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Managing Diabetes

Home Blood Glucose Monitoring (HBGM)

What is HBGM?

Effective management of your diabetes often requires regular testing, especially if you are aiming for tight control. Home blood glucose monitoring uses small portable meters to accurately measure glucose concentrations in finger prick blood samples. Refer to the leaflet on 'tight control' for more advice on the benefits and difficulties of achieving tight blood sugar control.

HBGM provides useful information for you and your carers to

  • assess 'trends' in your day to day glucose levels
  • evaluate factors causing high or low blood sugars
  • assess the impact of diet, exercise, work and stress on your blood sugar
  • take decisions when you are sick
  • take decisions on changes in treatment

Who should monitor their sugar levels?

There is no reason why anyone with diabetes should not measure their blood sugars, however certain people are strongly advised to do so

  • Type 1 diabetes
  • Poorly controlled diabetes
  • 'Brittle' diabetes - widely fluctuating levels
  • recurrent hypoglycaemia
  • shift workers, athletes, drivers,
  • during intercurrent illness

How often should I be monitoring my levels?

Discuss this with your doctor or diabetes nurse. As a general rule test at different times of the day, rather than at a single fixed time each day. It is useful to have a general idea of your blood glucose before breakfast, lunch and dinner and at bedtime. Blood glucose concentrations two hours after meals also provide useful information. Remember that blood glucose levels go up and down all the time. Eating will make your sugar go up; exercise, insulin and oral hypoglycaemic tablets will make your sugar go down.

It would be nice to have information about your glucose concentrations 4-6 times a day but this is not very practical and we would not usually ask you to do this unless you happen to be pregnant! If your control is good, a single reading each day is adequate for most people providing you sample at different times from day to day.

This is painful!

Fingers being sensitive, sore fingers are an occupational hazard of checking your blood sugars frequently ! Reduce the pain factor by avoiding overly frequent sampling and by using the side of your fingers rather than the pulps. Also avoid using alcohol to wipe your fingers before a test. Studies have shown it does nothing to prevent infection.

It also helps to use different fingers - you have ten to choose from! One of my patients had a particular finger assigned for each day of the week ! This allows the site to heal before you inflict another 'stab'.

Some modern meters use very tiny amounts of blood, thereby reducing the depth of finger stab which is necessary. This can also influence the pain factor.

What is the normal blood sugar?

Blood sugars vary throughout the day. Target blood sugars will also vary according to how tightly you need to be controlled. Your doctor or nurse will advise you on the range of blood sugars you should aim for.

When should I consider doing extra tests?

Extra blood tests are useful during

  • illness or stress
  • changes in insulin regime
  • treatment with steroids
  • pregnancy
  • when control is 'unstable' e.g. recurrent hypoglycaemia
  • when your level of activity changes dramatically eg. vigorous exercise
  • driving long distances

Extra night-time tests are sometimes used to help identify the cause of nocturnal hypos.

How do I set about doing a test?

  • Wash your hands with warm water and dry them thoroughly. This will improve the blood supply to your fingers. Avoid using alcohol as it stings.
  • Select a different finger or different part of your finger for each test you do. Repeated tests in the same place will make your fingers very sore and may give rise to callus
  • Avoid using your finger tips. Fingertips are very sensitive and have a higher density of pain receptors. Use the sides of your fingers as denoted in the picture.
  • Hold the fingerprick device against the side of your finger. Remember if you press hard, the puncture will be more deep.
  • Press the release button and gently squeeze your finger to obtain a drop of blood
  • Apply the drop of blood as instructed in your meter manual and proceed with the test

Why do doctors sometimes request a sample from my arm?

Laboratory blood glucose measurements are more accurate when your blood glucose concentrations are very high or very low. Furthermore capillary (finger prick) blood gives a different reading from venous (arm) blood.

Keeping records

Most blood glucose meters have memory functions for storing reading. It is recomended, however that you keep a paper-based record or diary. Ask your diabetes nurse for a log book. Write down any comments on changes in food, activity, sickness or stress in the column provided.

Always bring your log book with you to clinic as it helps decision making ! 

Choosing a blood glucose meter

The following features may be worth considering in selecting a glucose meter

  • how easy is it to use?
  • Size
  • speed

If you are constantly on the move, a smaller meter may be more important to you. People with visual impairments may require a large display. If you like keeping paper records, memory functions may be less important. Most meters available on the market today are reasonably accurate within certain limitations.

Are the strips available on prescription?

Yes, if you are on tablets or insulin treatment, your doctor will be able to prescribe test strips and lancets for you on a standard NHS prescription. If you are on diet alone, you will have to purchase the test strips. The blood glucose meters, finger pricking device and control solutions are not available on prescription as yet.

Alternative site testing

Alternative site testing is now being trialled though still not in widespread use. Further information will be provided when available.

Downloading data to a PC

Some meters allow you to transfer the readings from your meter, using special software and a connecting cable, on to your Personal Computer. The data is then analysed by the Computer and made available in the form of graphs and charts. If you wish to have this facility check with your meter supplier before purchase as this is likely to involve an additional cost.

 

Dr Nishan Wijenaike, Consultant Physician,
West Suffolk Diabetes Service
October 2002