Illness, Not Age Itself, Most Often the Trigger of Sleep Problems in Older Adults

When older adults sleep poorly, medical illnesses, or treatments for those illnesses, likely are at fault, not age per se, sleep specialists say. Sleep disorders may exacerbate medical illnesses or complicate their treatment.

Progress in sleep and aging research in the past 5 years has yielded some effective interventions that benefit both sleep and overall health, according to speakers at a congress on sleep, health, and aging held in Washington, DC, this spring. Presented by the National Sleep Foundation (NSF) in cooperation with the National Institute on Aging (NIA) and a host of other agencies and medical groups, the conference aimed to bridge the gap between science and the bedside.

It's a hefty gap.

Physicians gave International Classification of Diseases, Ninth Revision sleep diagnoses to only 20 of nearly 25 000 patients at a community health center, a prevalence rate of 0.1%, and to only 98 of more than 3100 patients at a university-based clinic in the same geographical area, a prevalence rate of 3.1%, sleep specialists found. At both centers, physicians failed to pursue sleep complaints patients had reported on symptom checklists (Sleep Med. 2001;2:4755). Large epidemiological studies show that about 25%-30% of the general adult population have sleep disorders, said NSF President James Walsh, PhD, of St Luke's Hospital, St Louis, Mo.

The NSF's 2003 Sleep in America poll (http://www.sleepfoundation.org/2003poll.html) found that 67% of US residents aged 55 years or older report trouble sleeping. Only 1 in 8 with disordered sleep say the problem has been diagnosed by a physician. Older adults with depression, stroke, heart disease, lung disease, diabetes, arthritis, or hypertension, report poorer sleep quality and get less sleep than their healthy peers. The poll affirms, Walsh said, that sleep problems "can significantly increase the overall burden of illness."

There are important consequences of disordered sleep in an older population, said Andrew Monjan, PhD, MPH, of the NIA. These include excessive daytime sleepiness, attention and memory problems, depressed mood, increased falls, overuse of hypnotic and nonprescription medications, possible interactions with comorbid conditions, and diminished quality of life.

Older individuals usually get less sleep than younger adults, but it is not clear whether the need for sleep or simply the ability to sustain sleep falls, said Meir Kryger, MD, of the University of Manitoba, Winnipeg. Those who average more than 9 hours or less than 6 hours sleep per night, he said, have a higher death rate, and a higher rate of heart disease and cancer than those who usually sleep between 7 and 8 hours.

A need to void proves the most common sleep disrupter in late life. Nearly 2 in 3 older adults get up to use the bathroom at least a few nights a week, the NSF poll shows. Some find it hard to return to sleep, noted Donald Bliwise, PhD, of Emory University Medical School, Atlanta.

Nocturia and nocturnal incontinence may be symptoms of obstructive sleep apnea (OSA), Bliwise said. His research suggests sleep-disordered breathing may contribute to nocturia not only by increasing urine output but also by mechanical factors (by a downward displacement of the diaphragm that puts pressure on the detrusor). Nocturia also increases the risk of falls, particularly in patients who use sedative hypnotics.

The prevalence of chronic renal disease increases with age, and individuals with this disorder commonly experience nocturia and neurogenic bladder, added Stuart Quan, MD, of the University of Arizona College of Medicine, Tucson. Hypersomnia/insomnia, restless legs syndrome/periodic limb movements in sleep, and sleep-disordered breathing are also common in patients with kidney disease; in those undergoing hemodialysis, disturbed sleep further decreases quality of life.

Individuals whose blood pressure does not show a normal nocturnal decrease are at higher risk for myocardial infarction or stroke. Patients who have had an acute stroke may experience either hypersomnia or insomnia, said Quan. Increased wake time after sleep onset is associated with a poorer outcome after a stroke.

Scientists studying the link between sleep and cardiovascular disease are probing the mechanisms that underlie this link. Blood pressure normally decreases in sleep and increases precipitously on awakening, noted Virend Somers, MD, PhD, of the Mayo Clinic, Rochester, Minn. Cardiac and cerebrovascular events follow a circadian pattern, peaking between 6 and 11 AM in individuals who sleep at night.

Arrhythmias also have ties to sleep and waking from sleep, she said. Ventricular tachycardia peaks between 4 and 9 AM and may account for sudden unexplained nocturnal deaths in individuals who were active and seemingly healthy. β-blockers reduce these peaks.

Half of patients with chronic heart failure develop sleep-disordered breathing, which is particularly pronounced when they lie down and cardiac filling pressures are increased. That in turn increases the likelihood of airway collapse when they sleep. Untreated OSA appears to increase the risk of recurrent atrial fibrillation. Thus OSA may play an etiologic role in what is thought of as essential hypertension, Somers said, adding, "It may, in fact, be OSA-related hypertension." Treatment of OSA with continuous positive airway pressure is associated with lower recurrence of atrial fibrillation (Circulation. 2003;107:2589-2594) and lower daytime blood pressures.

Chronic insufficient sleep—whether a lifestyle choice or age-related—alters glucose regulation, said Orfeu Buxton, PhD, of the University of Chicago School of Medicine. Lowering glucose effectiveness increases subjective sleepiness: "A tired brain gets less fuel," he said. A sleep debt also signals a need to overeat, and may be a previously unrecognized risk factor for insulin resistance, impaired glucose tolerance, obesity, and type 2 diabetes.

Sleep-disordered breathing may predispose individuals to have diabetes, said Quan. The Sleep Heart Health study found that as the apnea index rose, the likelihood of having diabetes increased. Participants with diabetes had worse cardiovascular disease risk factor profiles than those without the disorder (Diabetes Care. 2003;26:702-709). Sleep quality in individuals older than 65 years with diabetes is worse than in those without the disorder.

About one third of patients with Alzheimer disease have disordered sleep—reduced sleep, increased waking after sleep onset, more nocturnal wandering and confusion, and increased daytime dozing—and those with severe sleep disturbances appear to suffer more rapid cognitive decline, according to Michael Vitiello, PhD, of the University of Washington School of Medicine, Seattle. Individuals with dementia also generally prove more sensitive to adverse cognitive and motor effects of drugs prescribed for sleep than other older adults do (Sleep Med Rev. 2000;4:603-628).

About 9 in 10 patients with Parkinson disease have sleep problems that include prolonged nighttime awakenings, stiffness that limits movements, and nocturia, Vitiello said. Some develop behavioral parasomnias such as rapid eye movement (REM) sleep behavior disorder, which prompts them to act out dreams, and may result in injuries. Dopaminergic medications may further disturb sleep (CNS Drugs. 2001;15:777-796).

Nonpharmacological approaches including light therapy, behavioral techniques, and physical activity often can benefit sleep, improving quality of life in individuals with dementia, Vitiello said. Such tactics may also reduce sleep disruptions in caregivers.

Insomnia and daytime sleepiness are risk factors for later onset of depression. Depressed individuals who sleep poorly tend to have worse treatment outcomes, said Daniel Buysse, MD, of the University of Pittsburgh School of Medicine. Individuals with depression have impaired sleep continuity and earlier than normal episodes of REM sleep. They often awaken earlier than desired in the morning, feel unrefreshed, and experience daytime cognitive difficulties and sleepiness (Sleep. 2002;25:553-563).

This pattern of findings is specific to depression, Buysse said, but it is not sensitive enough to use as a diagnostic tool. Nonetheless, sleep symptoms may predict recurrences in major depressive disorder.

Sleep deprivation harms mood in healthy individuals. But a night of total sleep deprivation improves depression, and sleep deprivation in the second half of the night eases insomnia, suggesting a common diathesis for these two disorders, said Buysse.

Circadian rhythms alter with age, prompting an increased tendency to fall asleep earlier and awaken earlier. In extreme instances, a person may miss evening social activities by going to sleep around 8 PM, and may disrupt a household by rising about 3 AM, notes Sonia Ancoli-Israel, PhD, of the University of California School of Medicine, San Diego.

Individuals need 2 hours of daylight intensity light exposure a day for stable rhythms, she said, but most older adults average only 45 minutes. Proper timing of light exposure can help stabilize rhythms. Physicians should advise older adults to wear dark sunglasses if they go on early morning walks and to go outdoors in late afternoon, she suggests. Exposure to artificial bright light between 7 and 9 PM via a home light box can promote evening alertness. A light unit placed on top of a television, Ancoli-Israel said, will give viewers sufficient light.

In most nursing homes, low light levels further diminish day/night cues. Patients typically doze in the daytime, and spend considerable time at night awake. High levels of nighttime noise also interfere with patients' sleep. Mild symptoms of dementia may be secondary to sleep-disordered breathing, she said.

Two workshops at the conference focused on developing ways to integrate sleep better into the medical curriculum and clinical practice. Participants called for promoting the concept of sleep as a surrogate measure for health, and showing physicians that asking patients questions about sleep can be both time- and cost-effective.

Raising public awareness of sleep disorders, as well as encouraging patients to talk more about sleep with their physicians, it was suggested, may also heighten attention to sleep disorders in primary care settings. Action plans incorporating recommendations from the workshops are to be issued later this year.

It is good medicine to ask every older patient two questions, asserts Phyllis Zee, MD, PhD, of Northwestern University Medical School, Chicago:

Answers help uncover physical and mental health problems quickly. Follow-up questions include:

The next steps, which can be undertaken in a primary care practice if time permits, include a comprehensive sleep history, a review of sleep hygiene practices, a comprehensive drug use history, spousal or bed partner reports, sleep logs and related assessment tools, and a medical and psychiatric history and examination. Some patients will need referral to a sleep center for possible home monitoring or polysomnography.—L.L.