Astronauts get way better sleep when they pee in their pants. So according to a 2015 paper, the number one reason astronauts report lack of sleep is potty breaks. Peeing surpassed noise, light, and all other discomforts of being in space. But nocturia, or needing to be at night, is only tangentially related to being in space. A publication reporting on Dutch people aged 35 to 54 aka astronaut aged people found that 42% self-report experiencing nocturia. That's way more than the general population, which is at 13%. And among the general population who use tranquilizers like sleeping pills, nocturia reports are doubled. Since most astronauts do rely on sleeping pills to get some rest in space, it's not too surprising that they wake up to pee. But compared to earth sleepers, nocturia in space is reduced because astronauts are more willing to wear absorbent garments.