How to annoy your friends (and ruin your evening)

We were having dinner with some old friends. The friends, I should clarify, are longstanding rather than elderly. I was telling them about the painful ankle and my female friend said something about having to learn to live with it. My husband said we'd just add it to the list of stuff I have to live with and that's where things went rapidly downhill.
Like what, they wanted to know, like diabetes said my husband, who at this point had decided that he was my spokesperson. Once in a while you have the chance to sit back and see what people think of you, I decided this was one of those times. So I shut the hell up and watched the drama unfold.
The female friend was upset because she thought we had hidden this from them. When I say before every meal we have eaten together over the past ten years "I just have to go shoot up", what did she think I was doing? Did she think I had a bad heroin habit?
Her husband, one of my husband's best friends, was close to tears because his great uncle had died of diabetes. Turns out his relative was ninety-one and this was thirty years ago but it obviously traumatized him. At this point I thought I'd better interject but maybe my comment about being lucky to live nearly two decades past the normal life expectancy wasn't the most diplomatic thing I could have said. For the remainder of the evening he kept holding my hand, and shaking his head. He obviously thought I was about to expire at any moment.
Of course that was the only topic of conversation the whole evening. I actually apologized for not telling them, but although I've never hidden it (I inject at the table, I tell people if I need sugar NOW) I don't introduce myself as "Jane, and I have diabetes." I could only say that I tell people when it comes up and I was amazed they didn't know.
I was completely pissed at my husband who decided that he would stress his role as the martyr in this relationship, having to be aware of food, injections, testing etc. As the one time I let him carry my emergency candy because we were kayacking and he had a zipper pocket in his shorts, he forgot to do up the zipper and, well you can guess the rest.
And then came dessert, which I passed on. Oh, they said, that's why you don't eat desserts, because you are a diabetic. Aaagh. No, that's why I don't tell people, because they would make that assumption and maybe offer to make a "special sugar free" version that I still wouldn't eat.
I'm not sure how this will affect our relationship with this couple. Maybe once they get over the shock we'll be four friends bitching about work and politics and house prices again. Maybe.