What is hypoglycemia unawareness?

WRITTEN BY: Jordan Hoese, MD, MPH

What is hypoglycemia unawareness?

If you are like approximately 40% of people with Type 1 diabetes, you probably have some degree of hypoglycemia unawareness. This is a complication of T1D during which patients experience severe low blood sugars but do not feel them. Definitions and incidence rates vary across studies, but after reading a bunch of the studies it’s my professional opinion that 40% is a solid number to throw around. People with hypo unawareness are at a six times greater risk of complications from severe lows like heart arrhythmias, or impaired neurologic development during childhood and mortality from hypoglycemia than people who can feel their lows.

When your sympathetic nervous system is frequently exposed to low BGs, the response to these lows is dampened and the threshold at which you get symptoms like sweating, palpitations, hunger, dizziness, and anxiety resets. This response has been shown to be less even after one recent episode of hypoglycemia! So if you’re going low a lot, your body doesn’t want to be impaired by those lows, and will adapt. There are studies that show that during episodes of mild hypoglycemia, people with hypo unawareness return to baseline quicker once normal blood sugar is restored than those who do feel their lows; basically, the brain is less affected by this mild hypoglycemia.

This can create a vicious cycle — when you don’t respond to lows, you end up going even lower before you treat it, resetting your nerve’s response threshold and making you even less likely to feel your low the next time, increasing the risk of severe hypoglycemia and death. It would be great if our nerves didn’t adapt, but we’re stuck with the system we have, and sometimes that system leads to hypo unawareness and severe or life-threatening hypoglycemia.

The important thing is that we know for sure that hypoglycemia unawareness, or Hypoglycemia Associated Autonomic Failure (HAAF) requires these recurrent episodes of hypoglycemia to develop, which is really good news. Because even if we don’t know the exact details of how it happens, knowing why HAAF occurs helps us prevent, manage, and treat it.

How do we treat hypoglycemia unawareness?

Luckily, the treatment is simple: go low less often, and your nerves will adapt back to a higher low sensitivity threshold, improving your hypo awareness.

Easier said than done, though, right? Especially since nowadays the gold standard T1D treatment is intensive insulin therapy with a goal A1c of <6.5% to improve long-term outcomes for morbidity and mortality. Which is awesome! But A1Cs this low are also associated with a three-fold increase in the risk of hypoglycemia, which is not awesome and can lead to all sorts of morbidity and mortality of its own.

How can we safely go low less often?

So how do we reconcile this, and balance the goal of euglycemia (the technical term for having a normal about of glucose in the blood) with the added goal of improving or maintaining our hyposensitivity and avoiding severe hypoglycemia?

The overwhelming consensus is that the best way to do this is to take advantage of continuous glucose monitoring (CGM) technology. Intuitively, it makes sense that if we can see that we are headed for a low, we can be treat it earlier or avoid it altogether, helping our nerves learn a new normal and eventually reset their symptom threshold. This is even more significant and valuable during sleep, when our responses are blunted anyway and we need all the hypo identifying help we can get!

The American Association of Clinical Endocrinologists (AACE), the American College of Endocrinology, and the American Diabetes Association have all released recent position statements recommending CGM use in patients with T1D who have hypoglycemia unawareness, or severe or frequent hypoglycemic episodes.

That said, most of the people who study hypo unawareness have proposed that the answer to maintaining or improving hypoglycemia unawareness lies in intensive work on the part of the patient, the doctor, and the entire healthcare team to work together to come up with an individualized plan to prevent and/or reduce hypoglycemia through careful insulin management, diet, exercise, medication, and monitoring, regardless of CGM use.

What’s the one big takeaway? By working carefully with your doctor to recognize and prevent hypoglycemia, it’s possible to in turn prevent and reverse hypoglycemia unawareness and all the burdens it brings. It’s possible to #livebeyond!

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I have great diabetic awareness. My stomach tenses up and my head gets a little light. And that is only at 70 (I don’t know the European version of that number.)

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Sorry if I start editorializing off-topic during this response…

Up till about 2 months ago (when I got my Dexcom G6), I was ending up paralyzed on the floor of my bedroom with severe insulin shock about twice a week. Even though I tested and took the “latest long-acting insulin” (with supposedly no peaks) such as Lantus and Toujeo, I would still end up in this almost-fatal state.

My “diabetic specialist” endocrinologist suggested all sorts of stuff (but strangely, never a continuous glucose monitor) and didn’t believe my reports “But Lantus doesn’t HAVE any peaks!!!”… “I don’t believe you when you say that Humalog doesn’t take effect for 2.5 hours!!! It MUST be having an effect after 15 minutes!!!”…

Needless to say, I dumped that malpracticing &^&&%^ and now have a doctor (a general practitioner) who prescribes WHAT I TELL HIM TO. The first thing that I got him to sign for was the Dexcom which has been a life-saver since I warned about hypoglycemia at least 1/2 hour before it happens (anytime I’m 75 or lower).

On another related subject:
I also have a problem where even Fiasp, Humalog, etc don’t start to have an effect on me for 2.5 hours or so after injection. Nobody believed me on that either until I met some folks on this forum who have the same issue. Yesterday, I got my general practitioner to prescribe Afrezza which I started to use today. The Afrezza took effect in 10 minutes or less and lowered my blood sugar, counteracting what I eat in a predictable and controlled way.

Conclusion: Hypoglycemic unawareness is the most DANGEROUS, LIFE-THREATENING condition that I’ve ever faced.

Editorial comment on the Dexcom G6:
A CGM fixes it all. Get one if you don’t have one already. The Dexcom G6 is the best and easiest to use (I use it with XDrip on my Samsung G7 which automatically extends sensor-life – with my ObamaCare plan, it costs $75 a month, $225 when I have to replace transmitters). The only problem with the Dexcom G6 was finding a dealer which my ObamaCare plan would deal with…

Another solution to hypoglycemic unawareness for the near future:
The Freestyle Libre with the Miao Miao Bluetooth add-on acccessory will be another more inexpensive alternative once Miao-Miao supports the new 14 day sensors for the Libre. Luckily, the Freestyle Libre and it’s sensors can be bought at any pharmacy (Walmart is the cheapest and my ObamaCare insurance charges me only $30 per month for the sensors). Unfortunately, we must wait for Miao Miao to get their act together and support the 14 day sensors…

Hi @Mila this article specifically refers to T1s as getting hypo unawareness, but it can happen to T2s too, especially insulin dependant T2s. Not griping, but to the casual reader they may not be aware of that fact. :slightly_smiling_face:

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