Lack of Fluctuation in Growth Hormone Secretion During Early Sleep in Early and Midmenstrual Cycle

ABSTRACT To evaluate the influence of varying estrogen levels on nocturnal growth hormone (GH) secretion, sleep-induced GH secretion was evaluated in 5 women at midcycle and during the period of active menstrual bleeding. GH secretion varied from woman to woman, but no consistent difference in GH secretion was observed at different times of the menstrual cycle. The data show that nocturnal GH secretion is not altered by physiologic variations of estrogen levels.