Twenty-four-hour profile of growth hormone in cyclic nocturnal total parenteral nutrition

To detect the effect of the loss of alimentation rhythmicity on a circadian rhythm of human growth hormone (HGH) secretion, a 24-hour profile of HGH was studied in a growing child on cyclic nocturnal total parenteral nutrition (TPN). Twenty-four-hour profiles of substrates and metabolic hormones were also studied to evaluate the efficiency of cyclic nocturnal TPN on childhood growth.

Periodic blood samples from a child with megacystis-microcolon-intestinal-hypoperistalsis syndrome were obtained on five occasions, at ages 6, 7, 8, 9, and 11, when she was on cyclic nocturnal TPN.

Peak HGH secretion appeared with the onset of deep sleep despite the concomitant hyperglycemia and hyperinsulinemia induced by TPN at night. Smaller peaks of HGH were also observed during the noninfusion period during the day. Twenty-four-hour profiles of substrates and metabolic hormones indicated a switch from glucose use during the infusion phase to an oxidation of lipids during the noninfusion period.

The fact that the patient's growth curve remains within normal limits suggests that cyclic nocturnal TPN would be an efficient method of nutritional support. During cyclic nocturnal TPN, regular rhythm of HGH secretion occurs, and normal childhood growth is achieved.