The other night I found my wife sitting on the side of the bed staring intently into her Anatomy Coloring Book. Nicole was singing to the tune of “Dem Bones”:
Pancreas connected to the portal vein.
Portal vein connected to the liver.
Liver connected to the bloodstream.
Now hear the word of the Lord.
Yes, the pancreas, portal vein and liver has been on our minds lately. We just finished listening to an interview with Robert Geho. Geho is CEO of Diasome Pharmaceuticals, Inc. This company is focused on making insulin work better with the liver.
As Geho explains in the interview, in a non-diabetic, the liver plays a big role in blood sugar control. In a diabetic, it plays a very minor role. He explained how a non-diabetic will produce insulin in their pancreas. From there it goes into the portal vein. The portal vein brings it to the liver. Most of the insulin is absorbed by the liver. The rest is released into the bloodstream by the liver.
When someone like my wife injects insulin in her arm, none of this happens. The insulin goes straight into the bloodstream. Very little of that insulin ends up in the liver.
This may sound like a minor difference. After all, the insulin gets to the bloodstream, where it is needed, right?
First of all, I would speculate that the liver does a much better job of releasing insulin into the bloodstream. It almost sounds like the liver might store insulin and then release it as needed in response to blood sugar levels.
Geho talks extensively, however, about how insulin moving through the liver allows the liver to absorb sugar from the bloodstream. In a type-1 diabetic, he argues, this isn’t happening as much as it should. Injected insulin instead pumps sugar into the muscle and fat tissue.
This further complicates things because when the blood sugar drops too low the liver does not have readily available supply of glucose to release into the bloodstream.
This may explain why Nicole, for example, finds she craves sugar in between meals. Her liver may not have any stored glycogen to keep her blood sugar up. This would also explain why type-1 diabetics need to consume sugar while exercising. It may not just be about heightened insulin sensitivity.
So, Geho argues, that when insulin bypasses the liver, the body cannot properly raise and lower blood sugar. His company is working on an additive that will allow injected insulin to be more greatly absorbed by the liver. The small trial studies he shares in the video shows significantly better blood sugar control.
There were certain points made in the interview that I think may be in error. I’m going to check my facts and contact Geho before disclosing my concerns. But the big take away here is that the liver definitely plays a big role in the management of blood sugar. Since injected insulin does not travel through the liver, it emphasizes how imperfect insulin therapy is.
In closing, I’d like to confess that Nicole was not singing a diabetic version of “Dem Bones” the other night. She was, however, referencing the Anatomy Colouring Book. It’s actually a remarkably detailed and easy to reference guide to the body. No, she hasn’t coloured it in yet.
John C. A. Manley
P.S. You can watch the complete interview with Geho at the Diabetes Hands Foundation website: http://www.tudiabetes.org/video/tudiabetes-live-interview-with-robert-geho-the-liver-s-role-in
P.P.S. The interview also gave me an idea about how one might introduce insulin into the liver. My idea doesn’t involve needles or special drugs. I’ll write about this in a future column. You can subscribe at: http://diabeticdharma.com/subscribe