Going Beyond A1c - A Deeper Dive by diaTribe

Continuing the discussion from Help bring the patient voice to FDA!:

I was fortunate to attend the workshop above at the FDA on August 29th. An important part of the workshop was the participation of diaTribe. You can read their summary at Public Workshop on Outcomes Beyond A1c Brings Patient Preferences to the FDA. But I’d also like to highlight the huge amount of work that went into making this happen and preparing the supporting material. A post on August 25th by diaTribe highlighted this, it was called Going Beyond A1c - One Outcome Can’t Do It All. I’d encourage reading it, it is quite interesting. I’ve also embeded a video produced by diaTribe with help from HCMStrategists for this FDA meeting.

I watched and listened to the 8/29 FDA meeting and have read a good deal about the inadequacy of the A1c metric to convey a comprehensive survey of what life is like with variable and out of range blood glucose. I fear our advocacy is a little too polite. We’re telling the regulators and the pharma companies that “the A1c number you cherish is OK, but we’d like to add a few more metrics, if we could, please.”

I think the A1c number provides a convenient and cheap way for pharma and regulators to reduce diabetes to a snapshot. The A1c has been validated to work for a population but seriously breaks down when it comes to individual people. According to the diaTribe 8/25 citation, an A1c of 6.0% can translate to an average blood glucose ranging from 100-152 mg/dl. What a joke!

For those of us fortunate enough to produce good numbers with a reasonable effort, we are plagued with the chronic endocrinologist warnings that our 6.0% (or less) A1c raises red flags about excessive hypoglycemia. It wasn’t until I could bring in CGM proof that my hypo excursions experience are rational and safe for a person who takes insulin did my endo back off with the stock beware of hypos cautions. Even then the doctor had to get in at least one warning remark per visit about hypos.

The basis of this seemingly required warning is not logical, at all. The unscientific endo mythology says that any person who takes insulin and has an A1c of 6.0% or less must be spending a lot of time hypo. Otherwise, they reason, how could they average out all that time they spend above 200 mg/dl?

I don’t think we should be pushing the FDA to accept some additional metrics for outcomes. I think we should be pushing them to demote the A1c to its rightful place, a substandard measure that hides lots of flaws. We should push for the superior metric of time in range as the gold standard of diabetes regimen efficacy.

Now I know that everyone does not wear a CGM. But when it comes to the big bucks washing around the pharma marketplace, we should at least insist that all trials use a CGM to document the claims that this new drug or device is better.

Time range is king. One number rolls in exposure to hypo- and hyper-glycemia as well as glucose variability. It hides nothing and is easy to understand. We need to replace the flawed A1c with time in range.


I’m sure time in range (whatever range we’re talking about :slight_smile: ) is a better metric than the A1c but the A1c has been validated as a measure of risk of complications. I’m all for time in range studies but until there are some, the A1c does have the advantage of being validated,

I think we should give our endos a bit more respect when they warn us about the dangers of hypos. If you are working to maintain very tight control, the primary risk you face in the short term is a severe hypoglycemic incident or even a moderate hypo when driving or engaging in a potentially dangerous activity. Your endo and my endo know that we understand it isn’t a good thing to run high. Their value comes from highlighting what we may not be concentrating on. Of course an endo who harps on the dangers of lows with a patient who is running an average blood sugar of 160 is not being helpful unless the patient is on a rollercoaster.


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I agree, @still_young_at_heart, that we need to listen to our endos. However, when they fail to see a difference in my data with a high time in range, low variability (as measured by standard deviation), a low percentage of time (< 5%) in hypo range combined with no severe hypos when compared to their more typical patient, then I get frustrated. Respect must flow both directions. I’ve been at this a long time and certainly don’t need the standard reminder about the danger of hypos, especially if its simply based only on the A1c number.

I do get what’s going on in these situations. The endos are over-scheduled and individual patients end up as a blur in a long and busy day. I only have one doctor to deal with but they’re dealing wth dozens of patients.

I don’t think anyone at the meeting suggested dropping the A1c as an outcome. It was really about additional outcomes that matter.

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