Here is some I presume https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5467104/
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Could you direct me to the portion of that study that shows GVI and PGS (or another measurement) are better predictors of developing complications than A1c? Or any portion that states these are good predictors of long-term complications?
I scanned through it, but I don’t see anything like that. It looks like the study discusses how these measures can help assess the frequency of hypoglycemia. Reducing that is clearly important, but that’s not quite the same thing.
Do you use sensors or a pump? If you do maybe you use xDrip or Spike as well?
In the link @Lars_Hagerstrom included, I found this at end of Introduction section.
The PGS metric is intended to complement not replace A1c as a measure of the quality of patient’s glycemic control. The PGS metric is well suited for use assessing the effect of changes in medication on glycemic control. It is also well suited for use assessing the emerging technology of artificial pancreas on glycemic control. In addition to the PGS metric, the individual components of the PGS metric may be used by physicians to rapidly identify specific elements of glycemic control that could be adjusted to benefit the patient while at the same time continuing to strive to achieve current ADA guidelines for A1c.
So indirectly, using additional metrics helps identify specific areas to improve, which in turn may improve A1C and reduce complications.
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Thanks @MM2. Yes, I think these metrics are important because they can help you reduce your A1c safely (without increasing hypoglycemia).
I think the point to which @Lars_Hagerstrom replied was this:
Which was in reply to @docslotnick’s post below:
I think these metrics can be useful. I just think the A1c is the best predictor of long-term complications. I have not yet seen any studies that demonstrate the GVI or PGS as better predictors, and I don’t think this study shows that either.
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Yes, I use a Dexcom cgm. I do not use Spike or xDrip+. I’m content with the Dexcom app.
I agree in large populations/studies such as DCCT, the A1C and risk of complications can be correlated.
But on case by case, 2 people could have A1Cs of 6. One ranges 50-180, with average 120. The other ranges 80-150, with average 120. I would say the first one has higher chance of complications.
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We don’t have any studies that show this though.
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I agree. None that I’m aware of.
But we can speculate that time in range, that is mostly in non-diabetic range would reduce risk of complications.
Another factor is there are better tools for treating complications earlier and more effectively. In early 1980s, I was told I had early stages of retinopathy, but not treated until 1986. The lasers back then made larger “burns” on eye to stop/prevent bleeding and further damage. They were also less accurate, so good eye tissue could be damaged. This is why my treatment was delayed. Treatments and early prevention are much improved.
I’ll never show them or give them my pump again. I’ll take in my tide pool bg reports only. At least with one I have now.
AMEN! I haven’t let them run an A1c in years! Especially since the advent of CGMS. 1) What is the point of summarizing something with an average when I now have all the actual data points to look at? 2) I work HARD to control my BS and health. I am not going to work any less or more hard on it because some average moves up or down or it better or worse than someone elses average. Especially when it’s an AVERAGE and can be influenced by so many factors. Anyone remember debates over washing cells? Does the A1c have to be fasting? Does the BS taken when the A1c is pulled have to be above or below 100? Is the glycosolated better than the A1c? Must an A1c be done in the morning, or is afternoon accurate as well?
While your point is well taken that the CGMS offers a good amount of information, I wonder why you don’t want the additional information that an A1c provides? It isn’t like it is harmful, it is just another piece to the puzzle that has been well studied.
As far as you questions about the A1c test, it depends greatly on what test they are using. But getting a fasting lab value from the morning is probably the best solution to minimize variables. Also in these tests you are your own control to some point, so doing it the same way every time has some value so you can compare yourself to your previous self.
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we show our endos everything except the ketone meter and blood glucose meter data; the former because it’s basically no data most of the time, and the latter because it’s very unrepresentative, as we typically only test Samson when he’s low, high or the CGM isn’t making sense. But CGM data and pump data, check! A1C, check! Site change frequency, check! Pretty much everything that they need to know to accurately manage Samson’s diabetes.
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I use tidepool and upload my pump/w cgm, my libre and my meter every Sunday. At the beginning of each month I fax them the report from the previous month. I do not give them my pump. With my old endo I used to save settings before going in then afterwards reset to saved settings in case they played with it.
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I also work hard at managing my diabetes, but I find I have a different response to a higher-than-wanted A1c. I find I do want to work harder at bringing it down. A person can get complacent, or lazy, or inattentive. Maybe I’ve let my activity level slide. Maybe I’m not paying attention to my CGM as frequently and so I’m going higher or I’m slightly higher for longer. Maybe it’s been a while since I assessed my carb factors and basal rates. Maybe I can crack down on snacking, or alcohol, or overtreating lows, or having luscious sweet creamy desserts most nights. Smartening up just becomes the new normal. Until one gets lazy again and the A1c goes up again.
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My A1c tends to be pretty stable. My last two tests were exactly the same. The test before that was .3% higher. The drop correlated with a drop in my average bg levels as well.
In general, I see changes when my average bg levels (and maybe variance-not sure) have changed.
I find it hard to believe that any of the factors you mentioned play a major role. Sure, there are factors aside from bg levels that do influence A1c, such as anemia or which lab used (consistency is best). But I find it hard to believe that a fasting vs not fasting blood draw would play a large role.
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We can, and often do speculate that… and certainly I’d chose the 100% time in range example for myself—-but it’s just that; speculation
You can call it another piece of the puzzle or added information or any number of things, but untimely it comes down to 2 things:
- an effort to keep health care costs down. I mean it would be extra information if the endo wanted to run one weekly or monthly, would you allow it? Why?
- Why use an AVERAGE when I have REAL CONTINUOUS VALUES. Averages are used to summarize data to simplify them in lieu of looking at all the data points and not nearly as effective when it comes to discovering subtle changes and variances. If my BS is always 40 at 10pm and 160 at 10am, in theory the HbA1c will reflect a BS of 100, but that certainly isn’t the same as always being 100 at both 10pm and 10am. It also certainly lacks the information helpful in making changes to even out BS across the day.
In terms of the debates about which test, and which lab, amd which variables affect the results, I have lived through those debates and resolutions for YEARS. I am HAPPY to now have have CGM data, not get an A1C, and ignore those debates and new ones.
In most research studies the comparative gold standard is the A1c. I find it hard to believe that you are arguing with a gold standard in 3-4 decades of research.
How would you know if a study pertains to you if you don’t know how you compare to the cohorts?
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Well thankfully the US progressed and Nixon took us off an outdated gold standard close to 50 years ago! LOL! BUT, but in the same token why shouldn’t medical science move past previously limited means and knowledge. Gold standard treatment for an acute appendicitis used to be immediate surgical removal. That is no longer the case.
It seems likely that one of things making an A1c the gold standard for 3-4 decades, was that there wasn’t a better alternative. With CGM technology, we have alternatives.
Obviously, like most things we debate here, the question is, which alternative is best for each of us individually.