The surgery groups also shed more pounds — 25 percent and 21 percent of their body weight versus 4 percent for the medication group.
Some cholesterol and other heart risk factors also improved in the surgery groups and they required fewer medicines for these than at the start.
Doctors don't know how surgery produces these benefits, but food makes the gut produce hormones to spur insulin, and trimming away part of it affects many hormones and metabolism.
Four patients needed a second surgery within a year but none did after that. Out-of-control diabetes has complications, too — many patients lose limbs or wind up on dialysis when their kidneys fail, and some need transplants.