The Association Between Smoking on Olfactory Dysfunction in 3,900 Patients With Olfactory Loss

Abstract

Objectives/Hypothesis The association between smoking and olfactory loss remains a conundrum. Prior studies have found negative and positive effects of smoking on olfactory function in the general population. However, smoking cessation seems to improve both rated and measured olfactory function. The purpose of this study was to investigate the olfactory function and smoking habits in patients with olfactory loss caused by different etiologies to unveil underlying patterns related to smoking. Study Design Retrospective observational study. Methods Patients were included from two specialized taste and smell centers. Patients underwent olfactory testing, clinical examination including rhinoscopy, and the underlying etiology was identified. Patterns of olfactory test scores, demographics, and etiologies were analyzed. Results In total, 3,900 patients with olfactory loss were included. Of these, 521 were current smokers, and 316 were former smokers. Patients with a history of smoking did not have significantly lower olfactory function. Current smokers were more often affected by posttraumatic olfactory loss, but not sinonasal, postviral, or idiopathic olfactory loss. Conclusions Current smoking, but not former smoking, was associated with posttraumatic olfactory loss. In relation to measured olfactory function, a history of smoking was not associated to lower olfactory scores. Our findings suggest that the general recommendations of smoking cessation for patients with olfactory loss are especially relevant for patients with posttraumatic olfactory loss. The nature of this association between current smoking and posttraumatic olfactory loss has yet to be elucidated. Level of Evidence 2b Laryngoscope, 131:E8–E13, 2021

Pérdida del sentido del olfato durante la pandemia COVID-19

“…Sin embargo, el cese del hábito tabáquico parece mejorar la función olfativa. Un estudio que incluyó a 3.900 pacientes con pérdida olfativa, 521 fumadores activos y 316 exfumadores, concluyó que los pacientes con tabaquismo activo no tenían una función olfatoria significativamente menor 6 .…”

“…Especialmente utilizadas en el ámbito de la investigación, se han desarrollado pruebas objetivas en las que los datos no dependen de la subjetividad del paciente [5][6][7] . Entre ellas destacan las exploraciones electrofisiológicas del olfato (electroolfatograma, potenciales evocados olfatorios), las pruebas de imagen estructurales y funcionales olfatorias, y biopsias de la región olfativa.…”

Olfactory Dysfunction in the COVID-19 Outbreak

“…A recent study included 3,900 patients with olfactory loss; 521 were current smokers and 316 former smokers. They concluded that patients with a history of smoking did not have a significantly lower olfactory function [25].…”

Olfactory dysfunction during COVID-19 pandemic

“…A study that included 3900 patients with olfactory loss, 521 active smokers and 316 ex-smokers, concluded that patients who were active smokers did not have significantly lower olfactory function. 6 …”

“…Objective tests are especially used in research, and some have been developed in which the data does not depend on patient subjectivity. 5 , 6 , 7 Tests to be highlighted include the electrophysiological tests of olfaction (electro-olfactogram, olfactory evoked potentials), olfactory structural and functional imaging tests, and biopsies of the olfactory region. The limitations are that these tests can only be performed in highly specialised centres; furthermore, they do not discriminate between the different causes of OD, and they do not provide information on the possible location of the damage.…”