Symptom subtypes and cognitive function in a clinic-based OSA cohort: a multi-centre Canadian study

Aj Hirsch Allen; Andrew E Beaudin; Nurit Fox; Jill K Raneri; Robert P Skomro; Patrick J Hanly; Diego R Mazzotti; Brendan T Keenan; Eric E Smith; Sebastian D Goodfellow; Najib T Ayas

doi:10.1016/j.sleep.2020.05.001

Symptom subtypes and cognitive function in a clinic-based OSA cohort: a multi-centre Canadian study

Sleep Med. 2020 Oct:74:92-98. doi: 10.1016/j.sleep.2020.05.001. Epub 2020 May 11.

Authors

Affiliations

¹ Department of Medicine, Respiratory and Critical Care Divisions, University of British Columbia, Vancouver, BC, Canada; Canadian Sleep and Circadian Network, Canada.
² Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Canadian Sleep and Circadian Network, Canada.
³ Department of Medicine, Respiratory and Critical Care Divisions, University of British Columbia, Vancouver, BC, Canada.
⁴ Sleep Centre, Foothills Medical Centre, Calgary, AB, Canada.
⁵ Division of Respirology, Critical Care and Sleep Medicine, University of Saskatchewan, Saskatoon, SK, Canada; Canadian Sleep and Circadian Network, Canada.
⁶ Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Sleep Centre, Foothills Medical Centre, Calgary, AB, Canada; Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Canadian Sleep and Circadian Network, Canada.
⁷ Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
⁸ Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
⁹ Department of Civil and Mineral Engineering, University of Toronto, Toronto, ON, Canada.
¹⁰ Department of Medicine, Respiratory and Critical Care Divisions, University of British Columbia, Vancouver, BC, Canada; Canadian Sleep and Circadian Network, Canada. Electronic address: nayas@providencehealth.bc.ca.

Abstract

Background: Distinct symptom subtypes are found in patients with OSA. The association between these subtypes and neurocognitive function is unclear.

Objective: The purposes of this study were to assess whether OSA symptom subtypes are present in a cohort of Canadian patients with suspected OSA and evaluate the relationship between subtypes and neurocognitive function.

Methods: Patients with suspected OSA who completed a symptom questionnaire and underwent testing for OSA were included. Symptom subtypes were identified using latent class analysis. Associations between subtypes and neurocognitive outcomes (Montreal Cognitive Assessment [MoCA], Rey Auditory Verbal Learning Test [RAVLT], Wechsler Adult Intelligence Scale [WAIS-IV], Digit-Symbol Coding subtest [DSC]) were assessed using analysis of covariance (ANCOVA), controlling for relevant covariates.

Results: Four symptom subtypes were identified in patients with OSA (oxygen desaturation index ≥5 events/hour). Three were similar to prior studies, including the Excessively Sleepy (N=405), Disturbed Sleep (N=382) and Minimally Symptomatic (N=280), and one was a novel subtype in our sample defined as Excessively Sleepy with Disturbed Sleep (N=247). After covariate adjustment, statistically significant differences among subtypes (p=0.037) and among subtypes and patients without OSA (p=0.044) were observed in DSC scores; the Minimally Symptomatic subtype had evidence of higher DSC scores than all other groups, including non-OSA patients. No differences were seen in MoCA or RAVLT.

Conclusions: Results support the existence of previously identified OSA symptom subtypes of excessively sleepy, disturbed sleep and minimally symptomatic in a clinical sample from Canada. Subtypes were not consistently associated with neurocognitive function across multiple instruments.

Keywords: Cluster analysis; Neurocognitive outcomes; Sleep apnea; Sleepiness; Symptom subtypes.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Canada
Cognition
Humans
Sleep
Sleep Apnea, Obstructive* / diagnosis
Wakefulness

Grants and funding

P01 HL094307/HL/NHLBI NIH HHS/United States