Yes, an average of blood sugar levels over an average of red blood cell lives. And the red blood cell lives averages used or 'weighed' as they call it are 117 days for males and 108 days for females. Also the more recent blood sugar readings have a larger influence of the HBA1C result than older ones. There was also a recommendation on some sites that at HBAIC readings of 64 mmol/mol ( = 8 %) or less, further testing should be done to distinguish an averaging effect of high and low blood sugars vs a more constant level of blood glucose readings above normal range e.g. by frequent glucose monitoring by finger prick or CGM. How many diabetics are advised of this after say a HBA1C of 48 mmol/mol (= 6.5%) or 53 mmol/mol (= 7%) ?
There is a test called Gylco-mark which, through a different mechanism not involving red cells, can give information on how many blood sugar readings , particularly after meals have been > 180 mg/dL (= 10 mmol/l) over the preceding 20 days to one month. This is a blood test but research suggests close correlation (whatever that means) between saliva and blood samples. So a possible saliva test in future might help. Another test to at least help with the interpretation of HBA1C.
But in the end can any thing beat a well-calibrated CGM ? Oh, but the expense.
Exactly, as you say, perhaps on the horizon saliva test on it own and/or in conjunction with another test may prove medically in the best interests of so many out there, dont want to bore yourself or others out there with my journey saga, sadly it has lead to my feeling skeptical overall about Diabetes, this is my thoughts only and not to be read taken or followed by anyone, and based on the grounds of my own experience from day one, such situation I am sure others may hav similar, and hence, such tests as Glyco/mark as you inform very interesting I might add.
1. First blood test 40 years finger prick showed 197mg/dl random 4 hours after eat a breakfast of sugar cocktail mango, pawpaw, kiwi, banana, orange, apple, being from Oz, abunance of tropical fruits was order of the day, how naive was I....but well.
2.
Chemist stated, problems monitor, testing error during morning, many people. they changed monitor re did test albeit cocktail of fruits, result 180mg/dl. Still high, lower, "normal" range, as it was under the cut off threshold arbitrary set of 200mg/dl caution time kicked in, sufficient to do something about it.
3.
Attended Doc informed level. He did a test 189mg/dl. High Yes, normal range, as again below the so called threshold 200mg/dl. Action. Immediate Metformin given, A1C arranged.with advices, you can still eat your rice paellea on sundays, make sure your next course is veggies. How crazy is that, give me a pill to keep sugars at bay, the symptom! informed its OK to eat rice, how crazy is that again, my decision gut feeling. I declined metformin, and of course, did not follow recommendation of diet given. Instead, went low carb by doing
www.dietdoctor.com
4.
A1C 8.1%. equated average blood sugars of 126mg/dl note, right on the cut off threshold i.e. was average blood sugars, inicating Pre Diabetes and/or Diabetic range, whatever, 8.1% as Doc said is diabetic range. Note. All finger tests at this point were down and normal fasting, 2hr after eat and random on the low normal ranges. So what did we have here, possible lab error, it was discordant with "majority" finger tests. Diagnostic Specialist in Germany on my contact due to this, wrote and recommended I seek 2nd A1C immediately as may be typographical or lab error, as although average sugars are not that important, they are taken into consideration with A1C, but normally 8.1% equates to approx 186mg/dl supported by Mayo Clinic America and other reputable sources, to have an A1C 8.1% with average sugars value of 126mg/dl should be queried
Diagnosis given with only one A1C, not two, no symptoms present, and majority all finger pricks low normal at all times.
Yes, it proved error on Lab on demanding clarification.
Requested 2nd A1C due to this, pleaded begged Doc said, convince yourself your diabetic, forget the sugars your A1C cannot be wrong its 8.1% that means your diabetic, take care exercise a little more, and dont drink coffee...
5.
Finally got 2nd A1C it proved 6.6% again all normal sugar finger tests continued consistently. I asked Doc as 1 point over threshold and there is 0.5% error marginal so my A1C could be 6.2% or up to 7% perhaps? Confirmed Spain its 100% diabetes as one point over the threshold even though arbitrary set threshold, in spain if this is the case, that is clear, yet not so black and white, as NZ it would not be viewed as Diabetic. On asking Doc if the low carb and extra exercise had contributed to 6.6% even though lab error previously, was informed no, the result of this is due to the fact your taking Metformin. On informed Doc decided not to take metformin, had not taken any medications whatsoever, opted lifestyle change instead. This did not go down well with my Doctor
This seemed clear, with the
exception, NZ 6.6% falls under pre diabetic range, as differs from Spain. There cut off for Diabetes 6.7% two tests and if two tests show same, along with symptoms, indicates range of Diabetes. Good news is A1C lower, the not so good news, that result proves different diagnosing depending where you reside.
Result of this 2nd A1C 6.6% spain diabetic 100% again without second test to show same and no symptoms. If I jumped on plane to NZ would fall under diagnosis as pre diabetic, lifestyle change, caution and monitoring x 12 months.
Victim, depends where one resides time of diagnosing. Spain v. NZ.
One Lab test discordant error confirmed. 2nd Lab test average sugars showing 108mg/dl discordant again as normally would be in range of 146mg/dl, thankfully finger pricks continued normal on all counts.
Finally took charge, not sure if Pre or Diabetic either way. Changed life by four things.
1. Keto diet low carb, no snacking inbetween meals
2. Tread 10 mins after each meal plus 5/9klm walk daily and surfing as and when
3. Intermittent fasting, 3 days a week, 2 days 18hr fast 8pm to 2pm next day, and 8pm til 8pm following evening
4. No medications from day one prescribed to time of writing.
Result. Finger levels continue as normal and infact, 79mg/dl the other day for 2hr after eat to be below 140mg/dl is a little too low, tests only take place every 3 months, i.e. same day same time, but three months apart, and results are clear more or less same each time to show consistency not just a lucky or good day, fasting in 81mg/dl 2hr 79mg/dl to 83mg/dl random 84mg/dl examples.
A1C ranges now have gone from 8..1% lab error, 6.6% result pre NZ yet Spain Diabetes?? who is right or wrong, ultimately, who cares, the rest of A1C that followed since 5.8%, 5.7%, 5.4%, 5.2% 5.0%. Supported by A1C now home test kit as tool used inbetween regards lab tests show ......5.7%, 5.4%, 5.3% and 5.0%.
thankfully the 8.1% result has been taken off my medical record as Diabetic, with notes, 6.6% still discordant result overall, due to this, placed pre diabetic Spain, with now further notes officially, non diabetic range, excellence of control without medication 5.0% A1C.
What to do next, continue with f
our simple life changes, they work for my body, results prove this, 100%, but that does not change the fact, tests need backups, better tests more accurate may be available for the future, to save a person having a lab error and only getting confirmation of that, after plead and pressure to determine that, lab test that differs worldwide levels leaving limbo situation pre or diabetic situation, discordant numbers on tests, and finally, after taking charge of ones own body, results are as outlined within,??
The just of this journey story, indicates yes more interpretation of A1C in my opinion too, there can be cases as my own, lab errors, discordant results, victim different levels values worldwide that affect that particular individual situation, whatever inbetween it cannot be ignored, that fasting, random and 2hr after eat levels for now going on 2 years in November 2018 have been consistently and constantly normal, normal normal ranges, and thats not just a good day, or good luck day, I have tested one month on the hour every hour x 3 days one after the other, and yes, all levels were normal normal normal, Yes, the A1C now support these sugar levels, but before, there was doubt concern, lingering, as something did not support this majority consistent, perhaps until Salvia tests, always two tests taken one day after the other, should be the order of the day A1C both tests to show high or same, especially if patient does not have symptoms to have more surety that a lab error is not in place, everyone is human, a chef can have an off day, a machine depending on who puts the into in can make a mistake....
for this, I am skeptical on any lab tests from now on I am sure 98% of the time they are correct,but when one has been victim of error, and told your diabetic 100%, and turned out this was not the case, and 2nd test, indicated lower, yet still discordant results, who can blame anyone in that situation.........dont take the first result is my motto, and ask for 2nd and third if thats what it takes, especially, when life span of blood cells can differ with individuals.
thanks for your great informative post, I am sure others will appreciate also.
Wishing a lovely day from..
Mallorca....