Toggle Main Menu Toggle Search

Open Access padlockePrints

Muscle function in monozygotic female twin pairs discordant for hormone replacement therapy

Lookup NU author(s): Dr Marika Noorkoiv


Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Postmenopausal monozygotic twin pairs discordant for hormone replacement therapy (HRT) provide an advantageous study design controlling for genetic background for elucidating the relationships between aging, sex hormone levels, muscle strength, contractile capacity, and fatigability.Thirteen postmenopausal monozygotic twin pairs discordant for HRT were measured for maximal voluntary torque (MVC) and twitch characteristics using electrical stimulation before and after intermittent dynamic plantarflexor exercise until exhaustion.Peak twitch torque was 32% higher in HRT users than in their non-HRT, genetically identical sisters (P = 0.002), but MVC did not differ. There were no differences in the activation level or twitch time characteristics between the co-twins. Fatigue caused decreases in MVC (P = 0.001), twitch torque (P = 0.001), time to peak (P = 0.013), and half-relaxation time (P = 0.001) similarly in HRT users and non-HRT users.In early postmenopausal women, involuntary but not voluntary force-generating mechanisms of the plantarflexors are augmented by the use of HRT.

Publication metadata

Author(s): Finni T, Noorkoiv M, Pöllänen E, Ronkainen PHA, Alén M, Kaprio J, Kovanen V, Sipilä S

Publication type: Article

Publication status: Published

Journal: Muscle & Nerve

Year: 2011

Volume: 44

Issue: 5

Pages: 769-775

Print publication date: 17/10/2011

ISSN (print): 0148-639X

ISSN (electronic): 1097-4598

Publisher: John Wiley & Sons, Inc.


DOI: 10.1002/mus.22162


Altmetrics provided by Altmetric