Matthew Anson, blood testing, HbA1c, CGM and Time In Range

LIVINGLIVING

MORE THAN A NUMBER?

T

he management of

diabetes is, in its purest

form, a numbers game,

from blood glucose, to

HbA1c, to carbohydrate

counting. It is not by any means an easy

feat. Blood glucose is by far the most

difficult of all the blood parameters to

control artificially due to the plethora of

factors that influence glucose levels and

to the relatively unpredictable nature of

our treatment, insulin.

Tackling this minefield of numbers and

their respective units of measurement is

quite a challenge, interpreting what they

mean and how to act upon the data in

front of you is another.

First of all, most of us are familiar with

the HbA1c test. HbA1c is essentially how

much of your red blood cells (the ones that

carry oxygen and give blood its distinctive

colour) have glucose attached to them,

with a healthy range lying somewhere

between 4-6%. In other words, 4-6%

of red blood cells have a molecule of

glucose stuck to it. Because red blood

cells have a lifespan of roughly 120 days,

it gives a fairly good representation of the

average glucose control of the preceding

three months.

However, 'time in range' (TIR) is a

relatively new parameter that has come

from the use of continuous monitoring

of blood glucose (CGM). Using this

technology makes it possible to calculate

how much time your blood glucose is

within your individual target range (e.g.

4-7mmol/L). This can be expressed as a

percentage (e.g. 'You spent 70% of time

between 4-7mmol/L in the preceding two

weeks).

About time

The major limitation of 'time in range' is

that it can only be gleaned by use of CGM

sensor technology constantly measuring

blood glucose, yet it is a much more

powerful and accurate representation of

glucose control, far superior to HbA1c.

For example, Patient A and Patient B can

both have a HbA1c of 7.5%, but taking a

look at 'time in range', Patient A spends

only 40% of the time in range with 15% of

time being hypoglycaemic. Compare this

to Patient B who spends 70% of time in

range, with only 2% as hypoglycaemic.

Traditional HbA1c cannot differentiate

between Patient A and B.

It comes as no surprise then that

clinicians and patients alike are keen

to adopt this new method of reporting

glycaemic control, hindered not least by

the poor access of devices capable of

calculating 'time in range' as well as the

cost of these items.

Improving access to such

technologies has been priority for the

NHS in recent years, with the Abbott's

FreeStyle Libre, which uses Flash

glucose monitoring, arguably having

been the most significant disruptor of

the glucose monitoring market to date.

The Libre certainly qualifies as a device

able to report 'time in range', however,

does it qualify as being a CGM device?

In essence, no, but is this the question

we should be asking? The distinction is

important for certain groups of people

with diabetes who share common

characteristics who require the real-time

alarms offered only by 'traditional' CGM

devices, such as Medtronic's Enlite or

Dexcom's G5 and G6 sensors. But for

the majority of patients, the distinction

between Libre's flash monitoring system

and 'bells and whistles' traditional CGM is

not that significant. Then again, with the

arrival of an augmented Freestyle Libre 2

announced last year, promising to alarm

when glucose falls or rises above pre-set

thresholds, the line between what is and

isn't CGM will be even less clear.

About right

When it comes to glucose sensors of

any nature there is naturally a concern

over the accuracy of the technology. All

blood glucose meters and 'benchmarked'

Thoughts on ways of doing blood tests,

using CGM, and the analysis of test

results by medical student and T1

diabetic Matthew Anson.

continued over

Index

  1. Desang diabetes magazine diabetes information
  2. Abbott Freestyle Libre, Flash Glucose Monitoring, blood testing without lancets
  3. Desang diabetes magazine diabetes information, Sue Marshall
  4. Desang diabetes magazine diabetes news
  5. Desang diabetes kitbags, free online diabetes magazine, diabetic kit
  6. Now Patient repeat prescription delivery service
  7. Now Patient repeat prescription delivery service
  8. Desang diabetes magazine diabetes news, Diabetes UK
  9. Now Patient repeat prescription delivery service
  10. Desang diabetes magazine diabetes news, Diabetes UK
  11. JDRF Type 1 tea party, raise awareness Type 1 diabetes
  12. Desang diabetes magazine diabetes diet
  13. Page 0013
  14. Roche Diabetes Care UK
  15. Dexcom CGM, continuous glucose monitoring
  16. Page 0016
  17. Input diabetes, help to get diabetes technology, access to diabetes technology
  18. Sleeping and diabetes, sleep and diabetes, diabetes and sleep
  19. Sleeping and diabetes, sleep and diabetes, diabetes and sleep
  20. Sleeping and diabetes, sleep and diabetes, diabetes and sleep
  21. Ascensia Contour Next One Diabetes blood test meters
  22. Sleeping and diabetes, sleep and diabetes, diabetes and sleep
  23. Ypsomed MyLife Diabetes care blood glucose monitoring systems
  24. Desang Diabetes Magazine, free diabetes magazine, living with diabetes
  25. Desang Diabetes Magazine, free diabetes magazine, living with diabetes
  26. Matthew Anson, blood testing, HbA1c, CGM and Time In Range
  27. Dexcom CGM, continuous glucose monitoring
  28. Page 0028
  29. Matthew Anson, blood testing, HbA1c, CGM and Time In Range
  30. Omnipod Insulet insulin pump with insulin pods, podders
  31. Omnipod Insulet insulin pump with insulin pods, podders
  32. Omnipod Insulet insulin pump with insulin pods, podders
  33. Omnipod Insulet insulin pump with insulin pods, podders
  34. Making Carbs Count, carb counting for diabetes
  35. Desang Diabetes Magazine, Making Carbs Count, carbohydrate counting for diabetes
  36. Accu-Chek Insight insulin pump
  37. Accu-Chek Insight insulin pump
  38. Desang Diabetes Magazine, free diabetes magazine, living with diabetes

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