激素替代疗法治疗的同卵双胞胎女性双生子肌肉功能的差异。

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

机构信息

Neuromuscular Research Center, Department of Biology of Physical Activity, P.O. Box 35 (VIV227), University of Jyväskylä, FI-40014 Jyväskylä, Finland.

出版信息

Muscle Nerve. 2011 Nov;44(5):769-75. doi: 10.1002/mus.22162.

DOI:10.1002/mus.22162

PMID:22006692

Abstract

INTRODUCTION

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.

METHODS

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.

RESULTS

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.

CONCLUSION

In early postmenopausal women, involuntary but not voluntary force-generating mechanisms of the plantarflexors are augmented by the use of HRT.

摘要

简介

绝经后接受激素替代疗法（HRT）和未接受 HRT 的同卵双胞胎为阐明衰老、性激素水平、肌肉力量、收缩能力和易疲劳性之间的关系提供了有利的研究设计，可控制遗传背景。

方法

使用电刺激对 13 对绝经后接受 HRT 和未接受 HRT 的同卵双胞胎进行最大自主扭矩（MVC）和抽搐特征的测量，在间歇性动力性跖屈肌运动直到疲劳之前和之后进行。

结果

HRT 使用者的峰值抽搐扭矩比未接受 HRT 的同卵双胞胎高 32%（P = 0.002），但 MVC 没有差异。双胞胎之间的激活水平或抽搐时间特征没有差异。疲劳导致 MVC（P = 0.001）、抽搐扭矩（P = 0.001）、峰值时间（P = 0.013）和半松弛时间（P = 0.001）在 HRT 使用者和未接受 HRT 的使用者中同样下降。