Correlation of olfactory dysfunction with lung involvement and severity of COVID-19

Abstract

Background Olfactory dysfunction (OD) is a significant symptom of COVID-19 and may be the earliest symptom, or it may sometimes be the only manifestation of the disease. Aims To investigate whether OD is correlated with chest computed tomography (CT) findings, blood test parameters, and disease severity in COVID-19 patients. Methods The files of COVID-19 patients were retrospectively reviewed, and the ones who had information about smelling status and CT were taken into consideration. A total of 180 patients were divided into two groups: the OD group consisted of 89 patients with self-reported OD, and the No-OD group consisted of 91 subjects who did not complain of OD. The two groups were compared for the amount of lung consolidation on CT, intensive care unit (ICU) admission, and blood test parameters (complete blood count, alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), ferritin, D-dimer, interleukin-6 (IL-6)). Results The amount of lung consolidation and ICU admission were significantly higher in the No-OD group ( p < 0.001 for both). White blood cell ( p = 0.06), monocyte ( p = 0.26), and platelet ( p = 0.13) counts and hemoglobin ( p = 0.63), ALT ( p = 0.89), and D-dimer ( p = 0.45) levels of the two groups were similar. Lymphocyte count ( p = 0.01), neutrophil count ( p = 0.01), and AST ( p = 0.03), CK ( p = 0.01), LDH ( p < 0.001), CRP ( p < 0.001), ESR ( p < 0.001), ferritin ( p < 0.001), and IL-6 ( p < 0.001) levels were significantly higher in the No-OD group. Conclusions The patients presenting to the hospital with self-reported OD may have less lung involvement and a milder disease course compared to patients without OD on admission.

Olfactory dysfunction in COVID‐19, new insights from a cohort of 353 patients: The ANOSVID study

“…Regarding more specifically laboratory data, we can observe a tendency of less abnormal results in the OD group compared to the no‐OD group with less lymphopenia ( p = 0.126), longer prothrombin time ( p = 0.126), and higher kidney clearance ( p = 0.154). Other studies have also found a significant relationship between OD and less abnormal laboratory results 9,13,18,34 . Concerning the radiological data, we did not find any significant correlation between OD and thoracic imaging features but a tendency with the high OD group that was associated with less extension >25% (43.1% vs. 59.3%, p = 0.157) on the thoracic CT scan.…”

“…Only one study in our review mentioned a significant prevalence of OD in cardiovascular disease. 33 Concerning laboratory data in the first analysis, there was no significant difference between the OD group and the no-OD group but some trends like less lymphopenia (as for some studies: Talavera et al, 9 Yağmur et al, 34 Foster et al, 18 and Izquierdo-Dominguez et al, 13 ), higher clearance CKD (as for Talavera et al, 9 ), longer TP, and an lower level of hemoglobin in the OD group compared with the no-OD group. Interestingly in the second analysis, we did not find the previous trends except for creatinine clearance CKD, high OD being associated with significantly higher clearance CKD (mean 89.0 ± 21.1…”

“…Ardestani et al did not find significant difference. 32 On the other hand, some studies have found significantly lower lung involvement, 19,34,51 pleural effusion, progression on CT 51 and percentage of lung volume with consolidation. 34 We did not find that OD is a good at predicting COVID-19.…”

“…32 On the other hand, some studies have found significantly lower lung involvement, 19,34,51 pleural effusion, progression on CT 51 and percentage of lung volume with consolidation. 34 We did not find that OD is a good at predicting COVID-19. Our main assumption to explain these results is the low number of critical patients, only 5.1% patients were admitted in ICU (n = 18/353); the required number of patients to conclude for ICU admission or mechanical ventilation requirement was probably not reached.…”

Olfactory Dysfunction in Patients With Coronavirus Disease 2019: A Review

“…In contrast, Singer-Cornelius et al suggested, based on a lack of significant associations between the two conditions in objective tests, that GD and OD are two independent symptoms ( 37 ). A negative correlation has been demonstrated between OD and post-admission severity and mortality of COVID-19 in several studies ( 49 , 50 ), in direct contrast to a report on clinical outcomes by Tabari et al ( 51 ). Speth et al showed that in addition to GD, OD severity was significantly associated with depression and anxiety ( 52 ).…”