Artificial Pancreas (Closed Loop)
This is currently only available via research studies with your diabetes team. It involves wearing an insulin pump and glucose sensor, and carrying a handset device similar to a smartphone. The sensor tells the device the glucose levels, which calculates the necessary insulin and tells the pump to deliver it. This constant messaging replaces the usual set basal rate in the pump. All meals and snacks need to be calculated for carbohydrate content and a bolus given in the usual way.
Autoimmunity
The process by which the body develops antibodies (like when fighting infection), but they are directed against some part of the body’s own tissues. In type 1 diabetes, the antibodies are against the beta (β) islet cells which make insulin, resulting over time the failure to make insulin and the diagnosis of type 1 diabetes.
Basal Bolus
This refers to combining fast acting bolus insulin (Novorapid, Humalog, Apidra) for meals and corrections, with a long acting basal insulin for those on injections, or continuous insulin for those on an insulin pump. If on injections, it can also be called multiple daily injections (MDI).
Basal Insulin
Everyone has a requirement for a background level of insulin in their blood. This is required to deal with the glucose released by the liver. In someone with diabetes, this is provided by long acting insulin such as Lantus, Levemir or Tresiba, or the basal rate of a pump. A pump only contains fast acting insulin, delivered in very small amounts over 24 hours.
Blood Pressure/Hypertension
Blood pressure should be measured regularly when you attend clinic. It may increase in association with prolonged high glucose levels and may need treatment with tablets. It is rare in childhood. You can minimise risk of high blood pressure by keeping glucose in target, maintaining a healthy weight, keeping active and reducing the amount of salt in your food choices.
Bolus Insulin
This refers to the insulin given as a single dose to cover carbohydrate containing foods or drinks (food bolus), or to correct if BG levels are high (correction bolus).
Carbohydrate Counting
This is how you decide how much insulin to give with meals or snacks. By counting the grams of carbohydrate, you use your own insulin:carbohydrate ratio to calculate the dose. All insulin should be given before food.
Circadian Rhythm
Most hormones in the body are released in different amounts at different times over 24 hours. This is controlled by the natural day/night pattern and in part explains jet lag when you are flying across time zones and the circadian rhythm is disrupted. Due to the circadian rhythm of 2 hormones, cortisol and growth hormone, more insulin is needed in the early morning and late afternoon.
Continuous Glucose Monitoring Systems (CGMS)
These are devices that are able to constantly measure glucose levels in the tissues by inserting a small probe under the skin. As it is not measuring blood glucose there is a small lag time, and so should be checked with a blood glucose in case of feeling hypo. There are alarms that can be set for high and low glucose levels. Some devices share information to pumps, others can share information via smartphones. There are specific criteria for these devices to be funded on the NHS.
Dawn phenomenon
This occurs particularly in growing teenagers. It refers to the natural circadian rise in blood glucose towards early morning, due to the release of growth hormone. This is why teenagers require high levels of insulin at night.
Diabetic Ketoacidosis (DKA)
This is a very serious condition that can be fatal if untreated. Symptoms include dehydration, fast breathing and vomiting. It is usually associated with high glucose levels but not always. Ketoacidosis refers to the build-up of ketones in the blood due to the breakdown of fat. Ketones are acidic and toxic to the body. Ketones are made if you have not had enough insulin, either by missing it or not giving sufficient doses regularly, or sometimes due to illness.
Diasend/Glooko
This is the system most clinics use to download most meters and insulin pumps. More than one device can be combined together to give a complete picture of glucose levels in table and graph displays. You can also download your devices at home using Diasend between clinic visits – ask your diabetes team how to do this.
Fats
These are a calorie dense food group and source of energy. Healthy fats as found in oily fish, nuts, seeds, avocado, olive or rapeseed oil should be encouraged as they are heart protective. Less healthy fats are those found in processed foods. Too much fat of any type can lead to being overweight. Diabetes increases risk of heart disease at a young age, and young people will have their cholesterol measured from age 12 as part of annual review.
GlucaGen ®
This is the trade name for artificially made glucagon and comes in an orange box. This is used to treat severe hypos if the person is unconscious, unable to swallow or take glucose by mouth.
Glucagon
This is a natural hormone secreted by the alpha (α) islet cells of the pancreas, which is released when blood glucose levels drop too low. It causes the liver and muscles to release stored glucose to stop blood glucose levels falling too far. If you have T1 diabetes, this process is slower than in someone without diabetes.
Glucose
A simple sugar which is absorbed through the gut very quickly and easily. It is the main food source for the brain and an essential energy source for the body. It is stored in the liver and muscles. Without diabetes, the blood glucose level is controlled very accurately between 4-7mmol/L. If blood glucose is high, glucose spills into urine and takes water with it resulting in passing large quantities of urine. This can also create thirst. Low glucose levels result in feelings of dizziness, hunger, shakiness and feeling weak (hypoglycaemia).
Glycaemic Index (GI)
This refers to how quickly glucose in the food is absorbed from the gut into the bloodstream. A high food is absorbed quickly, a low GI food is absorbed slowly. Naturally low GI foods are better for health (oats, wholegrains, beans, legumes, dairy foods, fruits) and can help reduce the glucose rise after meals. High GI foods (sugary cereals, white bread, mashed potato) raise glucose levels quickly and can be harder to match with insulin. If you are on a pump, different bolus options can be given to manage low GI food.
Glycaemic Load (GL)
Glycaemic Load (or GL) combines both the quantity and quality of carbohydrates. The GL of food is a number that estimates how much the food will raise a person’s blood glucose level after eating it and is calculated by knowing both the amount of carbohydrate (in grams) and the GI of the food. It will not describe an exact rise in glucose, just whether the load is high, medium or low and therefore its predicted effect on glucose. A large amount of carbs of a low GI can have less effect than a smaller amount of a high GI food.
Glycation
The HbA1c test is for glycated haemoglobin, and refers to the binding of glucose to proteins such as haemoglobin around the body. It measures how many red blood cells have glucose attached. Glucose binds to proteins in all tissues of the body and if glucose levels stay high for a long time, it can lead to irreversible changes to these proteins. It is the mechanism by which microvascular disease probably occurs.
Glycogen
Glucose is stored in the liver and muscles as a complex substance called glycogen. It is a source of glucose particularly when extra energy is required or if blood glucose levels drop too low. Glycogen is converted to glucose when stimulated by the glucagon released by the α islet cells of the pancreas or if you have given GlucaGen for a severe hypo. Glycogen stores only last about 12 hours if you do not eat and top them up.
HbA1c (glycated haemoglobin)
This term is often misunderstood; it is not a blood glucose level. It reflects blood glucose levels over a period of time, but is a measure of the number of red cells which have glucose attached. The ideal target for HbA1c is less than 48mmol/mol (also described as 6.5%) but this can be hard to achieve or maintain. As red cells last about 3 months before they are replaced by the body HbA1c reflects blood glucose levels over 2-3 months.
Hormone
This is a chemical which is made and stored in a particular part of the body (e.g insulin in the β cells of the pancreas, or thyroid hormone in the thyroid gland in the neck). When hormones are released they travel around all the body acting on all the tissues to do a specific job (e.g insulin transfers glucose from the blood into cells throughout the body).
Hypoglycaemia (hypo)
This is the name for a low blood glucose level, usually defined as less than 3.9mmol/L. If it is associated with symptoms such as sweating, dizziness, feeling shaky, it is classed as a symptomatic hypo and needs quick treatment. It needs fast acting glucose to treat and a blood glucose recheck after 15 minutes. Common triggers for hypos are too much insulin for an amount of food, exercise and alcohol. Mild hypos are to be expected as part of good diabetes management, but should not be a frequent daily occurrence.
Hypoglycaemic Unawareness
This can occur in young children, if someone has frequent hypoglycaemia, or if they have diabetes of long duration. It means that they are less able or unable to detect hypoglycaemia at all, or until glucose levels are really low (less than 3mmol/L). If you think this is happening, discuss with your diabetes team.
Insulin
This is a hormone produced by the beta (β) islet cells of the pancreas. When glucose levels start to rise in the blood (after eating), insulin is released by these cells. Insulin allows glucose to move from the blood into muscles and cells to be stored around the body, maintaining the right amount of glucose in the blood between 4-7mmol/L. In T1 diabetes, this system does not work, and insulin must be given as an injection or via a pump.
Insulin Pen
A device which delivers insulin by injection. Some are prefilled with insulin and are disposable, some contain a 3ml cartridge (300 units) which is replaced. Half and full unit pens are available.
Insulin Pump
This is another way of giving insulin. There are different brands available but they all deliver fast acting insulin via a small tube placed under the skin. A continuous basal rate is pre-programmed into the pump, but decisions have to be made around food and high glucose levels to give extra insulin when needed. When used properly they can help to manage diabetes very well and provide more flexibility than injections.
Insulin Resistance
This is seen more commonly in T2 diabetes, but is also relevant in T1. As you become older you require more insulin due to growth, but particularly during the rapid growth of puberty. During this time, growth hormone causes insulin resistance i.e insulin does not work as well as it has done previously and more insulin is required to have the same effect. This is shown by a changing insulin:carbohydrate ratio of 1 unit per 15g carbs in a 7 year old, but 1 unit per 5g carbs in a 13 year old for the same amount of carbs. If someone with T1 diabetes is overweight, this can also cause insulin resistance. Physical activity for teenagers (whether overweight or not) can help reduce insulin resistance.
Insulin Sensitivity (correction dose)
This is the amount of insulin needed to bring a high blood glucose level back to target (5mmol/L). It varies depending on age, duration of diabetes and total daily dose of insulin.
Islet Cell
The Islet Cells (Islets of Langerhans) are found in small clumps throughout the pancreas. The beta (β) and alpha (α) cells are the ones most involved in diabetes. The β cells usually produce insulin in response to rising blood glucose levels. These are the cells which get destroyed in the autoimmune process of T1 diabetes and stop the body making insulin. The α cells usually produce glucagon in response to very low blood glucose levels, but this process can be impaired in T1 diabetes.
Ketones
Ketones are made by the body as a result of breaking down fat as an energy source. This can be a normal occurrence overnight as no food is being eaten for many hours, and these are called starvation ketones. They disappear quickly when breakfast is eaten. In T1 diabetes, ketones might be produced at other times of day, and this is a sign that the body cannot use glucose as a fuel source due to lack of insulin allowing it to be transferred from the blood to the cells. Ketones are more likely during other illness such as a cold or infection. Ketones should be measured in the blood and anything over 0.6mmol needs treatment with extra insulin and fluids. Blood glucose and ketone levels must be checked more frequently to make sure the treatment is working. Ketones can be dangerous (see diabetic ketoacidosis).
Type 2 Diabetes
This is the most common form of diabetes in the world, particularly in adults. In the early stages of the condition, lots of insulin is made, but it does not work well, so blood glucose levels rise. It is now starting to be seen in young people, usually those with a family history of T2 diabetes and those with an Asian or Afro Caribbean background. Being overweight and doing little physical activity also contribute to risk of T2 diabetes. Treatment for young people under 18y involves weight management, increased activity, and tablets to manage glucose levels. If this is not successful, insulin may have to be started.