Types of Diabetes

There are different types of diabetes, and the causes for the elevations in blood sugar differ depending on the type of diabetes you have. In this book I focus on the two major types of diabetes. The first form of diabetes that I'll discuss is called type 1 diabetes mellitus (or simply type 1 DM), (see Figure 1.1) sometimes referred to as insulin-dependent diabetes (IDDM), because people with this type of diabetes are reliant on an external source of insulin, which is injected. Type 1 DM is a condition in which the blood sugar levels are elevated because there is no production of insulin by the pancreas. In other words, these people do not produce the keys to the doors of the cell, and thus the glucose in the bloodstream cannot get into the cell (see figure 1.2a). These people have symptoms early in their lives, typically occurring in childhood or when they are young adults. Some people with type 1 diabetes may have inherited a susceptibility this condition. We think that in these people there is a reaction in the body that destroys insulin-producing cells in the pancreas, making it necessary for these people to take insulin in order to survive.

(a)

(b)

Figure 1.2. Two types of diabetes: (a) With type 1 diabetes, insulin is not present, so the glucose cannot get into the cell. (b) With type 2 diabetes, insulin is present, but the cell is less sensitive to it, so the glucose has a hard time getting into the cell.

The second type of diabetes is called type 2 diabetes mellitus (type 2 DM), sometimes referred to as non-insulin-dependent diabetes (NIDDM), because people with this type of diabetes typically do not need to take insulin (although some with type 2 diabetes will require insulin to control their glucose). This form of diabetes accounts for around 95 percent of people who have diabetes, and this form is the primary focus of this book. As in all cases of diabetes, those with type 2 have elevated blood glucose levels. However, unlike those with type 1, these people can produce insulin. Some even may produce more insulin than normal. The problem in this case has not much to do with the "key,"-insulin, but rather with the door's keyhole that allows it to open. If you have type 2 diabetes you have a high glucose level and either a low, normal, or high insulin level at the same time. The main problem in this case is that your cells are significantly less sensitive - or more resistant to - insulin and, in an attempt to keep the level of glucose inside the cells normal, the body creates a high concentration of glucose outside of the cells (see figure 1.2b). A type of diabetes similar to type 2 diabetes occurs during pregnancy, and I briefly discuss this later in this chapter. However, the information in this book is not intended as a comprehensive resource for those who are pregnant but only to give you a basic understanding of this condition.