The anatomy of one insulin dosing decision

This morning I made an insulin dosing decision that I make on many mornings. I will present this information in the five minute increments that the Dexcom G6 uses to update. This particular instance turned out well for me; every decision I make does not always work this well. I’m right, however, a lot more often than I’m wrong.

The primary driver of glucose elevations at this time of day for me is the combination of the circadian rise known as dawn phenomenon and what many of us refer to as “feet on the floor” or FOTF phenomenon. This is a rise in glucose that is not so much connected to the clock but related to arising from bed and changing your body orientation from horizontal to vertical.

5:08 am. – 93 mg/dL
I woke up about 30 minutes earlier at 82 mg/dL. My wake-up goal is < 100.
5:13 — 93
5:18 — 93 +0
5:23 — 93 +0
This steady BG in my goal range requires no action from me.
5:28 — 100 +7
This +7 jump catches my attention but I will wait for more data to confirm a trend.
5:33 — 103 +3
5:38 — 109 +6
5:43 — 114 +5
I see a valid trend and decide to inhale one 4-unit cartridge of Afrezza, a dose I find equivalent to 2 units of liquid insulin. I took this dose at 5:44.
5:48 — 119 +5
This continuing steep rise of about 1 mg/dL/minute causes me to take another 4-unit dose of Afrezza at 5:51.
5:53 — 122 +3
First 4-unit Afrezza dose starts to make its effect felt. Now I’m wondering if I reacted too quickly with the second Afrezza dose.
5:58 — 122 +0
6:03 — 121 -1
6:08 — 120 -1
6:13 — 118 -2
6:18 — 112 -6
6:23 — 109 -3
6:28 — 104 -5
At this point I continue to wonder if I overdid the Afrezza this morning. My BG is dropping about 1 mg/dL/min for the last 15 minutes. I certainly don’t want to go hypo but I decide to just keep a close eye on events.
6:33 — 99 -5
6:28 — 94 -5
6:43 — 89 -5
6:48 — 85 -4
This is the end of the steep and a little worrying drop.
6:53 — 83 -2
6:58 — 80 -3
7:03 — 78 -2
The BG drop moderates and it looks like I made an aggressive but accurate correction.
7:08 — 78 +0
7:13 — 77 -1
7:18 — 77 +0
7:23 — 77 +0
It looks like the effect of the two 4-unit doses of Afrezza has worn out. I usually find that a single 4-unit Afrezza dose finishes at about 1:20 after inhaling. As you see, there is still a little more drop to come. 7:18 am is 1:27 after the second dose.
7:28 — 76 -2
7:33 — 74 -2
7:38 — 72 -2
7:43 — 71 -1
Here’s the bottom of the BG-lowering caused by the two Afrezza doses. It’s 1:52 after the second dose.
7:48 — 70 -1
7:53 — 70 +0
7:58 — 71 +1
I landed safely!

Here’s the Nightscout graph of the event:

The blue top portion of the graph is the basal insulin profile controlled by Loop. As you can see, Loop decides to halt any basal insulin once it comprehends the two doses of Afrezza that I delivered. Since my experience with Afrezza observes that a 4-unit cartridge of Afrezza is equivalent to 2 units of liquid insulin, I log it as two 2-unit doses.

The dashed blue line across the basal profile is the background basal rate that’s programmed into the pump and Loop. It is the basal rate that would have occurred if my BG had stayed closer to target of 83 mg/dL.

You can see the “Pre-Meal” notes on this graph. This is when I shift my Loop target from 83 to 65 to make it more aggressive. It’s the equivalent to “stepping on the gas” when driving a car. When it’s set, it will automatically time-out at 60 minutes unless you terminate it and reset it again for another 60 minutes.

The green dot glucose reports in Nightscout represent glucose from 65-120 mg/dL. The yellow dots are those above 120 mg/dL

Loop also provides a way to set the target BG higher for situation like exercise when you want to pre-empt a hypo.

This account may be more detail that some people find useful. They may not like to operate at this level a minutia; I understand that. I like getting into the nitty-gritty of these kind of things since I believe in the end that it is less complicated and demanding when I can keep my glucose levels in range.

It’s alway easier to prevent hyperglycemia than it is to rein it in when it’s already gone too high.

Loop takes the every five-minute burden out of managing my blood sugar and permits me to take a higher level view of things. I should be able to program in a basal rate and insulin sensitivity to programmatically take care of this but that effort is still a work in progress.

I realize that this type of post is not of universal interest and I appreciate the chance to give others a view of how I manage my insulin. This exercise helps cement and reinforce my experience.

If you’ve read this far, I thank you for your attention. I’m happy to answer any questions.


Terry, as you know I don’t use a pump. I went to bed at 10:00 pm with a glucose level of 106, and when I got up at 7:00 am I was at 90. I gave no insulin during the night nor did I eat any glucose. I read that during the night glucose levels of non diabetics change quite a bit. I see my reading as very good, what do you think?

Thanks for posting your readings, I found them to be interesting. I really want to be able to use Afrezza.

Anytime I can wake up below 100, I count as a success. Anything in the 80s is even better. Yes, I think your wakeup reading of 90 is excellent.

These days, I find comparison to non-diabetics as a poor standard. One study found only 12% of the US population to be metabolically healthy. Comparing to “metabolically healthy non-diabetics,” I would agree with that. I’m not aware, however, just how much this latter group would fluctuate over night.

I find Afrezza an amazing tool. I’ve lost insurance coverage to pay for it and I now pay out of pocket due to its utility. I use about three 4-unit cartridges per day. It’s fast-on, fast-off characteristic is closer to what a healthy pancreas does.

I didn’t score quite high enough on the breathing test to get a prescription, but I was sick on the day I took the test. I need to exercise my lungs. I have a breathing device, but I haven’t used it yet. I am not anxious to go get another breathing test while Omicron is so bad here.

I’ve taken several of those breathing tests but my diabetes clinic has not followed through with requiring them.

Yeah, I think avoiding any medical facilities for the next few months is a good idea while the Omicron variant rages through the population. It makes me wonder when I will be given the Omicron challenge. I’ve upgraded my mask usage to N95 only recently.

I really want afrezza too just as a quick correction when I miscounted carbs or my site has failed. My insurance doesn’t cover it though

I am not going to get challenged by Omicron. We are doing everything we can to not get it. We don’t go anywhere, get food delivered to the car, and hopefully prescriptions too. We don’t see our son anymore. Our hospital is full of unvaccinated people. Last week a 33 yr old woman, who had defeated stage 4 breast cancer, died in the emergency room when she came down with covid and there wasn’t a free ICU hospital bed in 3 states. She was fully vaccinated and boosted.

1 Like

My insurance also didn’t cover. I did cash pay online here.

I haven’t used as often, but have expired supply in refrigerator that still works. Great to hammer down a quick rising trend at meals.

A 4 unit afrezza is equal to about 1.5-2 units novolog in pump (for me).
With Tandem CIQ, basal reduced if drops too much, so works quite well. Need RX from MD.

1 Like

That’s $99 per box, 3 boxes max per month, whether that box contains 4, 8, or 12-unit cartridges. This is the pharmacy that I buy Afrezza from. Each box contains 90 cartridges so it works out to just over $1/cartridge. It’s definitely worth it to me.


Oh maybe I’ll look into this.
I should have been more clear though, my insurance will pay for it, but not if you are on a pump.
My current doctor also thinks I should make adjustments to my pump instead, but I find it can be too slow when a a miscalculation was done or if my site isn’t working right.