Sleeping in on weekends may cause period pain by disrupting normal reproductive cycles, a study in female university students suggests.
We already know that female shift-workers are more prone to irregular menstrual cycles, difficulties falling pregnant and miscarriages, possibly because their irregular schedules affect the circadian rhythms that control their hormone cycles.
Yoko Komada at Meiji Pharmaceutical University in Japan and her colleagues wondered if social jetlag 鈥� a pattern of sleeping in on weekends to make up for early starts during the week 鈥� may have similar effects.
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To find out, they surveyed 150 female Japanese university students about their sleep habits and menstrual patterns. The students were defined as having social jetlag if the midpoint of their sleep was an hour or more later on their days off than on their university days.
Those with social jetlag reported significantly more pain, bloating and behavioural changes during their periods. Moreover, the greater the social jet lag they had, the worse their symptoms were.
These adverse health effects could not be explained by late-night drinking or smoking at the end of the university week, since almost none of the students drank alcohol and none smoked.
Getting up later on days off may throw out the body鈥檚 circadian rhythms, which are reset daily by light exposure upon waking, says at Uppsala University in Sweden. 鈥淚n either聽social jet lag or shift work, you mistime when your聽body is expecting to sleep and be exposed to聽light,鈥� he says.
This in turn may affect circadian-controlled hormone cycles that regulate menstruation and inflammation, Cedernaes says. Previous research has found that sleep disruption can and cause signs of , which may explain the link between social jetlag and menstrual pain, he says. However, more research is needed to confirm this.
Chronobiology International
