I’m really glad you’ve made the appointment with the internist. Yukie’s situation is complicated enough that guidance from a specialist should be very helpful!
In all my years on K9C, I don’t know that we have ever discussed the impact of melatonin on diabetic management. In honesty, I can probably count on one hand the number of dogs on our forum who have presented with the dual diagnosis of “Atypical” Cushing’s as well as diabetes. As I’ve talked about before, it’s the combo of the elevated cortisol of traditional Cushing’s and elevated glucose levels that we commonly encounter. So Yukie’s situation is a bit of a new frontier for us all.
Given Tennessee’s anecdotal report of melatonin complicating diabetic management, I believe I’d stop it, too. Partly because its efficacy in resolving Cushing’s-like symptoms is hit-and-miss even when diabetes is not involved, and partly because I don’t think it helps with lowering progesterone/17-hydroxyprogesterone levels (which sound to me to be the most worrisome elevations in Yukie’s profile in terms of insulin resistance).
Please bear in mind that all of this is largely supposition on my part. I’ll feel a whole lot more comfortable when you can get some professional feedback from a specialist. In general, there remains a lot of controversy about the significance/impact of elevated adrenal hormones other than cortisol, and the “Atypical” diagnosis is not one that is even universally recognized among endocrinologists. So this is a long-winded way of saying that I’d probably ditch the melatonin right now, too, if there’s any chance that it’s interfering with the insulin.
Looking ahead, if elevated adrenal hormones — including cortisol — do seem to be complicating things for Yukie, there is a medication alternative to Vetoryl named Lysodren. It’s an older medication and is no longer used as frequently as Vetoryl to treat traditional Cushing’s. But unlike Vetoryl, it has the ability to lower several of the other adrenal hormones, including progesterone, as well as cortisol. So it is much more powerful than melatonin, and might be considered down the road.
By the way, good job for researching the possible link between melatonin and insulin resistance! This may be very helpful information for all of us on K9C.
Marianne