Incongruities with the Dawn effect

#1

When I first started testing my BG at dawn it was very high between 150 and 170. It has come down but I still average between 130 to 145.

However, lately I’ve had some breakthroughs where I test, 125 or below. Here’s my question or concern. After I test I follow the same routine. I fast with 3 cups of coffee, black, usually I will add a bit of MCT oil to one cup, usually my last. If my BG is high at dawn by noon, when I test again, it will frequently fall by thirty points. If it is low for me, by noon it has often risen by ten to twenty points.

I know coffee can cause a rise in glucose, but it is definitely not consistent.

In answer to another question I asked about strange readings, PaulL asked about the quality of my meter. I now have a meter which is suppose to measure within 10%.

Any ideas as to why I experience this phenomenon? Any suggestions to improve my readings?

(You've tried everything else; why not try bacon?) #2

Okay, you have a reasonably accurate meter, so the likelihood is that you are observing a real phenomenon. Good! We got that out of the way.

Now, as a number of scientists and philosophers of science like to point out, real science begins when observations fail to match expectations. So could you go into what precisely you are expecting to happen, and what happens instead? We may still not get anywhere, but it seems like a great place to start.

So how about a chart listing times, measured serum glucose, and expected serum glucose? It would also be helpful to indicate whether the reading was fasting, pre-prandial, or post-prandial. That way, we might get a handle on what’s going on. The more days of observations you can give us, the better.

#3

Thank you Paul.

I almost always eat my last meal about 6PM. My initial measurement can be anywhere from 5AM to 7:30, depending on when I get up. I try to do it first thing. I usually don’t eat until after 1 PM. So all measurements are taken while fasting, except for the coffee.

My expectation is that as the dawn effect is supposed to be high that my glucose would either fall or at least remain level. It tends to do this if the initial reading is above 140. If I have a reading of 125 or lower, it almost always goes up.

For instance, one day my initial BG was 128. At noon it was 146. The following day I was 141 then at noon 128.

It will take me a bit to make a chart as everything is hand written. I’m old.

(Bob M) #4

The problem with these meters is the error. Even if it’s as you say it is (within 10%), 128*0.1 = 12.8, which means the value could actually be 141 (128+13). Assuming the other values are actually accurate, then this all makes sense.

If you are actually getting wildly varying values as you describe, that IS odd. Not sure what to do with that except keep going to keep repairing your metabolism.

(Joey) #5

@Janet3 Another variable (besides dawn effect) that may be influencing your pre-lunch glucose variability is your activity level.

E.g., I find that gentle activity will generally lower my fasted glucose level from my “dawn” level upon arising for the morning. But more exertion (like strength workouts) will serve to increase my glucose above what it had been prior to exercise, reflecting my liver producing glucose from fat stores as demanded by muscles working.

Are you doing any exercise in the periods you’re observing increases or decreases in serum glucose beyond what you’d otherwise expect to see based solely on the passage of time? :thinking:

(You've tried everything else; why not try bacon?) #6

Now, everybody correct me if I’m wrong, but I was under the impression that (a) not everyone experiences the dawn phenomenon; and (b) even people who do don’t get it every day. Couldn’t tell you where I got that impression, so I am perfectly prepared to be shot down on this.

(Bob M) #7

I got it every day I wore my CGM, and I wore one for over a year. Or at least I think I did get it… Certainly the monthly data showed a clear dawn effect(1), though I’m not sure about every single day.

Does everyone get it? That, I don’t know.

(1) I exercise in the morning while fasted, and that raises my blood sugar. That’s only 2-3 days a week at that time, though. Only data I have easily available, shows a workout Tuesday morning (no breakfast on any day):

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(You've tried everything else; why not try bacon?) #8

Interesting. That’s not as pronounced an effect as I understood dawn phenomenon to be. The exercise effect is more like what I was expecting.

(Bob M) #9

Pulled out my data:

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Here’s one over 28 days:

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On this one, 30 December is pizza at night, but 31 December, I still get a rise.

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(Bob M) #10

@PaulL It might be because my blood sugar is pretty stable eating keto. A normal day:

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4.7 to 6.0 is 1.3, about 23 US units.

To put that in context, 6.0 is 108, and the original poster is way higher in the morning. But I started 1/1/2014, and the data is from 4 years later, after tons of short- and long-term fasting. So, I’m not the average person entering keto (and I never took data at all for years into keto).

I’m hopeful the original poster can do the same.

#11

Paul had mentioned this when my meter had a variable of 20 %. Even with 10% that may explain most of it. I’m quite new at this. Will be going to the Doctors at the end of the month for my third Hba1c. I started at 8.6, then 6.6. I’m hoping to be at 6 or under this time, all thanks to keto.

It’s just frustrating when you finally get a Seven AM reading of 106 only to have it rise to 124 when still fasting.

It helps to hear from more experienced folks who can put things in perspective.

#12

My activity level is fairly constant. Put it in the “not enough” category.

I’ll keep this in mind as I continue to lose weight. 70 lbs. so far. My stamina, energy levels and general activity levels have improved.

#13

I think you are correct, especially when applied to people who have the great glucose readings posted here. Even those with high blood sugars may not have the effect.

I am happy that my average AM level in the last three month has dropped about thirty points.

I started making the chart and realized that the phenomenon I observed is not as frequent or as volatile as I thought. For instance, one day I went from a 111 to 115. However, that was in the middle of a 24 hour fast.

I really appreciate all the info I get from this site.

(Bob M) #14

I totally get that. I went back through some of my (really old) data, and it looks like I would take my blood sugar twice in a row from two different fingers and get readings 10-13 points different, and I was only starting around 100.

And you may have fairly high morning effect issues. If you seen the doc, see if they can get a CGM, even if for only two weeks or a month. They tend to be less “jumpy”.

Let us know the next A1c, I’m betting it could be a lot less.

(Joey) #15

:joy:

Awesome. Whatever your glucose levels might be doing intraday, you’re clearly making vast improvements in your health profile. Congratulations! :vulcan_salute:

(You've tried everything else; why not try bacon?) #16

Knowing all that stuff is grist for the mill. I’m glad you started making the chart. It can only help.