Ladies, ever feel like there are certain points in the month where you just can’t get some shut-eye? You might be on to something because a study presented recently in the ENDO 2019 conference suggests that women are more likely to have disturbed sleep in the days leading up to their period. The study took place at the National Institute of Environmental Health Sciences (NIEHS).
Researchers gathered information from 10 healthy women ages 18 to 28 who have regular periods and tracked their sleep for two menstrual cycles. To do this, they took data from the actigraphic sensors on the women’s wrists to record their sleeping patterns and also took urine samples to get an idea of their hormone activity by measuring the concentrations of some chemicals.
Sleeping patterns were assessed using the following:
– Sleep efficiency: The percentage of the total time spent in bed that actually involved sleeping;
– Wake after sleep onset (WASO): The periods spent awake after falling sleep (measured in minutes);
– Sleep fragmentation index (SFI): A measure used to assess the extent of sleep disruption in people who have fragmented sleep.
The chemicals measured in the urine sample were luteinizing hormone (aka LH, which triggers ovulation), estrone-3-glucuronide (E1G, a by-product of the female hormone oestrone, a type of oestrogen), and pregnanediol-3-glucuronide (PDG, a by-product of the female hormone progesterone).
The participants also had to stick to a particular diet during the early follicular phases of both menstrual cycles (around the time they would be having their period). The diet during the first cycle was described as having “neutral energy availability”; this means that the energy taken in from the food was roughly the same amount used by the body. But for the second cycle, the participants ate a diet that was 55 per cent lighter in calories. The menstrual cycles of the women were counted as 28-days long, with a 14-day follicular phase and a 14-day luteal phase (after ovulation). All ten women ovulated during both cycles.
Participants were more likely to experience poor sleep in the days running up to their period, also known as the late luteal phase of the menstrual cycle, according to one of the study’s researchers, Anne E. Kim, a medical student from Case Western Reserve University in Cleveland, Ohio.
Kim says that during that phase, sleep efficiency was an average of 3.3 per cent lower in comparison to the early follicular phase. WASO was also found to be an average of 15 minutes longer and participants tended to wake up three more times during the night.
Kim also says that the caloric restriction underwent by the participants in the early follicular phase of the second cycle also affected their sleep during both the late follicular stage (the days right before ovulation) and the late luteal phases. This is thought to be because reduced energy availability leads to more sleep disruption, a greater WASO and a higher SFI.
It’s also thought that these differences in sleep quality are brought about by the variation of hormone activity throughout the cycle. For instance, E1G was found to be linked to more awakenings at night, and PDG was related to more sleep fragmentation.
The findings of this research seem to validate a pretty common experience amongst women, as 25 to 33 per cent of women surveyed in the US’s National Sleep Foundation report having more disrupted sleep in the weeks ahead or during their period.
What you can do
Kim says that keeping track of your cycles and practising good sleep hygiene in the week before your expected period could be the key to help you get a sweeter snooze. “Good sleep hygiene includes many different lifestyle habits,” she tells All and About, and gives keeping a consistent sleep/wake schedule and reducing caffeine intake and screen-time in the evening as examples.
She also says that while there’s not enough evidence yet to tell women to not restrict their calorie-intake by dieting during the late stages of their follicular and luteal phases, she does encourage them to practice good sleep hygiene if doing so.
“Adopting these lifestyle changes and being aware that these sleep changes can occur in relation to their [women’s] menstrual cycles may increase the chance of having better sleep quality,” she says.
Written by: Tesneem Ayoub
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