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The following represent additions to UpToDate from the past six months that were considered by the editors and authors to be of particular interest. The most recent What's New entries are at the top of each subsection.
SLEEP-RELATED BREATHING DISORDERS
CPAP in obstructive sleep apnea does not reduce cardiovascular events (August 2016)
Whether continuous positive airway pressure (CPAP) therapy can reduce the increased risk of cardiovascular morbidity and mortality associated with obstructive sleep apnea (OSA) is unknown. The largest trial to address this issue randomized 2717 patients with moderate to severe OSA and established cardiovascular disease to CPAP therapy plus usual care or usual care alone (eg, education, risk factor modification) and followed patients for 3.7 years . Despite adequate control of OSA, there was no difference in cardiovascular events (eg, cardiovascular deaths, myocardial infarction, or stroke). However, the exclusion of patients who are among the most likely to benefit from CPAP (eg, patients with “sleepy” OSA) and a low adherence rate to therapy (mean was 3.3 hours per night) may have limited the potential benefit from this therapy. While the cardiovascular benefits are unproven, CPAP should be administered for the associated noncardiovascular benefits (eg, improvement in symptoms and quality of life) and should remain the mainstay of therapy for patients with moderate to severe OSA. (See "Obstructive sleep apnea and cardiovascular disease", section on 'Cardiovascular events'.)
Prevalence of central sleep apnea in the community (July 2016)
Central sleep apnea (CSA) occurs with increased frequency in patients with heart failure and other comorbid cardiovascular diseases, but the prevalence in the general population has not been well established. In a population-based study of over 5000 community-dwelling adults age 40 years and older who underwent polysomnography, the prevalence of CSA was 0.9 percent . By comparison, obstructive sleep apnea was present in 48 percent of patients. Risks factors for CSA included age older than 65 years, male gender, and self-reported heart failure. Cheyne-Stokes breathing was present in approximately half of patients with CSA. (See "Central sleep apnea: Risk factors, clinical presentation, and diagnosis", section on 'Epidemiology'.)
Sleep disorders in the menopausal transition: Telephone-based cognitive behavioral therapy (August 2016)
New-onset sleep disturbances are common in perimenopausal and menopausal women, occurring most often in women with hot flashes, but also in women without hot flashes. Midlife women with insomnia are usually treated with pharmacologic therapies (estrogen or hypnotic agents), but effective behavioral therapies are also available, including in-person cognitive behavioral training (CBT) for insomnia. In-person CBT, while effective, has practical limitations (availability, cost, and scheduling challenges), so alternative CBT strategies have been explored. In one trial, 106 peri- and postmenopausal women with insomnia and hot flashes were randomly assigned to an eight-week intervention with telephone-based cognitive behavioral therapy for insomnia (CBT-I) versus standard menopause education control (MEC) (also telephone-based) . After eight weeks, CBT-I, but not MEC, resulted in a clinically meaningful insomnia score reduction. The percentage of women who achieved Insomnia Index Severity scores in the “no insomnia” range was 70 and 24 percent for CBT-I and MEC, respectively. CBT-I reduced hot flash “bother” but not frequency. (See "Menopausal hot flashes", section on 'Promising therapies: Need further study'.)
CENTRAL DISORDERS OF HYPERSOMNOLENCE
Flumazenil in patients with refractory hypersomnolence (December 2016)
Preliminary data suggest that compounded preparations of flumazenil, a gamma-aminobutyric acid type A receptor antagonist, may benefit some patients with hypersomnolence of central origin. In a case series of 153 patients with refractory hypersomnolence due to idiopathic hypersomnia, obstructive sleep apnea, or other disorders, compounded sublingual or transdermal flumazenil was well tolerated and associated with sustained improvement in subjective sleepiness in 39 percent of patients . These results suggest that controlled studies of flumazenil in this patient population are warranted. (See "Idiopathic hypersomnia", section on 'Pharmacotherapy'.)
Chronic sleep-wake disturbances after traumatic brain injury (July 2016)
Sleep-wake disturbances are very common in the weeks to months following traumatic brain injury (TBI), and a new study suggests that many of these symptoms persist long term. In a prospective case-control study in which 31 patients with TBI of any severity were evaluated at 18 months after injury, 67 percent of patients had evidence of excessive daytime sleepiness on objective testing, compared with only 19 percent of healthy controls . Patients also had persistent pleiosomnia (increased need for sleep), requiring an average of one more hour of sleep per 24 hours than controls. As in earlier studies, patients tended to underestimate their symptoms, emphasizing the importance of both subjective and objective sleep testing in patients with sleep-wake complaints after TBI. (See "Sleep-wake disorders in patients with traumatic brain injury", section on 'Natural history'.)
PARASOMNIAS AND SLEEP-RELATED MOVEMENT DISORDERS
Complications of dopaminergic therapy for restless legs syndrome (August 2016)
The main complication of long-term dopaminergic therapy for restless legs syndrome/Willis-Ekbom disease (RLS/WED) is “augmentation,” or an increase in symptom severity with increasing doses of medication. This may present as earlier onset of symptoms during the day, increased intensity of symptoms, or spread to previously uninvolved body parts (eg, arms, trunk). New consensus-based guidelines on the identification and management of augmentation recommend avoiding dopaminergic drugs as first-line therapy for RLS/WED when possible, screening patients on dopaminergic therapy for augmentation as part of routine clinical follow-up (table 1), and using the lowest doses possible to control symptoms . Treatment options for augmentation reviewed in the guideline include altering the dopaminergic dosing schedule, switching to an extended release preparation, and transitioning to an alpha-2-delta calcium channel ligand (eg, gabapentin enacarbil, pregabalin). In addition, alternative causes of worsening symptoms should be sought, such as low iron stores, sleep deprivation, and certain drugs such as serotonergic antidepressants. (See "Treatment of restless legs syndrome/Willis-Ekbom disease and periodic limb movement disorder in adults", section on 'Augmentation'.)
PEDIATRIC SLEEP MEDICINE
Sleep duration in preschool children and progression to obesity (August 2016)
Increasing evidence supports an association between shortened sleep duration and obesity in children. In a recent large longitudinal study, the risk of adolescent obesity in preschool children with early bedtimes (8:00 PM or earlier) was about half that of preschool children with late bedtimes (9:00 PM or later), after adjustment for several confounding variables, including maternal obesity, education, and income level . (See "Definition; epidemiology; and etiology of obesity in children and adolescents", section on 'Sleep'.)
GENERAL SLEEP MEDICINE
Inadequate sleep and adverse cardiometabolic outcomes (December 2016)
The adverse health outcomes of inadequate sleep duration (<7 hours per night) and quality are increasingly recognized. A new scientific statement from the American Heart Association reviews data linking sleep restriction with adverse cardiometabolic outcomes and recommends that healthy sleep behavior be addressed in public health campaigns to promote ideal cardiac health, alongside blood pressure, cholesterol, diet, blood glucose, physical activity, weight, and smoking cessation . (See "Insufficient sleep: Definition, epidemiology, and adverse outcomes", section on 'Cardiovascular morbidity'.)
- McEvoy RD, Antic NA, Heeley E, et al. CPAP for Prevention of Cardiovascular Events in Obstructive Sleep Apnea. N Engl J Med 2016; 375:919.
- Donovan LM, Kapur VK. Prevalence and Characteristics of Central Compared to Obstructive Sleep Apnea: Analyses from the Sleep Heart Health Study Cohort. Sleep 2016; 39:1353.
- McCurry SM, Guthrie KA, Morin CM, et al. Telephone-Based Cognitive Behavioral Therapy for Insomnia in Perimenopausal and Postmenopausal Women With Vasomotor Symptoms: A MsFLASH Randomized Clinical Trial. JAMA Intern Med 2016; 176:913.
- Trotti LM, Saini P, Koola C, et al. Flumazenil for the Treatment of Refractory Hypersomnolence: Clinical Experience with 153 Patients. J Clin Sleep Med 2016; 12:1389.
- Imbach LL, Büchele F, Valko PO, et al. Sleep-wake disorders persist 18 months after traumatic brain injury but remain underrecognized. Neurology 2016; 86:1945.
- Garcia-Borreguero D, Silber MH, Winkelman JW, et al. Guidelines for the first-line treatment of restless legs syndrome/Willis-Ekbom disease, prevention and treatment of dopaminergic augmentation: a combined task force of the IRLSSG, EURLSSG, and the RLS-foundation. Sleep Med 2016; 21:1.
- Anderson SE, Andridge R, Whitaker RC. Bedtime in Preschool-Aged Children and Risk for Adolescent Obesity. J Pediatr 2016; 176:17.
- St-Onge MP, Grandner MA, Brown D, et al. Sleep Duration and Quality: Impact on Lifestyle Behaviors and Cardiometabolic Health: A Scientific Statement From the American Heart Association. Circulation 2016; 134:e367.