MADRID – Because of the hormone changes that occur throughout their lives, women experience sleep problems that differ significantly from those experienced by men. Indeed, 75%-84% of pregnant women don’t sleep well during the third trimester, and up to 80% of women in menopause have symptoms that prevent them from getting a good night’s rest. For those seeking a precision medicine approach, the challenge is to identify the relationship between the different sex-related phenotypes and the sleep conditions.
Irene Cano, MD, PhD, is the coordinator of the sleep department at the Spanish Society of Pulmonology and Thoracic Surgery. She spoke with this news organization about the significant impact of hormones on sleep disorders in women.
“Reproductive hormones like estrogen and progesterone play a meaningful role in brain functions – not only those linked to the regulation of reproduction but also other physiological processes related to the regulation of circadian rhythms, cognitive performance, mood, and sleep. In addition, other hormones – for example, prolactin, growth hormone, cortisol, and melatonin – have sex-dependent effects on sleep,” Dr. Cano said.
Girls start puberty at a younger age than boys. As girls enter adolescence, they go to bed later and waking up earlier. So, girls are getting less than the 10 hours of sleep that they should be getting at this stage of life. The result is sleep debt, which gives rise to various problems: poor academic performance, ADHD, obesity, and metabolic problems, to name a few. As Ariadna Farré, RN, a sleep unit nurse, noted at SEPAR’s Joint Winter Meeting, “schools would have to start morning classes later to get adolescents to perform well academically. As the situation is now, half of the kids are falling asleep at their desks.”
Influencing sleep quality
Dr. Cano explained the issue as follows: “In adolescence, along with changes in young women’s hormone levels, we begin to see differences between the sexes. The changes in levels of estrogens and progesterone are what’s responsible for the changes that, to some extent, cause those disturbances in the quality of our sleep and in the stages of our sleep.”
Thus, sleep can be affected by the changes in hormone level that occur during a menstrual cycle. Estrogens, which increase during the follicular phase, are associated with REM sleep, while progesterone, which increases during the luteal phase, increases non-REM sleep. “In the 3-6 days prior to menstruation, it’s quite common for a woman to report difficulties falling asleep and staying asleep, in connection with a decline in the percentage of time she spends in REM sleep, in the context of premenstrual syndrome. In addition,” Dr. Cano pointed out, “menstrual bleeding, that loss of blood, is associated with a drop in iron levels, making it more likely that the woman will experience restless legs syndrome.”
Cardiovascular system
This news organization also spoke with Milagros Merino, MD, PhD, president of the Spanish Sleep Society. “The consequences that lack of sleep have on the cardiovascular system – we’re essentially talking about certain arrhythmias, high blood pressure, thrombosis in some cases, stroke, and heart attack. Lack of sleep also gives rise to endocrine and metabolic issues, like overweight and being at a greater risk of developing diabetes. And as for mental health, we see, among other things, attention and memory problems, emotional lability, and irascibility. Numerous studies have confirmed all of this.”
Sleep apnea also deserves mention, Dr. Merino added. “Although this disorder is more common in men, we’re seeing it more and more now in women, along with the cardiovascular issues that it brings about.”
Another cardiovascular risk factor is insomnia, said Dr. Merino. “This sleep disorder is more prevalent in women. As hormones constantly change, the ways women sleep constantly change, from one stage of life to the next. They sleep one way in childhood, another way in adolescence, and yet another way in menopause.”
Sleep in pregnancy
During pregnancy, hormone changes are much more pronounced. During the first trimester, progesterone levels increase, making the woman drowsy. On top of that, her sleep is interrupted by more frequent visits to the bathroom as well as greater general discomfort.
In the second trimester, sleep interruptions persist but are not as bad as they were during the first 3 months. In the third trimester, 75%-84% of pregnant women find it difficult to sleep because of aches and pains, the need to urinate during the night, cramps, and heartburn.
“Major physical changes are happening. When the bladder gets compressed, the woman has to get up and go to the bathroom. There’s an interruption in her sleep,” Ms. Farré explained. In addition, as the pregnancy progresses, the woman gains weight and her body mass index (BMI) increases, which can bring on obstructive sleep apnea, high blood pressure, preeclampsia, and diabetes, if not closely monitored.
Other factors include concomitant treatments, such as contraceptives, and the stages of life, such as pregnancy and lactation. “When a woman of childbearing age has restless legs syndrome, more often than not, this means that she has an iron deficiency that needs to be treated with oral iron supplements,” said Dr. Merino. “However, there are few medications that can be given to a pregnant woman – and RLS is relatively common during pregnancy. So, we have to turn to oral or intravenous iron supplements. Yet another matter is narcolepsy. In these cases, all medications have to be stopped during pregnancy and lactation, as they can be harmful to the baby.”
Sleep apnea
While one in five menopausal women are asymptomatic, the others experience mild to severe symptoms of apnea that frequently interrupt their sleep. In this stage of life, which begins around age 50 years, the hormones that had provided protection against sleep disruptions start to decrease. As a result, there is a rise in sleep problems, especially insomnia, breathing-related sleep disorders (for example, apnea), and restless legs syndrome.
The prevalence of breathing-related sleep disorders during menopause is attributable to weight gain, the drop in levels of estrogens, and the redistribution of adipose tissue in the body. Other factors also increase a woman’s risk of experiencing apnea. They range from stress, depression, and other psychological and psychiatric conditions to health status, medication use, and simply the fact of getting older. “Sleep apnea is more common in men than in premenopausal women. The numbers even out, though, when we compare men against menopausal women,” Dr. Cano noted.
In women, symptoms of sleep apnea are frequently attributed to menopause. There is some overlap: insomnia, headache, irritability, low mood, decreased libido, fatigue during the day, and feeling sleepy. Only much later is the woman’s condition correctly diagnosed as sleep apnea. So, even though presenting with the same complaints, a man will be diagnosed with sleep apnea sooner than a woman will – in some cases, around 10 years sooner.
“On the other hand, we’d always thought that, in menopause, insomnia was characterized by awakenings occurring throughout the second half of the night. But perhaps what happens more often is that women are regularly waking up repeatedly over the course of the entire night, as opposed to experiencing a wakefulness that starts early and lasts throughout the night or having a problem falling asleep to begin with,” said Dr. Merino. “The good news is that hormone replacement therapy can get things back to the way they were. And getting better sleep will help to overcome insomnia.”