Hypoglycemia and Diabetes: Testing the Limits
Questions, problems, and issues that confront my patients on a daily basis often inspire my blogs. Hypoglycemia is on everyone's list of concerns during a visit. Unfortunately, unintended low blood sugars are here to stay until a true artificial pancreas is developed in which a glucose sensor is "married" to an insulin pump. In this scenario, the sensor will provide information to the pump continuously and insulin will be given (or not) appropriately. We are not there yet; so we need to make do with options that are available now. These include blood glucose meters, continuous glucose sensors, monitors for sounds (baby monitors etc.), and hypoglycemia trained animals.
Firstly, let's define hypoglycemia. We all talk about it and each of you has experienced a hypoglycemic episode. In general, most diabetes experts define hypoglycemia as blood sugars less than 70 mg/dl. However, it is important to realize that in smaller children and infants, lows may be considered to be less than 80 mg/dl. Keep in mind that you may or may not experience symptoms of hypoglycemia (see following) with a low blood sugar (even less than 50 mg/dl). People that have difficulty knowing that they are low have hypoglycemic unawareness, a condition that may occur after many years of diabetes.
It also is important to understand mild, moderate, and severe hypoglycemia to know how to treat the symptoms appropriately. In situations with mild hypoglycemia, you start to feel sweaty, shaky, and very hungry. Your body is attempting to release hormones (epinephrine and glucagon) to raise blood sugar. Your body is talking to you: listen! Test your blood sugar and consume carbohydrate.
In moderate hypoglycemia, you start to feel dizzy, a bit out of it, develop mood and behavior changes, and maybe lose focus. This is called neuroglycopenia (low blood sugars affecting your brain) and must be taken seriously. In these situations you can still test blood sugars and consume carbohydrate. It is important that you do so quickly before the hypoglycemic episode becomes severe and you develop hypoglycemia associated with major brain disturbance.
Examples of severe neuroglycopenia include seizures and loss of consciousness. In these scary situations, someone else will need to come to your assistance and give you carbohydrate (by glucose paste or cake mate if you can swallow), glucagon, or glucose by vein. Your family or trained school personnel will be ready to assist with either glucose paste or glucagon. The Emergency Medical Transport team (911) is usually called in these situations to take vital signs and in some cases, administer IV glucose. A trip to the hospital for observation sometimes occurs. The goal, of course, is to avoid moderate and severe hypoglycemia as much as possible.
How can we minimize episodes of hypoglycemia in the era of intensive insulin therapy? How do you walk the fine line between tight glucose control and hypoglycemia? Answer: you do the best you can!
In teens and children, the most effective means of avoiding moderate and severe low blood sugars is to check frequently and treat accordingly. A recent study published in the prestigious New England Journal of Medicine demonstrated that the continuous glucose sensor is most effective in people with diabetes over the age of 25. In people ages 14 to 25, as well as in younger children, there was no statistical significant improvement of hb A1c. Therefore, at this point, the simple blood glucose meter is the way to go unless you are particularly motivated to use the sensor as it is medically indicated. Of course, in younger kids, it is the parent that is doing all the work and even in that situation there is no significant change in the hb A1c.
Nighttime is particularly stressful for all families. My hope is that a glucose sensor for nighttime use only will be developed to signal lows to you or your family. Many families really want the continuous glucose sensor for these nighttime concerns only. A number of my families use the monitors that allow noises to be heard if their teen or child is restless and making unusual sounds that might indicate the onset of hypoglycemia. Other interesting glucose sensors are dogs trained to detect hypoglycemia in their owners. One of my families is training a border collie to sense hypoglycemia in their young adult daughter. These animals are amazing and are able to detect subtle changes in behavior that signal low blood sugars in their owners. The dog and future owner must be trained together for several weeks prior to graduation. There are several web sites that discuss hypoglycemia-sensing dogs: www.heavenscentpaws.com, and www.dogs4diabetics.com/.
Now would be the best time to ask your family for a pet that actually will work for you!
In summary, hypoglycemia is unfortunately an evil that is here to stay...at least for the present. The best way to prevent moderate and severe hypoglycemia is to understand how your insulin regime, diet (carbohydrates), and exercise work together. In this way, you can be proactive and prevent as many hypoglycemic episodes as possible. When you do experience hypoglycemia, the next step is to know how to detect and fix it, hopefully without outside intervention.