Effects of age and gender on sleep-related plasma renin levels

In young normal males large oscillations of plasma renin activity (PRA) with a 90min periodicity occur, which show a distinct association to the rapid-eye-movement (REM)-nonREM (NREM) sleep cycle. PRA increases during NREM sleep and decreases during REM sleep. Changes during the life span and gender differences were found in sleep- electroencephalogram (EEG) and nocturnal secretion of various hormones. In order to clarify whether aging and gender affect free renin levels, we investigated sleep electroencephalogram (EEG) and PRA in 47 healthy subjects (24 females, 23 males, age 18–69yrs). Simultaneously sleep EEG was recorded (23:00–07:00) during sleep and renin plasma samples were collected every 20 minutes. The characteristical oscillations of renin concentration were preserved during ageing and occur in women and men as well. Similar to previous findings on PRA at daytime in humans, an age related decline of renin mean concentrations was found. Subjects 40 years and younger had higher nocturnal renin levels than those older than 40 years. Furthermore a negative correlation between age and renin mean concentrations was found. As expected slow wave sleep (SWS) showed also a negative correlation with age. Similar to growth hormone and melatonin sleep associated renin secretion appears to decline between adolescence and adulthood. At daytime lower PRA was reported in women than in man. As well we found lower nocturnal renin mean concentrations in women than in man.