Sleep and the transition to adolescence: a longitudinal study

Abstract

Study objectives: To assess the links between sleep and pubertal development using a longitudinal design.

Design: Three consecutive annual assessments of sleep and pubertal development. Sleep was assessed using a week of home actigraphy.

Setting: Naturalistic sleep in the home setting of school children, Tel Aviv Area, Israel.

Participants: A sample of 94 (41 boys) typically developing healthy school-age children (age range at first assessment: 9.9-11.2 years).

Intervention: N/A.

Measurements and results: The Petersen's Pubertal Development Scale (PDS) and Sexual Maturation Scale (SMS) were used to assess pubertal development, and a week of actigraphy served to assess naturalistic sleep patterns. The results reflect expected developmental trends: an increase in signs of pubertal maturation, delayed sleep onset, and shorter sleep time. After controlling for age, significant relationships were found between sleep onset time, true sleep time, and number of night wakings at Time 1 and pubertal ratings at Time 2, and pubertal changes from Time 1 to Time 2. Delayed and disrupted sleep at Time 1 predicted faster pubertal changes from Time 1 to Time 2. These results were supported by structural equation modeling. These findings were similar in boys and girls.

Conclusions: Based on these longitudinal data, it appears that pubertal changes in sleep (delayed sleep phase and disrupted sleep patterns) antedate bodily changes associated with puberty. The underlying mechanisms explaining these predictive links should be further explored.

Figure 1

Developmental changes in sleep and puberty rating. Time 1, 2, and 3 refer to measurement points. At Time 1, the average age was 10.5 y and at Time 2 and Time 3, 11.5 and 12.5 y, respectively. The left upper figure is based on the PDS and the right upper figure is based on the SMS. Sleep measures are based on actigraphy. Post hoc analysis revealed that all discrete differences between Time 1, Time 2, and Time 3 are statistically significant. Significant gender differences are marked by *.

Figure 2

Sleep measures on weekdays versus Friday. Time 1, 2, and 3 refer to measurement points. At Time 1, the average age was 10.5 y and at Time 2 and Time 3, 11.5 and 12.5 y, respectively. Friday night is the only night that is not followed by a school day. Arrows between Time 1 and Time 3 indicate that all discrete post hoc analyses of the differences between Time 1, Time 2, and Time 3 were statistically significant.

Figure 3

Correlations between sleep measures (sleep onset time and true sleep time) at Time 1 and the increase from Time1 to Time 2 in puberty rating on the SMS. Regression lines are plotted in black for girls and in broken gray line for boys. No significant sex differences were found.

Figure 4

Cross-lagged structural equation model for the relationships between sleep and puberty rating (Time 1 and Time 2). Puberty1 = SMS puberty score on pubic hair development. Puberty2 = SMS puberty score on genital development in boys and breast development in girls. D1 and D2 represent “disturbances,” namely, the part of the variable of an endogenous (“dependent”) latent variable that is not accounted for by predictors in the SEM model. * P < 0.005, ** P < 0.001.