Overview of This Entry
I will present what somebody said about why duodenal switch resolves diabetes. I will then mock that. I will thereafter explain more academically why I think the explanation is either wrong or severely limited, and what it would take to prove it was right.
Someone Else's Explanation of Why Duodenal Switch Works
This article attempts to explain the diabetes reversal effect of duodenal bypass surgery in the following way. Dr. John Husted is quoted.
(undigested food enters the non-bypassed part of the stomach and therefore) ...secretion of GLP-1 is enhanced. Enteroglucogan (GLP-1) has the effect of suppressing the secretion of insulin in response to a carbohydrate meal, resulting in a lesser amount of ingested carbohydrates being converted to body fat.
The portion of intestine that is bypassed holds an important role as well. Enterogastrone is a hormone that is secreted by the upstream small intestine when food passes through it. This hormone has the effect of converting food to fat. When the upstream portion of the intestine is bypassed - as is the case with Duodenal Switch - enterogastrone secretion is suppressed. The effect of this bypass is that the patient's body after Duodenal Switch has less of a tendency to convert food to fat.
Not quoting Dr. Husted now, the article then states: "The metabolic effect of Duodenal Switch surgery... explains why there is a 99% cure rate for type 2 diabetes following the Duodenal Switch procedure."
I Mock This Explanation
Are you telling me that an increase in something that suppresses the secretion of insulin can help cure diabetes? What about the insulin spike needed to shut down the liver and get the whole business of muscles absorbing gluocogan going? Did that just go out the window? You're saying that what diabetics have needed all along was a way to suppress insulin release, not increase it? Are you mad?
I have read that one of the horrible realities of diabetes is that muscle requires insulin to absorb glucogan, but fat doesn't. Therefore, when there is insulin resistance in the muscle cells, fat cells just gobble up a lot of the glucogan - they 'convert food to fat.' Now you're telling me that that isn't exactly true, that fat cells need insulin to ingest glucogan just as muscle cells do. Ok, fine, whatever. So now, you're telling me that duodenal switch surgery decreases insulin (thus stopping fat cells from absorbing glucogan as quickly as they would) and it also decreases the fat cells' ability to absorb food by suppressing enterogastrone secretion. By two ways fat cells just aren't going to take as much of the glucogan that is out there as they would otherwise. Fine. How exactly does that help the muscle cells? Wouldn't that mean that there'd be even more glucose in the blood even longer, because fat cells weren't absorbing glucogan, and because there'd be less insulin for the muscle cells? Wouldn't that, in the short term, create even greater hyperglycemia, and all the damage resulting therefrom?
Keep in mind that duodenal switch surgery resolves diabetes nearly immediately - before fat is lost. The longterm goal of fat reduction, albeit noble, ought not to come into consideration when trying to understand why duodenal switch bypass resolves diabetes in the near term. Dr. Husted's explanation might help explain longterm fat decrease, but what's happening in the blood, in the muscle and fat, before fat is lost is the more relevant concern. So, really, after all the jargon slinging, absolutely nothing is proposed to explain the diabetes reversal. Some explanation!
Keep in mind that duodenal switch surgery resolves diabetes nearly immediately - before fat is lost. The longterm goal of fat reduction, albeit noble, ought not to come into consideration when trying to understand why duodenal switch bypass resolves diabetes in the near term. Dr. Husted's explanation might help explain longterm fat decrease, but what's happening in the blood, in the muscle and fat, before fat is lost is the more relevant concern. So, really, after all the jargon slinging, absolutely nothing is proposed to explain the diabetes reversal. Some explanation!
A Slightly More Academic Response
O.k, o.k., I'll try to be calm. Clearly what we are presented with is a great, mysterious truth: duodenal switch surgery resolves diabetes. It is wonderful. But why? Well, let's look at what the bypassed parts do. That's a good place to start. Bypassed Part #1 absorbs proteins and sugars. Bypassed Part #2 makes enterogastrone. So, maybe the presence of more proteins and sugars, and less enterogastrone, explains diabetes reversal. But does it? Where are the follow-up experiments that prove it? Let's say you bypass part of the stomach in a diabetic rat without bypassing the duodenum - just the stomach. Does that resolve diabetes?
I think that the part of the "upstream small intestine" that releases enterogastrone is not the duodenum, but the jejunum. Let's say you bypass part of the jejunum after the duodenum, without bypassing either the stomach or duodenum. Does that resolve diabetes? Show me!
Perhaps I am wrong. Perhaps enhanced enteroglucogan (GLP-1) and decreased enterogastrone, through a series of as-yet unexplained steps, resolve diabetes. Until that is conclusively shown, however, I'm sticking with the Reduced Blood Flow Theory.
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