Beyond total sleep time: Associations between sleep characteristics, weight status, and lifestyle behaviors in 6-10-year-old children.

Sleep is increasingly recognized as a multifaceted construct; however, most studies rely on self-reported sleep duration and overlook other key characteristics. We analyzed cross-sectional data from the REACT project, which included 738 Portuguese children (398 girls) aged 6 to 10 years, using 7-day wrist actigraphy. Latent profile analysis based on total sleep time, sleep onset, wake-up, sleep efficiency, and sleep regularity identified four profiles: "Relatively Favorable Sleepers" (45.4%), "Late Starters & Short Sleepers" (34.3%), "Long Sleepers & Late Risers" (15.6%), and "Early Risers & Poor Quality" (4.7%). Children in the "Early Risers & Poor Quality" profile had higher odds of having overweight or obesity (OR: 2.09, 95% CI: 1.03-4.22) compared to those in the "Relatively Favorable Sleepers" profile. Children in the "Long Sleepers & Late Risers" profile were more likely to meet moderate-to-vigorous physical activity (MVPA) recommendations (OR: 1.78, 95% CI: 1.05-3.03) and accumulated less sedentary time (β = -0.26, 95% CI: -0.50 to - 0.03). Conversely, the "Late Starters & Short Sleepers" profile was associated with higher sedentary time (β = 0.55, 95% CI: 0.38-0.73) and higher unhealthy diet scores (β = 0.41, 95% CI: 0.24-0.57), although no differences were observed in healthy diet scores. These findings highlight the value of multidimensional sleep assessment using objective measures for identifying pediatric subgroups at risk of adverse health outcomes.