Longitudinal sleep multi-trajectories from age 1 to 5.5 years and their early correlates: results from the Étude Longitudinale Française depuis l'Enfance birth cohort study

STUDY OBJECTIVES

To identify sleep multi-trajectories in children from age 1 to 5.5 years and their early correlates.

METHODS

We collected early family, maternal, and child characteristics, including children's nighttime sleep duration (NSD) and daytime sleep duration (DSD), night waking (NW), and sleep-onset difficulties (SOD), by parental phone interviews at age 2 months and 1-, 2-, 3.5-, and 5.5 years. Group-based multi-trajectory modeling identified sleep multi-trajectory groups. Multinomial logistic regression assessed associations with early factors.

RESULTS

We identified five distinct sleep multi-trajectory groups for NSD, DSD, NW, and SOD in 9273 included children. The "Good sleepers" (31.6%) and "Long sleepers" (31.0%) groups had low NW and SOD prevalence and shorter NSD but longer DSD in "Good sleepers" than in "Long sleepers." The "Good sleepers but few SOD" group (10.3%) had long NSD and DSD but a SOD peak at age 3.5 years; the "Improving NW and SOD" group (9.6%) showed short but rapidly increasing NSD to a plateau and high but decreasing NW and SOD; the "Persistent NW and SOD" group (17.5%) had persistent high NW and SOD. Maternal depression during pregnancy and sleep habits at age 1 (e.g. parental presence or feeding to fall asleep, sleeping at least part of the night away from own bed) were common risk factors associated with the most disordered sleep multi-trajectory groups.

CONCLUSIONS

We identified distinct sleep multi-trajectory groups and early life-associated factors in preschoolers. Most of the factors associated with the most sleep-disordered multi-trajectory groups are likely modifiable and provide clues for early prevention interventions.

Natural history trajectories of frailty in community-dwelling older Japanese adults

Background

The gap between the average life expectancy and healthy life expectancy remains wide. Understanding the natural history of frailty development is necessary to prevent and treat frailty to overcome this gap. This study elucidated the trajectories of 5 frailty assessment components using group-based multitrajectory modeling.

Methods

Overall, 845 community-dwelling older adults (aged 65–91 years; 433 males and 412 females) who underwent longitudinal frailty assessments at least 3 times were included in the analysis. The mean follow-up period (±SD, range) was 7.1 (±2.3, 3.8–11.3) years. In each wave, the physical frailty was assessed for the following 5 partially modified components of the Cardiovascular Health Study criteria: shrinking, weakness, exhaustion, slowness, and low activity. Using group-based multitrajectory modeling, we identified subgroups that followed distinctive trajectories regarding the 5 frailty components.

Results

Five frailty trajectory groups were identified: weakness-focused frail progression group (Group 1 [G1]; 10.9%), robust maintenance group (Group 2 [G2]; 43.7%), exhaustion-focused prefrail group (Group 3 [G3]; 24.3%), frail progression group (Group 4 [G4]; 6.7%), and low activity–focused prefrail group (Group 5 [G5]; 14.4%). The Cox proportional hazards model analysis showed that G1, G4, and G5 had significantly higher mortality risks after adjusting for sex and age (G2 was the reference group).

Conclusion

Based on the natural history of frailty, the 5 distinctive trajectory groups showed that some individuals remained robust, while others remained predominantly prefrail or progressed primarily owing to physical mobility decline. Therefore, identifying individuals belonging to these progressive frailty groups and providing interventions according to the characteristics of each group may be beneficial.