Behavioral State, Sleep Stage and Growth Hormone Levels in Human Infants

Abstract

Four normal human infants were studied on 24 occasions between the first and fifteenth week of life to assess the relation of 4 behavioral states (crying, quiet wakefulness, and the REM and NREM stages of sleep) to plasma growth hormone levels. The state of quiet wakefulness in 23 of 24 instances demonstrated low plasma levels of growth hormone similar to basal adult levels. HGH levels during the other behavioral states were distinctly higher and more variable. In contrast to the adult, no relation of HGH secretion to sleep stage could be noted, nor was there any clear relation to emotional stress (crying).