Endocrine Abstracts

Resistin, a novel signalling molecule isolated in mice, has been suggested to be the putative hormone thought to link obesity with type 2 diabetes. As central obesity is associated with a higher risk of diabetes, we compared resistin mRNA expression in abdominal fat depots to thigh and breast adipose tissue. Mononuclear cells are also known to expression resistin, therefore, CD45 expression (a marker of mononuclear blood cells), was also analysed. RNA was extracted from 32 human adipose tissue samples (13 abdominal subcutaneous, 7 omentum, 6 thigh, 6 breast). Resistin and CD45 mRNA expression was subsequently analysed by real time PCR. The abdominal subcutaneous and omental fat depots had similar levels of resistin mRNA (Delta=D); Dct ± SE mean; subcutaneous 21.20±0.59 compared with omentum 21.27±0.78). The abdominal depots had a 418% and a 510% increase in resistin mRNA expression than the thigh depot (DCt 23.30±0.43, p=0.038), and the breast depot respectively (DCt 23.59±0.31, p=0.018). No difference in the level of CD45 mRNA expression was shown in the four adipose tissue depots analysed for resistin mRNA expression (DCt ± SE mean; subcutaneous abdominal adipose tissue 20.03±0.52; abdominal omental adipose tissue; 20.43±0.27; subcutaneous thigh adipose tissue 19.79±0.31; breast adipose tissue 19.83±0.39). In conclusion, this study demonstrates firstly, the expression of resistin mRNA in human abdominal adipose tissue and that this is not due to the presence of mononuclear blood cells; secondly, that abdominal adipose tissue depots express higher levels of resistin mRNA. The increased expression of resistin in abdominal fat depots may be relevant to the increased risk of diabetes in individuals with central obesity and requires further investigations.