The side of the fingertip generally is less sensitive than the very tip.
Quite likely. I should say that the blood tests are already a kind of self-diagnosis situation. I don’t have a regular doctor, but I am getting older, so I wanted to establish some baselines here. Hence the original questions. The CGM has at least acted to demonstrate that the dawn effect is real and the explanation for the title question. I’ll certainly continue to monitor the A1c for changes, though.
Forgot to mention: I screwed up the first few tests before figuring things out. I was initially trying to get the drop of blood on top of the tip of the strips, since the pictures suggested this and the text wasn’t very clear. Eventually I realized that it was the edge of the tip that you need to touch against the drop, and it slurps in the blood quite readily if you do that. I didn’t actually need such a large drop, though I suppose it probably gives slightly better results (less dilution from interstitial fluid, etc.). I can probably dial it back to 4.
I did get some minor bruising from the finger stick. Not a big deal but I’m glad I don’t have to do this constantly!
Heh. My son once measured his temperature a few times a day for a week. He was curious what was normal for him. Now, when he feels sick and takes his temperature, he knows if it’s abnormal for him.
When i first got a pulse oximeter i played around with it a lot. I also tried it with and without a facemask, and right after running up a flight of steps, and … This is one reason I’m certain that face masks don’t significantly reduce my oxygen levels. (And i doubt they are dangerous for anyone with a normal ability to breathe.)
I don’t view information about my bodily functions as something that is only valuable to optimize some improvement.
Also, professionally, I’m a data junkie. A lot of my value as an employee was to look at everything i could get my hands on to poke around and see what matters. And to apply common sense to data. I like data.
But… If one is inclined to grab a single metric and ignore common sense to optimize it, there are already a plethora of options on the market. A generation or two ago it was popular to invest ridiculous emotional energy in being “regular”. Health advice during the 1918 flu pandemic even included instructions to keep your bowels regular to protect you from the flu. More recently, i think BMI has served that function. And hydration. And sleep. People measure their sleep in ways that i suspect are counter-productive. One more option in the market of metrics may change the focus, but I sincerely doubt it will affect the inclination. Some people will pick one great thing to over-emphasize, and others won’t.
And finally, i think US medicine has a tendency to over-simplify, to our detriment. I think a lot of the failings in our response to the pandemic stemmed from well-intentioned dumbing down of information to make a simple story. But then, when underlying knowledge and even facts changed as the virus mutated, the simple story changed without any obvious reason, and a lot of people felt they’d been lied to. Basically, sounds bites make for bad medicine. IMHO.
The old adage is as true here as ever: “When a measure becomes a target, it ceases to be a good measure.”
I think I understand why you want to do this.
And it’s honorable, for the most part.
More info is always better than less.
I just don’t see how a baseline will help you.
If you become ill, I know of no doctor who will accept your charts as the baseline. They will want their own.
Just like they will hardly accept another doctors labs.
They always always send you down for more.
Believe me, I’ve fought docs over this.
Ended up in the lab anyway.
A finger stick is trivial to them. Heck, a huge blood draw means little.
I have successfully submitted an MRI disc from another hospital and my doctor accepted it, grudgingly. Only because it was less than 2 days old.
And finally, Get you a regular doctor. I mean it.(signed:Mom 
)
As we age, it is vital.
I have plenty of doctors who accept other doctor’s labs. The only time they send me for new stuff is if the labs were out effectively too old.
My urologist, for instance, used to order a PSA every 6 months. I realized I was having other blood work done by my GP every 3 months, so I asked if I could just send the urologist the results. He was fine with that, so my GP adds the PSA whenever I ask.
I had an endocrinologist appt just after my physical this year. I had my GP add one or two extra thyroid tests, and brought the entire panel to my endo. No issues there.
I also find that doctors generally accept each other’s labs. Especially doctors in the same network.
But i agree with Beck that older adults ought to have a primary care physician. Really, i think everyone should.
The inclination has been exploding with the availability of more metrics available. It’s the tendency you yourself jumped on to: gamify it! Yes sleep, body battery, HRV, steps, pulse ox … sharing data on Strava. My impression (probably there is data on it!) is that more and more people are looking at more and more data and trying to optimize their health by imposing simple stories on it.
US medicine is often accused of that, but it isn’t true. The media presents information in that way and buries any complexity. And some who know the complexity will play into that, trying to give a simple message that will be heard and have positive impact that the fuller story that is not read or understood by most. “We don’t know.” does not satisfy the average article clicker.
This rush to CGM as a health metric for a general population, and the rush to monetize it by some, will fall into that. There is no medical consensus that minimizing glucose variability prevents future impaired glucose regulation in the currently healthy, or has other significant benefits, but the general public wouldn’t know that from what they hear and read. If a few years from now a large study comes out showing that it is … much more complex than that … the public will say that yet again “they” keep changing what they tell us, were wrong again, and dumb it down.
No, i think you have misread a large fraction of my posts. I observed that lifting weights didn’t have much immediate impact on my interstitial glucose, and you were winging your hands over how i might stop lifting weights as a result. That hadn’t even occurred to me. Rather, my conclusion was that i couldn’t just do more weights and avoid the aerobic exercise i dislike, i probably actually need to do both.
And the gamify comment was intended to be sarcastic. I think that’s a horrible idea.
Should healthy people try to minimize the variation in their glucose? Probably not. The pancreas and hormones regulate glucose in healthy people. And i suspect it’s a good thing that my blood sugar rises when I’m driving on a rainy night. (Substantially, and for the full time of the drive.) That’s probably adaptive, reducing the much more immanent risk of getting into an auto accident.
And comparing my cgm results with those of diabetic friends, the differences were obvious. Yes, my blood sugar runs higher than ideal (pre diabetes). No, I’m rather obviously not diabetic. My blood sugar drops reliably and substantially (and fairly quickly) if i lie down and close my eyes and relax, for example. Really, the shapes of all the curves just look different.
But you seem to be arguing that healthy people shouldn’t ever try a CGM, shouldn’t look at their temperature, shouldn’t play with a pulse oximeter. And i disagree. Like the stock market, you probably shouldn’t look at it that stuff too often. And if it stresses you out in a way that’s not actionable, or that is likely to provoke unhelpful actions, maybe you should avoid it. (I have been avoiding looking at the stock market recently, fyi.) But i think the availability of the data is mostly a good thing.
Honestly I think you are misreading here?
My point, that apparently was less clearly made than I thought, was that hopefully you were smart enough not to do that, but many people seeing that would, that any conclusion that strength training wasn’t helpful for glucose management (which you agreed “if i had taken up strength training in the hopes that it would improve my blood glucose profile, i suppose i might have.”) is faulty.
Any “winging” of my hands was using that as an example of how a goal of minimizing glucose variability could result in actions that actually go against the bigger goal of improved daily function and longer/better healthspan: not every extra bit of data is better.
Sarcasm often fails horribly on message board posts. Who knew? 
I agree with the probably not. I personally empathize the “probably” … maybe additional study will show more benefit than harm, maybe the other way round. I suspect the latter, don’t know, but see CGMs being used (not by the OP, notably), widely and increasingly, with that “glucose flattening” goal in mind, companies selling services of “personalized nutrition” based on CGM curves …
Healthy people thinking that minimizing the variation in their glucose is the secret hack to better health is what is driving the bulk of their use in people not living with diabetes. It is what “they” are saying. And they scoff at the notion that any harms can result.
Not quite. There is however no particular reason they should. And a healthy person using a CGM just because, taking their temperature or measuring when they are feeling completely well, is not typically adding information more likely to do good than harm.
It is occasionally a symptom of anxiety, it does frequently increase anxiety, it can result in poorer health choices. There is no shortage of people who are less rational than @Dr.Strangelove, who would have reacted to being told they had “a spike” and should consider making a change to fix it with the conclusion that they are in fact not healthy, who would now be avoiding bananas and possibly other fruit, because damn look at that unhealthy spike.
Your default, if I understand correctly, is that more data is better. Mine is never order a test without good reason. I’ve seen the cascade leading to harms that testing just because sometimes results in.
The question for screening tests in general is if the screening has solid evidence of more benefits than harms.
This adds in a selection bias I think. I think those baseline healthy people buying these CGMs overrepresent the subgroup at higher risk to pathologize the results, at higher risk of anxiety regarding them, and at higher risk of trying to “fix” the new “problem” they have now identified.
Well, i don’t entirely disagree. Especially for “screening tests”, which are a little more formal than casual “i want to learn about my function”. I’ve actually joined a study which is trying to demonstrate that fewer mammograms improve health outcomes for low-risk women. I’m in the low risk group (based on family history and a genetic test) so I’m only getting mammograms every other year. And i regularly fill out a questionnaire that includes questions like “how often do you worry about breast cancer”. They are, of course, also keeping track of how many women in each group die of breast cancer, and various other health outcomes.
But for numbers that tend to move around, and that can slowly change over time, i prefer keeping track of “where am i?” and not struggling to interpret one number out of the blue. Take blood pressure. My mom had high blood pressure for years. And because she was very skinny, it was sometimes painful to have her blood pressure taken, which made it spike. When she was nearing the end of her life, and hospitalized for other things, her doctors sometimes freaked out when they first read her blood pressure. And (as her healthcare proxy, at that point) I’d tell them it was normal for her, and they shouldn’t take any immediate action. And that was the right choice, her blood pressure was one of the few systems that wasn’t involved in her eventual death, and aggressively treating it has problematic side effects.
And yet, I was a low-risk woman by those criteria, was found to have cancer in both breasts, the worse of which wasn’t visible on imaging until the mammogram led to a contralateral MRI, and if I had not been at an age and in a cohort that got mammograms every year, it’s thought likely that the undetected IDC would have progressed to a higher stage and crept into more lymph nodes by the next interval. YMMV, and I hope it does.
Sort of an interesting data point this morning.
Aside from being timeshifted a bit from typical, I usually have a pretty normal/healthy sleep schedule. Drift off around 3, wake up around 11, probably getting 7.5 good hours of sleep most nights. I set an alarm but most days I wake up shortly before it goes off.
Today I had a super early meeting that required waking up before 8. And boom, a sharp spike right when the alarm went off. Went from somewhere below 70 to ~110. Not that high in absolute magnitude, but it was over the course of 15 minutes. Somewhat curiously, there are two missing data samples. I only see 7:41 and 7:56 (alarm was 7:45), but it samples every 5 minutes. I wonder if it was rising fast enough that it couldn’t calibrate or something.
Regardless, this doesn’t seem like a vaguely defined dawn effect. I was deep in sleep, possibly REM, and the alarm went off and my body went “All right, gotta be alert? Here comes the juice.” And within a few minutes I was alert.
Curious now about the relationship between BG and sleep cycles. I do see plenty of overnight variation. Presumably correlated with deep/light sleep?
I do, too. And i hope you are doing well.
One year isn’t a magic number. I have a friend who found an aggressive breast cancer (by feeling it) 3 months after a clean mammogram. She’d had the mastectomy and a lot of other treatments before her next scheduled mammogram.
I realize i am assuming some risks by participating in this study, but i hope the results, whatever they find, will be useful.
Apparently glucose levels drop during REM compared to non-REM sleep. Also here. And greater glucose variability if hypoxic with obstructive sleep apnea
Your doctors must be nicer than mine 
I think my personal bloodwork probably changes more than daily.
They never let me off the hook.
This seems of interest-
This was my takeaway from comparing readouts with diabetic friends. I had a lot of spikes and a few little plateaus above 140, and almost never went higher than 180. Diabetic friends who were well controlled had more stable numbers. Stable above 140, often. They didn’t have the sharp drops that i had routinely, throughout the day. Presumably because they didn’t have a working pancreas to kick in, and generally didn’t worry about anything under 180.
(A friend with newly diagnosed diabetes who was still struggling with controlling it had huge swings, with highs that the rest of us never saw.)
See, that’s exactly the kind of research I like to see from CGMs. Getting a better idea of what constitutes “normal” will help everyone.
The Stelo gives a “target range” of 96% of the time between 70 and 140. That’s only 20 minutes, not 3 hours! Assuming that study holds up, it seems like the Stelo targets are way too aggressive (even counting that maybe you want a more aggressive target than the average).
Curious about one thing, though. The study defines normoglycemic as:
They observed that normoglycemic participants (without traditional diabetes risk factors: elevated blood glucose or HbA1c)
But then goes on to say:
Another important finding was that the majority of participants with normoglycemia and prediabetes had a similar range of mean CGM glucose (100-140mg/dL).
Isn’t HbA1c a marker for mean glucose, though? I.e., shouldn’t prediabetic patients by definition have elevated mean glucose since they have elevated A1c? Or is the observation that mean glucose can actually diverge from A1c? Or that the CGM, measuring interstitial fluid rather than blood, can diverge from blood glucose levels and/or H1c?
Maybe I need to read the study itself.