Does that nap make a difference?

This past year I have been considering much more about the importance of early development and napping after becoming an aunt, and about the circumstances of circadian misalignment because I work a nightshift job. My night job’s shifts are from midnight to eight in the morning the following day, so my circadian cycle is probably enduring the consequences of misalignment. I am curious as to whether naps can possibly make up for this circadian misalignment. It also interests me to analyze the differences in toddlers who nap compared to toddlers who do not nap.

Individuals with later dim light melatonin onsets are more likely to have later bedtimes, midsleep times, and morning wake times. Sleep/wakefulness occurring at inappropriate circadian phases results in a circadian misalignment. This factor contributes to the increased risk of disease, work-related accidents, and poor school performance. Very little is known about the processes of DLMO and the consequences of circadian misalignment in early childhood. Previous findings provide evidence of maturational circadian shifts which likely occur as a result of biological processes changing (pubertal development) and relevant social and environmental time cues. Sleep disturbances is early-childhood persists into school-age years and is associated with attentional problems and predicts the onset of emotional/cognitive problems in adolescence.

Akacem (2015) hypothesized that napping toddlers would have later sleep timing, longer sleep onset latencies, and shorter nighttime sleep durations than those who did not nap, that napping in comparison to non-napping toddlers would have later circadian phases, and that nap frequency, duration, and timing would be positively correlated with melatonin onset. The researchers also explored the associations between napping and phase differences.  

Children required to stop napping may not be able to adapt to associated increases in homeostatic load and may suffer from daytime sleepiness, poor daytime functioning, or parasomnias like night terrors. The time of life at which children stop napping varies across cultures. Napping ending occurs on average at a later age in the United States and varies across ethnicities. The results indicate that napping in toddlerhood is not only associated with evening sleep timing, shorter nighttime sleep duration, and longer sleep onset latencies, but also later timing of the circadian clock.

The limitations of this study were that the sample size was small (20 toddlers) and the researchers only used healthy good sleeping toddlers, so the findings may not be reflective of the general population.

Reference: Akacem, Lameese D., et al. “The Timing of the Circadian Clock and Sleep Differ between Napping and Non-Napping Toddlers.” Plos One, vol. 10, no. 4, 2015, doi:10.1371/journal.pone.0125181.