Olfactory dysfunction persists after smoking cessation and signals increased cardiovascular risk

Abstract

BackgroundOlfaction plays a critical role in health and function in older adults, and impaired sense of smell is a strong predictor of morbidity and mortality. Smoking cigarettes causes olfactory impairment, but the mechanism of damage and ability to recover after cessation are unknown. We investigated the relationship between time since quitting and olfactory dysfunction in order to elucidate the mechanism(s) by which smoking damages the olfactory system and to inform patient counseling.MethodsUsing longitudinal data from the National Social Life Health and Aging Project (n = 3528 older adults, including 1526 former smokers), we analyzed the association between odor identification performance and time since smoking cessation using multivariate ordinal logistic regression, adjusting for cognition and demographic variables. To test whether vascular disease plays a role, we also assessed the relationship between olfactory decline and incidence of heart attack and heart disease.ResultsFormer smokers who quit ≤15 years before testing had significantly impaired olfaction compared to never smokers (p = 0.04), but those who quit >15 years prior did not. Olfactory decline over 5 years showed modest evidence toward predicting increased incidence of heart attack or heart disease (p = 0.08).ConclusionOlfactory impairment in smokers persists 15 years after quitting, which is consistent with a vascular mechanism of impairment. Indeed, olfactory decline is a predictor of the development of cardiovascular disease. Taken together, these data suggest that olfactory loss may be a useful sign of underlying vascular pathology. Further investigation of olfactory loss as an early biomarker for cardiovascular disease is warranted.

The association between olfactory dysfunction and cardiovascular disease and its risk factors in middle-aged and older adults

“…Previous studies have raised controversy surrounding the association between olfactory dysfunction and CVD 3 , 4 , 8 . A recent study using longitudinal data from older Americans reported that olfactory impairment may be a predictor for increased risk of CVD; older smokers with olfactory dysfunction over five years exhibited an increased incidence of heart attack or heart diseases.…”

“…Olfactory dysfunction is a common condition, affecting approximately 20% of the general adult population 1 , 2 . Olfaction decreases by degrees with aging, and is related to a reduced quality of life and critical health outcomes 2 , 3 . In older adults, poor olfaction is associated with higher long-term mortality, neurodegenerative diseases, and poor health outcomes 2 , 4 .…”

“…Accumulating evidence has suggested that cardiovascular health may be associated with olfactory dysfunction 3 , 7 . In older Americans, poor olfaction was reported to be associated with higher mortality from cardiovascular disease (CVD) 7 ; however, some studies have reported that there was no association between CVD and olfactory dysfunction 8 , 9 .…”

Prevalence and recovery time of olfactory and gustatory dysfunction in hospitalized patients with COVID‑19 in Wuhan, China

“…The results indicated a significantly higher incidence of cardiovascular disease in patients with COVID-19 with a chemosensory disorder than in patients with COVID-19 without a chemosensory disorder. Some studies have suggested that a decreased sense of smell is a predictor of cardiovascular disease development ( Schubert et al, 2015 , Siegel et al, 2019 ). Despite the small number of cases in our study, we speculated that cardiovascular disease might be related to the development of olfactory or taste disorders in patients with COVID-19.…”

Age-Related Olfactory Dysfunction: Epidemiology, Pathophysiology, and Clinical Management

“…A systematic review and meta-analysis also demonstrated that current smoking, but not former smoking, was associated with a significantly increased risk of olfactory dysfunction, suggesting that the effects of smoking on olfaction may be reversible (Ajmani et al, 2017 ). However, olfactory impairment in smokers has been reported to persist 15 years after quitting (Siegel et al, 2019 ). In animal studies, intranasal administration of tobacco solution induced degeneration of the olfactory neuroepithelium (Ueha et al, 2016a , b , 2018c ).…”