Cardiovascular Health and Lifestyle in Aragón Adolescents (CHIARA): protocol for a longitudinal cohort study integrating cardiovascular, behavioural and psychosocial assessment v1

Background: Cardiovascular risk originates early in life and is shaped by a complex interplay of biological, behavioural and psychosocial factors. Late adolescence represents a critical developmental window during which these determinants may have long-term implications for cardiometabolic health. Despite increasing recognition of these early-life influences, there is still a lack of integrative and standardized approaches combining clinical, lifestyle and emotional health dimensions within well-characterized longitudinal cohorts. Methods: The CHIARA study is a follow-up of the CALINA birth cohort, established in Aragón, Spain, in 2009–2010. Participants were previously assessed during early childhood, including a detailed evaluation at approximately 7 years of age. The current wave focuses on adolescents aged 16–17 years and includes a comprehensive assessment integrating questionnaire-based data, clinical measurements and biological sampling. Completion of the questionnaire package was the only mandatory requirement for participation, allowing broad inclusion across the region. Self-reported weight and height were collected in all participants. Optional in-person assessments included body composition measured by bioelectrical impedance (Tanita MC-580), blood pressure and blood sampling. Lifestyle behaviours were assessed using validated instruments, and emotional and psychosocial health were evaluated using standardized questionnaires. The primary outcome is cardiovascular health assessed through the Life’s Essential 8 score. Expected results: This protocol will enable the characterization of cardiovascular health profiles in late adolescence and the identification of associations with lifestyle behaviours, psychosocial factors and early-life determinants. Conclusions: This protocol provides a robust and scalable framework for studying cardiovascular health across the life course and may contribute to the development of early preventive strategies in adolescent populations.