Hello. This is JoAnn Manson, Professor of Medicine at Harvard Medical School and Brigham and Women's Hospital. I'd like to talk about the relationship between nighttime hot flashes and vasomotor symptoms and sleep interruptions and quality of sleep.
It's a common perception that night sweats and vasomotor symptoms can lead to sleep disturbances and awakenings at night. But surprisingly, this hasn't been consistently demonstrated in previous studies of sleep using objective measures such as polysomnography. Previous results have been mixed.
In a recent article in the journal Sleep, Hadine Joffe and colleagues [1] in Boston reported on a very interesting and elegant study of a model of menopause using leuprolide, a gonadotropin-releasing hormone agonist, in young premenopausal women. The study included 29 women with an average age of 27 years. After leuprolide administration, a rapid suppression of estradiol was observed as well as the development of persistent vasomotor symptoms in about two thirds of the women. This study demonstrated a strong correlation between the frequency of nighttime vasomotor symptoms and sleep interruptions, awakenings after sleep onset, poor Insomnia Severity Index and Pittsburgh Sleep Quality Index scores, and evidence of sleep fragmentation associated with increased frequency of vasomotor symptoms.
There was a correlation, whether the vasomotor symptoms were subjectively reported in diaries or they were objectively recorded using a monitor. Using objective measures of vasomotor symptoms, there was a correlation with awakenings after sleep onset. These objective measures of sleep awakenings using polysomnography were strongly correlated with both objective and subjective measures of nighttime vasomotor symptoms.
This study really validates women's perceptions that night sweats and vasomotor symptoms are associated with sleep disruptions and sleep fragmentation.
Joffe H, Crawford S, Economou N, et al. A gonadotropin-releasing hormone agonist model demonstrates that nocturnal hot flashes interrupt objective sleep. Sleep. 2013;36:1977-1985. Abstract