S-43-5: A PROSPECTIVE OBSERVATION FOR ORTHOSTATIC DYSREGULATION AND INTOLERANCE IN ADOLESCENCE: STUDY PROTOCOL OF THE SUITA OFFSPRING STUDY

Abstract

Background: In recent years, the number of adolescents who do not attend school due to orthostatic dysregulation (OD) has increased rapidly in Japan, and countermeasures are urgently needed. In contrast, orthostatic intolerance (OI) is used as its counterpart in Western countries, and no internationally unified disease concept exists. Therefore, it is necessary to compare a population-based prospective study of OD and OI in adolescent urban communities. Objective: This study aims to show the clinical characteristics and prognosis of OD and OI in adolescent urban communities. Methods: We will launch the offspring cohort in 2022 in two school districts of Suita City, where we encourage medical examinations for all 11-, 14-, and 17-year-old adolescents. Approximately 200 adolescents of each age group will be undergoing medical examinations as research participants. We will perform a medical check-up to detect the constituents of metabolic syndrome, OD, and OI. We will implement questionnaires for the participants based on the Japanese OD Diagnostic and Treatment Guideline (OD symptoms) and diagnostic criteria in Western countries (OI symptoms). If any of the OD or OI symptoms (at least 3 points, 1 point or more) are positive, they will continue with a 10-minute standing test and their parents will fulfill the checklist for diagnosis of OD with psychosomatic disorder based on the aforementioned OD Guideline. Participants who are positive in the standing test will undergo echocardiography, Holter electrocardiography, and Parent-child home blood pressure measurements. We will refer to the Maternal and Child Health Handbook, Infant Health Examination, School Health Examination, and Lifestyle Related Disease Prevention Health Examination to explore OD and OI risk factors (for example, rapid change in growth curve and circadian rhythm formation). We will compare the prevalence of OD and OI by category using the respective diagnostic criteria in Japan and Western countries and reveal the relationship with classical risk, the diurnal variation in HBP of participants and their parents, cardiac function, and autonomic function. We will conduct follow-up studies every 3-year until 20 years old to examine morbidity and prognosis. In addition, we will perform a selected lifestyle questionnaire focusing on diet and physical activity for adolescents and then use metabolomic analysis to compare plasma metabolite profiles of with and without OD and OI participants to detect modifiable risk factors targeted in future interventions.