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

运动相关性闭经（EAA）常发生在高强度训练的女性运动员中，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。本研究的目的是探讨血管内皮功能在高训练的女性运动员EAA。方法和结果研究对象包括26名女子排球运动员，谁有规律的月经周期（定期组，n=15）和EAA（EAA组，n=11）。通过使用高分辨率超声检查测量内皮依赖性流量介导的血管舒张（FMD）和硝酸甘油（一种非内皮依赖性扩张剂）诱导的血管舒张来评估肱动脉的血管舒张反应。测定所有受试者的血浆雌二醇和孕酮水平。在常规组中，所有测量均在末次月经周期第一天后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）。两组间血浆孕酮水平无差异。常规组和EAA组在基线时的动脉直径和血流量方面没有差异，充血时的血流量也没有差异。EAA组的FMD明显小于常规组（p<0.05）。硝酸甘油诱导的血管舒张在两组之间没有差异。FMD与血浆雌二醇水平呈显著正相关（r= 0.41，p <0.05）。结论高强度训练的女排运动员EAA患者存在低雌激素状态，其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.