Every 3 months, or whenever we get there, those of us with diabetes find ourselves having that all-important A1C lab test that assesses how well we manage our blood sugar levels over time. It can be a lot of pressure, especially when we’ve put in a lot of work hoping to see improvements.
The American Diabetes Association generally recommends aiming for an A1C of 7% or less for adults and children with type 1 diabetes (T1D). Corn recent search shows that only a minority of patients achieve these goals.
Because, frankly, diabetes can be wildly unpredictable – so most of us struggle to get our A1C down, with the constant worry of not hitting the mark.
Have you ever wondered what could be the highest A1C in history? Who would even hold this dubious record, and how far can you go without falling into a coma with any type of diabetes?
DiabetesMine investigated this question because curious minds like to know.
We started by looking in the “Guinness Book of World Records”, of course. Oddly enough, Guinness staff don’t seem to have any A1C-related lists. They do however report that Michael Patrick Buonocore survived a blood sugar (BG) level of 2,656 milligrams per deciliter (mg/dL) when he was admitted to the emergency room in March 2008 in East Stroudsburg, Pennsylvania. Buonocore was just a child at the time, and this record sugar level led his parents to start a non-profit organization called Michael’s Miracles which offers financial assistance to families with T1D in need.
So, does Buonocore also hold the highest A1C record?
No, he doesn’t. That’s because if he’s living proof that it’s possible to survive stratospheric blood sugar levels, an A1C skyscraper requires both altitude and time. Remember that A1Cs provide a 3 month average of our blood sugar levels. Individual high blood sugar readings, even the highest ones, don’t change the test as much as you might think if they last only a short time. Because T1D presents so quickly in children, Buonocore’s actual A1C level at diagnosis would likely have been more in the middle of the road. It takes a long, slow burn to boil an A1C.
But just to be sure, I contacted his parents, who told me his A1C was 11.9% at the time of diagnosis. Higher than expected but not too high given the four digit blood glucose reading.
The highest A1C turns out to be a tricky piece of data to find. If you try Google, you’ll find a million people talking about their own highest A1C and comparing their ratings with others.
Most point-of-care A1C machines cap out at a certain number, including at-home A1C test kits that you can buy online.
At the federal clinic where I had worked for more than a decade, our A1C results topped out at 14%. If the A1C is higher than this – especially when diagnosing T2D – the machine simply reads “>14%”. How much higher is someoneguess. It could be 14.1% or 20%.
If you do the math, 14% means you might have an average 24/7/90-day blood sugar of 355 mg/dL.
Of course, labs can calculate higher A1Cs. Personally, the highest I’ve ever seen is an A1C result in the low 20s. If your A1C was, say, 21%, that would require a 3-month average blood sugar of 556 mg/dL.
How is it possible? If your blood sugar was in the 500s, wouldn’t you go into a coma long before the 3 months were up? People with T1D would, but those with T2D don’t usually go into a coma because they have insulin in their bodies all the time, even though they can’t process it well enough to keep their blood sugar levels at safe levels.
Now, coma-free doesn’t mean problem-free. Such high blood sugar is toxic. People diagnosed with very high A1Cs are usually also diagnosed with complications from the start – most often retinopathy and sometimes kidney and nerve damage as well.
But that doesn’t answer the question of the unfortunate who holds the highest A1C record of all time.
Someone I know mentioned that they had seen an A1C of 27% before, but that’s hard to believe without any documentation to back it up. Asking my own healthcare colleagues, I posed this question online to a group of endocrinologists: What’s the highest A1C level you’ve ever seen, or what’s the highest level you’ve ever heard a colleague talk about?
I had my money on 35 percent. That would be a 3-month blood sugar average of 1,000 mg/dL. But the answers I got were surprising, because none of my esteemed colleagues had ever seen or heard of A1C as high as me. commonly seen in my clinic in New Mexico.
Dr. Silvio Inzucchi at Yale School of Medicine is a diabetes guru who wrote a must-have e-book for clinical facts, “Diabetes Facts and Guidelines.” He told DiabetesMine, “The highest we usually see is between 12 and 14%, although I think I saw 18% a long time ago.”
In the same stadium is Donna Tomkya New Mexico nurse practitioner and diabetes educator who served as past president of the American Association of Diabetes Educators (now the Association of Diabetes Care and Education Specialists).
“Over the years, I’ve seen an A1C as high as 19% in a type 1 person who intentionally omitted insulin and was admitted for DKA,” she said.
With regard to young people and children, Dr. Shara Bialo, a pediatric endocrinologist and T1D colleague from New Jersey, told DiabetesMine that his clinic uses the same point-of-care A1C test that does not exceed 14%. But when one of his patients lands in the hospital, a serum draw is done to determine that person’s A1C.
“The highest I’ve seen personally is 17%, but my colleague had a patient with 19%,” she said, noting that both were “adolescent girls with established T1D, one of whom just found out she was pregnant.
Dr. David Hite, a California-based diabetes education consultant, reports, “I had a patient at the clinic with 17%. It’s rare. I usually see new diabetics at the clinic under 14%. They come because they feel like they suck and can’t tolerate the conditions necessary to bring it down.
Well-known endocrinologist from USC Keck School of Medicine Dr Francine Kaufman (who is now the Chief Medical Officer of Senseonics, Inc.) won my survey’s top prize with their one-word answer: 22%. Repeat after me: wow!
If you’re wondering why the results aren’t usually higher, maybe it’s because diabetes endos and clinics usually see people with T1D, people who can’t survive long in the high octane environment needed to clock those dangerously high A1C scores. . That honor must go to our T2D cousins, who are typically seen by GPs and primary care physicians.
Often, surveys of these physicians show initial elevated A1C results at the time of T2D diagnosis, with these results decreasing significantly after the T2D patient begins treatment.
The American Association of Clinical Chemistry is the leading authority on these laboratory diagnostic tests, and Dr Darci Block is one of the great wigs that has been part of the Clinical Core Laboratory Services division of the Mayo Clinic. While some lab tests may show higher results than a clinic’s point-of-care method, she wonders why it would matter how much higher than 14% a particular result is. For her, anything older than 14 is so poor that it becomes “not clinically important” given the already urgent need to address diabetes management, Block says.
Again, other experts believe that lowering an A1C from 22% at diagnosis to 17% could be clinically important. This is definitely an indication that the patient is on the right track.
But Block also points out that extremely high A1C test results likely have a large error range. For what it’s worth, she says she’s personally never seen readings above 17% in her career.
Dr. David Goldstein, the diabetes diagnostic laboratory at the University of Missouri Health Sciences Center, said it is not aware of any group or company that monitors elevated A1Cs. But he personally saw an 18% result, reflecting a blood sugar level of around 400 mg/dL. In newly diagnosed T1D children, the average A1C is around 10 to 12 per cent, he said – similar to what was recorded in Buonocore, the boy who scored the highest blood sugar reading of history in the “Guinness Book of World Records”.
But Goldstein went on to point out an interesting fact that no one else has.
“There is a practical limit to elevated A1C because the kidneys filter and excrete glucose from the blood when plasma glucose levels exceed 180 to 200 mg/dL,” he said. “It’s called the
This means that while we may not be able to conclusively determine the highest A1C on record, experts are making it clear that whoever holds this dubious honor also has ruined kidneys. This goes back to Block’s assertion that “too high is just too high”, and the specific numbers don’t really matter.
Maybe she’s just there. Renowned diabetes educator and author Gary Schein of Integrated Diabetes Services in Pennsylvania put it more colorfully. Of any A1C above 12%, he said: “At this level, it is impossible for the patient to think clearly. A little bird should appear and start humming’purple mist.’”