NOCTURNAL DAYTIME URINE NORADRENERGIC MEASURES AND SLEEP IN COMBAT-RELATED PTSD

Prominent heightened arousal symptoms and clinical/laboratory findings implicate the central noradrenergic system in posttraumatic stress di sorder (PTSD), Heightened arousal frequently manifests in relation to sleep in PTSD. Central noradrenergic systems have a role in regulating arousal levels during sleep, We therefore evaluated noradrenergic pro duction via urinary excretion in relation to sleep/wake activity in PT SD patients and controls, Twenty patients-all Vietnam veterans diagnos ed with combat-related PTSD-and eight non-ill, non-combat-exposed cont rols had overnight sleep studies under medication and substance-free c onditions. In association with sleep recording, subjects saved their u rine for 24 hours in three 8-hour collections in order to obtain ''day time'' (8:00 AM to 4:00 PM, 4:00 PM to MN) and ''nocturnal'' (MN to 8: 00 AM) catecholamine measures. PTSD patients had decreased sleep effic iency relative to controls and increased REM density; 24-hour norepine phrine and MHPG (the more centrally derived metabolite) did not differ between patients and controls. ''Nocturnal'' excretion of MHPG minus the average of the two ''daytime'' values was negative in the controls , slightly positive in the patients, and differed significantly betwee n the two groups. ''Nocturnal minus daytime'' MHPG also correlated neg atively with total sleep time in the PTSD patients (R = -.45, p < .05) , Our data support a relationship of nondiminished central noradrenerg ic activity at night, and sleep disturbance, in chronic combat-related PTSD.