my wife is type 1 with a pump. the tsa people usually know what the pump is. they are pretty understanding of saying, "i am diabetic". They read the labels of the extra insulin and are fine with it.

the occassional dumbass TSA will attempt to be difficult and all you have to say is, "i will die without that medicine for the duration of my trip without insulin. If I have to speak to someone senior to explain my situation, could you help me talk to that person."

It has happened once where the TSA person refused to acknowledge that the pump was a necesity. That was what we said and that TSA person brought over a different person who knew what a pump was immediately.

you don't have to be a jerk about it, but you do have to be insistant that it is crucial to your well being.