Investigation of flow-mediated vasodilation in female athletes with exercise-associated amenorrhea

背景：运动相关性闭经（EAA）在高训练的女性运动员中经常观察到与雌激素水平低下有关。血管内皮功能在月经周期中受到调节。本研究的目的是研究高度训练的EAA女性运动员的血管内皮功能。方法与结果研究对象为月经周期规律的女排运动员26例（常规组，n=15）和月经周期规律的女排运动员（EAA组，n=11）。通过高分辨率超声测量内皮依赖性血流介导的血管舒张（FMD）和三硝酸甘油（一种内皮非依赖型扩张剂）诱导的血管舒张，评估肱动脉的血管舒张反应。测量了所有受试者的血浆雌二醇和黄体酮水平。在常规组中，所有测量在最后一次月经周期的第一天后12至14天进行。EAA组血浆雌二醇水平显著低于常规组（p<0.05）。血浆黄体酮水平在两组之间没有差异。常规组和EAA组在动脉直径和基线血流量方面没有差异，充血时的血流量也没有差异。EAA组FMD显著小于常规组（p<0.05）。三硝酸甘油诱导的血管舒张在两组间无差异。FMD与血浆雌二醇水平显著相关（r=0.41, p<0.05）。结论高强度训练的EAA伴低雌激素状态的女排运动员内皮依赖性血管舒张功能受损。因此，剧烈运动训练对血管内皮功能的不利影响可能对女性运动员的健康具有重要的临床意义。

Background Exercise-associated amenorrhea (EAA) is frequently observed in highly trained female athletes associated with a hypoestrogenic state. Vascular endothelial function is modulated during the menstrual cycle. The purpose of the present study was to investigate vascular endothelial function in highly trained female athletes with EAA.Methods and Results The study subjects consisted of 26 female volleyball players, who had a regular menstrual cycle (regular group, n=15) and EAA (EAA group, n=11). Vasodilatory responses of the brachial artery were evaluated by measuring endothelium-dependent flow-mediated vasodilation (FMD) and glyceryltrinitrate (an endothelium-independent dilator)-induced vasodilation using high-resolution ultrasonography. Plasma levels of estradiol and progesterone were measured in all the subjects. In the regular group, all measurements were performed at 12 to 14 days after the first day of the last menstrual cycle. Plasma estradiol levels were significantly lower in the EAA group than in the regular group (p<0.05). Plasma progesterone levels did not differ between the two groups. The regular and EAA groups did not differ in terms of arterial diameter and blood flow at baseline, nor in blood flow during hyperemia. FMD was significantly smaller in the EAA group than in the regular group (p<0.05). Glyceryltrinitrate-induced vasodilation did not differ between the groups. FMD significantly correlated with plasma estradiol levels (r=0.41, p<0.05).Conclusions Endothelium-dependent vasodilation was impaired in highly trained female volleyball players with EAA associated with a hypoestrogenic state. Thus, the detrimental effects of vigorous exercise training on vascular endothelial function may have important clinical implications for the health of female athletes.