Combination of hormone replacement therapy and high physical activity is associated with differences in Achilles tendon size in monozygotic female twin pairs

Abstract

Finni T, Kovanen V, Ronkainen PHA, Pöllänen E, Bashford GR, Kaprio J, Alén M, Kujala UM, Sipilä S. Combination of hormone replacement therapy and high physical activity is associated with differences in Achilles tendon size in monozygotic female twin pairs. J Appl Physiol 106: 1332-1337, 2009. First published January 22, 2009 doi:10.1152/japplphysiol.91439.2008.-Estrogen concentration has been suggested to play a role in tendon abnormalities and injury. In physically active postmenopausal women, hormone replacement therapy (HRT) has been suggested to decrease tendon diameter. We hypothesized that HRT use and physical activity are associated with Achilles tendon size and tissue structure. The study applied cotwin analysis of fourteen 54-to 62-yr-old identical female twin pairs with current discordance for HRT use for an average of 7 yr. Achilles tendon thickness and cross-sectional areas were determined by ultrasonography, and tendon structural organization was analyzed from the images using linear discriminant analysis (LDA). Maximal voluntary and twitch torques from plantar flexor muscles were measured. Serum levels of estradiol, estrone, testosterone, and sex hormone binding globulin were analyzed. Total daily metabolic equivalent score (MET-h/day) was calculated from physical activity questionnaires. Results showed that, in five physically active (MET Ͼ 4) pairs, the cotwins receiving HRT had greater estradiol level (P ϭ 0.043) and smaller tendon cross-sectional area than their sisters (63 vs. 71 mm 2 , P ϭ 0.043). Among all pairs, Achilles tendon thickness and cross-sectional area did not significantly differ between HRT using and nonusing twin sisters. Intrapair correlation for Achilles tendon thickness was high, despite HRT use discordance (r ϭ 0.84, P Ͻ 0.001). LDA distinguished different tendon structure only from two of six examined twin pairs who had a similar level of physical activity. In conclusion, the effect of HRT on Achilles tendon characteristics independent of genetic confounding may be present only in the presence of sufficient physical activity. In physically active twin pairs, the higher level of estrogen seems to be associated with smaller tendon size. tendon structure; women; strength; calf; image analysis TENDONS NEED STRENGTH FOR transferring forces from muscles to bones and resilience to do this task effectively. The most studied components of tendon strength are tendon thickness and cross-sectional area (CSA) (5, 13). A thicker tendon has to bear lower stress and is stiffer than a tendon with the same qualities but thinner or smaller CSA. The Achilles tendon (AT) can bear stresses near to the maximum failure stress of 100 MPa, and this may make AT susceptible for tears and ruptures (23).Both repetitive loading (19) and intermittent high-load physical activity (13) have been shown to increase tendon CSA. Besides physical activity, pathological conditions and high cholesterol level may also increase tendon size (12). Furthermore, sex, probably as a result of hormonal status and, specif...

Repeatability of ultrasound in assessment of distal biceps brachii tendon

“…Published by Sciedu Press Repeatability of resting dBB tendon CSA aligns with previous studies on the patellar [7][8][9] and Achilles [7,[10][11][12][13] tendons and extends the findings of repeatability to the upper limb. In contrast to our hypothesis and previous studies on the Achilles tendon [14][15][16] resting dBB tendon length differed statistically between days.…”

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Does menopausal hormone therapy (MHT), exercise or a combination of both, improve pain and function in post-menopausal women with greater trochanteric pain syndrome (GTPS)? A randomised controlled trial

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