P079 Chronic variable sleep deficiency and menstrual phase affects declarative memory

Abstract Introduction Chronic variable sleep deficiency (CVSD) is a pattern of insufficient sleep characterized by sleep loss on weekdays to accommodate social/occupational demands and “catch-up” recovery sleep on weekends. We examined the impact of experimental CVSD on declarative learning and memory by menstrual cycle phase. Methods Healthy naturally-cycling pre-menopausal women (n = 16, mean age [±SD]: 28.4 ± 4.8 years) completed an 11-day inpatient study randomized to begin during the follicular- (n = 8) or luteal-phase (n = 8). Participants underwent three 3-day blocks consisting of a 10-hour sleep opportunity followed by two nights of 3-hour sleep opportunities. After the first and third 10-hour sleep, participants were trained on a paired-associates task where they were tested on 36 unrelated word-pairs until they achieved a 50% learning criterion. Participants were asked to recall the same word-pairs the next morning after a 3-hour sleep opportunity. Different sets of word-pairs were used in the first (acute CVSD) and third (recurrent CVSD) blocks in counterbalanced order. Results Women learned and recalled a similar number of word-pairs in the follicular- and luteal-phases in the acute and recurrent CVSD blocks (both p≥.99 and p≥.37, respectively). Participants in the luteal-phase recalled significantly more words in the recurrent CVSD block compared to the acute CVSD block (p=.04), but participants in the follicular-phase did not show a similar improvement in recall between the acute and recurrent CVSD blocks (p=.63). Conclusion The preliminary results indicate that women in the follicular-phase may be more susceptible to CVSD related impairment of declarative memory than in the luteal-phase.