Effects of sleep loss on waking actigraphy

Study Objectives: To assess the effect of sleep loss and the effect of a se dating drug on waking actigraphy Design: N/A Setting: N/A Participants: Seventeen healthy volunteers, aged 19-35 yrs Interventions: Four night-day treatments presented in a Latin Square Design : placebo-8 hr time-in-bed (TIB), placebo-4 hr TIB, placebo-0 hr TIB, and d iphenhydramine 50 mg-8 hr TIB. Measurements and Results: After the appropriate TIB, medication was adminis tered at 09:00 hr, the Multiple Sleep Latency Test at 09:30, 11:30, 13:30, 15:30, and 17:30 hr, and a 45 min performance battery at 10:30, 14.30, and 16:30 hr, Each day the volunteers wore actigraphs from 0700-1800 hrs. Decre asing TIB was associated with decreased daily mean sleep latency on the MSL T with 4 and 0 hrs differing from 8 hrs and each other. Daytime activity al so was reduced by the reduced prior TIB. Increased inactivity relative to t he 8 hr TIB developed between the 4 hr and 0 hr TIBs, with 4 hrs differing from 0 hrs, but not 8 hrs. Diphenhydramine 50 mg reduced mean daily sleep l atency and increased percent inactive time relative to placebo. On the MSLT diphenhydramine was intermediate to 4 hr and 0 hr TIB and on actigraphy it was similar to 0 hr TIB. Conclusions: The difference in the effect of diphenhydramine on these actig raphy and MSLT may reflect the different sensitivities of the measures.