What's new in sleep medicine

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

Management of residual excessive sleepiness in obstructive sleep apnea (January 2024)

The first expert consensus statement on the management of residual excessive sleepiness (RES) in patients with obstructive sleep apnea (OSA) was recently published [1]. Key points include the assessment of RES at regular intervals throughout the patient's life, use of the Epworth Sleepiness Scale and detailed clinical sleep (including sleep deprivation and inadequate sleep), neurologic evaluation to comprehensively investigate non-OSA RES etiologies, and evaluation of adequate adherence to and optimal application of positive airway therapy before embarking on wakefulness-promoting agents. We agree with these recommendations. (See "Evaluation and management of residual excessive sleepiness in adults with obstructive sleep apnea", section on 'Evaluation'.)

INSOMNIA

Risk of fractures with benzodiazepine receptor agonists (January 2024)

Benzodiazepine receptor agonists (BZRAs), including benzodiazepines and nonbenzodiazepine BZRAs such as zolpidem, can cause excess drowsiness and imbalance leading to falls and fractures. In a recent meta-analysis of 20 observational studies in over six million individuals, BZRAs were associated with increased risk of osteoporotic fractures across a range of drug classes and fracture types, with odds ratios ranging from 1.2 to 1.4 [2]. Most but not all studies included adults 50 years of age or older. These data reinforce the need for caution in prescribing BZRAs for insomnia and other indications, particularly in older adults. (See "Pharmacotherapy for insomnia in adults", section on 'Special populations'.)

Nurse-delivered brief behavioral treatment for insomnia (October 2023)

A growing body of evidence supports the use of brief, behaviorally-focused treatments for insomnia, which involve fewer sessions than traditional cognitive behavioral therapy and can be delivered by clinicians with varied levels of expertise. In an open-label randomized trial in England involving nearly 650 adults with insomnia disorder recruited from 35 general practices, four sessions of nurse-delivered sleep restriction therapy (table 1) improved patient-reported insomnia severity scores and six-month response rates compared with a sleep hygiene booklet alone (table 2) [3]. Training nurses or advanced practice providers to deliver brief behavioral treatments may be a feasible and cost-effective way to improve outcomes for insomnia. (See "Cognitive behavioral therapy for insomnia in adults", section on 'Brief behavioral treatment approaches'.)

CENTRAL DISORDERS OF HYPERSOMNOLENCE

Liver injury halts trials of novel oral orexin agonist (September 2023)

Novel therapies are under investigation for narcolepsy with cataplexy, which is associated with loss of orexin-producing neurons in the hypothalamus. Recently, two phase II trials of an oral orexin 2 receptor-selective agonist, TAK-994, showed improvements in sleepiness and cataplexy in patients with narcolepsy but were halted early due to clinically important elevations in liver enzymes and drug-induced liver injury in several patients [4]. Other orexin agonists are in development. (See "Management and prognosis of narcolepsy in children", section on 'Emerging therapies'.)

PARASOMNIAS AND SLEEP-RELATED MOVEMENT DISORDERS

Neurostimulation device for restless legs syndrome (November 2023)

Noninvasive neuromodulation techniques are of interest for treatment of restless legs syndrome (RLS). One new device, tonic motor activation (TOMAC), delivers peroneal nerve stimulation via bilateral therapy units worn externally just below the knee, over the head of the fibula. In a randomized sham-controlled trial of TOMAC in 133 adults with medication-refractory RLS, TOMAC improved clinician-rated responses and RLS severity scores at 4 weeks [5], and the device was well tolerated for up to 24 weeks [6]. TOMAC received marketing approval in the United States in 2023 [7], and availability is anticipated in 2024. (See "Management of restless legs syndrome and periodic limb movement disorder in adults", section on 'Neurostimulation'.)

GENERAL SLEEP MEDICINE

Effect of short-term sleep restriction on insulin sensitivity in females (January 2024)

Short sleep duration has been associated with risk of type 2 diabetes, but whether this reflects a causal relationship is uncertain. In a crossover study in 38 females aged 20 to 75 years with baseline sleep duration of seven to nine hours nightly, participants underwent sequential, six-week phases of sleep maintenance (usual sleep time maintained) and sleep restriction (sleep time reduced by 1.5 hours nightly) [8]. Sleep restriction led to increases in fasting insulin concentration and homeostasis model assessment of insulin resistance (HOMA-IR), indicating diminished insulin sensitivity. These changes were independent of changes in adiposity and were more pronounced in postmenopausal compared with premenopausal participants. Further studies are needed to verify the findings in a larger cohort of patients, including males, and to determine whether prolonged sleep restriction causes progressive worsening of glucose homeostasis. (See "Type 2 diabetes mellitus: Prevalence and risk factors", section on 'Sleep duration'.)

Lack of evidence that blue light-filtering lenses improve sleep (September 2023)

Blue light-filtering glasses are marketed widely to reduce adverse effects of light-emitting screens on sleep, but supporting evidence is lacking. A recent systematic review identified six small randomized trials examining sleep outcomes with use of blue light-filtering lenses [9]. Trial results were inconsistent, and meta-analysis could not be performed due to high heterogeneity and lack of quantitative outcome data. We counsel patients to avoid use of electronics at least 30 minutes before usual bedtime and in the middle of the night if nocturnal awakenings occur (table 2). Based on available evidence, we advise that blue light-filtering glasses are not a substitute for avoidance of screens. (See "Insufficient sleep: Evaluation and management", section on 'Counseling on lifestyle changes'.)