Consequences of the timing of menarche on female adolescent sleep phase preference

Abstract

Most parents experience their children's puberty as a dramatic change in family life. This is not surprising considering the dynamics of physical and psychosocial maturation which occur during adolescence. A reasonable question, particularly from the parents' perspective, is: when does this vibrant episode end and adulthood finally start? The aim of the present study was to assess the relationship between puberty and the changes in sleep phase preferences during female maturation and adulthood by a cross-sectional survey. The results from 1'187 females aged 5 to 51 years based on self-report measures of sleep preferences on weekdays and on free days as well as the occurrence of menarche, show that in contrast to prepubertal children, adolescent females exhibit a striking progression in delaying their sleep phase preference until 5 years after menarche. Thereafter, the sleep phase preference switches to advancing. The current study provides evidence that a clear shift in sleep-wake cycles temporally linked to menarche heralds the beginning of "adult-like" sleep-wake behaviour in women and can be used as a (chrono)biological marker for the onset of adulthood.

Figure 1. Chronotype distribution within the study sample.

The MSF_sc score reflects the midpoint of sleep and therefore time of day (N = 1187).

Figure 2. Development of sleep phase preference with reference to pubertal maturation.

Chronotype as indexed by the MSF_sc value is a measure for sleep phase preference. MSF_sc represents local time in hours. Shaded area represents±SD; * indicate significant values compared to 5 years after menarche (Bonferroni adjusted alpha levels, for further statistics please see text).

Figure 3. Sleep and wake up times during free days and weekdays with reference to pubertal maturation.

Mean values; N = 1187±SD; * indicate significant values compared to 5 years after menarche (Bonferroni adjusted alpha levels, for further statistics please see text).

Figure 4. Difference in sleep midpoints between free days and weekdays with reference to pubertal maturation.

Mid-sleep represents the average difference between sleep phase midpoints on free days and sleep phase midpoints on weekdays. A striking switch-over from a consecutive delaying of the sleep midpoint difference to an advancing occurs 5 years after menarche. Shaded area represents±SD; * indicate significant values compared to 5 years after menarche (Bonferroni adjusted alpha levels, for further statistics please see text).

Figure 5. Average weekly sleep duration per day with reference to pubertal maturation.

Average weekly sleep duration per day reflects the average value calculated on the basis of 5 weekdays and 2 free days. Two years after menarche the average sleep duration per day remains remarkably stable between 7.5 and 8 hours for the remainder ‘distance to menarche’ classes. Shaded area represents±SD; * indicate significant values compared to 5 years after menarche (Bonferroni adjusted alpha levels, for further statistics please see text).

Figure 6. Sleep debt with reference to pubertal maturation.

Sleep debt represents the amount of sleep which is compensated for during free days due to a chronic sleep loss due to social demands during weekdays. The highest level of sleep debt occurs 1 year after menarche. Afterwards, a decrease in sleep debt was observed. Shaded area represents±SD. * indicate significant values compared to 1 year after menarche (Bonferroni adjusted alpha levels, for further statistics please see text).