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ABC of Diabetes
by Peter J. Watkins
Blood glucose monitoring: optimising
diabetic control
There are two important reasons for optimising diabetes
control: the first is to eliminate symptoms, and the second
is the longerterm aim of aborting the development of
diabetic complications. Before embarking on complex
programmes, it is essential to have a clear view of the
requirements of each individual patient. The malaise
associated with poorly controlled diabetes almost always
responds to better treatment with considerable improvement
in well-being. Occasionally, those whose control has been
persistently poor for very long periods may for a time feel
less well when blood glucose levels are reduced and
consequently are at first reluctant to make the effort to
improve control.
Blood glucose measurement
Equipment
* A spring-loaded finger pricking device.
* A blood glucose meter and test strips.
* For some, a blood ketone meter combined with a blood
glucose meter and test strips.
Note: The MiniMed
Continuous Glucose Monitoring System measures interstitial
glucose levels every 10 seconds using a sensor inserted
under the skin of the abdominal wall; and Glucowatch worn on
the wrist is a new technique which repeatedly measures
subcutaneous glucose levels. They are still expensive, and
more experience in ascertaining their reliability is needed
before recommending them for routine use.
Purpose
* Spot check to detect
hypoglycaemia or impending hypoglycaemia.
* Assess control at times of illness.
* Assess blood glucose profile over 24 hours in order to
achieve ideal diabetic control.
Apart from the first two indications, isolated blood glucose
readings are of little value for optimising control.
Timing and frequency of
testing for blood glucose profiles for Type 1 diabetes
* One or two tests should be performed each day as a routine
for stable patients.
* Tests should be done at different time points each day to
build up a profile over several weeks (see page 27).
* A 12-hour profile can be measured on a single day from
time to time, taking recordings before meals (four times a
day), one to two hours after meals (three times a day) and
at bedtime. Occasionally it helps to record a reading around
3 am.
Detecting and eliminating
hypoglycaemia (see also chapter 8) Measurement of blood
glucose by patients themselves, or by their relatives, when
hypoglycaemia is suspected is the only way of establishing
whether or not the blood glucose is actually low. This is of
particular value in the assessment of children during
periods of bad behaviour, unconsciousness or convulsions.
Prediction of hypoglycaemia and therefore prevention is also
valuable especially at vulnerable times, notably
mid-morning, and at bedtime. Methods of reducing the risks
of hypoglycaemia are described in chapters 5 and 8.
Blood glucose profiles
Assessment by insulin-treated patients of the daily
fluctuations of their blood glucose values gives a much
greater understanding by patients and doctors of both
diabetic control and the effects of different insulin
preparations. Indeed, home blood glucose measurement
provides an important educational exercise for all seriously
motivated diabetic patients as well as being the essential
tool to achieve tight blood glucose control. Reproducible
blood glucose profiles are essential for making rational
adjustments to treatment. They can show not only the times
of the peaks and troughs of blood glucose concentration but
also the duration of action of different insulin
preparations in an individual patient. Unfortunately, those
whose lifestyles are chaotic also produce chaotic blood
glucose profiles.
Note: The rest of the chapter
is omitted.
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