As this topic was at risk of derailing another thread, I thought I'd raise it as an individual topic as it piqued my interest as well. So for the benefit of @Oldvatr, @sud5nala and @SunnyExpat here it is.
Firstly, what is the difference between Whole blood, Plasma and Interstitial fluid glucose and secondly, what do meters measure?
Technically, the difference is that plasma contains more glucose as it has a higher water content and therefore more dissolved glucose. There is some discussion of this in the following paper looking at technical challenges for glucose tester makers: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2769957/
There is also a difference when looking at Interstitial fluid, detailed in the first part of this paper: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2903977/
In addition, Capillary glucose and Arterial glucose have been shown to have similar glucose concentrations, which differ from those in venous samples (Foster B. Studies in carbohydrate metabolism. J Biol Chem.1922;1:291–301), so as it stands a venous sample is not a good comparison for a blood glucose meter. Alternate site monitors suffer during rapid changes. In this case alternate site testing can produce different result (http://www.ncbi.nlm.nih.gov/pubmed/14633348/).
The question then is, which testers use "Plasma" levels and how do they do it? Well the answer to the latter part of the question is by an algorithm and different meters don't use the same algorithm. All the test strips measure the glucose in whole blood and apply a correction to it to give a plasma-like result. Most meters that were made after 2010 seem to provide "plasma-like" results.
Meter lines that provide a "Plasma-like" calculation include:
Accu-Chek - All Aviva models
Bayer/Acensia - All Contour Next models
Abbott - Freestyle Insulinx using Lite strips
SD - CodeFree
If you have others, please add them here.
Firstly, what is the difference between Whole blood, Plasma and Interstitial fluid glucose and secondly, what do meters measure?
Technically, the difference is that plasma contains more glucose as it has a higher water content and therefore more dissolved glucose. There is some discussion of this in the following paper looking at technical challenges for glucose tester makers: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2769957/
There is also a difference when looking at Interstitial fluid, detailed in the first part of this paper: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2903977/
In addition, Capillary glucose and Arterial glucose have been shown to have similar glucose concentrations, which differ from those in venous samples (Foster B. Studies in carbohydrate metabolism. J Biol Chem.1922;1:291–301), so as it stands a venous sample is not a good comparison for a blood glucose meter. Alternate site monitors suffer during rapid changes. In this case alternate site testing can produce different result (http://www.ncbi.nlm.nih.gov/pubmed/14633348/).
The question then is, which testers use "Plasma" levels and how do they do it? Well the answer to the latter part of the question is by an algorithm and different meters don't use the same algorithm. All the test strips measure the glucose in whole blood and apply a correction to it to give a plasma-like result. Most meters that were made after 2010 seem to provide "plasma-like" results.
Meter lines that provide a "Plasma-like" calculation include:
Accu-Chek - All Aviva models
Bayer/Acensia - All Contour Next models
Abbott - Freestyle Insulinx using Lite strips
SD - CodeFree
If you have others, please add them here.
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