I am Diabetic and take insulin, I also have low Thyroid and take meds for that.
I went on estrogen, spiro, etc and had no changes in my A1C readings or thyroid readings. Most Doctors panic when you tell them you want to start hormones and they really have "no" idea what will happen with your pre-existing conditions. Its a build in "safety" response, "Oh, you might have a worsening reaction".