Activity, energy metabolism and postnatal age relationship in low-birth-weight infants.
The relationship between heat production and different activity levels was examined in 30 low-birth-weight (premature and small-for-gestational age) infants. A low level of spontaneous activity was preponderant, with a gradual shift from activity scores near zero to higher intensities with increasing postnatal age. There was a close correlation between activity and heat production. Older infants displayed a greater amount of spontaneous activity and a larger variation in heat production and activity-intensity relationship. The rise in heat production at a given activity intensity was greater in older than in younger infants indicating that the energy cost of identical activity increases with postnatal age. "Maximum" oxygen consumption increased with postnatal age.
D001724:Birth Weight; D001833:Body Temperature Regulation; D004734:Energy Metabolism; D005865:Gestational Age; D006128:Growth; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D010101:Oxygen Consumption