Demystifying Diabetes

UNC Diabetes Experts answer your frequently asked questions. 


Is an Insulin Pump Right for me?

Before you can determine if an insulin pump is right for you, you need to first understand what an insulin pump is, what it does, and what are the requirements for its use.

 Insulin pumps have been around since the 70’s.  The early pumps were the size of a large backpack and were thus rarely used.  They became smaller and commercially available in the late 80’s but still did not become a standard of care until about 2000.  Today, there are over 300,000 people in the US that use an insulin pump.

 Most insulin pumps are about the size of a small pager that holds a cartridge or reservoir of insulin that is connected to tubing which enters the body through a needle or Teflon cannula that is placed under the skin.  There are currently about eight different insulin pumps on the market.  One pump does not have tubing but is applied directly to the skin and delivers insulin to your body through a Teflon cannula.  The many insulin pumps have subtle differences but all do essentially the same thing.

 In the simplest of terms, an insulin pump is an insulin delivery device that continuously delivers rapid-acting insulin in a manner more like what the pancreas would normally do.

 Pump terminology include bolus and basal rates.  The basal rate replaces the long acting injecting of insulin and is delivered continuously over the 24 hour day.  The bolus is additional insulin supplied based on user input to help control blood sugar at various time throughout the day, for example to cover food intake or correction of high blood sugar. You can think of it as replacing your mealtime or rapid-acting insulin.

 All the pumps on the market today have a “smart bolus” feature where the user inputs their current blood sugar and amount of carbohydrates they are about to eat and the pump calculates the appropriate amount of insulin to inject for that amount of carbohydrate.  This calculation takes into account consideration of your insulin-to-carbohydrate ratio, insulin sensitivity, target blood sugar, and active insulin time.  These parameters are provided by your health care provider based on your current insulin therapy.  Before starting pump therapy it is thus important to be using an insulin-to-carbohydrate ratio, correction formula, and monitoring your blood sugar regularly.

The requirements of someone using an insulin pump include monitoring blood sugar at least four times a day.  When a person is first trained on using a pump, monitoring 6-8 times a day may be required to help the provider determine the best parameters for the pump.  The user is also trained on filling the reservoir, attaching the infusion set, and inserting the infusion set every three days.  The person is initially followed closely by their health care provider to determine the basal and bolus requirements.   From a pump user’s perspective, the pros are increased flexibility for lifestyle activities and convenience.  For example, a temporary basal rate feature allows the user to decrease insulin delivery for exercise or increase insulin delivery for periods of increased need such as illness.  With insulin pump therapy it is possible to more accurately match your physiological insulin needs and thus achieve a better hemogloblin A1C.

 Are there downsides? Some people don’t like the idea of constantly “wearing” something. Pump therapy is also expensive, and even with insurance coverage you need to consider the out-of-pocket costs of the pump and supplies. And people on pumps need to check their blood glucose frequently because they have no long-acting insulin on board. Severe hyperglycemia and ketones can come on quickly if the infusion of insulin is blocked.

 Most people who start pump therapy find that the advantages far outweigh the disadvantages. If you want to find out more about what a pump can do for you, ask your physician to refer you to the UNC Diabetes Care Center for a consultation with our pump experts!

Why are diabetes rates going up so much?

November is American Diabetes Month, so it’s a good time to look at the impact of diabetes in our country. The most recent estimate is that about 29 million people in the U.S. have diabetes. This is about 9% of the population, about 12% of adults, and about one quarter of people over the age of 65. We know that rates of type 2 diabetes (the more common type of diabetes) are going up for several reasons. First of all, more and more people are overweight and sedentary, and these (along with genetics) are known risk factors for type 2 diabetes. In addition, type 2 is more likely to be diagnosed as people get older, and the population as a whole is aging (partly thanks to my baby boomer generation!).

But it’s not just type 2: Rates of type 1 diabetes also seem to be increasing in the U.S. (and other parts of the world) for reasons that aren’t entirely clear. Type 1 diabetes is an “auto-immune” disease, where the body’s immune system turns on itself (in this case, the immune system destroys the insulin-producing beta cells in the pancreas). Other types of auto-immune diseases, such as asthma and allergies, are also on the rise. One interesting theory is what’s called the “hygiene hypothesis.” We know that the immune system normally develops and learns to regulate itself by having to fight off germs in our environment. The hygiene hypothesis proposes that as we’ve increasingly gotten rid of dirt and germs, immune systems in infants and children might not learn to do their jobs properly, pre-disposing some people to auto-immune diseases. (A disclaimer before we all stop taking showers and cleaning our homes: this is just a hypothesis, and not all germs are good!)

The fact that diabetes is much more common now is not all bad news. How can that be? We have to think about the difference between incidence (new cases) and prevalence (how many people have a disease like diabetes at this point in time). Some of the increase in prevalence of type 1 and type 2 diabetes is due to more new cases. But people with both types of diabetes are living far longer than they did in the past, which also contributes to the increase in prevalence. In fact, the difference in average life expectancy between people with type 1 and others of the same age without type 1 used to be years or even decades. Now, with advances in medical care and self-management, someone diagnosed with type 1 today is likely to live as long as someone of the same age and gender as someone who doesn’t get type 1. For type 2 diabetes, the difference in average life expectancy between those of similar age with and without diabetes has also declined a lot—although not to zero difference.

During American Diabetes Month, we can think about both the good news and bad news of the increasing prevalence of diabetes. We should continue research towards preventing and curing all types of diabetes, while we also celebrate the long lives of so many among us with diabetes.

M. Sue Kirkman, MD

Professor of Medicine, University of North Carolina