The Journal of Clinical Endocrinology & Metabolism · 1976 · 153 citations · 0 references
MedicineEndocrinologyCircadian RhythmsReproductive EndocrinologyReproductive PhysiologyChronobiology Of HormonesCircadian EndocrinologyCircadian PhysiologyHormonal InfluencesSeasonal EndocrinologyCircadian Rhythm PhysiologyCircadian Rhythms Of Adrenal HormonesCircadian Variation Of TestosteroneCircannual Reproductive CyclesEndogenous Circannual RhythmsHormonal ProfilesSeasonal Hormonal RhythmsSerum Testosterone Measurement
In a groups of 15 healthy male subjects a statistically significant circannual cycle in plasma testosterone levels was assessed by sampling blood at 3-monthly intervals. Peak levels were found in summer and early autumn and a nadir in the winter and early spring.