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Meta-Analysis
. 2022 Dec;30(6):2079-2087.
doi: 10.1007/s10787-022-01066-z. Epub 2022 Sep 12.

Association between chemosensory dysfunctions and inflammatory biomarkers in patients with SARS-CoV-2 infection: a systematic review and meta-analysis

Elisama Gomes Magalhães de Melo  1   2 , Rayle Monteiro Andrade  1   2 , Sara Juliana de Abreu de Vasconcellos  3 , Priscila Lima Dos Santos  4   5 , Diego Moura Tanajura  2 , Lucindo José Quintans-Júnior  5   6 , Jullyana de Souza Siqueira Quintans  5   6 , Paulo Ricardo Martins-Filho  7   8   9
Affiliations
Meta-Analysis

Association between chemosensory dysfunctions and inflammatory biomarkers in patients with SARS-CoV-2 infection: a systematic review and meta-analysis

Elisama Gomes Magalhães de Melo et al. Inflammopharmacology. 2022 Dec.

Abstract

Background: There is evidence that chemosensory dysfunctions, including smell and taste disorders, are common findings in patients with SARS-CoV-2 infection. However, the underlying biological mechanisms and the role of inflammatory markers are still poorly understood.

Aim: To investigate the inflammatory biomarkers levels in patients with COVID-19 presenting chemosensory dysfunctions.

Methods: This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. A systematic literature search was performed from January 1, 2020, to May 12, 2022. Observational studies that provided data on hematological, biochemical, infection-related indices and cellular immunity, and coagulation function in patients with COVID-19 experiencing smell and/or taste disorders were considered eligible. Effect sizes were reported as standardized mean difference (SMD) with 95% confidence intervals (CI). A negative effect size indicated that the inflammatory biomarker levels were lower among patients with chemosensory dysfunctions.

Results: Eleven studies were included. Patients with chemosensory disturbances had lower levels of leukocytes (SMD - 0.18, 95% CI - 0.35 to - 0.01, p = 0.04), lactate dehydrogenase (SMD - 0.45, 95% CI - 0.82 to - 0.09, p = 0.01), IL-6 (SMD - 0.25, 95% CI - 0.44 to - 0.06, p < 0.01), and C-reactive protein (SMD - 0.33, 95% CI - 0.58 to - 0.08, p < 0.01) than patients without chemosensory disturbances.

Conclusion: Patients with SARS-CoV-2 infection who have olfactory and gustatory disorders have a lower inflammatory response than patients who do not have chemosensory alterations. The presence of these symptoms may indicate a more favorable clinical course for COVID-19.

Keywords: Ageusia; Anosmia; COVID-19; Cytokines; Inflammation mediators; Olfaction disorders; SARS-CoV-2 infection; Taste disorders.

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Conflict of interest statement

The authors declare that there is no competing interest. All authors have approved the manuscript for submission.

Figures

Fig. 1
Fig. 1
Flow diagram of study selection
Fig. 2
Fig. 2
Results of meta-analysis analyzing the levels of inflammatory biomarkers in patients with COVID-19 with and without chemosensory dysfunctions
See this image and copyright information in PMC

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