I don't know whether anyone else here has picked up on it, but I heard an item on today's news about a study in Japan which had uncovered a link between excessive salt consumption and nocturnia - the need to get up and pee at least once or twice a night which is a common experience for people over a certain age. Personally I'm inclined to treat the findings with a little scepticism as I'd expect salt to have the opposite effect if anything, but then I'm no chemist.