Obstructive sleep apnea in patients with head and neck cancer: a systematic review.

STUDY OBJECTIVES: Head and neck cancers (HNCs) may modify the upper airway anatomy and thereby increase the risk for obstructive sleep apnea (OSA). If untreated, OSA is associated with adverse outcomes. Identification of risk factors for OSA in patients with HNC is essential to promote proper evaluation, treatment, and improvement of sleep-related outcomes. In this review, we assessed associations between tumor stage, cancer treatment, and OSA in the population with HNC. METHODS: A systematic search of PubMed, EMBASE (Embase.com), Cochrane Library (Cochranelibrary.com), Scopus, and Web of Science was conducted to identify articles related to OSA in patients with HNC. A total of 215 articles were identified, of which 14 were included in the qualitative synthesis. These studies included 387 participants. RESULTS: The most common cancer type, tumor location, and cancer therapy were squamous cell carcinoma, oropharynx, and surgery, respectively. Three of six articles reported an association between surgical treatment and OSA. Conversely, associations between tumor stage, radiotherapy, and OSA were found in only a minority of studies (15%). The prevalence of OSA was between 57% and 76% pre-cancer therapy and 12% and 96% afterward. CONCLUSIONS: This review suggests a potential association between HNC surgery and OSA. An association between tumor stage, radiotherapy to the head and neck, and OSA is inconclusive. Further research is needed to examine the relationship between HNC and OSA.

Orexin-A is Associated with Increases in Cerebrospinal Fluid Phosphorylated-Tau in Cognitively Normal Elderly Subjects.

STUDY OBJECTIVES: To evaluate the role of orexin-A with respect to cerebrospinal fluid (CSF) Alzheimer disease (AD) biomarkers, and explore its relationship to cognition and sleep characteristics in a group of cognitively normal elderly individuals. METHODS: Subjects were recruited from multiple community sources for National Institutes of Health supported studies on normal aging, sleep and CSF biomarkers. Sixty-three participants underwent home monitoring for sleep-disordered breathing, clinical, sleep and cognitive evaluations, as well as a lumbar puncture to obtain CSF. Individuals with medical history or with magnetic resonance imaging evidence of disorders that may affect brain structure or function were excluded. Correlation and linear regression analyses were used to assess the relationship between orexin-A and CSF AD-biomarkers controlling for potential sociodemographic and sleep confounders. RESULTS: Levels of orexin-A, amyloid beta 42 (Aß42), phosphorylated-tau (P-Tau), total-tau (T-Tau), Apolipoprotein E4 status, age, years of education, reported total sleep time, number of awakenings, apnea-hypopnea indices (AHI), excessive daytime sleepiness, and a cognitive battery were analyzed. Subjects were 69.59 ± 8.55 years of age, 57.1% were female, and 30.2% were apolipoprotein E4+. Orexin-A was positively correlated with Aß42, P-Tau, and T-Tau. The associations between orexin-A and the AD-biomarkers were driven mainly by the relationship between orexin-A and P-Tau and were not influenced by other clinical or sleep characteristics that were available. CONCLUSIONS: Orexin-A is associated with increased P-Tau in normal elderly individuals. Increases in orexin-A and P-Tau might be a consequence of the reduction in the proportion of the deeper, more restorative slow wave sleep and rapid eye movement sleep reported with aging. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov registration number NCT01962779.