Monitoring of glycaemic control

Introduction

Diabetes mellitus is a life-long condition. Blood sugar levels vary between different times of the day and can fluctuate with activity, emotional stress or illness. The disease can also progress. Good blood sugar level control today does not mean that the blood glucose control will be good for the rest of your life without any change in treatment. Since we aim to achieve lifelong control of blood sugar, it is important that we monitor the control of our blood sugar regularly. When there is a change, a higher dose of medication may be needed. Alternatively, a different type of medication or insulin may be required.

There are 2 ways to monitor the adequacy of your blood glucose control

1. Regular visits to your doctor

You should visit you doctor regularly, at least once in 3 months and more often if your diabetes is not well controlled. Your doctor can check your blood sugar. However, this will only tell you what your blood glucose is at that time and not what it has been over the last few months. Your doctor can also measure the level of glycosylated haemoglobin in your blood. Haemoglobin is the red substance in the red blood cells that carry oxygen. When the red cells are exposed to glucose in the blood, glucose attaches itself to the haemoglobin in the red cells and forms glycosylated haemoglobin in the blood. Since each red blood cells lives for 2-3 months in the blood stream, the amount of glycosylated haemoglobin in the blood gives an average of the blood sugar over the last 2-3 months. You should aim for a normal glycosylated haemoglobin. Ask your doctor what the normal level is because the value is different depending of the laboratory where the test is carried out. Even though we now have this test available, it is important to remember that this is an average of the blood glucose. A good result can be due to very well controlled diabetes mellitus or it can result for a combination of very high blood sugar at some times and very low blood sugar (hypoglycaemia) at others resulting in that same average. To avoid the latter situation, you need to get an idea of how well your blood sugar is controlled between your appointments with your doctor. Since your doctor cannot be with you all the time, it is important that you or your family member takes responsibility for the day to day monitoring of blood sugar levels.

b) Home blood glucose monitoring

A person with diabetes cannot always be in the care of a doctor or nurse every hour and every day. This is especially if the person is independent, active and has to work. Therefore learning to test blood sugar levels by him/her self is essential.

The results from the self-checks provide information about how meal intake, timing, medication, exercise and stress affect blood sugar levels.

When and How often to Check

• How often a blood sugar level check is done depends on
• What treatment is used
• What goals of treatment are
• Affordability.

• Discussion with your doctor or nurse educator is necessary to find out what your goals of treatment are.

• Frequency options (1 – 8 times a day)
  1. before each meal and at bedtime
  2. fasting and 2 hours after each meal
  3. before and 2 hours after each meal
  4. once a day, a different time each day
  5. twice a day, once fasting and one more at different times of the day
  6. fasting only.
• For options 1, 2, 3 and 6 – checks can be done everyday or one day a week or 2 – 3 days a week.
• For options 4 and 5 – checks must be done at least 3 days a week to obtain a better profile.
• When ill, it may be necessary to check the blood sugar as often as 4 hourly.
• The tighter the required control, the more often you will need to check you blood sugar.
• Monitoring can be less frequent if the blood sugar level has stabilized.

How do I measure my blood sugar

• You need to obtain a drop of blood by pricking your finger with a small needle(see hints).
• The drop of blood is then applied to the specific area or pad on a test strip and after a fixed amount of time, depending on which strip is used, the results can be read in one of two ways.

(1) Results from the test can be read by wiping the blood from the strip after the required length of contact with the strip.

• The enzyme on the strip would have reacted with the amount of glucose in the blood. How much reaction takes place will be determined by the level of sugar in the blood.
• The reaction causes the strip to change colour. By visually comparing the colour of the strip and the colours on a graded chart, the level of sugar can be read.

(2) Results can also be read using a glucose meter (this is more accurate and is the method that we would encourage).

• The meter is programmed to read the sugar level from the test strip.
• Some meters require the individual to wipe the blood from the strip. This is when the part where the blood is applied has to be inserted into the meter.
• Most meters however, do not require this.
• It is up to the individual to choose which meter is preferred taking several factors into account.

Getting started

• As with all things, practice is what makes the steps easier to remember.
• Always wash your hands before starting. This will make sure you do not have any juices from fruits etc on your skin which will give an inaccurate result.
• Always make sure you have everything you need in front of you. This will save you from constantly searching for things while doing the test.

Results

Each individual has a his / her own target range. This depends on how old you are, which type of diabetes and the duration of the diabetes. This target range would vary when there are changes in your state of health and lifestyle. How much control you want or your doctor suggests you need will also play a part is setting your target. A rough guideline would be :

Please refer to your doctor or diabetes nurse to get a proper assessment so you can both set your target ranges.

• Keep a consistent record of the results you get.
• Note the pattern of results at different times of the day.
• If there are any great changes in the result from your "usual" pattern consider the following :

1) Does what you feel at the time match the test result. eg. Do you have symptoms of hypoglycaemia when your blood sugar read low on your glucometer?

2)Did you wash your hands ?

3)Are the steps you took in order ?

4)Do the codes on your strips and meter match ?

5) Did you have enough blood on the test pad ? (too little will give a result that is too low)

6)What was time of the last meal / snack ?

7)Has there been any changes in your eating pattern / meal content / life style ?

8)Do you have a fever / flu / coughing ?

9)Have you been taking your medication properly ?

• If the change is due to (1) treat accordingly, consult your diabetes nurse / doctor for the immediate treatment method of hypoglycaemia or hyperglycaemia if you do not already know this.

• If the change is due to (2) to (4), repeat immediately correcting the step that was not done properly.

• If the change is due to (5) repeat at a more appropriate time.

• If the change is due to (7) to (9) continue monitoring closely and consult your doctor / diabetes nurse as soon as you can.

• When washing your hands before the test, use warm water.

• Squeeze your finger, just below the areas where you want to prick. This should turn the area red.

• Prick the sides of the fingertips. Do not prick the soft fatty area in the middle. It will be as more painful to do so. Try to avoid using the thumb and forefinger as these are used more (e.g in holding pens / chopsticks / cutlery). Rotate between fingers – using the same spot or the same finger may lead to callused fingers.

Decide which meter to buy based on :

(1)Cost

(2)Convenience

- Size : if the meter is to be carried around, a big meter may be cumbersome. A smaller meter is more discreet and portable.

(3)After-sales Service

This will be needed if should there be a fault in the meter after purchase.

Your doctor or diabetes nurse educator should have a number of different meters that he/she can show you and let you try them so as to assist you in your selection. In addition, members of the Diabetes Society of Singapore get discounts on certain meters and test strips and you can make enquiries at the society regarding this.