Older men exhibited 28% higher daytime and 75% higher nighttime norepinephrine levels than young men (P<0.01), potentially linking increased sympathetic activity to age-related sleep disturbances.
Observational
Do plasma catecholamine levels and sleep patterns differ between young and old healthy men?
Older men exhibit higher daytime and nighttime norepinephrine levels, which may be linked to age-related decreases in sleep quality and increased sympathetic nervous system activity.
Effect estimate: +28% day, +75% night
p-value: p=<0.01
Young and old healthy subjects with indwelling venous cannulae were found to undergo significant diurnal variations in plasma catecholamine levels. Both norepinephrine and epinephrine levels peaked in late morning and reached lowest values at night during sleep. Catecholamine levels were similar during slow wave and rapid eye movement sleep. While epinephrine levels were unaffected by age, norepinephrine levels were greater in older subjects by 28% during the day (at 1100 h; P less than 0.01) and by 75% at night (between 2200--0900 h; P less than 0.01). Older subjects slept less well; they had 90% less stage 4 sleep, 27% less rapid eye movement sleep, and twice as much wakefulness at night (P less than 0.05). These findings raise the possibility that this well known age effect on sleep may be related to increased sympathetic nervous system activity.
Prinz et al. (1979) conducted an observational in Healthy. Older age vs. Young age was evaluated on Plasma norepinephrine levels (+28% day, +75% night, p=<0.01). Older men exhibited 28% higher daytime and 75% higher nighttime norepinephrine levels than young men (P<0.01), potentially linking increased sympathetic activity to age-related sleep disturbances.