The biggest achievement of bariatric surgery was to demonstrate that obesity co-morbidity improve or even reverse with long-term weight control. This evidence was achieved with the Swedish Obesity Study for mortality and diabetes incidence.
Diabetes resolution rates range from 55 to 96% depending on the surgical procedure and length of follow-up. Diabetes improvement or resolution almost reaching the 100%. The type of surgery seems to play a role in diabetes and other co-morbidity improvement, the procedures associated with a greater percentage of excess weight loss presenting better results. This could suggest that diabetes improvement is directly related to excess weight loss. Although systematic review and meta-analysis suggest this is true, changes in gut hormones have been claimed for procedures involving changes in gut anatomy. Several hormones, namely GLP-1, GIP, PYY and ghrelin, have been carefully studied, results changing with type of surgery and protocols used. The role of changes of GLP-1 and GIP in diabetes improvement deserves great interest. The roles of caloric restriction, weight loss and alterations in the small intestinal anatomy, the importance of foregut exclusion and of rapid ileal exposure to nutrients, the changes in gut hormones, changes of the gut brain axis and the role of the vagus nerve as well as changes in gastric emptying and gut motility need to be better elucidated. Experimental procedures such as ileal interposition and foregut exclusion trying to better elucidate the importance of changes in gut hormones in diabetes improvement.
Controlled studies comparing diet versus surgery and different types of surgery are scarce and are urgently needed.
The length of follow up is of utmost importance to characterize diabetes improvement. Even with diabetes recurrence will there be a legacy effect as happened with other type of interventions as in UKPDS, DPS and DPP?
Several reports related poor responders to longer duration of diabetes preoperatively, revealing the importance of early surgical intervention for diabetes resolution. Bariatric surgery in type 2 diabetic patients poorly controlled with a BMI ≥30 is matter of debate.
Last but not least short term and long-term safety is a very important issue.
30 Apr - 04 May 2011
European Society of Endocrinology