ADIPOQ and type 2 diabetes mellitus: Based on the ELISA analysis of the adiponectin protein expression in the healthy population (control group, n = 8) and in patients with T2DM (T2DM group, n = 32), the T2DM group was sub-divided into two subgroups, one with a disease course of <5 y (<5 y T2DM group, n = 16) and another, >15 y (>15 y T2DM group, n = 16).