As far as I know neither of my parents who are passed their 70's have any IC issues, even at night. But then growing up I had nocturnal enuresis (aka bedwetting). I recall when I was 4 having plastic pants put back on me at night over my training underwear even though at age 2 - 3 I was potty trained and then had no issues for when I was 3 - 4. So between ages 4 - 12 I had accidents at night, sometimes many weeks with no accidents and sometimes nightly for a few months. My mother just told me that some boys just had this issue a bit longer than others and since I think my brother had this until he was about 7, I just assumed that was normal for me also as a boy in the family.
No one ever made a big deal about it but at age 8 after a year of being dry at night, I heavily wet my friend's bed at my first sleepover. It was significant enough that I had to wear a full diaper and pp at a later sleepover and though distraught at first, it showed me I could wear proper protection at night to wake up with dry sheets and pjs even though I had nocturnal enuresis. By age 10 it was slacking off and by age 12 my plastic mattress cover was gone along with any wettings at night.
Fast forward to age 18 and having secondary nocturnal enuresis return and I was back in diapers and pp as an acceptance I had to make for myself. The doctor I saw in college for basic health reasons thought it was always due to stress and being a deep sleeper. There was nothing ever medically found with me growing up though I was given an "anti bw" prescription but it gave me some side affects that had me off that medication very quickly and I readily accepted being back in nighttime protection. I wear training underwear and pp at night now as my own choice just because I have some slight wetting about 2 - 4 times per year so I just ensure my dryness every night even though I do not really need it. This is more my DL side telling me logically I should do this.
Is it "normal" for any adults who never had accidents much at night as a child to occasionally wet the bed maybe 1 per year or every other year as they get older? I always assumed everyone had accidents at night now & then, just some more than others.
I asked my doctor if there was any connection to boys that had enuresis up to age 12 to be fine as an adult but then maybe at middle age (50 or 60's?) they start wetting at night again like when they were an older boy. He said he knew of no studies that showed this but it still hovers in the back of my mind as being probable. As for genetics, this may be true for when my brother and I were young boys but does not appear to be something that arises even as we get older (at least as far as looking at my parents now).