Diet and infant behavior

Exploration of the Contribution of Biobehavioral Variables to the Energy Expenditure of Preterm Infants

Variation in energy expended by preterm infants may be due to infant maturity and history of resolved acute lung disease (respiratory distress syndrome [RDS]) as well as growth, caloric intake, and activity. Indirect calorimetry was used in this exploratory, short-term longitudinal study to estimate energy expenditure (EE) from measures of inspired and expired O2 and CO2 .The sample included 35 assessments for 10 preterm infants (5 with and 5 without RDS history). Lung disease history (resolved RDS, no RDS diagnosis), weight gain (g/d) from the day on which birth weight had been regained to the study day, mean activity level, the number of the assessment (1 6), and the interaction of lung disease history and time were included in a linear mixed model for repeated measures. Time was an index of postconceptional and postnatal age; all 3 were highly correlated. Because of high correlation with weight gain, caloric intake was not included in the analytic model. Lung disease history, mean activity level, and time were significant contributors to EE. A more precise measure of medical status than absence or presence of lung disease history, evenly spaced repetitions of EE assessment, and exploration of contexts in which the infants exhibit a higher activity level are needed in a replication study with a larger sample.

Does sympathetic activity contribute to growth of preterm infants?

BACKGROUND

Emerging evidence on faster growth in preterm infants with higher heart rate as opposed to the classical approach calls for further research.

AIMS

to test whether (1) high or low heart rate and (2) heart rate during the first days of life predict greater weight gain in preterm infants.

METHODS

A retrospective study analyzing two daily measures of heart rate obtained during restful sleep, total daily calorie intake and daily weight gain measured always in the morning before meal were collected from the medical files.

RESULTS

Analysis of 90 healthy preterm infants born at 32-36 weeks of gestation revealed that increased mean heart rate during hospitalization predicted greater weight gain even when controlling for calorie intake, birth weight, gestational age, appropriateness of birth weight for gestational age, and length of hospitalization. Mean heart rate during the first three days of life yielded the same pattern of results. Post-hoc analysis of variance between infants with mean daily heart rate </=139 bpm vs. >/=140 bpm showed that infants with higher heart rate achieved a significantly higher weight gain.

CONCLUSIONS

It is suggested that, contrary to adults, in neonates an anabolic activity is represented by increased sympathetic functioning within the normal range. The implications of a slower growth rate for additional developmental care and individual considerations of appropriate stimulation in preterm infants are discussed.

Protein demand in the premature neonate and in the small for gestational age full-term neonate

From our analysis, it may be seen that from simple data it is possible to evaluate the protein and energy adequacy of very low weight neonates, which is crucial to help them achieve normal intellectual and somatic growth and development.