Serum concentrations and tissue expression of components of insulin-like growth factor-axis in females with type 2 diabetes mellitus and obesity: the influence of very-low-calorie diet.

We explored serum concentrations and mRNA expression of insulin-like-growth factor-1 (IGF-1) axis components in subcutaneous adipose tissue (SCAT) and peripheral monocytes (PM) of 18 healthy females, 11 obese non-diabetic females (OB) and 13 obese women with type 2 diabetes (T2DM) examined at baseline and after very-low-calorie diet (VLCD). T2DM women had decreased expression of IGF-1, IGF-1 receptor (IGF-1R), IGFBP-2 (IGF binding protein-2) and IGFBP-3 in SCAT and increased expression of IGF-1R in PM compared to control group. IGF-1R and IGFBP-3 mRNA expression in SCAT of OB was comparable to control group. In T2DM women VLCD increased serum levels and SCAT expression of IGFBP-2 and PM expression of IGFBP-3. We conclude that decreased IGF-1, IGF-1R and IGFBP-3 expression in SCAT and increased IGF-1R expression in PM of T2DM subjects might contribute to changes of fat differentiation capacity and to regulation of subclinical inflammation by PM, respectively. Increased SCAT and circulating IGFBP-2 and IGFBP-3 in PM might participate in metabolic improvements after VLCD.