I was gonna point out that surely diabetes is a result of an OVER-reactive immune system, rather than under… But then no-ones 100% sure of the cause of T1 anyway, are they?
I think you’re possibly jumping the gun a little, EVERYONE gets some acne, some worse than others. Also, as someone who never got it badly (just remembering to wash my face properly usually works 
) and have still subsequently developed, I have to say either I’m an exception, or it’s nothing really…