MadSci Network: Medicine |
Dear William-
There are two types of diabetes: Type I and Type II. These were formerly called Juvenile Diabetes (Type I) and Adult-Onset Diabetes (Type II). They were also called Insulin-Dependent Diabetes Mellitus (IDDM, type I) and Non-Insulin Dependent Diabetes Mellitus (NIDDM, Type II). So why the reason for all the name changes? Well, the juvenile/adult-onset name was changed to reflect the fact that type II diabetes is now commonly seen in young people, due to the epidemic of obesity in this country. Likewise, type II diabetes is often managed with insulin therapy, so the name non-insulin dependent diabetes doesn't make as much sense.
So why are there two types of diabetes? Well, they're actually two very different diseases. Type I diabetes is actually an autoimmune disease, where the person's own immune system attacks and kills the cells that make insulin, the beta-islet cells. So a type I diabetic needs to inject insulin to make up for the fact that they no longer have the cells that make insulin in their own pancreas. Even insulin-dependent diabetics, though, can reduce their need for amount of insulin therapy by eating an appropriate diet.
Type II diabetes, on the other hand, results from dysregulation of the endocrine system. In this case, they can make plenty of insulin, but their body doesn't respond to it properly (referred to as insulin insensitivity). In this case, they may be treated with extra insulin, to compensate for their body's low response to insulin. Some type II diabetics, though, can be "treated" with proper diet, weight loss and exercise alone, and do not require extra insulin therapy.
There's actually a third type of diabetes, which is rarely talked about because it's a more unusual one. In people who have cystic fibrosis (CF), a disease characterized by unusually thick mucous secretions, the ducts leading out of the pancreas to the digestive system can become clogged. Once clogged, the enzymes that would normally go into the digestive tract to digest food get backed up into the pancreas, leading to the destruction of the pancreatic beta-islet cells that produce insulin. These people also need insulin therapy due to loss of the islets, but their disease doesn't fall into either of the two categories I've described above.
Hope this helps
ILD
MadScientist
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