Effects of transdermal estrogen on collagen turnover at rest and in response to exercise in postmenopausal women.
Level 2 - randomized trial
Randomized crossover trial
PubMed 22773769 · doi:10.1152/japplphysiol.01463.2011
What was done
In a randomized controlled crossover study, 11 postmenopausal women were tested under two conditions: transdermal estrogen replacement therapy (ERT; Evorel patches applied over the patellar tendons) and a no-patch control period. On day 2 of each period, participants performed one-legged exercise, allowing comparison between the exercised leg and resting leg. On days 3 and 5, microdialysis catheters were placed into the vastus lateralis muscle and in front of the patellar tendons of both legs to measure markers of collagen synthesis (procollagen type I NH2-terminal propeptide, PINP), IGF-I, and IL-6.
What was found
Neither exercise loading nor ERT alone altered peritendinous PINP levels. However, the combination of exercise and ERT significantly enhanced skeletal muscle PINP after 72 hours (interaction between loading and treatment, P = 0.008). Neither ERT nor exercise influenced IGF-I or IL-6 levels in skeletal muscle or peritendinous fluid. Absolute concentration values were not reported in the abstract.
Why it matters
The study indicates that estrogen availability in postmenopausal women facilitates acute exercise-induced collagen synthesis in skeletal muscle, suggesting a role for estrogen in post-exercise connective tissue remodeling and repair.
Limits
The sample size was very small (n = 11 postmenopausal women). The study measured only acute biochemical marker responses over 72 hours following a single exercise bout, without evaluating long-term functional outcomes or systemic hormone administration effects given the local patch placement over the patellar tendons.
Cited by
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