Endocrine Abstracts

Adiponectin (acrp30) is an adipocyte derived-hormone, associated with insulin sensitivity and lower risk of atherosclerosis. Plasma adiponectin concentrations are decreased in obese and type 2 diabetic subjects with insulin resistance. As central rather than gluteo-fermoral fat is known to increase the risk of type 2 diabetes and cardiovascular disease we investigated the expression of adiponectin in human adipose tissue depots. We examined expression of adiponectin mRNA levels in adipose tissue depots from non-diabetic subjects compared with biopsied abdominal subcutaneous fat from diabetic subjects. RNA was extracted from 46 human adipose tissue samples (non-diabetic (age: (mean±SD) 44.33±12.4; BMI 28.3±6.0): 21 abdominal subcutaneous, 13 omentum, 6 thigh; diabetic subjects (age: 66.6±7.5; BMI 22.9±3.17; abdominal subcutaneous 6). Quantitative PCR was used to determine adiponectin mRNA expression. mRNA expression studies indicated that in non-diabetic subjects, thigh adipose tissue contained similar amounts of adiponectin ((Delta=D)DCt ( ±SEM) 10.6±0.16) compared with the abdominal subcutaneous adipose tissue (DCt 10.58±0.26). However, adiponectin levels were significant reduced in omental adipose tissue (DCt 11.83±0.24; p=0.0027) from the non-diabetic subjects. Furthermore, the expression in abdominal subcutaneous adipose tissue from the diabetic subjects was also reduced (DCt 12.69±0.54; p=0.0007) compared with the same depot in non-diabetic subjects. In conclusion, adiponectin mRNA expression is reduced in abdominal subcutaneous adipose tissue in diabetic compared to non-diabetic subjects. In addition, in non-diabetic subjects, adiponectin mRNA levels are reduced in omental adipose tissue compared to other depots. These finding suggest that the observed differences in serum concentrations of adiponectin in diabetic and non-diabetic subjects may be related to distinct patterns of expression of adiponectin mRNA in adipose tissue. These differences in fat distribution between the diabetic and non-diabetic subjects may also contribute.