3. Problems with blood sugar – May 2015
Glucose is a key cell need along with oxygen. Glucose, a type of sugar, is an important substance used to provide energy production to fuel cell activities. It isn’t used directly in these actions. Rather it is used to create another chemical called adenosine triphosphate. Now there is no great reason to remember this name so call it ATP. ATP hangs around in cells and can be used whenever the cell needs energy. In a way it works like a battery. This is a useful feature since the amount of sugar available varies depending on whether the person is eating or not. The other useful fuel source is fat usually stored in adipose tissue.
When glucose is taken in to the body it faces one of two fates. Some can be used by the cells for immediate energy needs. However the remainder will not be needed immediately but will be needed later before the next meal. Much of the sugar is stored for this purpose. There are two places sugar is stored. Most is in the liver as a chemical named glycogen. This is pretty much a whole lot of sugar molecules all joined together. The rest of the sugar is stored in big muscles such as in the legs. With it stored there it can be used if there is a sudden need for exercise.
Even with the ‘ATP battery’ process, there is still a need to deliver a fairly constant amount of sugar to the cells all the time to make more ATP. The body needs to be able to store and able to go back to the storage and get it out again for later use. The body uses two hormones produced in the pancreas to do this.
The first is insulin. When a lot of sugar arrives, such as just after eating, it is detected as it rises in the blood. The body tells the pancreas to release some insulin. The presence of insulin allows blood to move into cells for use and into the liver for storage. In short, insulin moves sugar out of the blood.
The second is glucagon. Not to be confused with glycogen which is the stored sugar even though they are spelt similarly. Glucagon is a hormone also released by the pancreas only this time when the sugar level in the blood gets too low. Glucagon tells the liver to turn the stored glycogen back into sugar and release it into the blood. In short, glucagon moves sugar back in to the blood.
This works well when there is no problem. But there all too often are problems. The most common is diabetes mellitus. Diabetes is a failure of the insulin side. There is more than one type but they all have some things in common. Firstly they all mean, because the insulin is the broken bit, that the work of insulin fails to happen properly. Recall that insulin moves sugar out of the blood. Hence diabetes means that sugar stays in the blood. This leads to blood sugar levels rising. When they rise above normal hyperglycaemia is said to exist.
When this happens the body makes some attempts to respond. It tries to clear some sugar from the blood through the kidneys and urine. This works a little bit but in the process increases urination. This also causes thirst. If fluid loss is not replaced, dehydration will result. These are the classic signs and symptoms of diabetes and high blood sugar.
This can happen early in life, particularly during childhood and come on quickly. This is one type of diabetes, type one. Hence it used to be called juvenile onset but not anymore. This type is an autoimmune disease. The pancreas is attacked from within leaving it unable to manufacture insulin. This type of diabetic will need to inject insulin into themselves for the rest of their life. For this reason it was called insulin dependent diabetes though this is no longer used either.
The next type of diabetes is type two. This is different to type one. It typically comes on later in life. It uncommonly requires insulin. It is not so much an autoimmune disease and it does not result in failure to be able to produce any insulin at all. However in every other respect it is the same. The blood sugar rises and causes the problems that go with that.
Type two diabetes creeps up on people. Many will have it and not even know. Others will have it discovered through routine doctor assessment or investigation of symptoms. Type two diabetes is in part not enough insulin production but more particularly by the insulin that is made not working properly. This is referred to as insulin resistance.
Type two diabetes is managed differently depending on how serious it is. For some it is simply to be careful with how much sugar they eat. For others, medication is needed. This is usually tablets. There are different types. The actions can include reducing the insulin resistance, slowing the uptake of sugar or helping more insulin to be made.
Occasionally these medications and diet are still not enough. In this less common case the type two diabetic will have to inject some insulin as well. This group form the third major type of diabetes, the type two insulin dependent diabetic.
Where problems present for diabetics, as said, it will usually be because the blood sugar rises too high. For the type one patient, the sugar rises very quickly. Without insulin, the only option is for cells to burn fats and proteins instead. When used for energy production these can produce waste chemicals called ketones. This makes the blood more acidic that normal. Combined with the dehydration from high sugar the patient will get sick very quickly. The same can happen to type two diabetics but usually takes longer. Prolonged very high blood sugar is a big problem.
High blood sugar is also a long term problem making it important for the patient to manage their condition carefully. High blood sugar damages small blood vessels meaning that diabetics frequently end up with damaged blood vessels in feet and toes, in eyes and in the arteries of the heart and brain predisposing to heart attack and stroke. Diabetics need to monitor their blood sugar regularly.
Somewhat confusingly though a commonly thought of problem with diabetes is actually low blood sugar. Referred to as hypoglycaemia, or ‘having a hypo’, this problem is commonly encountered by first responders but actually uncommon amongst diabetics. Recall that blood sugar in diabetes usually rises upward. It takes some interference in this process to make the blood sugar drop below normal. Typically there is one of three things that can go wrong.
Firstly, in almost all cases the patient must be taking medicine to make the blood sugar go down. Usually this is insulin but sometimes it can be the oral tablets that does it. Each and every day, the diabetic person has to eat the right amount of food, have the right amount of exercise and take the right amount of insulin. These three elements are the daily formula that have to right.
A hypo can occur if the right insulin is taken but then the person is late to eat or does not eat enough. In this case the insulin moves all the sugar out of the blood leaving not enough left. A hypo can also occur if the person eats the right food but takes too much insulin by mistake. Since sugar provides the fuel for activity, too much exercise will burn up all the sugar. So a change in activity can cause a hypo. Of course if the person is sick from some other illness the increased activity as the immune system fights the infection can also burn up more sugar than normal. It is important to ask questions in history taking to establish where things have gone wrong to lead to a hypo happening.
Jeff Kenneally www.prehemt.com
Jeff is the author of the 2014 – 2016 Ambulance Victoria First Responder clinical practice protocols and accompanying education program