Explanation for gastric bypass curing diabetes found
1 May 2013
A team from Lund University in Sweden has discovered why a
gastric bypass sends diabetes into remission in the majority
of cases, opening the door to developing treatment with the same
85% of patients with type 2 diabetes who undergo a gastric bypass
procedure recover from the disease within a few days, showing a
return to normal blood sugar levels long before any weight loss.
Until now it has not been known why this happens.
“Most previous studies have analysed samples taken from patients
before and after a gastric bypass, but there is a risk that the
results are misleading. They may not be attributable to the
operation itself, but rather to factors such as weight loss and
reduced food intake”, says Nils Wierup of the Lund University
Diabetes Centre in Sweden.
In a gastric bypass, food bypasses the majority of the stomach
and duodenum. Just a small part of the upper stomach is connected
directly to the small intestine. In some cases, the surgeon inserts
a catheter into the part of the stomach that no longer has contact
with food as a precautionary measure. This was what gave the
researchers an opportunity to study the exact difference between
food intake before and after the procedure.
The participants were given a set amount of a nutritional drink
and blood samples were taken before, during and at short intervals
after it was ingested. The next step was to inject the same amount
of nutritional solution through the catheter over the same length of
time as it had taken the patient to drink it and the same samples
were taken. The food then ended up where it would have been before
the gastric bypass.
The comparison revealed a major difference. “When the patient
drank the solution, the insulin levels in the blood rose almost five
times as much as when it was injected into the closed-off stomach.
Intestinal hormones, which play a significant role in controlling
blood sugar levels, rose sharply, as did certain amino acids. There
was also a major impact on blood lipids, with the levels roughly
halved”, says Nils Wierup, observing:“We believe these changes are
part of the answer to why gastric bypass cures type 2 diabetes. We
have looked at just a few intestinal hormones. There may be a
hundred or more involved in the body’s complex sugar metabolism.”
Jan Hedenbro, one of the surgeons in the study, adds: “If we can
identify the mechanism behind this, it will open the way for both
more individually tailored operations and, in the long run, the
possibility of achieving the same results with pills rather than
Lindqvist A, et al. Effects of Ingestion Routes on
Hormonal and Metabolic Profiles in Gastric-Bypassed Humans, The
Journal of Clinical Endocrinology & Metabolism, JCEM jc.2012-3996;