abdomen has built up to the extent that it is likely to have a negative impact on health. Central obesity has been strongly linked to cardiovascular disease, Alzheimer's disease, and other metabolic and vascular diseases. Abdominal obesity, also known as central obesity, occurs when excessive abdominal fat around the stomach and abdomen has built up to the extent that it is likely to have a negative impact on health. Central obesity has been strongly linked to cardiovascular disease, Alzheimer's disease, and other metabolic and vascular diseases. Visceral and central abdominal fat and waist circumference show a strong association with type 2 diabetes. Visceral fat, also known as organ fat or intra-abdominal fat, is located inside the peritoneal cavity, packed in between internal organs and torso, as opposed to subcutaneous fat, which is found underneath the skin, and intramuscular fat, which is found interspersed in skeletal muscle. Visceral fat is composed of several adipose depots including mesenteric, epididymal white adipose tissue (EWAT) and perirenal fat. An excess of visceral fat is known as central obesity, the 'pot belly' or 'beer belly' effect, in which the abdomen protrudes excessively. This body type is also known as 'apple shaped', as opposed to 'pear shaped', in which fat is deposited on the hips and buttocks. Researchers first started to focus on abdominal obesity in the 1980s when they realized it had an important connection to cardiovascular disease, diabetes, and dyslipidemia. Abdominal obesity was more closely related with metabolic dysfunctions connected with cardiovascular disease than was general obesity. In the late 1980s and early 1990s insightful and powerful imaging techniques were discovered that would further help advance the understanding of the health risks associated with body fat accumulation. Techniques such as computed tomography and magnetic resonance imaging made it possible to categorize mass of adipose tissue located at the abdominal level into intra-abdominal fat and subcutaneous fat. Central obesity is associated with a statistically higher risk of heart disease, hypertension, insulin resistance, and type 2 diabetes (see below). With an increase in the waist to hip ratio and overall waist circumference the risk of death increases as well. Metabolic syndrome is associated with abdominal obesity, blood lipid disorders, inflammation, insulin resistance, full-blown diabetes, and increased risk of developing cardiovascular disease. It is now generally believed that intra-abdominal fat is the depot that conveys the biggest health risk. Central obesity can be a feature of lipodystrophies, a group of diseases that is either inherited, or due to secondary causes (often protease inhibitors, a group of medications against AIDS). Central obesity is a symptom of Cushing's syndrome and is also common in patients with polycystic ovary syndrome (PCOS). Central obesity is associated with glucose intolerance and dyslipidemia. Once dyslipidemia becomes a severe problem, an individual's abdominal cavity would generate elevated free fatty acid flux to the liver. The effect of abdominal adiposity occurs not just in those who are obese, but also affects people who are non-obese and it also contributes to insulin sensitivity. Recent validation has concluded that total and regional body volume estimates correlate positively and significantly with biomarkers of cardiovascular risk and BVI calculations correlate significantly with all biomarkers of cardio-vascular risk. Ghroubi et al. (2007) examined whether abdominal circumference is a more reliable indicator than BMI of the presence of knee osteoarthritis in obese patients. They found that it actually appears to be a factor linked with the presence of knee pain as well as osteoarthritis in obese study subjects. Ghroubi et al. (2007) concluded that a high abdominal circumference is associated with great functional repercussion. There are numerous theories as to the exact cause and mechanism in type 2 diabetes. Central obesity is known to predispose individuals for insulin resistance. Abdominal fat is especially active hormonally, secreting a group of hormones called adipokines that may possibly impair glucose tolerance. But adiponectin which is found in lower concentration in obese and diabetic individuals has shown to be beneficial and protective in type 2 diabetes mellitus.