Hi Pat
First, let me say I really admire what a great job you are doing with Brady and your commitment to him. It makes it easier for us to help when we have data like this so well done you!!
I know it makes it difficult to know what’s going on when there isn’t a clear pattern. Like you, I always wanted to understand why each number fell where it did.
I have seen early and late nadir cats on Lantus and PZ. As a Deb said, Levemir is a late nadir insulin so it’s very common to see the nadir at the next shot time or, in the case of my Gracie, she could nadir at +15 shortly before the next dose was onsetting.
In regard to Brady, he’s not what I would call a late nadir cat. These cats nadir late just about every cycle but Brady doesn’t do it every cycle. For most of the times he did it in March, he was clearing a bounce and you can expect to see the lowest number of a cycle at the next shot time when clearing a bounce. As an example, look at 3/24. That AMPS was likely the bounce clearing that started after the blues on 3/21. He likely started down on the evening of 3/22. You shot a reduced dose so he went up.
However, between less insulin and spending more time in blues, he bounced again and the 1.5u dose helped him with a short bounce cycle so he dropped into green the next day....and bounced back up.
A few things to know about bounces:
- They can take up to six cycles to clear (and I have occasionally see it take a little longer).
- Fast drops or even BGs in the 100-199 range can trigger a bounce.
- As cats get more regulated and used to lower numbers, you might see green nadirs with bounces into blue instead of yellow or higher.
The PMPS of 4/2 and 4/4 both look like he was clearing a bounce. While Lantus and a Levemir have Depots that can keep the numbers going lower if you’d shoot a reduced dose, PZ doesn’t so between less insulin and duration waning, you get the BG rising after PMPS.
The blue at PMPS on 4/16 is different because we can’t see a BG that would have triggered a bounce. He did get a higher dose of insulin that day and, if his absorption increased as well as duration, you could see a late nadir.
In summary, the things that can cause a nadir at PS include:
- Bounce clearing cycle
- Increased absorption
- Extended duration
- He’s a cat
and we don’t know.
I found it really hard to admit that I wasn’t really in control of the FD and the cycles or the bounces. It seems that, at least for a while, we are just along for the ride until things start to settle a bit as we get to a good dose and we learn how and when to feed and how to shoot lower numbers like the blues you’ve skipped.
You are doing great by asking questions. My suggestion is that you study his SS so you can figure out his onset, nadir, and duration. That will help understand his cycles. Keep asking questions.
On a different subject is it possible to resize columns A, B, and C on the SS so it’s easier to read? If you don’t know how, pls send me a PM and I can fix it for you. Also, if you test at the +.25, +.5, or +.75 times, you want to stack those in the cell with the hour they match. For example, if you test at +4.5, just put it in the +4 cell and annotate it “125 @ 4.5” (no quotations). You can even stack several numbers in the same cell such as: 125, 110 @ 4.5, 86 @ 4.75”. You can look at my Gracie’s SS and there will be an example on there somewhere

Thank you!!