I'm most interested in Kirsten's reply, because she brings up an important related issue -- that it's much easier (with Levemir or Lantus) to maintain a cat in euglycemic ranges (say, 75-160 or so), than to maintain them at some randomly chosen range that scares some people less. Blood sugar simply seems to get more stable (in the non-complicated kitties) when you keep it near normal...because it's way harder for most diabetic cats to get regulated between 150-250 than it is between 75-150, but you won't know this until you try. This is, as Kirsten says, because hyperglycemia stresses the pancreas and makes regulation hard.