Prevention of Muscle Loss After Menopause Using Testosterone: The PAMELA study

There is a progressive and generalized loss of muscle mass and strength associated with human aging. Women experience an accelerated decline in muscle mass and strength around menopause (approximately 51 years of age). This loss leads to impaired physical function, reduced quality of life, and an increased risk of falls and fractures. Currently, no drug therapy exists to prevent muscle loss and strength in women. In women, blood testosterone levels decline by about 25% during the reproductive years (18–45 years old), remain relatively stable through natural menopause (45–54 years old), and reach their lowest levels around age 60, resulting in relative testosterone insufficiency. This insufficiency contributes to the loss of muscle mass and function in postmenopausal women. While testosterone therapy has been shown to increase lean mass in two pilot randomized controlled trials, our systematic review and meta-analyses found that testosterone therapy had no effect on muscle strength or performance, or bone density, as based on studies with small sample sizes (<20 participants per group) and of short duration (6-16 weeks). Thus, an adequately powered, longer-duration clinical trial is needed to discern the effects of testosterone therapy on muscle and musculoskeletal health in postmenopausal women. The aim of this two-arm, parallel-group, randomized, placebo-controlled trial is to determine whether 6 months of transdermal testosterone therapy leads to significant gains in muscular power compared to placebo in postmenopausal women. Secondary aims are to examine whether transdermal testosterone therapy results in improvements in physical function, body composition, bone mineral density, and health-related quality of life. If effective, testosterone therapy could offer a new treatment to reduce muscle loss and improve musculoskeletal health in this population. The study is currently underway. The successful honour applicant will contribute to the final stages of data collection and the analysis of the results.