The individual development of circadian temperature rhythm in infants

Abstract

The aim of this study was to explore the individual development of the circadian rhythm of human body temperature. Dailyperiodicchanges of body temperature were examined longitudinally in four infants from 3 to 18 months of age. At the 3rd month of life, the day‐night rhythm of the body temperature was obscure but at the 6th month it became moreevident. From the 12th month on, the circadian temperature rhythm with phase similar to that of the adult was discerned. However, the amplitude in circadian rhythm was significantly larger in children between 6 and 18 months of age than in the adult. These findings suggest that the adult type of circadian rhythm of human body temperature is established during the first year of life with regard to phase but not to amplitude.