I'm 52 and type 2 diabetic as well. I had a stress test done this past Feb. after trying to act my shoe size and ride up a hill that was more than I was capable of. MY heart seemed to take forever to slow down and I was dizzy for a while. Scary!!??
They did the isotope injection and I got to the running portion on the treadmill until my MHR was 100%. The nap on the xray scanner was great. Turns out I'm fine and all is clear. The doctor reminded me to remember to act my age and build up to riding that hill sometime later. Also, he recommended seeing a cardiologist yearly for a while since I am just starting to ride after many years as a couch potato.
It is reassuring to know that everything is in good working order in there. Even so, I don't push myself as hard. Slow and sure helped the tortoise win the race.