Obesity adipose tissue distribution

Bjomtorp, P. (1991). Adipose tissue distribution and function. M. /. Obesity 15,67-81. 

Bjomfoip, R (1996). The regulation of adipose tissue distribution in humans. Int.. Obesity 20,291-302. 

Kekes-Szabo, T, Himter, G. R., Nyikos, I., Williams, M., Blaudeau, T, and Snyder, S. (19%). Anthropometric equations for estimating abdominal adipose tissue distribution in women. Int. J. Obesity 20,753-758. 

Goodpaster BH, Thaete FL, Kelley BE. Thigh adipose tissue distribution is associated with insulin resistance in obesity and in type 2 diabetes mellitus. Am J Clin Nutr 2000 71 885-892. 

Katzmarzyk PT, Perusse L, Rao DC, Bouchard C. Familial risk of obesity and central adipose tissue distribution in the general Canadian population. Am. J. Epidemiol. 1999 149 933-942. 

Auboeuf D, Rieusset J, Fajas L, Vallier P, Frering V, Riou JP, et al. Tissue distribution and quantification of the expression of mRNAs of peroxisome proliferator-activated receptors and liver X receptor-alpha in humans no alteration in adipose tissue of obese and NIDDM patients. Diabetes 1997 46 1319-1327. 

Figure 7.22 A common difference in the distribution of adipose tissue between adult men and women. Men usually expand their adipose tissue around the waist to give an apple appearance, whereas women usually expand in the region of the hips to give a pear -shaped appearance (a difference readily observable on any beach). The differences are exaggerated in obese men and women. The biological, biochemical or physiological significance of this difference is not known, but see Pond, 1998.

Adipose tissue is second only to the liver in its ability to distribute fuel molecules. In a 70 kg man, adipose tissue weighs approximately 14 kg, or about half as much as the total muscle mass. In obese individuals adipose tissue can constitute up to seventy percent of body weight Nearly the entire volume of each adipocyte can be occupied by a droplet of triacylglycerol (Figure 24.4). 

A BMI greater than 28 is an independent risk factor (3 times higher than the general population) for cardiovascular diseases (Chapter 20), diabetes mellitus type 2 (Chapter 22), and stroke. The prevalence of obesity-associated morbidity depends on the location of fat distribution in the body. Intra-abdominal or visceral fat deposits are associated with higher health risks than gluteofemoral adipose tissue fat accumulation. 

The volume of distribution of aminoglycosides is increased in young calves relative to adults, as a consequence of high extracellular water volume relative to body weight, because volume of distribution is proportional to plasma volume. Volumes of distribution are lower in obese animals, as aminoglycosides penetrate very poorly into adipose tissue. Overall, volume of distribution (Vrf,area) is of the order of 0.15-0.45 1/kg, and the clinically relevant terminal half-life (P phase) is 1.0-2.0 h. 

The role of CLA in regulating body weight and composition and obesity-linked type 2 diabetes appears to be complex. It seems likely that the mechanisms will involve alterations in adipose depot distribution as well as energy expenditure and molecular pathways in tissue such as adipose, muscle, Uver, immune cells, and... 

It has been a consistent finding that Type II diabetes is almost invariably associated with obesity but of more fundamental interest is its association with a particular distribution of body fat. The excessive adipose tissue characteristic of obesity tends to be distributed in the upper body, including the waist (android or upper body obesity) or the lower body, including the hips and buttocks (gynoid or lower body obesity). The former is more characteristic of men and is more closely associated with Type II diabetes, hyperlipidaemia and other metabolic disorders while the latter is more usually seen in women and has fewer adverse metabolic implications. These relationships are so strong that risk can be assessed by a relatively simple index the ratio of waist to hip circumference. 

The mechanisms whereby body fat distribution may be associated with diabetes independently of overall adiposity are still unresolved but the subject of intense research attention. Subjects with predominantly upper-body fat distribution are more insulin-resistant than subjects equally obese but with a fat distribution predominantly in the lower body. Upper body obesity is associated primarily with fat cell hypertrophy (increased adipocyte size) while lower body fat distribution is associated more with fat cell hyperplasia (increased number of adipocytes). As fat cells enlarge, they become more resistant to insulin. The adipose tissue, however, accounts for only about 5% of total body glucose disposal, so that insulin resistance in this tissue alone should not account for significant increases in total body insulin... 

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