U.S. adolescent rest-activity patterns: Insights from functional principal component analysis (NHANES 2011-2014)

Authors: YEUNG, CHRIS - University Of Texas Health Science Center; LU, JIACHEN - University Of Texas Health Science Center; SOLTERO, ERICA - Children'S Nutrition Research Center (CNRC); BAUER, CICI - University Of Texas Health Science Center; XIAO, QIAN - University Of Texas Health Science Center

Submitted to: International Journal of Behavioral Nutrition and Physical Activity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/26/2023
Publication Date: 10/13/2023
Citation: Yeung, C.H., Lu, J., Soltero, E.G., Bauer, C., Xiao, Q. 2023. U.S. adolescent rest-activity patterns: Insights from functional principal component analysis (NHANES 2011-2014). International Journal of Behavioral Nutrition and Physical Activity. 20(1). Article 125. https://doi.org/10.1186/s12966-023-01520-3.
DOI: https://doi.org/10.1186/s12966-023-01520-3

Interpretive Summary: Human rest and activity patterns are regulated by the body's internal clock also known as the circadian rhythm. Suboptimal rest-activity patterns in youth are associated with poor health outcomes including obesity and obesity related disease risk factors. Identifying sociodemographic factors that impact rest-activity patterns can help identify adolescents that could benefit the most from interventions to improve physical activity and sleep behaviors. The purpose of this study was to use principal component analysis to identify rest-activity profiles in a nationally representative sample of U.S. adolescents to examine associations among rest-activity profiles with demographic and socioeconomic characteristics. To measure rest-activity patterns, participants wore an accelerometer for 24-hours a day for seven days. After analyses, four different profiles emerged from the data. One of those profiles was higher day-time physical activity, which was associated with age. Younger youth engaged in more day-time physical activity compared to older adolescents. Another profile included the early activity profile, describing youth who engage in activity earlier in the day. The early activity profile was associated with age, particularly younger adolescents, and Mexican American adolescents. The early activity peak profile, describing peaks in activity early in the day, was also associated with age as it was prevalent among older adolescents. Lastly, the prolonged activity/reduced rest window profile emerged from the data characterizing longer activity periods and shorter rest periods. Compared to boys, girls had a higher value for the prolonged activity/reduced rest window profiles. Additionally, Black adolescents had a higher value for prolonged activity/reduced rest window profiles. Our findings showed that age and race/ethnicity may shape the adolescents' rest and activity behaviors. These findings suggest that future studies may need to consider different strategies for different age and race/ethnicity subgroups to effectively promote healthy rest-activity rhythms.

Technical Abstract: Suboptimal rest-activity patterns in adolescence are associated with worse health outcomes in adulthood. Understanding sociodemographic factors associated with rest-activity rhythms may help identify subgroups who may benefit from interventions. This study aimed to investigate the association of rest-activity rhythm with demographic and socioeconomic characteristics in adolescents. Using cross-sectional data from the nationally representative National Health and Nutrition Examination Survey (NHANES) 2011-2014 adolescents (N=1814), this study derived rest-activity profiles from 7-day 24-hour accelerometer data using functional principal component analysis. Multiple linear regression was used to assess the association between participant characteristics and rest-activity profiles. Weekday and weekend specific analyses were performed in addition to the overall analysis. Four rest-activity rhythm profiles were identified, which explained a total of 82.7% of variance in the study sample, including (1) High amplitude profile; (2) Early activity window profile; (3) Early activity peak profile; and (4) Prolonged activity/reduced rest window profile. The rest-activity profiles were associated with subgroups of age, sex, race/ethnicity, and household income. On average, older age was associated with a lower value for the high amplitude and early activity window profiles, but a higher value for the early activity peak and prolonged activity/reduced rest window profiles. Compared to boys, girls had a higher value for the prolonged activity/reduced rest window profiles. When compared to Non-Hispanic White adolescents, Asian showed a lower value for the high amplitude profile, Mexican American group showed a higher value for the early activity window profile, and the Non-Hispanic Black group showed a higher value for the prolonged activity/reduced rest window profiles. Adolescents reported the lowest household income had the lowest average value for the early activity window profile. This study characterized main rest-activity profiles among the US adolescents, and demonstrated that demographic and socioeconomic status factors may shape rest-activity behaviors in this population.