Yep, i believe a lot of diabetic people have issues with Metformin some do better with the ER version of it, i can't remember right now were i found a very interesting artical about insulin resistance but anyway they done some research [ in mice] that showed that inflamation caused insulin resistance not obesity, this url explains it all.
http://ucsdnews.ucsd.edu/newsrel/hea...stanceDK-L.asp

Brian