Study of 6-sulfatoxymelatonin and interleukin-1β in infants fed a dayight dissociated formula milk

摘要

A newborn's correct growth requires the perfect consolidation of the sleep/wake rhythm since proper rest is reflected in the benign development of the nervous and immune systems. In the present study, we set ourselves two objectives: to analyze the effect in infants of 12 or more weeks in age of administering for one week a new nocturnal repose promoting, day / night dissociated formula milk both on the levels of the hormone melatonin, the principal endogenous agent responsible for the appearance and establishment of biological circadian rhythm, and the immune system. To measure the circulating levels of melatonin, we assayed the urine concentrations of its excretion metabolite - 6-sulfatoxymelatonin. We also quantified the content of interleukin-1β to evaluate the immune response of these infants when they were fed, using a double-blind protocol, one week with non-dissociated (standard) formula milk, and one week with milks dissociated into two formulas according to the properties of their nutritional components - night-formula as the sleep-promoting milk, and day-formula as the wake-fulness-promoting milk. The results showed that the infants who received the dissociated formula milk presented higher diurnal (06:00-18:00) urine levels of 6-sulfatoxymelatonin than both the nocturnal (18:00-06:00) levels and the diurnal of the infants who were receiving standard formula milk. During the week of administration with the dissociated milk, there was a significant increase in the nocturnal levels of interleukin-l(3 over the diurnal levels as a consequence of the entrainment of the circadian sleep/wake rhythm. We conclude that the administration of chronobiologically adjusted baby milk formula could therefore favour the synchronization of the melatonin and interleukin-1β cycle in the initial stages of development in the newborn.