Association Between COVID-19 Severity and Olfactory Disturbance

Background: there is little information about prognostic factors in patients with covid-19. one of the aspects of sars-cov-2 involvement is the sudden loss of smell, called anosmia. objectives: this study assessed the association between covid-19 severity and olfactory disturbance. methods: this cohort study was performed at taleghani hospital of iran from march 2021 to march 2022. patients with a definitive diagnosis of covid-19, according to a positive pcr test or chest ct scan, entered the study. data on demographic information, past medical history, severity of covid-19, olfactory disturbance at the time of hospitalization, and the course of the disease were gathered. data were analyzed using stata version 14 software. results: a total of 390 patients entered the study. according to the multiple logistic regression analysis, patients with severe and critical covid-19 were less likely to develop olfactory disturbance (or = 0.5, p-value = 0.035, 95%ci = 0.2-0.9). also, obesity was a statistically significant negative predictor of developing olfactory disturbance in patients with covid-19 (or = 0.4, p-value = 0.043, 95%ci = 0.1 – 0.9). diabetes mellitus was a statistically significant positive predictor of developing olfactory disturbance (or = 3.3, p-value = 0.029, 95%ci = 1.1 – 9.9). conclusions: patients with severe and critical covid-19 were less likely to develop anosmia. these patients had lower serum cytokines and presented with milder disease. the severity of olfactory disturbance could be a prognostic factor in covid-19. it is important to closely monitor patients who exhibit mild olfactory disturbance because they are at risk of more severe covid-19.