Help with insulin dosing with lower than normal preshot levels?
Hi, sorry I’m turning into quite a regular poster in here. Apologies for multiple posts. I don’t use Facebook so I don’t want to join the feline diabetes group, but I have looked at some of the feline diabetes forum website.
I have been phasing down my cat’s moderate to high carb foods to new lower carb food and I think his insulin dose is too high now but not too sure how much to reduce by. I looked at the SLGS (Start Low Go Slow) protocol but I’m worried it’s not the most appropriate given the change in his BG levels resulting from a relatively quick change in dietary carbs compared to slow insulin titration. I have also unfortunately made quite a few mistakes with his food timing in the last few days that have messed up my curves and making it harder to interpret the numbers.
Prior to food changes:
- All testing on AlphaTrak 3.
- Prozinc insulin 3 units BD has been on this dose since late May/early June, 3 x curved sent to vet and vet advised to remain on 3 units each time.
- preshot levels usually 450-600. Nadirs usually 250-300. Preshot levels likely often influenced by poor timing of dry food which was often given 15-60 minutes before preshot levels.
- Most recent curve which was when I had accidentally introduced slightly lower carb wet food (because of heat wave I was giving more wet food and he ate a bit less of his dry food but it was still the relatively high carb proplan diabetic dry food) I did see one curve where his morning preshot level was 450 and daytime “nadir” was 290 but this was at +12hr at his evening preshot time, nighttime nadir was 195, then it went back up to 430 by the next morning.
- my syringes only have 0.5 unit markings. I can probably try to give a 0.25 unit adjustment if I squint but it could be variable between days.
Currently, on lower carb foods:
Friday: AMPS level was 171. I wasn’t going to be home all day and I’ve never seen a preshot that low before so I gave only 1 unit of insulin. I got home late and checked his PMPS which was 626 at +12.5hrs, so I gave 3 units. I later realised I hadn’t reprogrammed the feeders correctly so he was given a bit of dry food (approx 8-9g) ~30-45mins before his PMPS level. I was also concerned there could have been an element of rebound hyperglycaemia since he’s accustomed to having sugars in the 300-600s.
Saturday: AMPS was 302, I gave 3 units of insulin. AMPS could still have been influenced by the previous day’s underdosing. However I later realised I had made ANOTHER mistake and I had only reprogrammed 1 of the feeders (thanks ADHD) so he likely got some of his sister’s higher high carb food about 30 minutes before his AMPS potentially bumped up that preshot level). I triple checked the feeders so they are now definitely going off at +3-4hrs from insulin and then he gets no more food until I give his evening insulin. Saturday nadir was 94 at +8hrs into insulin, which worries me because it’s such a late nadir? Usually his nadirs are at +4-5hrs as you’d expect. PMPS was 180. I wasn’t sure whether to give insulin so I followed the suggestion on Prozinc SLGS protocol to feed as normal but no insulin, then check BG later and shoot based on that. I checked it an hour later and it was up to 250, but then I wasn’t sure how much insulin to give in case it is influenced by his food? Because it was going to be nighttime so I couldn’t guarantee I’d see symptoms whilst I slept, and because I wasn’t sure how much of Friday’s levels had been influenced by sneaky food, I decided to only give 1 unit again. I did wake up in the night so decided to do a spot check which was at +5.5hr and his BG had gone up to 297 so I was satisfied his morning dose won’t be informed by any rebound hyperglycaemia and 1 unit is definitely too low of a dose.
Sunday: AMPS definitely fasted, but following a previous lower insulin dose (1 unit) his AMPS 466. I’ve given 2.5 units this morning and will check his BG at +4, +6, +8 and then PMPS (his poor ears).
Also all of this is on an AlphaTrak 3 but I’m running out of strips (only about 4-5 left). I had ordered a human dual glucose/ketone monitor but it hasn’t even been dispatched yet, so I’m going to try to buy another human glucose monitor from a pharmacy today. So the readings might be influenced by that. I’ll try to do some side-by-side testing before I run out of AlphaTrak strips.
Questions for the community:
- If his PMPS is <200 today, how much insulin should I give? 1 unit is not enough, and then is going to potentially have a knock on effect onto his levels the next day.
- if his PMPS is say 200-300, should I still give 2.5 units or should I give something lower e.g 2 units because his AMPS and potentially nadir was likely elevated from not having enough insulin last night?
- if his preshot shot levels are lower than ideal and I’m going to feed and then shoot later, should I wait at least 2 hours so there’s less likely to be influence from his food?
Full curve from Saturday; (had 1 fingernail sized piece of freeze dried duck with most of his BG checks)
Saturday AMPS: 302 (but possibly had a little bit of dry food before
+0 given 3 units Prozinc 100g wet food (1% wet carbs 5% dry carbs .total 1g CHO)
+3: 240
+3.5: given 8-10g dry food (9.5% wet carbs 10.2% dry carbs. Total 0.8-1g CHO)
+5: 144
+6: 119
+7: 103
+8: 94
+10: 139
+12: 180
+12: given 100g wet food (1g carb)
+13: 254 given 1 unit Prozinc
Sat/Sunday overnight:
+2.5: given 8-10g dry food (0.8-1g carbs)
+5.5: 297
Sunday AMPS: 466 + 2.5 units Prozinc (given at +11hrs from previous dose)
Would appreciate any extra advice on
- insulin dosing
- changes to slightly higher carb foods if his pre shot levels aren’t ideal. E.g to still give the planned dose but to give a different food? I still have the proplan food on hand and some wet food which is 12.5% carbs per dry volume in case of mild-mod hypo. I have honey in case of severe hypo.
- if I need to consider anything particular when switching from AlphaTrak to a human glucose monitor?
I’m not currently interested in buying any other low carb foods, joining the Facebook group, or specific brands for glucose/ketone monitors. I’ve converted all my readings to mg/dL because I gather most people work in those units here, but I am based in Europe and the brands people recommend often aren’t available or are expensive/difficult to get hold of.