Protocol for the Imagine HEALTH Study: Guided imagery lifestyle intervention to improve obesity-related behaviors and salivary cortisol patterns in predominantly Latino adolescents

摘要

Innovative lifestyle interventions are needed to reduce type 2 diabetes risk in adolescents. This report describes the protocol of the Imagine HEALTH cluster randomized control trial, that tests an intervention based in Self-Determination Theory (SDT) and uses lifestyle education combined with the mind-body, complementary health modality of guided imagery (GI), to address obesity prevention and treatment in predominantly Latino adolescents. The primary aim is to determine the unique effects of each of the three major components of the 12-week lifestyle intervention (lifestyle education, stress reduction guided imagery, and lifestyle behavior guided imagery) compared to control on primary outcomes of physical activity (accelerometry), dietary intake (3-day recall), and stress biomarker levels (salivary cortisol). Secondary aims assess changes compared to controls in psychosocial outcomes (stress, well-being, depression), diabetes-related metabolic outcomes (adiposity, insulin resistance), maintenance of outcome changes for one year post-intervention, and SDT-based mediation of intervention effects. The development and rationale for each of the intervention components, study design, and outcome measurement processes are described. Adolescent participants recruited from four urban schools are cluster randomized by school into one of four arms of the 12-week (3-month) intervention, followed by 6?months of maintenance and 6?months of no contact. Outcome measures are assessed at the end of each period (3-, 9-, and 15-months). Results to date show successful recruitment of 97% of the target study population. Future results will demonstrate the effects of this integrative intervention on primary and secondary outcome measures in adolescents at risk for lifestyle-related metabolic disease.