Baseline Adiponectin Levels Do Not Influence the Response to Pioglitazone in ACT NOW Diabetes Care 2014;37:1706–1711 | DOI: 10.2337/dc13-1745 OBJECTIVE

Plasma adiponectin levels are reduced in type 2 diabetes mellitus (T2DM) and other insulin-resistant states. We examined whether plasma adiponectin levels at baseline and after pioglitazone treatment in impaired glucose tolerance (IGT) subjects were associated with improved insulin sensitivity (SI) and glucose toler-ance status. RESEARCH DESIGN AND METHODS A total of 602 high-risk IGT subjects in ACT NOW were randomized to receive pioglitazone or placebo with a median follow-up of 2.4 years. RESULTS Pioglitazone reduced IGT conversion to diabetes by 72 % in association with im-proved b-cell function by 64 % (insulin secretion/insulin resistance index) and increased tissue sensitivity by 88 % (Matsuda index). In pioglitazone-treated sub-jects, plasma adiponectin concentration increased threefold from136 0.5 to 386 2.5mg/mL (P < 0.001) and was strongly correlated with the improvement in SI (r = 0.436, P < 0.001) and modestly correlated with glucose area under the curv