We are sure that hypoglycemia affects brain structure:
And I don’t have time to dig out the reference, but there is evidence in older Type 1 diabetics that too low of an A1c (<6 I think??) have worse outcomes than those above the threshold.
As to whether there is an article that directly says each low that results in seizures has X effect on the cognitive function, I don’t think that exists, but there is some population evidence that deep lows should be avoided.
It depends on your definition of lows. I know many diabetes who would say 60-70 is a hypo, and while it can be reasonable to treat at that point and that can feel low, coasting in the 60s seems unlikely to cause damage (also I find prolonged flat lows like that are usually not that uncomfortable either, although they do seem to deplete my liver stores and increase risk for subsequent hypos). Severe lows are a different story, and seizures and unconscious episodes are what you really want to avoid.
Not clear to me whether this result is an indictment of low A1C or merely reflects the population correlation between low A1C and “severe” hypos. Perhaps where severe has the emerging definition of 55 and below, rather than the traditional “required assistance to recover” or “became unconscious.”
It certainly is an area that demands more study as the answers aren’t clear cut. Watching my son deal with lows, our definition of a severe low is 40 or less. When he hits 28 on a blood stick for 30 minutes we get worried.
Interesting…and alarming. I really need to stop these 3hr early-morning hypos… my ‘CGM’ is hopefully going to be saviour on this front.
I hear you. I have plenty of lows, many of which are coasting along in the low 60s before i notice and then correct. But around twice a month i’ll drop to the 40s at 5 or 6am and sleep through my alarm until 10 or 11am, when my alpha cells kick in and release some glucose and adrenaline that wakes me up, with just enough energy to work out what happened and that i need sugar. The frequency of these episodes seems to have increased with a lower carb diet and an increase in exercise… i’ve dropped my basal from 20 to 16 and this has improved things a bit.
I struggle to see why a low A1C, in and of itself, can lead to a worse clinical outcome… it must be due to the high correlation to increased frequency of severe hypos.
I think you are correct, but honestly complicated problems rarely have simple answers, and diabetes is a complicated disease process with many effects across most of the bodies systems. So not sure, but hope they do more studies.
Oh dear. Your statement is sensible. Unfortunately, science is much harder than “it must be due to,” because the human mind is exquisitely apt to find sensible explanations for observations. Sometimes the compelling explanations are right, but sometimes they turn out not to be.
Let me fabricate a scenario and a couple explanations other than severe hypos. Suppose someone’s BG is very close to 3.7 (65mg/dL) all of the time. That would give an A1C of about 3.9 which sounds wonderful, and although this BG level of 3.7 or 65 is a little low, it doesn’t strike me as dangerously low. But at this BG level I can imagine that the cells are somewhat starved for energy from glucose (which burns nice and clean), so the body runs on an unusually high level of fat metabolism, which produces more toxins that must be removed by liver/kidney. Perhaps that added load of toxins has long-term adverse effects. Or perhaps hovering around this BG level maintains the body constantly on the edge of hypoglycemic adrenaline panic. I can imagine that a continuous sub-threshold stress could lead to harm over time. So maybe a low A1C in and of itself can lead to a worse clinical outcome by these two mechanisms.
Now let me fabricate another completely different explanation. Suppose a low A1C in some meaningful fraction of cases turns out to be a consequence not of low BG, but rather of some particular disorder or disease process not rare in the elderly population, and that this disorder interferes with the glycation reaction in hemoglobin. This disorder or disease process may itself cause poor clinical outcomes, completely unrelated to hypoglycemia. Seems less likely, but not completely implausible, and to know otherwise would require a proper investigation.
I can play this game at length, but let me sum up. Acceptance of a clear, plausible, convincing explanation without sufficient evidence is the canonical “jumping to conclusions.” A research scientist who inadvertently does that in a publication, well that could be a career-destroying own goal: Demotion from principal scientist to research assistant, or worse.
Sorry if I have been rude here. Some of us begin involuntary twitching at “it must be the case that…” Chris contained his reaction with much more grace than did I. And brevity. Grace and brevity, that’s the ticket. Hmm, seem to have lost my ticket.
+1
A couple of times a week I need 40-50 carbs to get out of a deep low. I don’t rebound that often, but sometimes I do.
I think the lowest I ever use is 7-8 carbs. But even that is sometimes enough to get me above 120 
and I have to correct again.
Thank you @bkh for this lengthy and philosophical reply. You weren’t rude at all. My comment, to which you were responding was, on reflection, flippant, and was somewhat deserving of a dressing down. It has in fact been my long-held opinion that with regard to much of these sorts of complex systems (in which i include fields as diverse as epidemiology, economics, quantum mechanics, cosmology) the simple truth is we are woefully ignorant. We just don’t know a lot of the answers, with any great certainty. We have heuristics and approximations based on empiricism and reasoning/inference, which are generally better than the sort of Anthropic-type ‘feeling’-based comment i made, but unless they’ve been falsified (Popper-style), we can’t really rely on them. Managing T1D i think fits this perfectly. The system is so complex, with so many variables, it’s like trying to forecast the future state of a physical system, with incomplete knowledge. We aren’t Laplace’s Demon. So, by inference, this must mean that surely everything we do to manage it must involve a certain percentage of guess-work. (c.f. recent comments on the forum about estimating carbs for dosing and the amount of members who don’t use scales… for me, getting a dose wrong by 1u is typically the difference between a hypo and hyper). When there is this much guesswork, and given (like most relations in nature), the relationship between A1c and effort isn’t linear (moving from 7 to 6 involves less effort than moving from 6 to 5), i feel (again, a feel, not a rigourous calculation) spending an increasing amount of time/effort/stress to keep ave BG/A1c/s.d. % lower, beyond a certain point, makes little sense. The question is: what is that point? Where is the optimal point on the curve? I’m sure it varies for people… a professional athlete might find it ‘easier’ to manage to a better set of A1c/ave b.g. if they spend a good part of their day managing their diet as part of their career, and hence be on a different point on the curve than an office worker who is running around attending meetings and having client lunches etc.
Two specific questions, if i may:
Did you ‘fabricate’ this, as you claimed to in the intro? Or do you genuinely believe that carb-burning is ‘cleaner’ than fat-burning? In all my years, i have never heard that. Do you have evidence for this for me to study? My nutrionist, along with many others i follow, for years have been advocating ‘low carb’ diets to be a safer, healthier way of living, and not just from the point of view of weight-management. Carbs, particularly processed carbs, are full of toxins (phytic acid, gluton, other man-made chemicals), compared with fat. Although this is a generalisation… to refine that, i think a better argument is in fact it is the quality of carb and fat that is of greater importance than the quantity. Not all carbs or fats are the same - puy lentils/butter beans vs white pasta/fries and industrial seed oils vs EV olive oil. But regardless of which side of the low-carb/low-fat fence you sit on, i would like to hear more about this ‘clean vs dirty metabolism’ of carb vs fat argument… unless you made it up to illustrate your point that ‘human instinct’ can be used to make almost any argument. (and i missed the point)
That would certainly appear to make sense to me. But again, are you making this argument on the basis of knowledge, or are you using it as another example of the perils of blindly accepting a ‘seemingly-sensible’ argument?
Apologies for the lengthy post, but i think yours was deserving of it!
I call it a fabrication because I was just trying to make up somewhat plausible-sounding assertions to illustrate the point. That said, I will perhaps elevate this particular claim, “carbs burn clean” to rumor, because I heard that once. But I have not looked into whether or not it actually happens to be true. It may well be nonsense.
Same with the fabrication about being on the edge of hypo panic. I simply made that one up. I’ve heard that continuing background stress on the body is harmful, but again it’s just a rumor and I have not taken any time to look for evidence about whether that rumor contains any truth or not, or whether being “close to” hypo has any adverse effect whatsoever.
Thanks for clarifying. I think the former is likely not true, versus what i’ve read in the past, although i have no idea about the latter. But then again, given their complexity, it’s not a case of saying they’re right or wrong, as there’s so much more to it than that.