This Saturday morning I woke up with a rather high BGL(Blood Glucose Level). My Accu-Chek Performa read 11.4mmol/L (205mg/dL) and the FreeStyle Optium 13.4mmol/L (241mg/dL). The previous morning the Performa read 3.3mmol/L (59mg/dL). No Optium test was taken.
Most people would ask “What is going on?” and doubting the accuracy of their meters.
I must state that I have found both the Abbott Optium and the Roche Performa to be very reliable and accurate meters. I have collected a lot of data and record BGL prior and after blood have been taken by my Doctor for every 3 monthly HbA1c blood tests.
Because I have been diagnosed as having Brittle Type 1 and was very quickly developing neuropathy in my feet back in 2010, I needed to know that the tests were correct.
I discussed these test anomalies with my Doctor and Endocrinologist. After ruling out all contaminations, e.g; not following the correct procedures prior to testing, humidity, temperature, sunlight and contaminated or faulty strips, I did the research into why these variations were occurring.
I ‘m a fisherman with a small cane farm doing all my own bookwork which, I know contributes to my unstable BGL. I have a background in Sugar Chemistry and know there are Doctors, Microbiologists and Molecular Scientists who read and contribute to this forum so it will be interesting to see your comments.
My “Before and After” Performa and Optium Tests have been different to my Blood Tests. Some are extreme.
Why and how did I find out something was wrong with the results?
I have Gilbert’s Syndrome and at times suffer from extreme hey fever. Murphy’s Law has had a big influence prior to some Blood Tests e.g; Changing a flat tyre on a hot day prior to a fasting Blood Tests, running 400 meters to another appoint and an appointment delayed for 3 hours.
The results that made me query the BGL at the time of the test was the 3 hour delay.
I had injected my morning Levemir to bring down a higher then normal BGL and increased my NovoRapid for my breakfast before working on the tractor, then drove to town.
This was not a fasting Blood Test but my appointment was delayed by 3 hours. When in town my BGL fell to below 5.0, so by law, I could not drive. Walking would lower my BLG and sitting caused my BGL to rise. The Doctors Practice was busy so I had to walk to the Pathology Lab for blood to be taken, a 500meter walk.
Results below.
Fri 27th Feb 2015 8th May 3.00pm Dr.
Time BGL BGL Carbohydrates Wt g Carbs Protein Wt g NovoRapid BGL BGL BGL BGL BGL
9.46pm 14.9 Bed Thu 26th Grams Levemir 30min 60min 90min 2hrs 3hrs
6.18am 13.2 20
6.20am 7
7.06am 11.8 Coffee & Xylitol 12 12 Computer work
FC Milk 300 15.3
7.20am 12.3 Grapes 150 28 Active physical work. Working on Slasher
8.36am 5.4 Grapes 150 28 Shower for town.
11.38am 4.1
11.46am 4.0 3.5 New FreeStyle Optium Test Strips. Tested @ Chemists Walking since 11.38am(BELOW 5.0)
11.59am 3.9 3.0 (Test Prior) Blood Test Before Blood Tests Blood test results 2.9 Note: The “AFTER TEST” is under 30 seconds from the Blood Test.
12.03pm 4.2 3.4 (Test After) 2.9 After Blood Tests Injected NovoRapid because of rising BGL (Usual response when activity stops.)
12.04pm 6
12.15pm Pie Chicken & Peas Walked 100m to park to eat pie. (DID NOT TEST BECAUSE BELOW 5.0.)
12.55pm 5.9 5.4 Stone Fruit 320 Walking around town & shopping.
1.48pm 9.4
1.50pm 8.8 9.2
1.51pm 9.1 8.9
3.12pm 5.9 Grapes 150 28 30
Coffee & Xylitol 12 12
FC Milk 300 15.3
5.37pm 2.8 Dextrose 10 10
Beer
7.30pm Gin & Diet Tonic Water
7.31pm 5.1 Meal High Protein 11
Eggs Crab Chicken
Grapes & Plumbs Not Weighed
Yoghourt 300 35.1
Pears in Syrup 215 31.6
10.12pm 7.4
TESTS: Prior & After. This is a normal BGL reaction if I have NO BOLUS on BOARD for BGL to rise quickly if I stop Physical Activity. BGL can rise from 2.8 to 3.5 within 10min(NO FOOD EATEN).
I know that the “Random BGL Blood Test” can not be correct as I did not have any Hypo symptoms and 40min later after the Pie BGL was 5.9.
Could the BGL be incorrect because the sample was not “Deproteinized” thus allowing the Red Blood Cells to take up Glucose?
Sat 28th Feb 2015 8th May 3.00pm Dr.
Time BGL BGL Carbohydrates Wt g Carbs Protein Wt g NovoRapid BGL BGL BGL BGL BGL
10.12pm 7.4 Bed Fri 27th Grams Levemir 30min 60min 90min 2hrs 3hrs
3.08am 5.7 Computer Work. HAY Fever.
4.05am 7.0 8.1 20 Back to bed.
8.12am 10.0 10.1 Coffee & Xylitol 12 12 7 Computer Work.
FC Milk 300 15.3
Grapes 150 28
11.18am 8.1 9.4 Plum 102 ?
12.25pm 8.9 10.0 Plum 96 ? 5
Grapes 150 28
2.44pm 2.5 1.4 Dextrose 20 20
Grapes 136 26
3.03pm 4.3 4.0 Coffee & Xylitol 12 12
FC Milk 300 15.3
Cheese 76
3.44pm 8.4 8.1 30
Olives 119 5
Yoghourt 431 58.6
6.04pm 5.9 5.2 Gin (50) & Tonic Water 400 35.2 7
Nectarine 98 Scrambled Eggs
Grapes 240 46 Crab & Tomato 280
8.33pm 11.4 13.3
I was in trouble with my Doctor until we both worked out what had had gone wrong. Because the Blood Glucose test came from the same vial for the Bulirubin (Gilbert’s Syndrome), the blood sample was not “deproteinized”. It takes 10 to15 minutes for the blood in the vial to coagulate before it can be centrifuged. This allowed sufficient time for red blood cells to take up glucose because there was IOB (Insulin on Board) and I had been physical activity prior to bloods been taken.
The only times that Blood Test Glucose Levels and both meter tests correspond for me, are when BGL are in normal range( 4.8 – 6.0mmol/L) when both meters read the same and the before and after test do not change, with no fast acting insulin on board and no physical activity prior to tests.
A disturbing trend that I have noticed with my tests is, that even if BGL are close to normal and the Optium is higher than the Performer but both are rising, the Blood Test is always higher than the highest reading. In the case below, I knew that the Blood Test was the more correct reading and actually could have been, higher because it is only the liver that can return Glucose back into the blood and only in the form of alpha Glucose. It is a bit disconcerting for me when the Optium is reading higher then the Performer as my BGL could actually be higher then both meters are saying.
See Below:
Thu 28th April 2016 5th May 2.00pm Dr.
Time BGL BGL Carbohydrates Wt g Carbs Protein Wt g NovoRapid BGL BGL BGL BGL BGL
Grams Levemir 30min 60min 90min 2hrs 3hrs
11.13pm 13.2 Bed Wed 27th 2 High BGL.Injected Novorapid before bed. Back FROM FISHING
2.42am 2.5 Dextrose 15 15
2.50am 2.9 2.9
3.40am 3.9
5.37am 2.6 Dextrose 15 15
5.42am 3.2 2.8
7.09am 4.2 4.2
7.30am 4.4 4.9
7.56am 5.3 5.0 DID NOT inject insulin BECAUSE FASTING BLOOD TESTS. (Drove to town after BGL reached 5.0.)
8.34am 6.0 6.5 (Test Prior) Blood Test Before Blood Tests
8.41am 6.2 7.2 (Test After) 8.2 After Blood Tests 22
9.11am 5.9 6.0 Chicken Pie & Peas 5
10.29am 9.3 Normal Food
3.46pm 8.9 28
6.07pm 2.5 2.2 Dextrose 15 15
6.21pm 4.0 4.4
8.08pm 6.1 Normal Meal 5
There were only a few occasions when BGL were between 8 – 10mmol/L and the Performa read higher then the Optium. Blood tests came back between the meter readings but much closer to the Performa result.
I have written to both Roche and Abbott but neither company addressed the variations that occur between different makes of meters.
I know the only ways to obtain a true and precise Glucose readings from a blood sample is first to deproteinize the sample (perchloric acid has been used for this purpose) then using HPLC (High Performance Liquid Chromatography ) to determine the Glucose level. The other way to obtain correct Glucose level is by titration. This would also would be complex but a simple reducing sugar titration would detect all other simple sugars (Fructose, Fucose, Glactose,Mannose, Xylose) that could be in the blood. A fasting Blood Test would all but eliminate these other simple sugars as the liver would by then be the only supply of energy, namely alpha Glucose. Compared to Glucose Meters, titration is still a very slow process.
Personal Glucose Monitors are the best technology available because they are affordable, give instant results and are accurate, giving good repeatability of tests WHEN EVERY THING IS IN A STEADY STATE AND BLOOD GLUCOSE LEVELS ARE WITHIN THE NORMAL RANGE.
Even the good brands of meters rely on enzymes as a component in their technology to deliver the Blood Glucose reading. I will not go into the chemistry of simple sugars but will say, even the glucose we can metabolize, D (+) Glucose comes in two forms called anomers; α- and β-glucose which mutarotate through the open chain aldehyde form and enzymes favour different structures of a molecule and react differently under different concentrations. Because each company use slightly different combinations of reagents and obtain enzymes by different methods, you may see variations between two different makes of meters even from the same drop of blood.
If your doctor orders a Random Blood Glucose which comes from the same vial involving protein tests, this Blood Glucose Test may not be accurate. For a Blood Glucose Test to be 100% accurate you have to be fasting and the sample has to be immediately deproteinized then the correct analysis of the blood has to be followed.
Before you call you meter “Liar” then throw it and bounce it off the wall because you do not believe the reading, remember these meters are the best, cheapest and quickest method to obtain BGL’s but they have their limitations.
It took me over 3 years of recorded data before I worked out why the meters that I use gave different readings. I now use the variations between meter readings to change my daily insulin injections.
I know this is a controversial subject and I hope I have not confused people more about the accuracy of Blood Glucose readings and which are the best meters. I repeat again, all good makes of Glucose Meters will give similar readings if every thing is normal. If BGL are outside of the preferred range, only trial and error and following the correct set of procedures for that set of circumstances can get levels under control. Having faith in your meter reading is a must if you are going to stabilize the unusual events that occur in the management of your diabetes.
Sorry I don’t think the data section copied across correctly.