Over the past several years, much research has focused on normal age-related changes in sleep as a function of aging. However, in addition to these common changes, aging is also associated with an increase in sleep complaints and chronic sleep disturbances, resulting in poorer daytime functioning and increases in health care usage. This chapter reviews sleep and sleep disorders in order adults, including information on presentation, etiology, pathophysiology, evaluation, and management of sleep-related issues.

Approximately 50% of community-dwelling elderly persons complain of some form of sleep difficulty. Subjective and objective reports show that when compared to their younger counterparts, older adults take longer to fall asleep, have lower sleep efficiency (defined as the amount of sleep given the amount of time in bed), have more nighttime awakenings, wake up earlier than they would like in the morning, and require more daytime naps (Table 55-1). Polysomnographic (PSG) sleep recordings have confirmed these findings, showing that despite older adults spending more time in bed, they have a harder time getting to sleep, get overall less sleep, and have more nighttime awakenings, resulting in reduced sleep efficiency. It is not surprising then that Multiple Sleep Latency Tests (MSLTs), objective measures assessing daytime sleepiness via PSG-recoded napping opportunities, indicate that older adults are significantly sleepier throughout the day than are younger adults.

One central question raised by researchers in the field is whether these age-related changes represent a decrease in the need for sleep or a decrease in the ability to sleep. Although this question is still being debated and there is no clear consensus on whether there is a reduced need for sleep, there is clearly a reduced ability to sleep in this population. As discussed in this chapter, sleep difficulties in this population are associated with several factors, including specific sleep disorders, changes in the endogenous circadian clock, medical and psychiatric illness, and medication intake (Table 55-2). Recent developments in sleep research have identified several effective treatments for many of these sleep difficulties. Given the high prevalence of sleep complaints and sleep disorders in this population and the link between insufficient sleep and heightened levels of morbidity and mortality, there is a clear need for increased awareness, assessment, and treatment of these sleep disturbances.

Definition

Sleep-disordered breathing (SDB) is characterized by respiratory events, including hypopneas (partial respiration) and/or apneas (complete cessation of respiration), during sleep. These respiratory events occur repeatedly over the course of the night with each respiratory event lasting a minimum of 10 seconds. The number of apneas per hour of sleep is called the apnea index (AI) and the number of apneas and hypopneas per hour of sleep is called the apnea–hypopnea index (AHI; also sometimes called the respiratory disturbance index [RDI]). Clinical diagnosis of SDB is traditionally given when a patient has an AHI of 10 to 15.

The cessations in breathing in SDB lead to repeated arousals from sleep, as well as to reductions in blood oxygen levels over the course of the night, which result in nighttime hypoxemia.

Epidemiology

SDB is more common in older than younger adults and among nursing home patients, specifically elderly with dementia, when compared to those elderly living independently. Table 55-3 summarizes several potential age-dependent risk factors in the development of SDB. The prevalence of SDB varies by severity level or AHI. Approximately 2% to 4% of middle-aged men and women (age 30 to 60 years) have an AHI ≥ 5, compared to 32% to 81% of older adults (age 60+ years). With increasing AHI, these percentages are slightly lower, with 19% to 62% of older adults having an AHI ≥ 15 and up to 24% having an AHI ≥ 20. In addition, within the older population, SDB is more common in men than in women and in patients with hypertension, and may be more severe in elderly people in the African-American than in the Caucasian population.

Pathophysiology

There are three types of apneic events: central, obstructive, and mixed. Central events are a result of a dysfunction of the respiratory neurons. Obstructive events are caused by anatomic obstruction of the upper airways despite respiratory effort. Mixed events are a combination of central and obstructive components.

Presentation

The cardinal symptoms of SDB are snoring and excessive daytime sleepiness. It is often one or both of these two symptoms that motivate the patient to seek evaluation and treatment of this sleep disorder. Additional symptoms may include insomnia, nocturnal confusion, and cognitive deficits, such as difficulty with concentration and memory.

Approximately 50% of regular snorers suffer from some degree of SDB and snoring may be an early precursor to SDB. Snoring is reflective of the airway collapse and is a component of the breathing cessation during an apneic event. It may be extremely loud, being heard all over the house. Often bed partners have moved into separate bedrooms. While not all snoring is associated with sleep apnea, snoring alone is associated with increased risk of ischemic heart disease and stroke.

The excessive daytime sleepiness seen in SDB is associated with sleep fragmentation or repeated nighttime awakenings, which frequently follow the apneic events, and with the nocturnal hypoxia. Daytime sleepiness may manifest as being unable to stay awake or falling asleep at inappropriate times during the day. Patients with excessive daytime sleepiness secondary to untreated SDB may fall asleep while reading, watching television, or at the movies, while in conversation with a group of friends, or while driving. Daytime sleepiness can be a very debilitating symptom, causing social and occupational difficulties, reduced vigilance, and cognitive deficits, including decreased concentration, slowed response time, and memory and attention difficulties. These symptoms may be particularly relevant to older adults who are at an increased risk of developing such symptoms with aging or already suffer from some initial cognitive impairment. SDB may therefore unnecessarily further exacerbate these cognitive deficits.

SDB is often associated with other serious health problems, including hypertension and cardiac and pulmonary disease, which can then lead to increased risk of mortality. Recent research indicates that even those patients with only five events per hour of sleep are at greater risk for developing hypertension. While cause and effect between SDB and cardiovascular disease has not yet been determined, increasing SDB has been associated with increased risk of developing cardiovascular diseases, including hypertension, coronary artery disease, and stroke.

Upon initial evaluation, sleep complaints such as snoring and/or gasping and excessive daytime sleepiness may be suggestive of SDB. The assessment should begin with a thorough sleep history from the patient, including information on daytime behavior. Because the patient is often unaware of (or not disturbed by) the loud snoring or cessations in breathing during the night, it is helpful to have the patient’s bed partner present at the assessment interview. The clinician should examine the patient’s airway and throat to check for obstruction of the airway. The medical history should include information on history of hypertension and any cardiac or pulmonary problems. The clinician should also collect information on recent weight gain or obesity (excess fatty tissue may contribute to airway obstruction), smoking history (may irritate oropharynx and/or nicotine may affect central nervous system), alcohol intake, and intake of any sedating medications (may result in airway relaxation thus facilitating obstruction). Although patients with SDB are often overweight, it may be less strong a predictor of the presence or absence of SDB in the older population. Thus evaluation of the older patient of normal or even slender weight should not be overlooked.

If the clinician suspects SDB, the patient should be referred for an overnight PSG recording in a sleep disorders clinic, or for ambulatory monitoring of sleep and respiration in the patient’s home. Based on the results of the objective recording, recommendations for treatment can be suggested.

Management

Pharmacologic treatments for SDB are ineffective; however, there are several effective nonpharmacologic treatments that have become first-line treatment of SDB.

Positive Airway Pressure

The gold standard for treatment for SDB is positive airway pressure. There are several types of devices that provide positive airway pressure, including continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), and auto-CPAP. CPAP is composed of a nose mask, which is connected via a hose to a machine that provides continuous air pressure. The air pressure acts as a splint to maintain the opening of the upper airway, thereby preventing the obstruction or collapse of the airway. The degree of air pressure (traditionally, 5 to 20 cm H2O) is set individually for each patient at the sleep laboratory and is dependent on the patient’s AHI or the severity of the patient’s SDB. CPAP alleviates all snoring and most of the apneic events, repeated awakenings, and nighttime hypoxemia in these patients. This intervention is also very effective in the reduction of daytime sleepiness and has been shown to improve cognitive performance.

BiPAP was designed to allow for the variation in positive airway pressure during expiration and inspiration. The device looks and acts similarly to CPAP but rather than providing continuous airway pressure, the BiPAP device has reduced expiratory positive airway pressure (EPAP) when compared to the inspiratory positive airway pressure (IPAP). The BiPAP prevents the obstruction of the airway by using lower EPAP levels when compared to CPAP. At this time, there are no data to suggest that BiPAP is more effective than CPAP, however some reports suggest better compliance with BiPAP, possibly because of its more gentle approach, when compared to CPAP.

The auto-CPAP was designed to allow for the overnight variability in airway pressure, which is adjusted automatically depending on the extent of airway obstruction, which may fluctuate with specific sleep stages and body position. In contrast to the constant airway pressure in traditional CPAP, this device adjusts for periods of reduced obstruction by providing lower airway pressure, while providing greater airway pressure with increases in obstruction. To date, no studies suggest increases in compliance with the auto-CPAP when compared to other positive airway pressure devices.

Clinicians should be aware of possible poor patient compliance, however, these devices are recommended for nightly use and are a long-term management approach. The addition of a humidifier to some units reduces the discomfort and possible nasal irritation associated with the use of these devices. Clinicians should not assume that elderly patients cannot tolerate CPAP; one study has shown the extent of dementia, older age, and AHI severity are not associated with compliance, rather only the presence of depression seems to be linked with poor long-term compliance.

Surgical Interventions

There are several different surgical approaches for the treatment of SDB, including (1) nasal reconstruction, which corrects nasal valve collapse, septal deviations, and turbinate hypertrophy; (2) uvulopharynpalatoplasty (UPPP), which corrects pharyngeal obstruction by removal of pharyngeal tissue, including soft palate, uvula, tonsillar pillars, and tonsillar tissue; (3) laser-assisted uvulopharynpalatoplasty (LAUP), which has the same standard procedure as UPPP, but uses a laser to remove the pharyngeal tissue; (4) genioglossus advancement, which corrects by the forward advancement of the insertion of the tongue (usually in conjunction with UPPP or LAUP); and (5) hyoid myotomy, which corrects hypopharyngeal obstruction by suspending the hyoid bone to the superior edge of the larynx (usually in conjunction with UPPP or LAUP).

The surgical approach or combination of approaches (including nonsurgical) chosen for an individual patient is decided on a case-by-case basis and is dependent on the location and the type of obstruction present. Depending on the choice of surgical approach, the effectiveness of the intervention in reducing AHI varies from 48% to 72% and depends on the severity of the SDB and the obstruction. Surgical methods should be approached with caution in the elderly patient, as the effectiveness of the treatment may be lower and their recovery may be longer and more difficult.

Oral Appliances

Oral devices are appropriate for the management of milder forms of obstructive sleep apnea and snoring. The two most common oral devices are the tongue-retaining device (TRD) and the mandibular advancement device (MAD). These oral appliances are anchored on the patient’s teeth or gums and work by moving the tongue or the mandibular forward, thereby preventing obstruction at the hypopharyngeal level. Depending on the type of device used, the effectiveness of this approach in decreasing AHI and increasing blood oxygen saturation levels varies from 40% to 81%. Clinicians need to be aware of possible side effects, including pain or discomfort in the temporomandibular joint or short-term occlusion abnormalities when removing the appliance, which occurs in an estimated 30% of patients. Newer devices can be used with dentures, which make them particularly appropriate for use in the older patient.

Diet and Lifestyle

There are several dietary and lifestyle factors that can exacerbate SDB, such as obesity, alcohol intake, and smoking. Obesity is a common problem in patients with obstructive sleep apnea, as the additional fatty tissue often results in the obstruction of the upper airways. These patients will benefit significantly from weight loss, which sometimes dramatically reduces or even eliminates apneic events.

Alcohol and certain medications, such as sedative-hypnotics, narcotics, and barbiturates, have a depressant effect on the upper airway musculature and may exacerbate SDB. Furthermore, given the usually high number of prescriptions taken by older patients, clinicians should be diligent when prescribing sedating medications, particularly to those older patients who are at higher risk for SDB. Smoking is also associated with exacerbation of SDB. Although the mechanism is not fully understood at this time, several theories have been suggested, including irritation of oropharynx by cigarette smoke and the possible effect of nicotine on the central nervous system.

For patients with mild SDB, positional SDB, or positional snoring, body position during sleep may account for many of the respiratory events in these cases. The supine position is associated with the majority of the positional apneic events, which are likely a result of the relaxation of the anterior neck and oropharyngeal structures while in this position. A simple behavioral technique for dealing with positional apnea is to place a tennis ball in a pocket sewn to the back of a night shirt, thereby deterring the patients from sleeping on their back and preventing positional respiratory events.

In general, treatment of SDB in the elderly depends on (1) the severity of the condition, (2) the extent of daytime symptoms, and (3) the presence of other comorbid medical conditions, such as hypertension, cardiac disease, or cognitive deficits. Decision to treat should be made on a case-by-case basis and age of the patient should not be a factor in making this assessment.

Definition

Periodic limb movements in sleep (PLMS) is characterized by clusters of repeated leg (or sometimes arm) jerks that occur approximately every 20 to 40 seconds over the course of the night. These clusters of movements last on an average 0.5 to 5 seconds and cause repeated brief awakenings. The number of limb movements followed by arousals per hour of sleep is called the periodic limb movement index (PLMI). Clinical diagnosis of PLMS is typically given when a patient has a PLMI >5.

Another disorder, often comorbid with PLMS, and believed to be more disruptive, is restless leg syndrome (RLS). RLS is characterized by dysesthesia in the legs, usually described by patients as “a creeping crawling sensation” or as “pins and needles,” which can only be relieved with vigorous movement. These sensations often occur in the evening or whenever the patient is in a restful, relaxed state. About 90% of patients with RLS also have PLMS, but only about 20% of PLMS patients suffer from RLS.

Epidemiology

The prevalence of PLMS increases significantly with age and is estimated at 45%, compared to 5% to 6% in younger adults. Despite this increase in prevalence, the severity of the condition does not worsen with age. The prevalence of RLS increases with age as well. There is no known gender difference in PLMS, however RLS is twice as common in older women than men.

Pathophysiology

The exact mechanisms underlying PLMS and RLS are not fully understood; however, current hypotheses suggest possible dysfunction of the dopamine system. These theories are derived from the therapeutic effects of dopamine agonists in RLS and PLMS. Recent studies have also suggested that the pathophysiology of RLS might involve iron homeostatic dysregulation, as ferritin levels in the cerebrospinal fluid are lower in these patients.

Presentation

The most common complaints of patients with PLMS are sleep initiation insomnia, sleep maintenance insomnia, and excessive daytime sleepiness. Patients may or may not be aware of leg kicks or jerks. Some may complain simply of having difficulty falling asleep or staying asleep with no knowledge that they kick. Often, bed partners may be aware of the leg movements and may have moved into separate beds. Many patients with PLMS also suffer from RLS and therefore may also complain of discomforting sensations in their legs during the day.

Evaluation

Patients are often unaware of the multiple nighttime awakenings and the associated sleep loss, therefore it is often helpful to have the patient’s bed partner present at the assessment interview. An accurate diagnosis of PLMS can only be made by recording limb movements and associated arousals. This can be accomplished via an overnight PSG recording in the sleep disorders laboratory, or in the home with unattended monitoring. Additionally, several actigraphic devices, placed on the ankle, have been validated against PSG for measurement of PLMS.

The diagnosis of RLS is based on the patient’s report of uncomfortable sensations in the legs, which are only relieved by movement. Patients with symptoms of RLS should be assessed for anemia, iron deficiency, uremia, and peripheral neuropathy prior to treatment.

Management

There is some discussion about the significance of PLMS and whether it does in fact constitute a sleep disorder. However, the treatment for PLMS and RLS is the same (Table 55-4). Currently, the first-line treatment for PLMS/RLS consists of dopamine agonists, as they reduce or eliminate both the limb jerks and the associated arousals. There are two medications approved by the Food and Drug Administration (FDA) for the treatment of RLS: ropinirole and pramipexole. However, carbidopa/levodopa, has also been shown to be effective. Shifting of limb movements from the nighttime to the daytime may occur with treatment and therefore continued evaluation is needed.