Diabetes and Blood Glucose Testing
Diabetes is a condition in which there is too much glucose (sugar) in the blood. Glucose comes from the carbohydrates we eat, and is present in the blood as an energy source. Glucose also comes from the liver, where it is stored in order to provide a constant supply for when we are not eating.
Blood glucose is regulated by a hormone, called insulin, which is produced by cells in the pancreas. Insulin transports glucose from the blood supply into fat and muscle cells, where it can be used for energy, and also switches off the release of glucose by the liver.
People with diabetes either do not make enough insulin or do not respond fully to the insulin their body makes, resulting in high blood glucose levels.
There are three different types of diabetes:
Type 1 diabetes
People who do not make any insulin, or very little, have type 1 diabetes. It generally develops in children aged seven to 12 years, although can occur at any age. People with type 1 diabetes need to inject insulin daily and must monitor their blood glucose levels regularly. The cause of type 1 diabetes is not fully understood.
Symptoms of type 1 diabetes are often severe and generally lead to a quick diagnosis. Symptoms include:
Excessive or constant thirst
Frequent passing of large volumes of urine
Tiredness or weakness
Weight loss
Mood changes.
Some people may also have pain in their tummy, feel sick or vomit, be prone to recurrent skin infections (especially fungal and yeast [thrush] infections), get extremely hungry, or have difficulty concentrating.
People with symptoms suggestive of type 1 diabetes need to see their doctor as soon as possible.
Type 2 diabetes
Type 2 diabetes is the most common type of diabetes and usually affects people who are middle-aged or older, although can occur earlier in people who carry excess weight or do limited exercise.
Type 2 diabetes comes on gradually with a decline in the production of insulin by the pancreas – known as insulin deficiency. It can also develop when your body becomes less responsive to the insulin your body does make – known as insulin resistance.
Not everybody has symptoms, but symptoms may include feeling tired or lacking in energy, excessive or constant thirst, frequent passing of large volumes of urine, recurrent or hard-to-heal infections, deteriorating eyesight, blurred vision, or hunger.
Some people with type 2 diabetes can control their blood glucose levels through altering their diet and losing weight. Many people will need to take oral medications to treat type 2 diabetes and some people will need insulin injections.
Risk factors for developing type 2 diabetes
You are at more at risk of developing type 2 diabetes if you:
Are of Maori, Asian, Middle Eastern or Pacific Island descent and over 30 years of age
Are of European descent and are over 40 years of age
Are overweight – especially if you carry most of your extra weight around your waist
Do not exercise regularly
Have a family history of diabetes
Had diabetes during pregnancy or gave birth to a large baby, weighing more than 4kg.
Many people with type 2 diabetes also have problems with their blood pressure and cholesterol being too high.
Diabetes in pregnancy – gestational diabetes
Gestational diabetes happens when a pregnant woman cannot produce enough insulin to cope with her body’s increased needs during pregnancy. It affects around 4–8% of pregnant women. Gestational diabetes can sometimes be controlled by dietary changes but some women need insulin injections. It usually disappears after the baby is born.
Long-term complications of diabetes
When sugar levels remain high in the blood for a long period of time, damage to all the blood vessels in the body occurs. Long-term complications include:
Kidney disease
Foot problems
Impotence
Increased risk of infections
Gum and mouth problems
Nerve damage
Visual problems
An increased risk of heart attack and stroke.
These problems usually only show up in people who have had diabetes for a few years, and can be reduced by keeping blood glucose levels and blood pressure in as healthy a range as possible.
Blood glucose testing
All doctors and some pharmacies can test the levels of glucose (or sugar) in your blood. Blood glucose testing is one of the most common screening tests used for diabetes, and is also used to monitor diabetes control in known diabetics.
Normally the human body keeps its blood glucose levels very stable (between 4.0mmol/L and 7.5mmol/L). Blood sugar readings that are higher than 7.0mmol/L are considered high in people who haven't eaten for a while (called a fasting blood glucose test). Even levels higher than 6.1mmol/L will need further investigation as it may indicate a condition called impaired fasting glycaemia or prediabetes. Blood glucose tests done too soon after eating can be falsely high.
Hyperglycaemia (high blood glucose)
If you get your fasting blood glucose level done in a pharmacy and it is high, you will need to go to your doctor for further investigations.
There are a number of different reasons for high blood glucose readings in people who already know they have diabetes. Blood glucose levels can be high if their food intake is increased over a period of several days, if they have not taken their diabetes medicine as directed by their doctor or if they do less exercise than normal. Known diabetics with consistently high blood glucose readings should also go and see their doctor.
Persistent hyperglycemia can be life-threatening. The following symptoms of hyperglycaemia require URGENT medical attention:
Signs of dehydration (constant thirst, dry mouth, confusion)
Passing large amounts of urine frequently
Stomach pain, feeling sick or vomiting
Uncontrolled heavy breathing
Fruity smell on the breath
Unconsciousness.
Symptoms of hypoglycaemia (low blood glucose)
People with diabetes can become hypoglycaemic if their diabetes medication is too high or if they have missed a meal. Symptoms include:
Blurred vision
Sweating
Feeling lightheaded or weak
Headache
Aggression or irritability
Poor concentration or confusion
Trembling or shaking
Tingling in the fingers or lips
Sometimes losing consciousness.
If you suspect hypoglycemia in a person with diabetes, give them simple sugars if awake (such as half a glass of fruit juice, two teaspoons of glucose, jam or honey, or five jelly beans) every 10 minutes until their blood glucose reading is within the normal range. Follow with a meal or complex carbohydrates (slice of bread, piece of raw fruit, two crackers or biscuits). If a person has lost consciousness consult a doctor immediately.
See Your Pharmacist or Medical Professional
Diabetes is a condition that must be diagnosed and treated by your doctor. However, many pharmacies offer a blood glucose testing service to screen for diabetes.
Advice for people having a blood glucose test at their pharmacy:
Blood glucose tests at a pharmacy are usually performed using a portable glucose monitor and testing strips
The finger is pricked to produce a drop of your blood, which is placed on a testing strip that contains a chemical
The strip is placed in the glucose meter and results appear as a digital display
When taking a blood sample, it is important to ensure your finger is clean – food or drink on your skin can interfere with the test
Some bleeding can happen after the finger is pricked and there is a slight risk of infection.
If you have a high blood glucose test result this does not necessarily mean you have diabetes. However, you should see your doctor for further tests.
Other medical problems that can cause high blood glucose levels include:
Severe stress can increase blood glucose levels
Some medications have also been associated with high blood glucose levels.
Treatment Tips
If you are a person with diabetes it is important that you:
Know how to use your blood glucose meter properly, and to contact a pharmacist or diabetes educator if the equipment is not working correctly
Use the correct strips for your meter. Check that they are in date and that the meter is coded for that particular packet of strips
Discuss with your doctor or diabetes educator how often you need to test your blood glucose and what to do if your results are not within the normal range. Make sure you record your results in a diabetes diary
Wash your hands before pricking, and prick your finger on the side, towards the tip, not on the pad or tip. Hang your hand down and squeeze your finger until a drop of blood appears
Are familiar with the signs and symptoms of both hypoglycaemia and hyperglycaemia and what to do if these occur. Make sure close friends and family also know what to look for and what to do
Wear a personalised medical bracelet (such as Mediband or MedicAlert)
Talk to your doctor about how to manage your diabetes when you are sick or can't exercise.
More Information
For more information about diabetes, see the Diabetes New Zealand website
