Association Between Olfactory Dysfunction and Mortality in US Adults

Abstract

oor olfactory function has been directly implicated in malnutrition, 1 decreased safety, 2 and overall worse quality of life. 3 It is responsible for more than 200 000 physician visits per year, representing a significant public health burden. 4,5 Emerging evidence suggests that olfactory dysfunction is significantly associated with increased all-cause mortality among older adults. 4,[6][7][8][9][10][11] Most notably, a recent study by Liu et al 12 examining community-dwelling older adults aged 71 to 82 years showed clear evidence that poor olfaction alone explains higher long-term mortality, particularly in individuals with excellent to good health at baseline. Liu et al 12 found the elevated risk of mortality of patients with poor olfaction was only partially explained by neurodegenerative dis-ease, cardiovascular disease, and weight loss. Olfaction is emerging as an early indicator of brain aging that can be objectively measured with a relatively simple smell test in the clinical setting.Choi et al 13 previously used the National Health and Nutrition Examination Survey (NHANES) to demonstrate that objectively measured olfactory dysfunction is associated with cognitive impairment independently of demographics and cardiovascular factors. Herein we further investigate the associations of olfactory dysfunction (measured by both objective smell test and self-report) with all-cause 5-year mortality in US adults 40 years or older, independently of cardiovascular factors, cognition, and depression. IMPORTANCE A study of olfactory dysfunction and mortality in a large national cohort will aid in better understanding their association when accounting for multiple relevant factors and possible underlying mechanisms. OBJECTIVE To investigate the association of olfactory dysfunction with all-cause 5-year mortality in US adults.

Olfactory dysfunction in cystic fibrosis: Impact of CFTR modulator therapy

“…Olfactory dysfunction can weaken sense of taste and adversely impact eating preference, which may affect nutritional status [26] . Beyond nutritional status, decreased olfactory function is associated with increased mortality [6] .…”

Olfaction and Aging: A Review of the Current State of Research and Future Directions

“…Furthermore, the authors reported that the association between olfactory deficits and risk of mortality was present also in middle-aged adults who were younger than the participants in previous studies. These results recently received further empirical support in large-scale studies ( Choi et al., 2020 ; Liu et al., 2019 ).…”

International consensus statement on allergy and rhinology: Olfaction

“…The peripheral olfactory organ is the OE, a true neuroepithelium that lines the olfactory cleft (OC) of the nasal cavity, including the ventral cribriform plate, the medial vertical lamellae of the superior turbinates as well as variable portions of the middle turbinates, and the superior portion of the nasal septum. [92][93][94][95] While the remainder of the nasal cavity and paranasal sinuses are lined by respiratory mucosa, the specialized olfactory neuroepithelium is composed of several distinct cell types: olfactory sensory neurons (OSNs), basal cells, sustentacular cells, microvillar cells, and ducts from Bowman glands. Deep to the OE lies a lamina propria containing olfactory nerve fascicles with nonmyelinating ensheathing glia, blood vessels, and Bowman glands.…”