PDA

View Full Version : Test on fore-arm and finger


doctordun
02-28-2008, 12:06 PM
After a very delicious Chinese lunch at my favorite restaurant and indulging in carbs for the 1st time in 4 weeks, I decided to test the difference between my forearm and finger bg. I have an accu-check advantage which doesn't state you can do alternate sites, but I understand that has mostly to do with how large a blood sample you can get and the time of the test. I tested 2 hours past lunch.
My forearm was 139 and my finger on the same arm was 130 within two minutes of each other.
Is that close enough to proceed with forearm testing? Of course I plan to do a few more comparisons. I can hardly feel the stick on my arm, so I'd like to alternate there to give my fingers a break.

princesslinda
02-28-2008, 12:25 PM
If you are more comfortable with sticking your forearm, by all means use it! If, however, you get a really high or really low reading on your forearm, i'd suggest you retest on your fingers to make sure all is well. When you blood sugars are changing rapidly...such as just after a meal or with exercise...or when you think you may be going low, test on your fingers.

wiseguy
02-28-2008, 12:42 PM
The blood in your fingertips is the same blood that is everywhere else on your body. I have also read that fingertip testing shows changes in BG more quickly than alternative sites. I'm not sure that I really buy into this theory because of the numerous times I have confirmed forearm readings with finger sticks. They were always as close as I would get from two separate finger sticks.

Many people state that they have a hard time getting enough blood from forearm sticks. I believe most of these people are simply not doing it right.

princesslinda
02-28-2008, 01:04 PM
In the interest of science...and because I was curious;) ...I tested on both the forearm and my finger...forearm test did leave a mark.

Forearm 92
Finger 106

My main reason for not testing on the forearm was that I bruise very easily...and I very noticeable spots on my arms...so much so that people noticed (as I test 4-5 times a day). I never have had problems getting blood from either place (probably because I am on BP meds).

doctordun
02-28-2008, 02:32 PM
In the interest of science...and because I was curious;) ...I tested on both the forearm and my finger...forearm test did leave a mark.

Forearm 92
Finger 106

My main reason for not testing on the forearm was that I bruise very easily...and I very noticeable spots on my arms...so much so that people noticed (as I test 4-5 times a day). I never have had problems getting blood from either place (probably because I am on BP meds).

Interesting that you were lower on your forearm and I was higher when compared to my finger.

Kim_in_TN
02-28-2008, 06:32 PM
Well that's as frustrating as a scale that weighs you something different every time you step off and on again! I think I'll "stick" to my finger! I'd be really frustrated with different readings all the time.

TomB
02-28-2008, 07:51 PM
Back when I slaved as an electronics engineer for a living I frequently had a run in with the words: Accuracy and Repeatability. So awhile back I did some back to back testing doing such things as making a big drop of blood and testing it a few times and even playing around with the Control Solution CTL stuff.
Bottom line: Accuracy and Repeatability is +/- 10%. It doesn't matter what brand of meter you use, so don't sweat the small stuff. About the only way you can get an accurate reading is to take the average of 5 from the same drop of blood. And by the time you've done that, your body has changed so you're back to scratching your head. Save your hair. Anyone up for a game of Statistical Process Control?
Tom

ant hill
02-28-2008, 08:42 PM
Bottom line: Accuracy and Repeatability is +/- 10%. It doesn't matter what brand of meter you use, so don't sweat the small stuff. About the only way you can get an accurate reading is to take the average of 5 from the same drop of blood. And by the time you've done that, your body has changed so you're back to scratching your head. Save your hair. Anyone up for a game of Statistical Process Control?
Tom

Just as was reading this thread, By having say 5 tests from 5 sites of your body and calculate the average you will have an overall BG measurement in which I think is the most accurate BG measurement would you think??

wiseguy
02-28-2008, 09:01 PM
Well that's as frustrating as a scale that weighs you something different every time you step off and on again! I think I'll "stick" to my finger! I'd be really frustrated with different readings all the time.
Good analogy and that's exactly what you will experience with BG monitors. Take two readings from the same finger stick and see how they compare. It's the accuracy (or inaccuracy) of the monitor and not the location of the blood sample.

TomB
02-29-2008, 07:05 AM
I'd be really frustrated with different readings all the time.

Glucose is a dynamic entity. Not even a single fasting glucose reading is all that representative of diabetes. Take a closer look at the diagnosis criteria. It requires at least 2 readings on seperate days. That tells me the lab guys figured this out a long time ago. Now isn't that comforting???

What you want to do is to get an average of several readings for the same activety. After that you can obtain the average readings that are a bit above the minimum and a bit below the maximum for a glucose "range" for a given activety.

I'm fortunate to have a real sharp doc who does my diabetes care. She will ask me for my fasting (morning) range. I'll tell her: "120 to 150." Then she hits me with a smart pill: "How long is that after you wake up?" My answer: "45 to 60 minutes and I've had at least 1 cup of coffee." Reason for the 2nd question is that she doesn't want dawn phenomina to bias the readings and she wants the criteria to be constant.

Ant Hill:
" By having say 5 tests from 5 sites of your body "

Compare the body artery system to the water plumbing in your house. How long does it take for hot water to get to the bathroom, how long to the kitchen. Same thing for glucose.
Tally Ho,
Tom