Biology of Visceral Adipose Tissue
In humans and other mammals, fat is deposited within anatomically discrete depots that are located throughout the body. In humans, while most fat is present in subcutaneous depots, up to 20% of total body fat is deposited in adipose depots within the abdominal cavity (see Table 1). The pattern of fat distribution is a main determinant of variations in body shape (1-3). Vague ﬁrst noted that that an upper body (android or male-type) fat distribution is associated with development of diabetes, atherosclerosis, and gout (4,5). Kissebah et al. (6,7) and Krotkiewski et al. (6), among others, conﬁrmed and extended Vague’s hypothesis, ﬁnding evidence for correlations of upper-body obesity and enlarged abdominal subcutaneous fat cells to hypertension, insulin resistance, and hyperlipidemia in clinical studies. Epidemiological studies showed that upper-body fat distribution, measured by the ratio of waist to hip circumferences, was a signiﬁcant determinant of diabetes, cardiovascular disease, and premature death in both men and women (3). These statistical associations were independent of overall obesity, as assessed by the body mass index. Thus, much research
attention became focused on the phenomenon of abdominal obesity.