Published online October 1, 2007
PEDIATRICS Vol. 120 No. 4 October 2007, pp. e769-e776 (doi:10.1542/peds.2006-3300)
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow P3Rs: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when P3Rs are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow E-mail this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My File Cabinet
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jenni, O. G.
Right arrow Articles by Largo, R. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jenni, O. G.
Right arrow Articles by Largo, R. H.
Related Collections
Right arrow Office Practice

ARTICLE

Sleep Duration From Ages 1 to 10 Years: Variability and Stability in Comparison With Growth

Oskar G. Jenni, MD, Luciano Molinari, PhD, Jon A. Caflisch, MD and Remo H. Largo, MD

Child Development Center, Department of Pediatrics, University Children's Hospital Zurich, Zurich, Switzerland

OBJECTIVE. Our goal was to describe the variability of sleep duration (time in bed per 24 hours) in healthy children from 1 to 10 years of age in comparison with growth measures.

METHODS. A total of 305 children were followed with structured sleep-related interviews and measurements of height and weight 12, 18, and 24 months after birth and then at annual intervals until 10 years of age. SD scores were calculated, and smooth curves were fitted by smoothing splines through the SD scores. The long-term variability channel within children (units SD score) was defined as the difference between the maximum and the minimum of the smooth curves and the short-term variability channel (units SD score) as the difference of the largest and the smallest deviations of the original SD scores from the smooth curve.

RESULTS. Sleep duration remained within a long-term variability channel <0.5 SD score in 21% of the children (34% for height, 21% for weight). Nearly every second child (46%) stayed within a long-term variability channel <1.0 SD score (76% for height, 64% for weight). Sleep duration of ~90% of all children ran within a long-term variability channel of <2.0 SD score (corresponding, eg, to the range between the 2nd and the 50th percentile). No single child's sleep duration remained within a short-term variability channel <0.5 SD score, indicating fluctuations from year to year (60% for height, 53% for weight). An association between aspects of sleep duration and somatic growth was not observed at any age.

CONCLUSIONS. Sleep duration during early and middle childhood shows large variability among children, as well as trait-like long-term stability and state-like yearly fluctuations within children. An individual approach to the child's sleep behavior is needed; expectations in terms of appropriate sleep duration of the child should be adjusted to the individual sleep need.

Key Words: sleep duration • growth • longitudinal • intraindividual stability • interindividual variability

Abbreviations: ZLS—Zurich Longitudinal Studies • SDS—SD score • STV—short-term variability • LTV—long-term variability

Accepted Feb 23, 2007.