I recently learned the word etiology and I like it. According to Dictionary.com it derives from the Greek to “determine the cause of, or equivalent”. (Hey, we all use dictionary.com, if you don’t…you should)
The etiology of the two forms of diabetes is quite different. Because of the similar names, people are generally confused regarding how each of the individual diseases is caused. I’d like to take a moment and share very basically their unique physiological causes.
Type 2 Diabetes
While the risk of T2D can be influenced by numerous things, nobody is quite sure exactly what causes it. Let’s talk about how a T2d’s body works.
When a non-diabetic person eats, the carbs in their food are broken down in the digestive system and absorbed as glucose into the bloodstream. In the bloodstream the glucose is carried all around the body and absorbed by cells as their energy source – it’s basically their only immediate energy source. Insulin’s job is to facilitate that cellular-level transfer. They are often described as the “key” to the cell “door”, letting glucose pass through the lining of the cell to where it’s needed. The pancreas works to secret this wonderful hormone which is triggered by rising glucose levels in the blood. This is how everything in your body stays working, through the energy provided by what you eat and insulin.
Okay. Insulin 101 out of the way.
In a T2d’s body a part of that system breaks down. The pancreas still works fine, secreting insulin to keep blood glucose levels in order, but the now the “key” doesn’t always fit the “door”. It’s called insulin resistance. As with anything, when you flood a system with too much of something, the effects of that something become weaker over time. People with T2D have this problem; the level of their circulating insulin is much greater than a non-diabetic’s. Their bodies need increasing amounts of insulin to control glucose into an acceptable range. The pancreas is an amazingly flexible organ, but it can only do so much and when it can no longer produce the level of insulin needed, you get Type 2 Diabetes. Their pancreases are still working, actually overworking, but their cells no longer receive the insulin as warmly as they did before.
Ah, here’s my baby. Alrighty *cracks knuckles* here we go.
The causes of Type 1 Diabetes are complex and not completely understood. We know that genetics play a big role, but environmental factors are usually needed to “jumpstart” the process. I’ll explain. Your pancreas is 97%-ish not-insulin related. Surprise! The hormone-producing cells in your pancreas are called the islets of Langerhans (awesome name right?), within those islets (EYE-lets) are the beta cells which produce insulin. These beta cells possess a certain antigen that makes them vulnerable to attack from an immune response. That’s right, initially T1D is an auto-immune disease. For whatever reason, my immune system attacked the beta cells in my pancreas and destroyed them, making me incapable of producing insulin at all. This process may take years to complete making it difficult to nail down an exact cause (I had a severe case of chicken pox as a baby – we think that is what triggered it). Once the insulin-producing beta cells are destroyed glucose has no way of getting into the cells where it’s needed, resulting in Type 1 Diabetes. And the pancreas can’t grow a new one. There is a period after diagnoses that the beta cells that aren’t quite destroyed up and decide they want to produce insulin again – this is known as the honeymoon phase and hardly ever lasts for more than a few months.
Diabetes, in both forms, results in an inability for the body to control blood glucose levels on its own. T2ds control their glucose through medication, diet, exercise, and in extreme cases, insulin. T1ds control their glucose primarily through insulin. Obviously being healthy includes diet and exercise, but those are not the main weapons of Type 1 diabetics.
T2D can be reversed – the body still produces the correct hormone and can be re-sensitized.
T1D cannot be reversed – the insulin-producing cells are dead with no hope of regrowth.
There you have it, the physiological differences between Type 1 and Type 2 diabetics. For me, I love knowing what my body is doing and why. For you non-diabetics out there, understanding the differences between the two types will score you lots of brownie points with your diabetic friends. And everybody likes brownie points.
If you want more information or to see my sources…
This is a fascinating video I found on the hormone insulin and its myriad of different jobs in the body. It’s a very long, technical video, but interesting if you are curious — don’t worry dictionary.com is always there! Some of the things he says here might seem to contradict what I wrote earlier, don’t worry, this is just a much closer look at the biology and chemistry of insulin — everything I said before still applies and is used by doctors regularly to simplify the process.
Obviously a lot of my information has been absorbed over my life experience, but please feel free to check it out and comment if you find something different.