‘Recovery’ in 70 per cent of cases after undergoing bariatric bypass

In gastric bypass surgery, the duodenum and proximal jejunum are bypassed

In Sweden, which has a population of nine million, close to 7,000 bariatric procedures per year are carried out. Clearly, the Swedes believe this is an effective treatment for obesity, diabetes and sleep apnoea. However in Ireland, which has roughly half the population of Sweden, only around 200 such procedures are carried out annually.

The improvement in diabetes happens as soon as the day after bariatric bypass surgery, before any weight is lost. “It’s clear that there’s a gut hormone axis that changes dramatically after surgery,” said Dr Donal O’Shea of the HSE Weight Management Clinic, in Dublin’s Loughlinstown Hospital.

Most of this change is due to incretins, such as glucagon-like peptide-1 (GLP-1). There are other factors that come into play that are not understood, yet it is a very profound effect. Essentially, type II diabetes disappears in 70-80 per cent of cases.

The effects of gut hormones on insulin release are mediated by GLP and gastric inhibitory polypeptide (GIP). It has been established that this accounts for about 80 per cent of the effect on diabetes. In gastric bypass surgery, the duodenum and proximal jejunum are bypassed. Food is delivered straight to a lower part in the bowel. The current belief is that this triggers an exaggerated release of GLP.

Bypass surgery interferes with gut hormones to a degree, which clearly does not occur with gastric banding. Diabetes is not an indication for this surgery on its own. However, 80 per cent of type II diabetes is weight related. The long-term benefits of the surgery have really only been demonstrated in cases where the body mass index is over 45.

“It’s very hard to see an obese type II diabetic and not consider this procedure,” Dr O’Shea said. There are capacity problems in providing this treatment in Ireland, however.