1. Diabetes Mellitus “A Brief Introduction” Presented by Rainsville Family Practice Thomas L. Horton, MD

2. Imagine that this picture represents a blood vessel in the body

3. The blood vessel contains many elements including red blood cells...

4. .. as well as other elements such as proteins, white blood cells, platelets, and glucose (or “sugar”) as represented by the blue shapes in this picture. Each living cell must come into contact with at least one blood vessel and typically uses glucose as fuel. Cells may be muscle, skin, nerves, or other types - it really doesn’t matter. The principle is the same.

5. When we eat, food is transferred from the gastrointestinal tract into the blood stream. Most of this food is converted to fuel, and most of this fuel is glucose. Some foods are more easily converted to fuel than others. Refined sugar is immediately available for use, and eating sweets or foods with this type compound in it may cause a rapid and uncontrolled rise in the concentration of glucose.

6. Other foods containing more complex carbohydrates are also converted to glucose, but it happens at a more controlled rate so that the body can transfer the glucose into the cells fast enough to avoid an abnormal rise in glucose. Bread and starches are not “bad,” but they must be taken in limited amounts to avoid problems.

7. A very specific and consistent diet is key to keeping good glucose control. The diet is designed to control both the number of calories and the balance of carbohydrates, fats, and proteins. All three are necessary for good health.

8. It is obvious that the glucose (“sugar”) must get into the cell from the blood stream in order to be burned as fuel.

9. Unfortunately, the glucose molecule is too large to get across the cell membranes and get into the cell without help. This “help” comes in the form of insulin - normally secreted by the pancreas.

10. Imagine that insulin acts as “key” to “unlock” tiny doors to allow the glucose to get into the cells. The more doors that are opened, the more glucose is pulled out of the blood stream.

11. When one checks a glucose, the number obtained represents how many milligrams of glucose are in each deciliter of blood (or mg% - basically the concentration of glucose in the blood at that point in time). The ideal value is somewhere between 60mg% and 110mg% in a fasting state (at least eight hours after eating) and may normally go as high as 175mg% in the first two hours after eating. During this time, fuel is being transferred from the G-I tract into the cells for consumption or storage. Depending on how efficiently the body is able to accomplish this transfer, the glucose may fluctuate substantially. Anything higher than 110mg% in a fasting state or 175mg% after eating represents diabetes mellitus. Many people have the misconception that the glucose is a steady number. In truth, it normally changes throughout the day, depending on diet and activity.

12. Diabetes is sometimes related to insulin resistance. In this case, the pancreas makes enough insulin, but it is ineffective and cannot easily “unlock” the doors. This is called Type II (adult onset or non-insulin dependent) diabetes. We generally use pills (oral agents) to help the body’s own insulin work more effectively. This condition is typically associated with being overweight. People often fail to realize that oral agents do not help immediately lower glucose. The body uses insulin to lower glucose. The oral agents simply help the insulin work better. Therefore, it is not appropriate to “take another pill” when glucose is high, nor is it appropriate to leave off the oral agents because the glucose is normal or low-normal. The daily dose of the oral agents needs to remain constant.

13. Sometimes, the pancreas simply does not make enough insulin. This is called Type I (juvenile or insulin dependent) diabetes. This type diabetes often results in weight loss - the cells “starve” because they cannot get adequate fuel. We must use extra insulin to treat this. This currently requires injections because insulin cannot be given in pills. Stomach acid digests insulin before it can be absorbed, so it has to be given by some other route. Efforts are under way to develop easier ways such as nasal sprays, but multiple daily injections are today’s best bet. Often, we use a combination of both oral agents and insulin to get the best results since people frequently have both insulin resistance and a relative deficiency of insulin in the body.

14. How well are you controlling your glucose? To understand how the glucose averages over time, we use another test. Some of the glucose molecules attach permanently to the red blood cells. Since the red blood cells typically survive 6- 8 weeks, one can make an estimate of how high the blood sugar has averaged over the past 6-8 weeks by measuring the amount of glucose attached to the red blood cells. The more glucose, the higher the average. This number is called a hemoglobin A1C.

15. We like to see hemoglobin A1C values of about 6. This indicates very good average control - glucose values around 110mg%. Ultimately, the cardiovascular consequences of diabetes such as retinal deterioration, heart attacks, strokes, peripheral vascular disease, and kidney disease are dependent on the average glucose, not what it does occasionally. It has been stated that for every day the glucose is not well controlled, one’s cardiovascular system ages two days. Therefore a 50 year old patient with poorly controlled diabetes for the past 20 years has the equivalent of a 70 year old heart and cardiovascular system.