Alterations of insulin-secreting response to glucose in human infants during the early postnatal period.

Oral glucose tolerance tests were performed in healthy infants, aged one to 29 days. Capillary blood samples were obtained from heel stabs for estimation of glucose and insulin immediately before and 30, 60 and 120 minutes after the administration of glucose (2.0g per kg body weight). The younger infants tended to have delayed and diminished insulin responses to a glucose load than did older infants. The ratio of the increment of insulin concentration to the increment of glucose concentration at 30 minutes following a glucose load in younger infants, aged one to 20 days, was below 0.4. The ratio in infants older than 20 days was above 0.5. From these results it is evident that the pancreas of human infants begins to respond to the stimulation by glucose during the early postnatal period and this response becomes even obvious after 20 days of age.