Circadian rhythm of cortisol and estradiol in healthy women

CIRCADIAN RHYTHM OF CORTISOL AND ESTRADIOL IN HEALTHY WOMENby KARYN G. BUTLERAugust 2011Advisor: Dr. Jean E. DavisMajor: NursingDegree: Doctor of PhilosophyDaily variation in human processes and behaviors has been identified for centuries. Studyof these circadian rhythms demonstrates their role in human health. Sickness behaviors includealterations in affect, sleep quality and energy. The study of the relationship between circadianrhythms has been limited to isolated rhythms. The role of temporal relationships among rhythmshas received little attention. Sickness behaviors are prevalent in many disorders includingdepression, cancer, and autoimmune disorders. Two hormones that have been shown to play arole in the manifestation of sickness behaviors are cortisol and estradiol. To date the role of therelationship between cortisol and estradiol circadian rhythms and sickness behaviors remainsunknown. The purpose of this study is to explore the temporal relationship between the rhythms of cortisol and estradiol and its relationship to sickness behaviors. It was hypothesized that a cortisol-estradiol phase angle difference (PAD) would exist that would correlate with optimalaffect, sleep quality and energy. A small scale, comparative, correlational design was used to test the hypothesis. Asample of twenty-three university women (11 morning-types and 12 evening-types) between theages of twenty to thirty-five were recruited from an urban university. Salivary samples were