Chapter 1

Getting an Overview of Diabetes

IN THIS CHAPTER

Picking up the basics about diabetes risk, blood glucose, and insulin

Defining the types of diabetes (including prediabetes)

Identifying diabetes symptoms and getting a proper diagnosis

Working with a blood glucose meter or a continuous monitor

Recognizing the important links between fitness and diabetes management

One in three Americans currently has diabetes or prediabetes; that's over 100 million people in the United States alone. This isn't a small health issue, and it's not likely to go away anytime soon. But what do you really know about diabetes, other than it involves having extra "sugar" in your blood? How do you know whether you have type 1, type 2, or prediabetes? What's the difference?

In this chapter, you find out what makes someone develop diabetes and the types, along with how each is diagnosed. I also explain why a blood glucose meter can become your new best friend and how to get the most information you can out of it.

Knowing Your Risks for Diabetes

What's your risk for getting diabetes? It has gone up substantially in the past few decades. In fact, anyone born in the United States from the year 2000 forward has a one-in-three chance of developing diabetes during his or her lifetime, and the incidence is closer to 50 percent if you're part of a minority group (like African Americans, Hispanics, or Native Americans).

More than 29 million Americans - close to 10 percent of the population - are estimated to already have diabetes, and this number is growing rapidly. Over a quarter of them don't even know they have it. Add in prediabetes, and the number goes up to over 100 million Americans, or one person out of every three.

Everyone knows someone who has diabetes, so why worry about it? Because high blood glucose levels can be deadly. Having poorly managed diabetes can rob years from your life, and the shorter time you do have may be lived in much poorer health. Ignorance isn't bliss; ignoring diabetes and not attempting to prevent or manage its possible health consequences isn't the way to go if you want to live long and well.

Worldwide, this disease causes more than 3.2 million deaths per year, or 6 deaths every minute. Many more deaths are likely related to health problems caused by diabetes that are attributed to some other direct cause, such as a heart attack or a stroke, even though diabetes lead to those events. Unfortunately, poorly managed blood glucose can cause problems with almost every part of your body, including your heart, blood vessels, brain, kidneys, nerves, muscles, and bones. It can even lead to impotence and hearing loss.

Okay, so far this section has been depressing. Here's some good news: Most diabetes-related health problems are preventable. You simply need to get more physically active and follow a more healthful diet. If your health care provider prescribes medications, taking those may also help prevent future health issues. The combination of these improved lifestyle choices helps lower your blood glucose and prevent systemic inflammation that leads to heart disease, nerve damage, and other health complications when not thwarted.

Well-managed diabetes can be the cause of nothing - that is, no health problems.

Understanding the Culprits: Glucose and Insulin

The human body has to manage its own blood glucose, which it does quite effectively in most people most of the time. You have to have enough glucose in your blood; it's required for your brain and your nerves to function properly. The amount in blood is regulated by a hormone called insulin. The following sections explain how these two components work.

Think of glucose and insulin as the actor and the director in a performance. The insulin (director) tells the glucose (actor) where to go and what to do to get the best showing out of it. It takes the two coordinating their roles to get the show done.

Glucose is the actor

When people talk about "blood sugar," they mean blood glucose, the primary sugar in your bloodstream that fuels the brain, nerves, muscles, and other cells around the body. Having too little in your blood can kill you. Unfortunately, so can having too much, especially over the long haul.

Normally, your body digests the food you eat and breaks it down into more easily absorbed molecules, of which glucose is one. It's a simple sugar that comes mostly from the carbohydrates you eat.

Blood glucose can come from different sources, but you get it mostly from your food and drinks (although your liver makes some, too). Foods rich in carbohydrates (such as grains, milk, fruit and fruit juice, starchy vegetables, most desserts, and sugary drinks) are released as glucose in your bloodstream after your body digests them. Blood glucose levels normally increase slightly after eating, even if you don't have diabetes. Your brain, nervous system, and active muscles use some of that glucose right away, although all cells in the body use glucose at some point. When everything is working right, the body stores away the rest for later.

When your blood glucose levels are higher (such as after a meal), extra glucose usually gets packed away and stored in the liver and muscles as glycogen. When your blood glucose is low, glucagon (a hormone made by the pancreas) is released and signals the liver to let out some of its stored glycogen as blood glucose. When you're active, your muscles also use some of the glycogen stored in them as fuel, but the glucose coming from muscle glycogen stores stays in the muscle and doesn't raise your blood glucose. Using up the glycogen in your muscles by exercising gives your body a place to easily store more carbohydrates after you eat the next time, reducing the amount of excess glucose flowing around in your blood, potentially causing inflammation and damage.

Insulin is the director

When your body is working normally, your blood glucose goes up after you eat a meal, and your pancreas senses this increase and releases a hormone called insulin to help lower it. Insulin works by binding to its receptors on cells in muscle and fat, the primary places where the body can store glucose for later use.

Two separate, but related, aspects of diabetes are associated with your body's insulin. One is how effectively insulin works. If you have type 2 diabetes or prediabetes, insulin may be abundant, but it doesn't work well to lower blood glucose - that is, you have insulin resistance. People with other types of diabetes can become insulin resistant as well. The second is the amount of insulin that is available. Persons with type 1 diabetes make little or no insulin; people with prediabetes and type 2 diabetes have an inadequate amount of insulin produced to meet their needs.

Insulin is a hormone made by the pancreas that, when released into the bloodstream, works to allow blood glucose to enter your cells that are insulin sensitive, primarily muscle, fat, and liver cells. Some of it gets used as a fuel by those cells, but the rest is stored in these tissues for later use. During rest, insulin works to make sure that glucose leaves the blood and goes into the cells, which keeps your blood glucose from going too high or staying that way after eating. Unfortunately, excess blood glucose that can't enter cells for any reason can cause damage to your body over time.

UNDERSTANDING INSULIN RESISTANCE

Regardless of which type of diabetes you have, you can become resistant to the effects of the hormone insulin, even if you have to pump or inject it instead of making your own. That fact makes insulin resistance relevant to everyone with diabetes of any type or prediabetes.

Think of insulin resistance with a lock and key analogy. In your body, glucose in the blood is trying to get through the door to your muscle and fat cells. To get inside the cells, the glucose must have a key to open the door. Insulin is the key that goes into the lock (or insulin receptors, in this case) to make it open. If you have the key (insulin), but the keyhole on the lock is blocked or the key won't turn when it goes in, then glucose can't enter, and you have insulin resistance - lots of insulin available but not working well. When the keys and the keyholes are functioning well together, the doors open, and glucose enters the cells and lowers the levels in the blood.

The other aspect is how much insulin the pancreas produces. You can be deficient in insulin, meaning that you simply don't make much. People with various types of diabetes can also have this issue. In that case, they may need to take medications to stimulate the pancreas to produce more, take insulin to supplement their supply, or use other medications that lower blood glucose other ways. In either case, your blood glucose may rise too high at various times, such as after you eat, when you're stressed out, if you're ill, and when you exercise vigorously.

Regardless of whether you have insulin that doesn't work well or too little of it overall, exercise can help your body use insulin more effectively. Weight loss can also help. Being more sensitive to the insulin you do have means that less insulin can lower blood glucose more. In people who have insulin resistance, improving the action of insulin may even reverse the course...