Sleep related growth hormone and prolactin secretion in children during constant rate enteral nutrition

The aim of this study was to investigate the nocturnal secretion of growth hormone and prolactin in a particular model where nutrients are delivered continuously. Six children with severe intestinal diseases undergoing total constant rate enteral nutrition for 1.5 to 8 months have been studied; all children had a normal nutritional status at the time of the recording. Sleep patterns were studied by the usual polygraphic methods from 10 p.m. to 8 a.m. Blood samples were taken every 20 min through an indwelling catheter for growth hormone and prolactin plasma level determination. Several growth hormone peaks were observed with a peak always secreted in connection with stage III-IV of the first cycle. This early peak was significantly higher than the following ones. Nocturnal patterns of prolactin secretion showed individual differences characterized by a series of episodic releases which consisted of a few long rises (4 patients) and several small fluctuations; no correlation was found with the sleep patterns; no increase in the level throughout the night was observed. Loss of the rhythmicity of alimentation does not alter the secretion of growth hormone during sleep.