• Guest, the forum is undergoing some upgrades and so the usual themes will be unavailable for a few days. In the meantime, you can use the forum like normal. We'd love to know what you think about the forum! Take the 2025 Survey »

What does insulin do?

K

Katiemorag

Member
Hi,

I'm trying to re motivate myself as a "good diabetic" - I've been very stupid for a few months.

One excuse I use for being stupid, is that I don't really know what the insulin is doing. The simple explanation given to me was that it is the key which unlocks the cell so the energy (sugar) can get in. However, if I exercise, I need less insulin so this can't be the whole story - surely exercise needs more energy so I'd need more insulin.

Can anyone help me silence this particular demon by explaining what I'm misunderstanding!

Thanks

Thanks


Sent from the Diabetes Forum App
 
I'm type 2 and mostly insulin resistant.
Certain cell types such as fat and muscle cells require insulin to absorb glucose. When these cells fail to respond adequately to circulating insulin, blood glucose levels rise.
So I need to improve my insulin resistance by taking metformin, which appears to work for me.
Others decide to bypass this entirely, low carb, and the replace the need for insulin by running the body (mainly) off fat.

So I found my bs rose, as my body got tired, and any spare glucose, (Which was a lot) got converted to fat instead.

As a type 1, I would guess you're slightly different, as you shouldn't be insulin resistant, and should be able to use the injected insulin to use the glucose in your body for energy.
Any extra calories will still be converted to fat though.

Insulin also does a host of other things, including keeping bg in the right range, by allowing the liver to dump glucagon, or to store it.

I sure there will be a few more along to explain the difference between the use of insulin to release energy for the muscles to use, and the use of insulin to store glucose when resting.
 
Dear Katiemorag,
Being a Type 1 diabetic is very different from the more common Type 2 diabetes, for in the case of a Type 1, then the insulin producing Beta Cells contained withing the pancreas are perminantly damaged and are unable to create and release the hormone 'Insulin' into the bloodstream as and when your body would demand it.
For that reason as a Type 1 you have the un-enviable task of trying to emulate your own pancreas's beta cell production, by injecting Insulin (slow/fast versions) into the bloodstream in an attempt to balance out what your are eating against what the body is requiring, against many other factors temperature/illness/exercise/stress etc: etc:
It's not an easy thing to acheive, but exercise does in many ways do the same thing as Insulin, hence with exercise the demand for Insulin is reduced.
 
Dear Shirty252,
I replied to another enquiry in this same section which might answer your question on a Type 2 having to resort to using Insulin.
It can be found on "Trying to understand the science of exercise"
Hope this helps.
Best regards - Lazybones
 
However, if I exercise, I need less insulin so this can't be the whole story - surely exercise needs more energy so I'd need more insulin.
Click to expand...
No, it's not the whole story.
Glucose can't just pass through a cell membrane into the cell, it needs a transporter to allow it to get in. Muscle and skeletal cells have specific transporters, known as GLUT4 . These have receptors which are responsive when insulin is present. They are 'called' to the surface of the cell and the glucose can then get in. As you said, when you are exercising you may need more fuel so GLUT4 has a second set of receptors which don't require insulin. This second set respond to muscle movements ie when you contract a muscle they also come to the surface. When you are exercising you may actually need very little (if any) insulin to get the fuel into the cell.
But you still need some, because insulin together with glucagon controls the amount of glucose being released by the liver .It's easier to point you to a diagram than try to explain http://science.howstuffworks.com/life/human-biology/diabetes1.htm
We have to control our own insulin and can't turn it on and off. The insulin we inject also lasts far longer in the body than natural insulin It's no wonder that it's not always easy to get it right, especially during exercise.
 
The main task for insulin is to lower blood glucose by storing it as fat.

It also stops your body from using body fat as energy. That is why a low carb high fat diet work so well for weight loss, I think. With very little carbs you don't need much insulin and your body is free to use the fat as energy. It also explains why t1 loose weight and t2 gain.
 
Hi Shirt252. T2s on insulin would normally also have a failing pancreas so the need for insulin is the same as a T1 assuming they don't have high insulin resistance due to high weight. In the latter case, insulin may be given to top up what is already in the blood to try to get the muscles to take it up which can be a bit of a vicious circle. Also some T2s are actually late onset T1s.
 
Another angle on activity is that when you exercise your muscles are working harder......because of this the usual number of cell doors that are present to allow in the glucose in increase, and its this effect which reduces your insulin resistance.

So in fact during exercise and after it, your muscles will take in more glucose with less insulin......:)
 
Back
Top