The Development of Circadian Rhythms in Human Infants

5.1.3 Melatonin secretion relative to temperature maturation
stage
Figure 5.4 and Figure 5.5 demonstrate the changes in night and day time melatonin
relative to the stage of maturation of core body temperature during sleep (as described
in section 4.3). Night melatonin shows again an increase with maturing of
temperature state while there is no change with the corresponding day time values.
Week zero is the reference week that temperature maturity was achieved in all infants.
All other weeks of measurements have been corrected, for example week -2 is two
weeks prior to temperature maturity was achieved, week +2 is two weeks after
temperature maturity was achieved. It should be taken into account when reviewing
this graphical presentation of the data that there are very few infants measured at - 10
weeks and + 8 weeks maturation, which creates the appearance of a sharp increase.
The steepness of the visual slope may be misleading.
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