Popp Kristin L, Bozzini Brittany N, Reynoso Marinaliz, Coulombe Jennifer, Guerriere Katelyn I, Proctor Susan P, Castellani Colleen M, Walker Leila A, Zurinaga Nicholas, Kuhn Katherine, Foulis Stephen A, Bouxsein Mary L, Hughes Julie M, Santoro Nanette
Military Performance Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
TRIA Orthopaedic Center, HealthPartners Institute, Bloomington, Minnesota, USA.
Br J Sports Med. 2024 Sep 9;58(18):1052-1060. doi: 10.1136/bjsports-2023-107716.
Less than half of servicewomen report loss of menses during initial military training. However, self-reported menstrual status may not accurately reflect hypothalamic-pituitary-ovarian (HPO) axis suppression and may underestimate reproductive health consequences of military training. Our aim was to characterise HPO axis function during US Army Basic Combat Training (BCT) in non-hormonal contraceptive-using women and explore potential contributors to HPO axis suppression.
In this 10-week prospective observational study, we enrolled multi-ethnic women entering BCT. Trainees provided daily first-morning voided urine, and weekly blood samples during BCT. Urinary luteinising hormone, follicle stimulating hormone, and metabolites of estradiol and progesterone were measured by chemiluminescent assays (Siemens Centaur XP) to determine hormone patterns and luteal activity. We measured body composition, via dual-energy X-ray absorptiometry, at the beginning and end of BCT.
Trainees (n=55) were young (mean (95% CI): 22 (22, 23) years) with average body mass index (23.9 (23.1, 24.7) kg/m). Most trainees (78%) reported regular menstrual cycles before BCT. During BCT, 23 (42%) trainees reported regular menses. However, only seven trainees (12.5%) had menstrual cycles with evidence of luteal activity (ELA) (ie, presumed ovulation), all with shortened luteal phases. 41 trainees (75%) showed no ELA (NELA), and 7 (12.5%) were categorised as indeterminant. Overall, women gained body mass and lean mass, but lost fat mass during BCT. Changes in body mass and composition appear unrelated to luteal activity.
Our findings reveal profound HPO axis suppression with NELA in the majority of women during BCT. This HPO axis suppression occurs among women who report normal menstrual cycles.
不到一半的女军人报告在初始军事训练期间出现月经失调。然而，自我报告的月经状况可能无法准确反映下丘脑 - 垂体 - 卵巢（HPO）轴抑制情况，并且可能低估军事训练对生殖健康的影响。我们的目的是描述使用非激素避孕方法的女性在美国陆军基础战斗训练（BCT）期间HPO轴的功能，并探索HPO轴抑制的潜在影响因素。
在这项为期10周的前瞻性观察研究中，我们招募了即将参加BCT的多民族女性。训练学员在BCT期间每天提供晨尿样本，并每周提供血样。通过化学发光分析法（西门子Centaur XP）测量尿促黄体生成素、促卵泡生成素以及雌二醇和孕酮的代谢物，以确定激素模式和黄体活性。我们在BCT开始和结束时通过双能X线吸收法测量身体成分。
学员（n = 55）较为年轻（平均（95%CI）：22（22，23）岁），平均体重指数为23.9（23.1，24.7）kg/m²。大多数学员（78%）在BCT前报告月经周期规律。在BCT期间，23名（42%）学员报告月经规律。然而，只有7名学员（12.5%）的月经周期有黄体活动证据（ELA）（即推测排卵），且黄体期均缩短。41名学员（75%）无ELA（NELA），7名（12.被归类为不确定。总体而言，女性在BCT期间体重和瘦体重增加，但脂肪量减少。体重和身体成分的变化似乎与黄体活动无关。
我们的研究结果显示，在BCT期间，大多数女性存在严重的HPO轴抑制且无ELA。这种HPO轴抑制发生在报告月经周期正常的女性中。
