donnahc said:
LOVE the pictures of your royal brood Jane :mrgreen: And your black chair is really cool too! I have always wondered about the inverse curve. Asher had some on PZI and I was never quite convinced if it always should have meant a dose reduction with him. Do you know of some formula, like if mid day is 100 points higher than ps time it’s inverse? Sometimes flat looks a little inverse. Very confusing.
).
Thanks, Donna, I'm pleased you like the kitty photos, and the art chair.
Regarding INVERTED CURVES:
As with a number of other features of FD and its treatment and/or treatment effects through insulin, the phenomenon of inverted curves is subject to a good amount of debate. I'll try to summarize for you as best I can. There are 3 main reasons why a visibly inverted curve (that is, a curve that has pre-shot BGs that are noticeably lower than the mid-cycle BGs) can occur.
(1) The cat is a late-nadir cat. BUT: For late-nadir cats, curves that are visually inverted are NOT considered symptomatic of changing/changed insulin requirements. Their curves are technically the "regular" shape, but they are shifted along the cycle's timeline. Jojo, an FDMB legend, explained this beautifully: "Take a clock down off wall. Put a yellow sticky on 6 o'clock and write "PS" on it. Now take another yellow sticky and put it at 12 o'clock and write "nadir" on it. Now turn the clock so that "PS" is at noon/midnight position and "nadir" yellow sticky is at 6 o'clock position. See? It is a normal curve, just the hours are changes. Late nadir cats just have their clocks turned." (Quoted from
this 2010 thread.)
(2) NOT ENOUGH insulin: Jill (of Jill and Alex), another FDMB legend - back when we first came here in 2008, we called Jojo and Jill "Team J" :mrgreen: - has pointed out over the years that it is possible for curves to become inverted when the cat is getting too little insulin.
(3) TOO MUCH insulin: Since Jack and I know our Karre to be something of an inverted-curve afficionado, as it were, we tend to look out for them in whatever SS we come across. In my personal experience, this type of inverted curve is a bit less controversial and hence a bit easier to identify. Here in the Tight Regulaton Lantus ISG, curves have been classified as inverted primarily when the cat is very close to going off insulin (OTJ), usually at a very low dose of 0.25u or even less. What happens is that as Lantus has its onset, the body (over-)reacts to the insulin's effect: the liver responds by releasing glucagon and counter-regulatory hormones as a preventative measure to keep the BG from dropping too low. That's the RISE in the curve, often around its middle (but not always - it *can* be earlier or later than +6). As the BG comes to a peak (when it should be coming to a "valley"/nadir), the pancreas responds, bringing the BG back down as the cycle approaches its end. Following are 3 BG-Curve graphs I made during Karre's first stint on Lantus in 2008 (btw, you can find ALL the graphs in sequence linked in our signature).
Please note that the graphs each show an AM-cycle with the subsequent PM-cycle, and the curves I am referring to are happening in the AM-cycles.
The 1st graph shows a REGULAR Lantus Curve (2. Nov 2008, on 0.75u - ca. 2 weeks away from OTJ).
The 2nd graph shows an INVERTED Lantus Curve (8 Nov 2008, on 0.25u - 1 week away from OTJ).
The 3rd graph shows an INVERTED Lantus Curve (11. Nov 2008, on 0.1u - 3 days away from OTJ).
2. Nov 2008, on 0.75u - ca. 2 weeks away from OTJ ---
REGULAR Lantus Curve
8 Nov 2008, on 0.25u - 1 week away from OTJ ---
INVERTED Lantus Curve
11. Nov 2008, on 0.1u - 3 days away from OTJ ---
INVERTED Lantus Curve
I hope this helps.
Jane
