The relationship between the morningness-eveningness questionnaire and incident cancer: A historical clinical cohort study.

OBJECTIVE: We conducted a retrospective cohort study to explore the relationship between chronotype measured by the total Morningness-Eveningness Questionnaire (MEQ) score and incident cancer. METHODS: We used clinical and provincial health administrative data on consecutive adults who underwent a Level 1 Polysomnography (PSG) and completed the MEQ between 2010 and 2015 in an academic hospital (Ontario, Canada) and were cancer-free at baseline. Cancer status was derived from the Ontario Cancer Registry. Individuals were followed until death or March 31, 2020. We used multivariable Cox cause-specific regressions to address the research objective. RESULTS: Of 3,004 individuals, 1,781 were analyzed: a median age of 54 years (IQR: 40-64) and 838 (47.1%) men. The median total MEQ score was 63 (IQR: 55-69); 61 (3.4%) were classified as evening (≤41), 536 (30.1%) as intermediate (42-58), and 1,184 (66.5%) as morning chronotypes (≥59). Over a median of 7 years (IQR: 5-8), 120 (6.7%) developed cancer. A U-shape relationship was found between the total MEQ score and an increased hazard of incident cancer, controlling for PSG measures of sleep apnea severity and sleep architecture, demographics, and comorbidities. Compared to the median of 63.0, a total MEQ score greater or less than the median was associated with an increased hazard of incident cancer, with the largest effect for those with a total score ≥76 (e.g., HR of a MEQ total score of 78 vs. 63: 2.01, 95% CI: 1.09-3.71). CONCLUSION: The U-shaped curve may reflect deviations from a standard circadian tendency, which may stress biological systems and influence malignancy risk.

Strengthening oropharyngeal muscles as an approach to treat post-stroke obstructive sleep apnea: A feasibility randomised controlled trial.

This study aimed to determine the feasibility of a randomised controlled trial (RCT) evaluating oropharyngeal exercise (OPE) intervention as an alternative therapy for obstructive sleep apnea (OSA) in patients with stroke or transient ischaemic attack (TIA). Despite the high prevalence of OSA in this population, the standard therapy, continuous positive airway pressure (CPAP), is often poorly tolerated. Thirty stroke/TIA patients with OSA unable to tolerate CPAP were randomly assigned to an oropharyngeal exercise or sham exercise protocol. They performed exercises for 6 weeks, 5 days per week, 30 minutes twice per day. Feasibility was ascertained by the proportion of enrolled patients who completed more than 80% of the OPE regimen. Isometric tongue pressures, apnea-hypopnea index (AHI), oxygen desaturation index (ODI), daytime sleepiness, and quality of life (QOL) outcomes were collected at baseline, post-training (6-week follow-up), and retention (10-week follow-up) to document preliminary efficacy. Adherence to study exercises was excellent, with 83% of participants completing more than 80% of the exercises. The isometric tongue pressures were observed to improve in the oropharyngeal exercise group (compared with the sham group), along with a decrease in OSA severity (measured by the AHI and ODI), reduced daytime sleepiness, and enhanced quality of life outcomes following the exercise programme. Only the effects on posterior isometric tongue pressure and daytime sleepiness remained significantly different between groups at the retention session. In conclusion, an RCT evaluating the efficacy of oropharyngeal exercises on post-stroke/TIA OSA is feasible and our preliminary results suggest a clinically meaningful effect.

Impact of sleep chronotype on in-laboratory polysomnography parameters.

Morningness-eveningness preference, also known as chronotype, is the tendency for a person to sleep during certain hours of the day and is broadly categorised into morning and evening types. In-laboratory polysomnography (iPSG) is the gold-standard to assess sleep, however, an individual's chronotype is not accounted for in current protocols, which may confound collected sleep data. The objective of our study was to assess if chronotype had an association with sleep physiology. Patients who completed the diagnostic iPSG and the Morningness-Eveningness Questionnaire (MEQ), which categorises patients into morning type, neither or evening type, were assessed. Multivariable linear regression models were used to assess if chronotype was associated with sleep quality, duration, and physiology during iPSG. The study sample included 2612 patients (mean age of 53.6 years, 48% male) recruited during 2010-2015. Morning type, compared with neither type, was significantly associated with an increase in total sleep time and rapid eye movement (REM) sleep, and a decrease in sleep onset latency and the arousal index. Evening type, compared with neither type, was significantly associated with a decrease in total sleep time, sleep efficiency, and REM sleep, and an increase in sleep onset latency and wake after sleep onset. Additionally, iPSG lights out time was significantly different between the different chronotypes. Overall, a morningness chronotype was associated with favourable sleep quality and duration while an eveningness chronotype was associated with reduced sleep quality. Our study quantifies the association of chronotype with iPSG metrics and suggests that laboratory protocols should consider chronotype in their evaluations.

Investigating changes in cognition associated with the use of CPAP in cognitive impairment and dementia: A retrospective study.

STUDY OBJECTIVES: To characterize the impact of CPAP use on cognition in a clinical cohort with obstructive sleep apnea (OSA) and cognitive impairment due to neurodegenerative or vascular etiologies after controlling for baseline sleepiness. METHODS: We retrospectively analyzed data from 171 patients with cognitive impairment and an OSA diagnosis confirmed with in-laboratory polysomnography or home sleep apnea testing (mean age 69.8 ± 10.6; 66% male) who were eligible to use CPAP. Baseline and follow-up Epworth Sleepiness Score (ESS), Montreal Cognitive Assessment (MoCA), and Mini-Mental Status Examination (MMSE) were obtained from clinical and research visits conducted before and after CPAP initiation. Good CPAP adherence was defined as CPAP use ≥4 h/night, for 7 days/week at follow-up. Associations between CPAP adherence and follow-up cognitive scores were analyzed using multivariable linear mixed-effects models. RESULTS: After adjusting for age, sex, body mass index, baseline ESS, duration of CPAP therapy, relevant comorbidities and the random effect of research study cohort, good CPAP adherence (compared to poor CPAP adherence or no use of CPAP) for a duration of 2-12 months was associated with a 2.3-point (1.2-3.3 95% CI) higher follow-up MoCA score (p < 0.001) and a 1.2-point (0.3-2.3 95% CI) higher follow-up MMSE score (p = 0.01). CONCLUSIONS: In patients with OSA and cognitive impairment due to a neurodegenerative or vascular etiology, use of CPAP is associated with improved cognitive outcomes. The findings of this study may aid in motivating patients to use CPAP and support future randomized controlled trials in this area.

SLEAP SMART (Sleep Apnea Screening Using Mobile Ambulatory Recorders After TIA/Stroke): A Randomized Controlled Trial.

BACKGROUND AND PURPOSE: Poststroke/transient ischemic attack obstructive sleep apnea (OSA) is prevalent, linked with numerous unfavorable health consequences, but remains underdiagnosed. Reasons include patient inconvenience and costs associated with use of in-laboratory polysomnography (iPSG), the current standard tool. Fortunately, home sleep apnea testing (HSAT) can accurately diagnose OSA and is potentially more convenient and cost-effective compared with iPSG. Our objective was to assess whether screening for OSA in patients with stroke/transient ischemic attack using HSAT, compared with standard of care using iPSG, increased diagnosis and treatment of OSA, improved clinical outcomes and patient experiences with sleep testing, and was a cost-effective approach. METHODS: We consecutively recruited 250 patients who had sustained a stroke/transient ischemic attack within the past 6 months. Patients were randomized (1:1) to use of (1) HSAT versus (2) iPSG. Patients completed assessments and questionnaires at baseline and 6-month follow-up appointments. Patients diagnosed with OSA were offered continuous positive airway pressure. The primary outcome was compared between study arms via an intention-to-treat analysis. RESULTS: At 6 months, 94 patients completed HSAT and 71 patients completed iPSG. A significantly greater proportion of patients in the HSAT arm were diagnosed with OSA (48.8% versus 35.2%, P=0.04) compared with the iPSG arm. Furthermore, patients assigned to HSAT, compared with iPSG, were more likely to be prescribed continuous positive airway pressure (40.0% versus 27.2%), report significantly reduced sleepiness, and a greater ability to perform daily activities. Moreover, a significantly greater proportion of patients reported a positive experience with sleep testing in the HSAT arm compared with the iPSG arm (89.4% versus 31.1%). Finally, a cost-effectiveness analysis revealed that HSAT was economically attractive for the detection of OSA compared with iPSG. CONCLUSIONS: In patients with stroke/transient ischemic attack, use of HSAT compared with iPSG increases the rate of OSA diagnosis and treatment, reduces daytime sleepiness, improves functional outcomes and experiences with sleep testing, and could be an economically attractive approach. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02454023.

Feasibility of unattended home sleep apnea testing in a cognitively impaired clinic population.

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) increases the risk of developing dementia. Home sleep apnea testing (HSAT) is a convenient and validated method to screen for OSA among cognitively well individuals; however, it is unknown if it is a clinically feasible and practical approach in clinic patients with cognitive impairment. We evaluated if HSAT was a feasible and practical approach to screen for OSA in clinic patients with cognitive impairment. METHODS: Patients with cognitive impairment due to neurodegenerative and/or vascular etiologies completed OSA screening using HSAT. HSAT was considered a feasible technique if ≥ 80% of those who attempted HSAT obtained analyzable data (ie, ≥ 4 hours of flow, effort, and oxygen evaluation), and a practical technique if ≥ 50% of all patients approached for study inclusion obtained analyzable data. RESULTS: Of the 119 patients who were approached for participation, 83 were enrolled and offered HSAT; 5 did not complete HSAT screening, and the remaining 78 patients attempted HSAT; mean age (± standard deviation) of 72.86 (± 9.89) years and 46% were male. In those that attempted HSAT, 85.9% (67/78) obtained analyzable data and 56.3% (67/119) of eligible patients approached for study inclusion obtained analyzable data. CONCLUSIONS: HSAT is a feasible and practical technique in a clinic population with cognitive impairment. As OSA is a modifiable risk factor for patients with dementia, HSAT has the potential to lead to expedited treatment for OSA, which may potentially improve health-related outcomes such as cognition.

Predictors of CPAP adherence following stroke and transient ischemic attack.

OBJECTIVE: Continuous positive airway pressure (CPAP) has been shown to improve functional, motor and cognitive outcomes in post-stroke obstructive sleep apnea (OSA). However, rates of CPAP adherence are often low and factors impacting CPAP adherence remain under-explored. Our objective was to determine predictors of CPAP adherence in patients who had a stroke or transient ischemic attack (TIA). METHODS: We screened 313 stroke/TIA patients for OSA using in-hospital polysomnography or the ApneaLink home sleep apnea test. Potential predictors were recorded at baseline and adherence to CPAP was recorded during a six-month follow-up visit. Selected variables from our univariate analyses were included in multivariate regression models to determine predictors of CPAP adherence. For our logistic regression analyses, CPAP adherence (CPAP use of ≥4 h per night) was the dependent outcome variable. In our linear regression analyses, total CPAP use per week (recorded in hours) was the dependent outcome variable. RESULTS: Eighty-eight patients (mean age 67.81 ± 13.09 years, 69.32% male, mean body mass index 27.93 ± 5.23 kg/m2) were diagnosed with OSA, prescribed CPAP, and assessed for adherence at a six-month follow-up visit. In these 88 patients, 46 (52.27%) were adherent with CPAP therapy. From our regression models, two significant predictors of CPAP adherence were identified: greater functional status (p = 0.04) and not endorsing daytime tiredness (p = 0.047) post-stroke/TIA. CONCLUSION: Patients with greater functional capacity and those with less daytime fatigue demonstrated stronger adherence to CPAP therapy. Our findings may facilitate future treatment strategies for enhancing CPAP adherence in the vulnerable stroke/TIA population.

Using a modified version of the "STOP-BANG" questionnaire and nocturnal oxygen desaturation to predict obstructive sleep apnea after stroke or TIA.

PURPOSE: Obstructive sleep apnea (OSA) is a risk factor and common morbidity for stroke and transient ischemic attack (TIA). However, screening for OSA in patients with stroke or TIA is uncommonly performed, due in part to difficulties associated with conducting polysomnography (PSG) and Home Sleep Apnea Tests (HSATs). The 8-point "STOP-BANG" questionnaire has been shown to have high methodological quality in screening for OSA. This study examined the clinical utility of a modified version of the "STOP-BANG" questionnaire, which removed neck circumference and included nocturnal oxygen desaturation in diagnosing OSA (ie, the "STOP-BAG-O" tool), with the goal of improving uptake and accuracy in diagnosing OSA. METHODS: In total, 231 participants completed both the STOP-BAG questionnaire and PSG or HSAT within 12 months of stroke/TIA. Using receiver-operating curves, scores on the "STOP-BAG-O" and "STOP-BAG" questionnaires were assessed for their ability to predict a diagnosis of OSA and classify at least 50% of the study population. RESULTS: Compared to an OSA diagnosis of AHI≥10, the STOP-BAG (using cut-offs of ≤3 and ≥4) had a sensitivity and specificity of 83.5% and 67.2%, respectively. The STOP-BAG-O (using cut-offs of ≤3 and ≥5) had a sensitivity and specificity of 95.9% and 78.4%, respectively. For all AHI cut-offs used, the area under the curve for the STOP-BAG-O was greater and statistically different (p < 0.001) than that for the STOP-BAG. CONCLUSIONS: The STOP-BAG-O is a valid tool for identifying risk of OSA post-stroke/TIA. The simplicity of this tool and ease of assessing nocturnal oxygen desaturation makes it a feasible option for widespread use.