European Journal of Endocrinology · 1978 · 127 citations · 0 references
MedicineEndocrinologyPhysiologyCircadian RhythmsReproductive EndocrinologyReproductive PhysiologyChronobiology Of HormonesCircadian EndocrinologyCircadian MeasurementCircadian PhysiologySeasonal EndocrinologyCircadian Variation Of TestosteroneDiurnal Hormone VariationHormonal ProfilesPlasma Renin ActivityProlactin Circadian RhythmProlactin RhythmsSeasonal Hormonal RhythmsSexual Activity
Every other month (plasma) and every month (urine) circadian rhythms were documented during the course of 14 months. Annual changes were validated in the 24 h mean of: plasma FSH (annual crest time: February), LH (March), thyroxine (September), cortisol (February), renin activity (April), testosterone (October), urinary 17-hydroxycorticosteroids (March), aldosterone (March), potassium (May) as well as sexual activity (September) [self-recorded daily]. Plasma prolactin did not show an annual variation. In addition, annual changes in the circadian acrophase (crest time location in the 24 h scale) occurred for some of the documented variables: plasma thyroxine, cortisol, renin activity, testosterone, urinary aldosterone and potassium.