Who should get treated for sleep apnea?

Sleep apnea syndrome and cognition

Obstructive sleep apnea (OSA) is a sleep-related breathing disorder characterized by repetitive episodes of airflow cessation resulting in brief arousals and intermittent hypoxemia. Several studies have documented significant daytime cognitive and behavioral dysfunction that seems to extend beyond that associated with simple sleepiness and that persists in some patients after therapeutic intervention. A still unanswered question is whether cognitive symptoms in OSA are primarily a consequence of sleep fragmentation and hypoxemia, or whether they coexist independently from OSA. Moreover, very little is known about OSA effects on cognitive performances in the elderly in whom an increased prevalence of OSA is present. In this review we will consider recent reports in the association between sleep apnea and cognition, with specific interest in elderly subjects, in whom sleep disturbances and age-related cognitive decline naturally occur. This will allow us to elucidate the behavioral and cognitive functions in OSA patients and to gain insight into age differences in the cognitive impairment. Clinically, these outcomes will aid clinicians in the evaluation of diurnal consequences of OSA and the need to propose early treatment.

Sleep in the elderly: normal variations and common sleep disorders

The most common complaints of older adults concern their difficulty initiating or maintaining sleep, which results in insufficient sleep and an increased risk of falls, difficulty with concentration and memory, and overall decreased quality of life. Difficulties sleeping are not, however, an inevitable part of aging. Rather, the sleep complaints are often comorbid with medical and psychiatric illness, associated with the medications used to treat those illnesses, or the result of circadian rhythm changes or other sleep disorders. Health care professionals specializing in geriatrics need to learn to recognize the different causes of sleep disturbances in this population and to initiate appropriate treatment. Nonpharmacological treatment techniques are discussed; pharmacological treatments are discussed in a companion article.

Why a polysomnogram should become part of the diagnostic evaluation of stroke and transient ischemic attack

Neurologists need to recognize, diagnose, and treat obstructive sleep apnea (OSA) in patients with stroke or transient ischemic attack (TIA). Increasing medical evidence suggests that OSA is an independent risk factor for stroke and TIA. Stroke (or TIA) is more likely a cause, rather than a consequence, of OSA because PSG studies have shown: 1) apneas in stroke are typically obstructive, not central or Cheyne-Stokes in type; 2) apneas are just as frequent and severe in patients with either TIA or stroke; 3) OSA severity is not influenced by the acuteness or location of the stroke; 4) untreated OSA patients have more strokes, stroke morbidity, and mortality than those who are treated. OSA alone can induce hypertension, especially in younger men. A causal relationship has recently been demonstrated between OSA and hypertension. A distinctive feature of OSA-induced hypertension is loss of the normal nighttime fall in blood pressure ("nondippers"). Data from the Sleep Heart Health Study showed a dose-response association between OSA severity and the presence of hypertension 4 years later. Hypertension or ischemic heart disease usually develops in untreated patients with OSA over time without particular worsening of OSA. Studies have shown sleep itself is not a risk factor for stroke because most stroke and TIAs begin between 6 am and noon, while the individual is awake. However, OSA promptly be considered in stroke beginning during sleep because 88% of strokes that develop during sleep occur in "nondippers." Premature death in OSA patients is most often cardiovascular, but occurs while the patients are awake. The risk of myocardial infarction is increased 20-fold in untreated OSA. Treating OSA patients with continuous positive airway pressure can prevent or improve hypertension, reduce abnormal elevations of inflammatory cytokines and adhesion molecules, reduce excessive sympathetic tone, avoid increased vascular oxidative stress, reverse coagulation abnormalities, and reduce leptin levels. If all this can be achieved by a polysomnogram, then this test should become part of a neurologist's armamentarium for stroke and TIA.

Diagnosis and treatment of sleep disorders in older adults

Among the most common complaints of older adults are difficulty initiating or maintaining sleep. These problems result in insufficient sleep at night, which then results in an increased risk of falls, difficulty with concentration and memory, and overall decreased quality of life. Difficulties sleeping, however, are not an inevitable part of aging. Rather, these sleep complaints are often secondary to medical and psychiatric illness, the medications used to treat these illnesses, circadian rhythm changes, or other sleep disorders. The task for the geriatric psychiatrist is to identify the causes of these complaints and then initiate appropriate treatment.

Patient- and bed partner-reported symptoms, smoking, and nasal resistance in sleep-disordered breathing

OBJECTIVES

Nocturnal and daytime symptoms are important determinants in clinical decision making in patients suspected of having sleep-disordered breathing (SDB). We compared patients' and bed partners' reporting of symptoms associated with SDB in a clinical sample of snoring men. The bed partners' view on snoring disturbance was assessed. The relationship between sleep parameters, anthropometric data, and selected subjective symptoms was assessed. Additionally, we evaluated the relationship between smoking, nasal resistance, and habitual snoring.

DESIGN

A cross-sectional, prospective study.

SETTING

University teaching hospital.

PATIENTS

Thirty-seven consecutive snoring men referred to ENT Hospital because of a snoring problem or suspicion of sleep apnea, and scheduled for surgical treatment of nasal obstruction.

INTERVENTIONS

The patients completed a sleep questionnaire, a questionnaire on nasal history, and the Epworth sleepiness scale. The bed partners were asked to complete a separate sleep questionnaire of the patient's daytime and nocturnal symptoms. Both patients and bed partners evaluated the intensity of snoring on a visual analog scale. The patients underwent polysomnography and anterior rhinomanometry.

RESULTS

Agreement of patients' and bed partners' reports on symptoms related to SDB was good in this material. One half of the bed partners were disturbed by snoring every night or almost every night, and one third of the bed partners reported disharmony in the relationship from time to time or repeatedly due to snoring. The combination of current smoking and total nasal resistance in a supine position higher than the median value in this patient sample was associated with history of habitual snoring.

CONCLUSIONS

Male patients and their bed partners seem to give congruent reports of snoring and symptoms related to SDB in a clinical population with mild SDB. One half of the bed partners found their sleep constantly disturbed. The combination of current smoking and high nasal resistance was related with habitual snoring.

Microsleep and sleepiness: a comparison of multiple sleep latency test and scoring of microsleep as a diagnostic test for excessive daytime sleepiness

STUDY OBJECTIVE

To compare multiple sleep latency test (MSLT) and scoring of microsleep (presence of sleep electroencephalograph between 3 and 15s in an epoch) as a diagnostic test for excessive daytime sleepiness (EDS).

DESIGN

A retrospective study.

SETTING

Sleep center at a tertiary care teaching hospital.

SUBJECTS

Patients referred to a sleep center who had an MSLT and one or more of the following symptoms; tiredness, sleepiness, memory loss, accidents/near accidents and gap driving.

INTERVENTIONS

Full night polysomnography (PSG) and next day MSLT were performed. Patients were classified as 'microsleep-positive' or 'microsleep-negative' according to presence or absence of microsleep.

RESULTS

Patients (n=92) were divided into three groups according to their MSLT results; group A had an MSLT</=5min (n=38), group B had an MSLT=6-10min (n=26), and group C had an MSLT>10min (n=28). The number of patients with symptoms of tiredness and memory loss were statistically higher in group A compared with groups B and C (P=0.036). The number of patients with symptoms of EDS, in groups B and C, was significantly higher in patients with microsleep than without microsleep (P<0.05). By a paired McNemar's test, the better performance of adding microsleep to MSLT (sensitivity 42.9%; specificity 63.6%) to assess EDS was statistically significant (P=0.0096).

CONCLUSIONS

Microsleep determination during an MSLT is a more sensitive and specific test for EDS as compared to MSLT alone.

Apneas, hypopneas, and respiratory effort-related arousals: moving closer to a standard

The spectrum of sleep disordered breathing ranges from intermittent snoring to the obesity hypoventilation syndrome with the obstructive sleep apnea/hypopnea syndrome fitting somewhere in between. Recently, improved definitions and monitoring techniques are allowing for clearer differentiation of the syndromes within this spectrum. These new standards have also produced better understanding of the prognosis and treatment options for patients fitting into different points within this spectrum. Furthermore, effective communication of current definitions and techniques has resulted in improved reimbursement for the treatments of patients with sleep disordered breathing.

Epidemiology of obstructive sleep apnea: a population health perspective

Population-based epidemiologic studies have uncovered the high prevalence and wide severity spectrum of undiagnosed obstructive sleep apnea, and have consistently found that even mild obstructive sleep apnea is associated with significant morbidity. Evidence from methodologically strong cohort studies indicates that undiagnosed obstructive sleep apnea, with or without symptoms, is independently associated with increased likelihood of hypertension, cardiovascular disease, stroke, daytime sleepiness, motor vehicle accidents, and diminished quality of life. Strategies to decrease the high prevalence and associated morbidity of obstructive sleep apnea are critically needed. The reduction or elimination of risk factors through public health initiatives with clinical support holds promise. Potentially modifiable risk factors considered in this review include overweight and obesity, alcohol, smoking, nasal congestion, and estrogen depletion in menopause. Data suggest that obstructive sleep apnea is associated with all these factors, but at present the only intervention strategy supported with adequate evidence is weight loss. A focus on weight control is especially important given the expanding epidemic of overweight and obesity in the United States. Primary care providers will be central to clinical approaches for addressing the burden and the development of cost-effective case-finding strategies and feasible treatment for mild obstructive sleep apnea warrants high priority.