While any effective weight-loss surgery can benefit obese patients and help change conditions that may lead to diabetes, researchers have found that a malabsorptive weight-loss operation, such as biliopancreatic diversion, can restore a body's normal sensitivity to insulin faster, resulting in a decreased risk of diabetes. Gastric bypass limits the stomach's capacity, causing the patient to eat less; biliopancreatic diversion involves rearranging the intestines so that the patient absorbs less of what is eaten. This small study from the University of Pisa involved 18 patients with severe obesity and 20 lean subjects. Both groups underwent testing for insulin sensitivity, an indicator of diabetes. The obese patients received either gastric bypass surgery or biliopancreatic diversion. While all patients experienced an average weight loss of more than 100 lbs, their insulin sensitivity differed. In the gastric bypass group, insulin sensitivity steadily improved. However, at the 16-month follow-up, scores were still well below those of the lean subjects. Conversely, in the biliopancreatic diversion group, insulin sensitivity had normalized by 6 months and had actually surpassed that of the lean group at 24-month follow-up?even though the surgery group was still overweight. These results suggest that biliopancreatic diversion restores insulin sensitivity at a faster rate than gastric bypass, although doctors are urged to weigh the pros and cons of each procedure on a patient-by-patient basis.
Ms. Farley is a freelance medical writer based in Wakefield, RI.