Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
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.

PubMed Disclaimer

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

References

    1. Bal KK, Alagoz S, Ozdas T, et al. Loss of smell in COVID-19 patients: new biomarkers. Indian J Otolaryngol Head Neck Surg. 2021 doi: 10.1007/s12070-021-02892-3. - DOI - PMC - PubMed
    1. Benkirane H, Heikel J, Laamiri FZ, et al. Study of clinical and biological characteristics of moroccan Covid-19 patients with and without olfactory and/or gustatory dysfunction. Front Physiol. 2020 doi: 10.3389/fphys.2020.595005. - DOI - PMC - PubMed
    1. Boscolo-Rizzo P, Borsetto D, Fabbris C, et al. Evolution of altered sense of smell or taste in patients with mildly symptomatic COVID-19. JAMA Otolaryngol Neck Surg. 2020;146:729. doi: 10.1001/jamaoto.2020.1379. - DOI - PMC - PubMed
    1. Boscutti A, Delvecchio G, Pigoni A, et al. Olfactory and gustatory dysfunctions in SARS-CoV-2 infection: a systematic review. Brain, Behav Immun - Heal. 2021;15:100268. doi: 10.1016/j.bbih.2021.100268. - DOI - PMC - PubMed
    1. Brann DH, Tsukahara T, Weinreb C, et al. Non-neuronal expression of SARS-CoV-2 entry genes in the olfactory system suggests mechanisms underlying COVID-19-associated anosmia. Sci Adv. 2020 doi: 10.1126/sciadv.abc5801. - DOI - PMC - PubMed