I would still argue for an L insulin. Substituting one in-out insulin for another - where response isn't, in truth, all that likely to be much different to the current response to Vetsulin - doesn't really have much to offer in terms of treatment benefit (and the sliding scale dosing method recommended for Prozinc could see Elmo's numbers become less stable as Linda touches on above). I think there is a very good chance that there would still be a lot of prannying around with microdoses and skipped shots on Prozinc, too.
Ultimately the treatment avenue which offers the greatest potential benefit to Elmo at this juncture is tighter regulation so that his pancreas can rest further, hopefully recovering more beta cell function and thus improving his prospects of achieving a strong remission. Going with tight regulation protocol means Lantus or Levemir are the available choices.
On remission rates, there is a ticking clock in terms of how long after initial diagnosis treatment with a depot insulin is initiated in order to give a cat the best chance of achieving remission. From the Roomp-Rand publised article (PDF attached below):
Remission Rates Comparison
There is only one controlled prospective study in 24 newly diagnosed diabetic cats that compared remission rates between glargine, PZI, and porcine lente insulin. Blood glucose curves were initially performed weekly, and insulin dose adjustments based on an algorithm were also performed weekly. Cats were fed a low carbohydrate diet (<8%–10% metabolizable energy). The reported remission rate for glargine was 100% (8 out of 8 cats), and this was significantly higher than the remission rate for PZI (38%, 3 out of 8 cats) and porcine lente insulin (25%, 2 out of 8 cats).30
The largest study for cats treated with glargine involved 55 previously treated diabetic cats. In this cohort, 91% of the cats had been previously treated with another insulin, predominantly porcine lente insulin, for a median of 15 weeks. Most cats were also fed a very-low-carbohydrate wet-food diet (<6% metabolizable energy) on the first insulin, yet did not go into remission. On switching to glargine, they continued to be fed a very-low-carbohydrate diet. Cats were monitored using home blood glucose measurements at least 3 times daily. The insulin dose was adjusted using an algorithm aimed at achieving euglycemia. Provided the protocol was initiated within 6 months of diagnosis, high remission rates (84%) were achieved. For cats that began on the protocol more than 6 months after diagnosis, a much lower remission rate was achieved (35%). The overall remission rate for all cats, regardless of when the protocol was initiated after diagnosis, was 64%.3
For detemir, a cohort of 18 diabetic cats, previously mainly treated with porcine lente insulin, was evaluated using an insulin dosing protocol aimed at achieving euglycemia and fed a very-low-carbohydrate wet-food diet. The remission rates were very similar to those achieved with glargine: the overall remission rate was 67%. Again, there was a difference between cats that initiated the protocol shortly after diagnosis and those that did not; for cats that began the protocol before or after 6 months of diagnosis, remission rates were 81% and 42%, respectively.6
No significant differences in terms of remission rate could be identified between glargine and detemir.
Time spent treating with Prozinc - possibly with no net gain - would eat away at the 6-month window of opportunity where statistically chances of remission are perhaps 50% higher provided the cat receives treatment with an L insulin following a protocol which aims to keep blood glucose levels within the euglycaemic range during that time.
Upon review of Elmo's current BG regulation it is possible that the vet will argue for him to be put on an OTJ trial. The concern I have about this is that Elmo currently spends the day in the upper part of the euglycaemic range - and it doesn't take long for his numbers to start drifting upwards if he skips a dose. If he were to stay in this 'prediabetic' range following withdrawal of insulin support it wouldn't take much to push him into diabetic numbers again.
Anecdotally it has been observed in cats at FDMB that the chances of achieving a more solid, long-lasting remission is greater in cats who spend a reasonable period of time where BG levels stay in the lower part of the euglycaemic range the vast majority of the time (approximately 70-120mg/dL on Alphatrak; better again if range is 70-100) before withdrawing insulin since it reeducates the body to run in lower, healthier numbers. Switching to an L insulin and following the tight regulation protocol would offer that opportunity to Elmo.
My two penn'orth.
Mogs
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