At the Metabolic Applied Research Strategy (MARS) course in San Francisco last week, Randy Seely PhD, gave an interesting presentation summarizing results of animal experiments on the vertical sleeve gastrectomy weight loss procedure. The sleeve is a lesser-known and irreversible bariatric surgery that is gaining in popularity. It limits the amount of food that can be eaten by removing a large portion of the stomach. The premise of Dr. Seely’s talk was dispelling the myth that the “vertical sleeve gastrectomy is not a metabolic procedure”. He presented the results of many studies which demonstrated that after sleeve gastrectomy, rats ate smaller, more frequent meals. This behavior, of course, was their own choice and not based on any “patient instructions” or “compliance” with recommended post-op diet. Interestingly, following sleeve gastrectomy, rats also chose lower fat meals compared to the control groups.
Next, Dr. Seely presented both human and animal data on glucose metabolism. His findings showed that the effects of sleeve gastrectomy on the time course of the rise and fall of serum glucose and insulin after a meal are the same as with the Roux-en-Y gastric bypass. It was discovered that, in both rats and humans, GLP-1 secretion is also the same after sleeve gastrectomy and gastric bypass. Dr. Seely discussed experiments which showed that the effect of the sleeve gastrectomy cannot be explained simply by rapid gastric emptying after the procedure. There are other metabolic effects of bariatric surgery, including effects on lipid metabolism. Surprisingly, sleeve gastrectomy affects how the gastrointestinal tract handles lipids.
Dr. Seely concluded his presentation with an overview of clinical studies of diabetes, displaying data that support the hypothesis that vertical sleeve gastrectomy appears to resolve diabetes as effectively as gastric bypass when patients are matched for the duration and severity of diabetes. However, several studies of severe or very poorly controlled diabetes suggest that gastric bypass may be more effective than the gastric sleeve in those unusual cases. Dr. Seely is primary a rodent-researcher, but this is interesting research, and the sleeve shows promise as a metabolic procedure.
Another study earlier this year compared weight loss results following the gastric bypass verus the sleeve. You can read more about this study here.
Weight Loss Studies & Clinical