Role of a critical visceral adipose tissue threshold (CVATT) in metabolic syndrome: implications for controlling dietary carbohydrates: a review

Arguably, the major pathogenic factor in the metabolic syndrome is central obesity [1,2]. While abdominal obesity is determined by the accumulation of both subcutaneous adipose tissue (SCAT) and visceral adipose tissue (VAT), the excess accumulation of VAT appears to play a more significant pathogenic role. VAT depots, located in the body cavity beneath the abdominal muscles, are composed of the greater and lesser omentum (peritoneum that is attached to the stomach and links it with other abdominal organs) and the mesenteric fat. A lesser amount of VAT is located retroperitoneally. In general, VAT accounts for up to 20 percent of total fat in men and 5–8 percent in women. The abdominal SCAT is located immediately beneath the skin and on top of the abdominal musculature. The predominance of lower body fat is SCAT, most of which is stored in the femoral and gluteal regions [3-5]. Abdominal obesity can reflect a predominance of flabby SCAT; a firm, only modestly enlarged waist line resulting from deep VAT pushing the abdominal musculature outward; or a combination of enlarged SCAT and VAT depots. With the advent of more precise imaging techniques, e.g., magnetic resonance imaging (MRI) [6], computed tomography (CT) [7], and ultrasound [8], it has become evident that the accumulation of VAT not only accompanies but antedates the onset of the components of the metabolic syndrome and related disorders, e.g., insulin resistance, hypertension [9], glucose intolerance [10], type 2 diabetes, and coronary heart disease [11].To date, it has not yet been established that insulin resistance, i.e., resistance of cells to insulin's effects, is responsible for the onset of the multiple risk factors associated with insulin resistance syndrome and subsequent development of atherosclerosis and cardiac events [12]. In fact, National Cholesterol Education Program Adult Treatment Panel (ATP III) criteria for Metabolic Syndrome have been found to have a low sensitivity for predicting insul