The Effect of Menstrual-Cycle Phase on Immune Responses to a 5-km Cycling Time Trial: An Exploratory Study.

PURPOSE Exercise has transient effects on the immune system that could influence infection risk and tissue recovery after exercise. Little is known about how the menstrual cycle interacts with the immune responses to acute exercise. This exploratory study sought to evaluate the effect of menstrual-cycle phase on peripheral blood mononuclear cell counts before and immediately after a bout of intense aerobic exercise. METHODS Seven naturally menstruating women (age: 27 [3] y) completed three 5-km cycling time trials coinciding with the early-follicular, late-follicular, and mid-luteal stage, confirmed by hormonal measurement. Venous blood samples were taken and examined for the presence of immune cell types using flow cytometry. RESULTS Reductions in circulating CCR7+CD45RA+ naïve CD4+ T cells, CD4+CD25+ regulatory T cells, and CD56+CD57+ natural killer cells observed during the early-follicular phase were attenuated when exercise was performed during the late-follicular phase. Similarly, reductions in circulating CD56+CD57+ natural killer cells and CD14+TLR4+ monocytes following exercise in the early-follicular phase were abolished when exercise was performed in the midluteal phase. CONCLUSIONS These preliminary findings indicate that the effect of acute high-intensity exercise on immune-cell mobilization and activation varies across the menstrual cycle, potentially impacting the anti-inflammatory effects of regulatory T cells and the cell-mediated effects of both natural killer CD57+ cells and monocytes expressing TLR4.

目的 运动对免疫系统有短暂影响，这可能会影响运动后的感染风险和组织恢复。关于月经周期如何与急性运动的免疫反应相互作用，人们知之甚少。这项探索性研究旨在评估月经周期阶段对一次高强度有氧运动前后外周血单个核细胞计数的影响。 方法 7名自然月经周期的女性（年龄：27[3]岁）在卵泡早期、卵泡晚期和黄体中期完成了三次5公里自行车计时赛，通过激素测量进行确认。采集静脉血样本，并使用流式细胞术检测免疫细胞类型的存在。 结果 在卵泡早期观察到的循环中CCR7⁺CD45RA⁺初始CD4⁺T细胞、CD4⁺CD25⁺调节性T细胞和CD56⁺CD57⁺自然杀伤细胞的减少，在卵泡晚期运动时减弱。同样，在卵泡早期运动后循环中CD56⁺CD57⁺自然杀伤细胞和CD14⁺TLR4⁺单核细胞的减少，在黄体中期运动时消失。 结论 这些初步发现表明，急性高强度运动对免疫细胞动员和激活的影响在月经周期中有所不同，可能影响调节性T细胞的抗炎作用以及自然杀伤CD57⁺细胞和表达TLR4的单核细胞的细胞介导作用。