Sleep-Disordered Breathing Is Associated With Impaired Odor Identification in Older U.S. Adults

• Published in: The journals of gerontology. Series A, Biological sciences and medical sciences Vol. 76; no. 3; pp. 528 - 533
• Main Authors: Siegel, Jesse K, Yuan, Xiandao, Wroblewski, Kristen E, McClintock, Martha K, Pinto, Jayant M
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 01-03-2021
• Subjects: Age Factors; Aged; Aged, 80 and over; Aging; Apnea; Body mass index; Central nervous system; Chemoreception; Cognition; Cohort Studies; Demography; Female; Humans; Information processing; Male; Mental depression; Middle Aged; Odds Ratio; Odor; Odorants; Older people; Olfaction; Olfaction Disorders - diagnosis; Olfaction Disorders - epidemiology; Olfactory discrimination; Risk Factors; Sensory evaluation; Sleep; Sleep Apnea Syndromes - complications; Sleep Apnea Syndromes - diagnosis; Sleep disorders; Socioeconomic Factors; Surveys and Questionnaires; THE JOURNAL OF GERONTOLOGY: Medical Sciences; United States; United States; United States > US; Sleep apnea; Cognitive impairment; Smell
• ISSN: 1079-5006; 1758-535X
• DOI: 10.1093/gerona/glaa276

Abstract
Background
Sleep-disordered breathing (SDB) is a common, underdiagnosed condition in older adults with major health consequences, including disrupted central nervous system functioning. Whether SDB may affect sensory function is unclear. We sought to address this question by comparing 2 forms of olfactory testing which measure peripheral and central olfactory processing.
Methods
We assessed SDB (survey-reported snoring frequency, nighttime apneic events, or diagnosis of sleep apnea) in the National Social Life, Health, and Aging Project, a nationally representative sample of older U.S. adults. Odor sensitivity (peripheral) and odor identification (central) were assessed with validated instruments. Logistic regression was used to test the relationship between SDB and olfaction, accounting for relevant covariates, including demographics, cognition, and comorbidity.
Results
Twenty-nine percent of older U.S. adults reported symptoms of SDB (apneic events or nightly snoring). Of these, only 32% had been diagnosed with sleep apnea. Older adults with SDB (those who reported symptoms or have been diagnosed with sleep apnea) were significantly more likely to have impaired odor identification (odds ratio 2.13, 95% confidence interval 1.19–3.83, p = .012) in analyses that accounted for age, gender, race/ethnicity, education, cognition, comorbidities (including depression), and body mass index. Presence of SDB was not associated with impaired odor sensitivity (odds ratio 1.03, 95% confidence interval 0.75–1.43, p = .84).
Conclusion
SDB is highly prevalent but underdiagnosed in older U.S. adults and is associated with impaired odor identification but not odor sensitivity. These data support the concept that SDB affects pathways in the central nervous system which involve chemosensory processing.