A study examines links between cortisol dynamics and human cognitive function. Cortisol replacement therapy for adrenal insufficiency is associated with low quality of life and poor psychological status. Basal plasma cortisol levels oscillate multiple times throughout a 24-hour day, but current cortisol replacement regimens do not reproduce this pattern. Stafford Louis Lightman and colleagues examined the effects of cortisol delivery timing on cognitive and behavioral processes in 15 male volunteers between 20 and 33 years of age. Participants received the same daily dose of cortisol either as physiologically normal oscillating pulses spread across 24 hours, the same dose as a constant nonpulsatile infusion over 24 hours, or as three daily oral doses. Participants who received the nonoscillating constant infusion reported poorer sleep quality, compared with the other treatment groups, whereas those who received oscillating infusions exhibited improved working memory capacity under high cognitive demands, compared with the other treatment groups. The authors also reported variation across treatment groups in the response patterns of certain glucocorticoid-sensitive brain regions to images of emotional faces. According to the authors, the findings suggest that the timing of cortisol delivery affects cognition and behavior, with implications for improving cortisol replacement therapy.
Article #17-14239: "Ultradian rhythmicity of plasma cortisol is necessary for normal emotional and cognitive responses in man," by Konstantinos Kalafatakis et al.
MEDIA CONTACT: Stafford Louis Lightman, University of Bristol, UNITED KINGDOM; tel: +44-117-3313167, +44-117-9737840; e-mail: <Stafford.Lightman@bristol.ac.uk>
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