Clinical and Psychosocial Factors Associated With Physical Activity Level in Adults With Marfan Syndrome

Background. Marfan syndrome is a genetic connective tissue disorder with cardiovascular and musculoskeletal involvement. Despite clinical advances, many patients exhibit low levels of physical activity, influenced by clinical and psychosocial factors such as fear of exertion, fatigue, or pain. Physical activity behavior in this population remains insufficiently characterized. Objective. To assess the level of physical activity in adults with Marfan syndrome and to identify the main associated clinical and psychosocial factors, in order to determine predictors of low physical activity. Methods. An observational, analytical, cross-sectional study will be conducted. Adults with a diagnosis of Marfan syndrome will be included. The primary outcome will be physical activity level, assessed using the International Physical Activity Questionnaire-Short Form. The main independent variables will include kinesiophobia (Tampa Scale for Kinesiophobia), physical activity self-efficacy, perceived fatigue (Fatigue Severity Scale), musculoskeletal pain (Brief Pain Inventory-Short Form), and cardiovascular clinical factors. Potential confounders will include age, sex, body mass index, time since diagnosis, medical recommendations regarding exercise, and current pain. Descriptive analyses and a multivariable logistic regression model will be performed to identify independent predictors of low physical activity. Expected results. To characterize the level of physical activity in adults with Marfan syndrome and to identify the clinical and psychosocial factors that independently predict low physical activity in this population.