Abstract
Background Aging leads to a decline in muscle mass and strength, contributing to frailty and decreased quality of life. Sirolimus (Rapamycin), an mTOR inhibitor, has shown potential in preclinical studies to extend lifespan and improve healthspan. This study evaluates the safety and efficacy of once-weekly Sirolimus (Rapamycin) administration on muscle strength and endurance in older adults engaged in a 13-week exercise program.Methods This randomized, double-blind, placebo-controlled trial will enrol 40 participants aged 65–85. Participants will be randomly assigned to receive either Sirolimus (Rapamycin) 6 mg/week or placebo for 13 weeks, in conjunction with an at-home exercise program. The primary outcome measure is the change in muscle strength and endurance, assessed by the 30-Second Chair-Stand Test. Secondary outcome measures include adverse events, changes in muscle strength and endurance as measured by the 6-minute walk test, handgrip strength, and participant-reported outcomes using the SF-36 survey. Assessments will be conducted at baseline, mid-intervention (week 6), and post-intervention (week 13). Blood samples will be collected for hematology and biochemistry analyses, including full blood count, urea and electrolytes, liver function tests, HbA1c, lipids, serum IGF-1, and hs-CRP. DNA methylation will be analyzed using TruDiagnostic™ to explore changes in biological age.Discussion This study aims to provide insights into the potential benefits of intermittent Sirolimus (Rapamycin) administration on muscle performance in older adults. By alternating periods of mTOR inhibition through Rapamycin and activation via exercise, this study will explore a novel approach to enhancing muscle strength and endurance in the aging population. The results could have significant implications for developing interventions to improve physical function and overall health outcomes in older adults. Safety and tolerability will also be closely monitored to ensure the feasibility of this regimen for wider application.Trial registration: The trial is registered in the Australia New Zealand Clinical Trials Registry (ACTRN12624000790549) on the 26th June 2024. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12624000790549