Sleep Disorders

Glossary

"The golden chain that ties health and our bodies together" - Thomas Dekker

Diseases and Their Relationship With Sleep

Cancer

Cancer is a general term for over 100 different diseases, and it affects the body in many ways. Pain from the tumor can disrupt sleep and various discomforts from treatment can wreak havoc on a patient’s ability to get to and stay asleep. A Duke University study found that the effect of cancer on sleep is “one of the most persistent and disruptive” challenges a typical cancer patient faces.

The stress of a cancer diagnosis and worrying about what is often a long-term disease and lengthy treatment causes a lot of insomnia.

Oncology nurses speak a lot about “cancer-related fatigue” (CRF), but sleep disturbances are more than just fatigue. Insufficient sleep can make the patient more irritable and less amenable (both psychologically and physically) to treatments. Chemotherapy patients experience insomnia at three times the rate of the general population

Fatigue is a side effect of chemotherapy, radiation therapy, and surgery. The patient feels sleepy during the day and experiences unrefreshing sleep at night.

Breast cancer often shifts the cortisol patterns so the levels of this stress hormone associated with sleep are higher in the afternoon than upon morning awakening. Also, cancer in the chest (e.g. esophageal or lung cancer) can make apnea worse.

Here’s an interesting PDF on cancer-related fatigue and sleep
disorders: http://theoncologist.alphamedpress.org/content/12/suppl_1/35.full.pdf

Both doctors and patients may be reluctant to use pharmacological treatments for insomnia because the cancer patient is already taking so many drugs. Opioids - strong pain drugs given to some cancer patients – depress breathing and are not given to people with apnea.

There is also interest among scientists in the connection between the body's circadian cycles and cancer growth.

Circadian rhythms and tumor growth.

Circadian Disruption Accelerates Tumor Growth and Angio/Stromagenesis through a Wnt Signaling Pathway

Multiple Sclerosis

Fatigue is one of the most complained-about symptoms of MS and the more advanced the disease is, the worse the fatigue. It is not clear how much of the fatigue is due to the disease and how much is due to sleep disturbances, which commonly occur in patients with MS. Recent studies indicate that fatigue plays a minor part in sleep disorders.

It may be that the sleep disorders contribute to the fatigue. REM sleep behavior disorder, and sleep disordered breathing, leg cramps, and insomnia are all prevalent in MS patients, and an Italian study found that half of MS patients had restless leg syndrome.

Medicines for the MS may interfere with sleep, as well as the pain of the disease. Because MS is incurable Doctors look at improving sleep quality and duration as a way of improving the quality of life Insomnia is more common in MS patients than in the general population and more common than in people many other chronic diseases. It also appears to be more common in women with MS than in men.

The bodies of people with MS have trouble with thermal regulation, which is tied to the sleep cycle. Yawning is also a common symptom of MS.

Hypertension

A study published in American Heart Association’s journal Hypertension found that quality of sleep was tied to cardiovascular health. Poor quality sleep is correlated with high blood pressure. Specifically, a lack of Stage 3 deep sleep and hypertension go together, regardless of the length of sleep time a person gets. It’s long been known there is a correlation between apnea and high blood pressure, although this could be due to a common cause (obesity). The correlation between poor quality sleep and high body weight has also been known for a long time. This Harvard Medical School study is the first direct tie between lack of deep sleep and high blood pressure.

On average, a person’s blood pressure drops 10 points (millimeters of mercury) when he or she goes into Stage 3. Although even the best adult sleepers spend less than two hours per night in deep sleep, this nightly respite appears to be important to maintaining reasonable waking blood pressure. An earlier study published in 2003 stated that people who lack the nighttime fall in blood pressure are at greater risk for cardiovascular events.

A similar result was found by the Dept of Veterans Affairs in a study specifically of older men. The men in the study did not have hypertension at the time the researchers started following them, but they did have poor quality sleep. A decrease in slow-wave sleep is common in the elderly. These men developed hypertension over the next several years at a high rate, further suggesting a connection between poor sleep and high blood pressure. http://www.ncbi.nlm.nih.gov/pubmed/21876072

A British study of women only found an even stronger correlation between insomnia and hypertension in premenopausal women:
http://www.ncbi.nlm.nih.gov/pubmed/20040890

Women who get high blood pressure during pregnancy also have higher rates of sleep-disordered breathing. The causes and effects here are not clear. People with the very serious problem of pulmonary hypertension are known to have poor quality sleep; this is an incidence of insomnia being a symptom of another condition.

Fibromyalgia

Fibromyalgia, despite being common, is still somewhat mysterious. Patients have a range on symptoms, including rather bad pain. This website addresses sleep issues. When formulating its most recent diagnostic definition of fibromyalgia in 2010, the American College of Rheumatology included excessive daytime sleepiness, fatigue, tiredness, and insomnia.

Polysomnographic tests have found fibromyalgia patients sleep about the normal amount, but with an increase in short-wave shallow sleep at the expense of deep sleep – a deterioration in sleep quality common to many illnesses. They also more frequently have periodic leg movements associated with cortical arousals, although if there is a connection with restless legs syndrome is not clear.

Detailed study has found that people with fibromyalgia and chronic fatigue syndrome more often transition from REM sleep to Stage 1 sleep and from Stage 3 or 4 sleep to Stage 1 sleep than healthy people, although the architecture of sleep patterns between the two illnesses are different.

Obesity is common in fibromyalgia patients and also the severity of the obesity correlates with lower sleep quality.