Were the results of the PROactive study likely to be a class effect of TZDs?
It is unknown. This study is an outcomes trial that was not designed to describe mechanistic reasons for the outcomes seen. There are many biological effects seen with pioglitazone that may contribute to outcomes, including effects on glycaemia, lipids, inflammation, etc. These actions are ligand-specific, which implies that results obtained with one thiazolidinedione might not be applicable to others.
