Department of Psychology, University of Toronto, Toronto, ON, Canada.
Rotman Research Institute, Baycrest Health Sciences, Toronto, ON, Canada.
Front Endocrinol (Lausanne). 2023 Oct 3;14:1265470. doi: 10.3389/fendo.2023.1265470. eCollection 2023.
Women with early ovarian removal (<48 years) have an elevated risk for both late-life Alzheimer's disease (AD) and insomnia, a modifiable risk factor. In early midlife, they also show reduced verbal episodic memory and hippocampal volume. Whether these reductions correlate with a sleep phenotype consistent with insomnia risk remains unexplored.
We recruited thirty-one younger middleaged women with risk-reducing early bilateral salpingo-oophorectomy (BSO), fifteen of whom were taking estradiol-based hormone replacement therapy (BSO+ERT) and sixteen who were not (BSO). Fourteen age-matched premenopausal (AMC) and seventeen spontaneously peri-postmenopausal (SM) women who were ~10y older and not taking ERT were also enrolled. Overnight polysomnography recordings were collected at participants' home across multiple nights (M=2.38 SEM=0.19), along with subjective sleep quality and hot flash ratings. In addition to group comparisons on sleep measures, associations with verbal episodic memory and medial temporal lobe volume were assessed.
Increased sleep latency and decreased sleep efficiency were observed on polysomnography recordings of those not taking ERT, consistent with insomnia symptoms. This phenotype was also observed in the older women in SM, implicating ovarian hormone loss. Further, sleep latency was associated with more forgetting on the paragraph recall task, previously shown to be altered in women with early BSO. Both increased sleep latency and reduced sleep efficiency were associated with smaller anterolateral entorhinal cortex volume.
Together, these findings confirm an association between ovarian hormone loss and insomnia symptoms, and importantly, identify an younger onset age in women with early ovarian removal, which may contribute to poorer cognitive and brain outcomes in these women.
卵巢切除（<48 岁）的女性晚年患阿尔茨海默病（AD）和失眠的风险增加，失眠是一种可改变的风险因素。在中年早期，她们还表现出言语情节记忆和海马体积减少。这些减少是否与失眠风险一致的睡眠表型相关仍未得到探索。
我们招募了 31 名有风险的年轻中年女性进行双侧输卵管卵巢切除术（BSO），其中 15 名正在服用雌激素为基础的激素替代疗法（BSO+ERT），16 名未服用（BSO）。还招募了 14 名年龄匹配的绝经前（AMC）和 17 名自然绝经后（SM）女性，她们年龄大 10 岁左右，不服用 ERT。参与者在家中进行了多个晚上的整夜多导睡眠图记录（M=2.38 SEM=0.19），同时记录主观睡眠质量和热潮红评分。除了睡眠测量的组间比较外，还评估了与言语情节记忆和内侧颞叶体积的关联。
未服用 ERT 的女性在多导睡眠图记录中观察到睡眠潜伏期延长和睡眠效率降低，这与失眠症状一致。这种表型也在 SM 中的老年女性中观察到，表明卵巢激素丧失。此外，睡眠潜伏期与段落回忆任务中更多的遗忘有关，之前在早期 BSO 的女性中观察到这种遗忘。睡眠潜伏期增加和睡眠效率降低与前外侧内嗅皮层体积减小有关。
这些发现共同证实了卵巢激素丧失与失眠症状之间的关联，重要的是，确定了卵巢切除的女性中更早的发病年龄，这可能导致这些女性认知和大脑预后较差。
