最近一項研究表明，處在絕經早期階段的女性更容易發生睡眠障礙。絕經期轉換的最早階段叫作更年期，處在這一階段的女性由於體內激素水平的波動，月經周期容易出現異常，還可能發生睡眠障礙和潮熱。近日，相關研究結果發表在國際學術期刊JCEM上。

　　這項研究對月經周期中黃體期和卵泡期產生的激素波動如何影響睡眠進行了檢測。結果發現更年期女性在月經到來之前的黃體期更容易產生睡眠障礙，而在月經期之後的階段這種現象會得到改善。通過對誌願者的大腦活動進行檢測可發現，即使是對於處在生育最後階段的更年期女性來說，孕酮仍然會影響女性睡眠。

　　參與該項研究的女性都要在睡眠實驗室睡兩次--其中一次是在月經期開始之前的幾天，而另一次則是在月經期之後的幾天。研究人員利用腦電波圖像對誌願者的睡眠和腦活動進行了監測，同時，每一位參與者還在進行實驗室監測之前填寫了睡眠質量調查表，並進行了血液檢測分析了血液中的激素水平。結果顯示在月經到來之前，誌願者們的深度睡眠更少，更容易醒來，同時她們的孕酮水平更高，而在月經之後的一段時間裏，這種現象得到改善。與此相比，年輕女性在整個月經周期中的睡眠都更加穩定。

　　研究人員最後指出，對於中年女性來說，月經周期中激素的變化僅僅是影響睡眠質量的一部分因素，而這項研究對於更好地理解更年期女性睡眠障礙問題提供了重要信息。

　　DOI: http://dx.doi.org/10.1210/jc.2015-1844

　　Menstrual Cycle-Related Variation in Physiological Sleep in Women in the Early Menopausal Transition

　　Massimiliano de Zambotti, Adrian R. Willoughby, Stephanie A. Sassoon, Ian M. Colrain, and Fiona C. Baker

　　Context:

　　Most studies show sleep homeostasis and continuity remain stable across the menstrual cycle in young women. The influence of the menstrual cycle on physiological sleep in midlife women is unknown.

　　Objective:

　　The objective of the study was to assess the impact of menstrual cycle phase on the polysomnogram and electroencephalographic (EEG) features of sleep in midlife women, accounting for the presence of an insomnia disorder.

　　Design and Participants:

　　This was a laboratory study of 20 women in the early menopausal transition (48.8 ± 2.9 y), 11 with a Diagnostic and Statistical Manual of Mental Disorders, fourth edition, diagnosis of insomnia, studied on one night each in the follicular and luteal menstrual cycle phases.

　　Main Outcome Measures:

　　Polysomnographic and sleep EEG indices were measured.

　　Results:

　　Both groups of women had more awakenings (P = .003) and arousals (P = .025) per hour of sleep and less percentage slow wave sleep (P = .024) when progesterone was raised (≥3 ng/mL?1) during the luteal compared with the follicular phase. Both groups had greater spindle density (P = .007), longer spindles (P = .037), and increased 14-17 Hz EEG activity in the luteal phase (P <.05), although for the 15- to 16-Hz bin, this effect was significant only in women without insomnia (P <.001). Women with insomnia had a shorter sleep duration (P = .012), more wakefulness after sleep onset (P = .031), and a lower sleep efficiency (P = .034) than women without insomnia, regardless of menstrual cycle phase.

　　Conclusion:

　　Sleep is more disrupted in the luteal phase compared with the follicular phase in midlife women, whether or not they have an insomnia disorder. There is a prominent increase in sleep spindles and spindle frequency activity in the luteal phase, likely an effect of progesterone and/or its neuroactive metabolites acting on sleep regulatory systems.