Sleep woes peak during the perimenopausal transition, says Barbara Phillips, MD, medical director of the UK Healthcare Good Samaritan Sleep Disorders Center, in Lexington, Kentucky, who notes that 12 to 40 percent of women report having trouble sleeping during these years.
"With impending menopause, most women experience a reduction in progesterone and estrogen," says David Slamowitz, MD, medical director of the SleepWell Center in Denver. "These hormones help regulate sleep, so declining levels can cause sleeping difficulties."
Although scientists are unsure exactly why sleep is so affected, there are several possible causes. The conventional wisdom is that hot flashes and night sweats interrupt sleep; however, Phillips says, the opposite may be true — that middle-of-the-night wake-ups may actually cause hot flashes.
Another possibility is that medical disorders such as restless leg syndrome, sleep apnea, or hyperthyroidism may be a contributing factor. The rates of restless leg syndrome and hyperthyroidism both increase with age, and the decrease in estrogen levels may play a role in sleep apnea. A 2007 study published in Menopause found that 53 percent of women over 44 who have trouble sleeping also have restless leg syndrome or sleep apnea. People with sleep apnea actually stop breathing during sleep, sometimes hundreds of times a night. When this happens, the brain must arouse the person slightly in order for her to breathe again. "If you snore, develop hypertension, or gain a lot of weight during perimenopause, talk to your doctor about sleep apnea," Phillips says.
Sleep problems can also be caused by depression, whose incidence more than doubles during perimenopause. Insomnia is one of the primary symptoms of depression.
And of course, the pressures of everyday life play a part, says ob-gyn Jan Herr, MD, a menopause expert at Kaiser Permanente Northern California. Toss in hot flashes and night sweats, plus the more frequent need to urinate during the night, "and it’s a wonder any of us sleeps well," she says.
Frequent wake-ups can interrupt REM sleep, which may be important for memory and mood regulation. In fact, reduced REM sleep time, as well as deep sleep time, can contribute to other symptoms we associate with perimenopause, such as fatigue, mood swings, irritability, and trouble concentrating.
As if memory lapses weren’t enough, sleep problems can also contribute to weight gain during perimenopause. Feeling fatigued can weaken your resolve to exercise and eat well, and it can also affect your appetite. Reducing sleep time can lower levels of leptin, a hormone that signals fullness. At the same time, lack of z’s increases ghrelin, a hormone that promotes appetite. This hormonal double punch may not only make you feel hungrier, it may also prevent you from feeling sated after eating. The level of orexin, a hormone that increases food cravings, also goes up in animals that are deprived of adequate sleep time.
If you’re having trouble sleeping, try improving your habits. If you continue to struggle, ask your doctor for help. You won’t be alone: One-third of perimenopausal women use sleep aids at least a few nights a week, according to the National Sleep Foundation.
A variety of medications may help you get a good night’s rest, including the over-the-counter antihistamine Benadryl, which can bring on drowsiness.