Sleep deprivation impairs 12-hr urine volume excretion in old rats.

Excessive nocturnal urine volumes (UVs) predict almost double the death rate in older adults. Furthermore, sleep-depriving environments may increase nocturnal UVs in old age. Thus, a pilot study was designed to examine the effects of sleep-depriving lighting treatments on the 12-hr UV excretion in young adult rats (6 months, n = 6), middle-aged rats (12 months, n = 12), old rats (16 months, n = 6), and old-old rats (>20 months, n = 5). Each animal was exposed continuously to the treatments beginning with 7 days each of standard laboratory lighting conditions of on 12 hr/off 12 hr, then 7 days continuous dim lighting, and finally 7 days of continuous dim lighting plus sleep deprivation with a noxious noise. Age group and lighting condition treatments influenced 24-hr urine volume excretion (F (2, 29) = 2.41, p = .007, r(2) = .8193). During sleep deprivation, rest-phase 12-hr urine volume excretion increased in both the old and old-old rats (F (2, 5) = 7.79, p < .00001).