Hormonal Update Volume 2 Number 12

Sleepless Nights, Irritable Days, and Fatigue?

It Could be Your Hormones...

Everyone loves a good night’s sleep. Why then are so few of us actually getting it? Most people need between 8 and 10 hours of deep, restful sleep. Yet, The National Sleep Foundation’s 2001 Sleep in America poll shows that nearly two-thirds of all Americans are not getting the sleep they need for good health, optimum performance and safety. According to The National Institute on Aging, over 80% of the aged population experiences some form of sleep disruption, with 25% of older folks experiencing regular insomnia. Sleep disruption can lead to reduced concentration during waking hours, as well as impaired task performance, and diminished cognitive ability. It can also lead to depression.

There are a number of different forms of sleep disturbance, or insomnia. These include taking longer to fall asleep, fragmented periods of sleep, more frequent and longer periods of wakefulness during the night, and earlier than desired waking. This leads to daytime drowsiness and fatigue. Insomnia can create a vicious cycle of dread and worry about not getting enough sleep that compounds the problem. Generally, more women than men have insomnia. Most men in their 50s seem to enjoy undisturbed sleep. However, once men reach the age of seventy there is a sharp increase in sleep disturbance, equal to that of women of the same age.

Some of the most common causes of insomnia are stress, illness, jet lag, and overwork. Coffee, tea, alcohol, and nicotine, stimulants that we use to keep us going like “Ever Ready™” bunnies can, and often do, prevent us from falling asleep. Notably, insomnia can be both the result of, and a contributing factor in alcohol or substance abuse. A survey reported that 14% of American adults use alcohol over the course of a month to help them sleep. Sometimes medications, such as beta-blockers, clonidine, thyroid preparations, cortisone, prednisone, bronchodilators, theophylline (for asthma), decongestants containing pseudoephedrine, and over-the-counter meds that contain caffeine can all interfere with a good night’s sleep.

Aging also plays a role in insomnia. The hormonal shifts in sex steroid hormone and melatonin production that occur naturally with aging can create hormone imbalances that influence the body’s circadian rhythms. Circadian rhythms are biological activities or functions that occur cyclically over a twenty-four hour period. Body temperature, melatonin secretion, and the sleep wake cycle are all circadian rhythms. Circadian rhythms are synchronized - when one is disturbed the others can be as well.

Understanding more about how sleep works can help us avoid some of those sleepless nights. In this two-part Hormonal Update we examine the relationship between insomnia and hormones. In part one we take a look at sex steroid hormones and sleep. In part two we take a look at melatonin, commonly known as the sleep hormone. A well-known and widely used sleep aid, there may be more to melatonin than first expected.

The Hormone Connection

On average, women tend to get by on less than six and a half hours of sleep during the week and seven hours on weekends, often interrupted. Job stress, family stress, that “not enough hours in the day feeling can all contribute to a woman’s sleepless nights. But so can her hormonal fluctuations and changes. Premenstrual syndrome, pregnancy and menopause bring with them estrogen and progesterone fluctuations that can lead to increased wakefulness at night.

During the luteal phase of a woman’s menstrual cycle, (days 14 to 23 after menses begins) as progesterone levels increase, sleep often comes easily. Then, as progesterone declines, falling asleep can become more challenging. Progesterone, known as the calming hormone, is also believed to influence sleep during pregnancy. Women generally experience increased sleepiness during the first trimester of pregnancy when progesterone is rapidly rising. During the second trimester progesterone continues to rise but at a slower rate. Most pregnant women enjoy restful sleep during this time. Once the third trimester begins sleep can be disrupted by the physical discomforts of pregnancy such as heartburn, frequent urination, and leg cramps.

In the Cool of the Night

One of the most common complaints of perimenopausal and menopausal women is a change in sleep patterns. Studies have shown that between 50 and 60% of all perimenopausal and postmenopausal women have difficulty falling asleep or staying asleep, or experience wakeful periods throughout the night, with shortened periods of deep restful sleep. This can be due to wildly fluctuating estrogen and progesterone levels.

Most of us fall asleep when our body temperature is declining. As heat is lost through the skin, and the core body temperature declines, drowsiness increases. The hormonal changes that come with menopause affect the body’s temperature- regulating mechanisms, which could account for the increased sleep difficulty that comes with menopause and aging. Women who experience hot flashes and night sweats have poorer quality sleep than women who do not. In fact, one study showed that nearly 100% of women who experience nighttime hot flashes also experience a waking episode at the same time.

The Stress Zone

Chronic insomnia increases levels of the stress hormone cortisol. Insomniacs with the highest degree of sleep disturbance secrete the highest amount of cortisol, particularly in the evening and nighttime hours when cortisol levels should be low. This means that insomniacs are producing stress hormone levels that actually prevent them from sleeping. They are suffering from sustained, round-the-clock activation of the body’s system for responding to stress. Continually living with the stress of too little sleep can aggravate and intensify other medical conditions like high blood pressure, digestive disorders, and weaken the body’s ability to fight off illness.

Hormone Replacement Therapy

Estrogen replacement therapy has been shown to improve sleep quality, facilitate sleep onset, and decrease nighttime restlessness and awakenings. Women taking estrogen replacement report feeling less tired in the morning, and throughout the day. They also report that other symptoms of menopause such as hot flashes, muscle aches, and mood swings are improved. A significant percentage of non-symptomatic women also reported improved sleep quality with estrogen replacement therapy (ERT). Women with low estrogen levels who are not receiving estrogen replacement enjoy less total sleep time, longer periods of wakefulness during the night, more frequent awakenings during the night, delayed onset of sleeping, and less deep sleep.

Another reason for the positive effect of estrogen replacement on sleep disturbance could be its ability to reduce stress reactivity. Low estrogen levels have been associated with increased heart rate and blood pressure in response to stress. Restoring estrogen to more youthful levels enables the body to respond to stressors more effectively. 

The role of replacement progesterone in sleep disturbance is not fully understood yet. However, it seems that progesterone may have a sedating effect because of its interaction with GABA receptors in the brain. GABA is an amino acid that has a calming effect on the brain. The connection between GABA and progesterone can at least partially explain why low levels of progesterone can lead to irritability, anxiety and even anger, while optimum levels help create feelings of calm and well-being. Clinically, women with low progesterone levels and sleep disturbance symptoms have shown improvement in sleep patterns with progesterone replacement.

Estrogen is Not Alone

Hormonal imbalances can be a significant factor in sleeplessness. If you are not sleeping and suspect it may be an imbalance in your hormones, you may want to consult with your health care practitioner about a saliva hormone level lest. Because each woman’s hormonal milieu is unique, salivary hormone level testing can be an effective tool for helping maintain a healthful and youthful hormone balance. The concept of one-size fits all doses of hormones for all women is out dated. Using salivary hormone level testing your healthcare practitioner can help you determine precisely what you need and whether the dose prescribed is adequate for you. 

The relationship among hormones is synchronistic, and delicate. What effects one, can affect the others. When one hormone is out of balance the synchrony can be disrupted. In this hormonal up date we have looked at the overall effect that hormone balance has on sleep. In our next update we focus more specifically on the hormone melatonin, which plays a key role not only in sleep, but other biological processes as well.