Expression of AdipoR1 in vivo in skeletal muscle is independently associated with measures of truncal obesity in middle-aged caucasian men.

The insulin-sensitizing effect of adiponectin (1–4) is mediated via adiponectin receptors (AdipoR1 and AdipoR2) (5). AdipoR1 is abundantly expressed in skeletal muscle, whereas AdipoR2 is also expressed in the liver, with lower levels of expression in skeletal muscle (5). Both receptors are expressed in adipose tissue (6) and pancreatic -cells (7). It has been shown recently that expression of AdipoRs in human skeletal muscle is correlated with insulin sensitivity (8). Because central obesity is associated with insulin resistance, we have undertaken detailed measurements of body fatness with bioimpedance, dualenergy X-ray absorbtiometry (DEXA), and five-slice magnetic resonance imaging (MRI) through the abdomen. We have determined whether expression of AdipoRs was associated with body fatness and in particular with measures of central obesity.