The two leading theories of why bypass is better focus on changes in hormones and food absorption in the small intestine, said Leon Katz, director of minimally invasive and bariatric surgery at Crozer-Chester Medical Center.
"Either it's the exposure of food to the more distant portion of the small intestine much earlier than normal," he explained, "or the exclusion of food" from the bypassed part of the intestine.
Despite some breathless media reports, bypass is not a "cure" for diabetes - at least, not yet. Patients with diabetes for a decade or more, or those on large amounts of insulin, are less likely to have a complete remission.
Bill Jacobson, 57, of North Wales, is a case in point. A diabetic for about 25 years, he was able to cut way back - but not quit - insulin, blood-pressure medicine and a cholesterol-lowering drug after his 2007 gastric-bypass surgery at Penn Presbyterian Medical Center.
Not that he's dissatisfied.
Jacobson, who oversees trials of obesity and diabetes drugs for a clinical-trials company, now carries 155 pounds, down from 235, on his 5-foot-6 frame. His sleep apnea is gone, his chance of an imminent heart attack has fallen from 96 percent to 2 percent - and it's far easier for him to put on socks.
He has had no complications, other than two episodes of "dumping" - the sudden cramping triggered by food that is too rich or too much to digest.
But he works hard, both mentally and physically, to stay healthy. He eats "smaller and smarter," attends support-group meetings, and works out daily on a treadmill, even when traveling.
"Surgery is nothing more than a tool," he said. "You can subvert it. But I'm motivated."
Contact staff writer Marie McCullough at 215-854-2720 or mmccullough@phillynews.com.
