Alternative site testing

[hanadr]

I mention this every so often and someone always pops up to say it's not accuate.

The issue is not accuracy, but response time. If BG is changing rapidly, the alternative sites lag a few minutes behind the fingertips. this lag may be as much as 20 minutes, but it may not be there at all. That is individual to each person. In any case if the site is rubbed briskly, the blood comes better to the surface and the lag[if it exists] is neutralised or minimised.
My BG doesn't change quickly, so using the inside of my forearm is a definite plus. There are very few pain sensors in that part of the skin. they are probably a good centimetre apart. This makes AST painless. In fact unless I hit a sensor, I don't usually feel it at all.
I test twice a day usually, Once fasting and then once somewhere else in the day. More wouldn't be helpful, because my BG changes slowly. Of course I had to find that out by testing.
Just thought this might help other people

 

[cugila]

Hi Hana. I wonder who that could be........ :wink:

Just a few comments from various websites about the subject.

Alternative testing sites'
Some meters offer alternate site testing, which allows a consumer to test on sites other than the fingertips, which can become sore and callused over time. However, alternate site testing is not as accurate as finger pricks. If your reading is low from an alternate test site (i.e., forearm), or you feel like you may be low, you still have to repeat the test on a fingertip.

The main drawback of alternative site testing is that they are not consistently reliable. A person may test higher on the forearm than if they had tested on their fingers. This can be a real problem if a person (especially child) is already on the low side. A false higher reading may prompt a parent to give a correction bolus when in fact, the child is already, or heading into, a state of hypoglycemia (low blood glucose).

IOH Health Tip: When traveling, it is better to use fingertips. Rapid changes in blood sugar, especially on airplanes, may not be detected in alternative testing sites.
For now, finger tip testing is still more reliable than alternate site testing.

OR THIS
When Is Testing On The Finger Preferred?
It is important to note that when your glucose is changing rapidly, there may be a difference in the glucose readings between your finger and other test sites, like the forearm, upper arm, thigh, calf, and other areas of the hand. Differences in blood glucose measurements between the other test sites and your finger many be observed after eating, insulin medication, or exercise. Because blood flow to the finger is three to five times faster than other alternative sites, blood samples from the finger may show changes in your glucose sooner than the forearm, upper arm, thigh, calf, and other parts of the hand. The possible difference in glucose readings between the finger and other alternative sites could delay your detection of hypoglycemia.

Testing On The Finger Is Recommended:
If you think your blood glucose is low (hypoglycemia). Blood glucose that is too low must be treated right away. If you have symptoms such as weakness, sweating, nervousness, headache, or confusion, follow your doctor's recommendation for treating hypoglycemia.
If you have a history of hypoglycemia unawareness (no symptoms when your blood glucose is low).

So, if you are new to all this. Don't use AST until you have discussed it with your GP or other HCP. It is important. Despite what some people say.

 

[hanadr]

Ken
I did say my blood glucose doesn't change fast. It has no reason to.

From your own post:

>>OR THIS
When Is Testing On The Finger Preferred?
It is important to note that when your glucose is changing rapidly, there may be a difference in the glucose readings between your finger and other test sites,<<

There must be many T2s like me whose BG is pretty stable and who don't use insulin or orals that stimulate insulin production and for whom the AST is ideal[as it is for me]
Hana
PS as far as can see, since all finger stick tests are only approximately the same as a venous test would be, consistently using the same area AST is perfectly valid.

 

[cugila]

Dear Hana.

Whatever you do is not the issue, it is what should be added about the advice to consult with your Gp or other HCP if considering the use of AST. You can stick it in your nose if you want to. :lol:

The caveat is for the benefit of any newly diagnosed Diabetic's, that's all. Experienced users are able to read the advice and will make their own minds up. New users need guidance.

Ken.

 

[Dobbs]

IOH Health Tip: When traveling, it is better to use fingertips. Rapid changes in blood sugar, especially on airplanes, may not be detected in alternative testing sites.

hi Ken.
Could you (or somebody) tell me a bit more about this "rapid changes in blood sugar especially on airplanes"? I fly often because of work - I don't like it and feel it's unhealthy, but does it mess my blood sugar around also?
Thanks.

 

[cugila]

IOH Health Tip: When traveling, it is better to use fingertips. Rapid changes in blood sugar, especially on airplanes, may not be detected in alternative testing sites.

hi Ken.
Could you (or somebody) tell me a bit more about this "rapid changes in blood sugar especially on airplanes"? I fly often because of work - I don't like it and feel it's unhealthy, but does it mess my blood sugar around also?
Thanks.

Hi Dobbs.
As far as I am aware it is not so much the actual flying that is the problem. It is that fact that if say you eat/drink something and it causes a rapid rise in Bg then that is the reason you should be testing normally using a finger. Conversely there is also the scenario I sometimes experience when I can be at a normal level then suddenly start to drop quickly after injecting my Byetta and then having a meal. Sometimes it is too effective !

 

[hanadr]

I should think that changing time zones could cause problems.
Otherwise test and find out.
Hana

 

[candyfloss]

Cugila, you said "Some meters offer alternate site testing". Do you mean the lancing device that comes with the meter offers alternate site testing? I dont understand how a meter knows from what part of the arm the blood came from.

I use a FreedomLite. Instructions state, "you can test your blood glucose on your forearm, fingers, upper arm, hand, thigh or calf." and "WARNING: If you are testing for hypoglycaemia (low blood glucose), or if you suffer from hypoglycaemia unawareness, we recommend that you test on your fingers". In view of these instructions and being a T2 with diet control I always test on my forearm which is of course a lot more comfortable than doing it on a finger. Twice I tested it on my finger at the same time and one result was identical and the other, I think .1 or .2 different.

So when there is talk of 'differences' or 'inaccuracies' regarding the forearm, finger, thigh etc etc what variances are we precisely talking about here? 1%, 5%, 20%, more ??
Unless you are hypoglycaemic, on insulin or medication is it really worth testing on a finger (with the inevitable discomfort) when the blood from the forearm will give as good a result?

 

[sugarless sue]

I test on my two fingers of each hand on alternate days and never have a problem doing it.
If you set your lancing device to the lowest setting to just pierce to skin and draw blood it should not be sore at all.

 

[cugila]

Cugila, you said "Some meters offer alternate site testing". Do you mean the lancing device that comes with the meter offers alternate site testing? I dont understand how a meter knows from what part of the arm the blood came from.

Hi candyfloss.
If you re-read my post, I didn't actually say that. This is what prefaced the two extracts from websites. "Just a few comments from various websites about the subject."
Giving the views from other places, not just mine.

Any blood that is taken is analysed by the meter regardless of where the blood came from. Perhaps whoever wrote it could have worded it better. The information it contains is still the same though.
Still valid.

Here is an extract from yet another website. I have loads more........ :wink:

1. Changes in glucose can be detected first on the finger, and the changes can lag on the forearm.

2. Rubbing the test site prior to testing stimulates blood flow and minimizes the difference between the alternate site and the finger.

3. The faster the changes the greater the difference between forearm and finger.

4. There are significant differences from person to person. In some people the lag time is very short, and the differences between arm and finger are negligible. In other people the lag time can be significant—15-20 minutes.

The lag is most significant in the detection of hypoglycemia. For some people the detection of hypoglycemia will be much more effective if the finger is used as the test site.


If you want to use it just be aware it is not accurate because of the 'lag time.

As for hurting your fingers, I test probably 7 or 8 times a day since January using the same three fingers on my left hand. No soreness or callouses. As Sue says, just make sure the pricker is set as low as you can to obtain the blood.

Whatever method you use is as I said before, up to you. Please don't shoot the messenger.....

 

[jopar]

You should discuss AST with your health care professional... Mainly to gem up on the pro's and con's of using this method...

Flying can have quite an effect on Blood Glucose levels more so if you dislike it, as this can produce stress which can effect your BG for most it increases it, by there are those that find stress drops there levels...

Time Zone's this is probably more probmatic for those that take medication for there diabetes, increasing with what type of medication you take, time zones crossed and final time difference... So it's wise to consider how you may adjust your medication or insulin before you travel...

I know that with my diabetic clinic, if you e-mail or phone then with the details of time zones etc they will work out a plan of action for you...

 

[candyfloss]

Hi Cugila,

just intrigued about these 'differences' you hear talked about when testing from the alternative sites and wondered how significant are they. No one mentions the numbers. Perhaps I'll do some more self testing.

thanks for your reply. I wouldnt shoot you - I find your posts too interesting!

 

[cugila]

candyfloss.

Thank goodness for that !!! I can come out of my bunker.....

I do have a pdf with comparisons and I will try to load it again, it just doesn't seem to want to upload for some reason. I am unable to copy it either ?? The figures are quite significant and I would certainly not be able to use AST as my numbers can change rapidly. I will try it later today.