Effects of the physical activity guidelines with or without the dietary guidelines on cardiometabolic disease risk among pre- and post-menopausal women: study protocol for the Multiple Risk Factor Intervention Trial (Ms. FIT) RCT

Abstract

Health Canada recommends that adults follow physical activity and dietary guidelines to reduce risk of cardiometabolic disease. However, there is a paucity of research on the effects of these guidelines on cardiometabolic health of women. This study aims to investigate the effects of a 6-month guidelines-based physical activity intervention, with or without following dietary guidelines, on biological systems involved in cardiometabolic disease development. This three-arm randomized controlled trial will recruit 180 women (60 women per arm, 30 pre-menopausal and 30 post-menopausal) with multiple risk factors for developing cardiometabolic disease: currently physically inactive, body mass index > 25 kg/m2, and ≥ 1 of central adiposity, hypertension, pre-diabetes, and dyslipidemia. Participants will be randomized with stratification by menopausal and metabolic syndrome status for 24 weeks to (1) exercise; (2) exercise + diet; or (3) stretching control. The primary outcome is change in Matsuda index (measure of insulin resistance) over 24 weeks. Secondary outcomes include Homeostatic Model Assessment for Insulin Resistance, metabolic syndrome z-score, and Framingham 10-year cardiovascular risk. Tertiary outcomes include cardiorespiratory fitness, cardiac, vascular, muscle and liver structure and function, skeletal muscle remodelling, body composition, blood biomarkers, psychosocial outcomes, and lifestyle behaviours. This study will reduce knowledge gaps around the effects of physical activity and diet in pre- and post-menopausal women towards a goal of evidence-based medicine to prevent cardiometabolic disease in women across the lifespan. This study is funded by the Canadian Institutes of Health Research, has University of Toronto research ethics approval, and is registered as a clinical trial (ClinicalTrials.gov #NCT06345937; registered on 03/28/2024, https://clinicaltrials.gov/study/NCT06345937 ).