Potential inflammatory biomarkers for tinnitus in platelets and leukocytes: a critical scoping review and meta-analysis

Abstract

Objective

To explore the association between platelets or leukocytes and tinnitus.

Design

A meta-analysis and scoping review examining the association between tinnitus and platelets and leukocytes. All 11 studies included were critically appraised using the Joanna Briggs Institute (JBI) checklist (2017a). A random effects model was used to pool the results of the studies examining mean platelet volume (MPV) and tinnitus.

Study sample

1935 studies were identified in the initial search, 11 of which were included in the scoping review. 6 of the 11 studies had their MPV values pooled in the meta-analysis.

Results

Pooled results of 818 subjects from 6 studies indicated that MPV was significantly higher in those with tinnitus compared to a comparison group without tinnitus. The overall mean difference was 0.43 fL with a 95% confidence interval (CI) from 0.31 to 0.55 and a p value of < 0.0001 which was statistically significant. MPV is the only haematological parameter which is reliably associated with tinnitus.

Conclusions

MPV could be a useful biomarker for tinnitus. Further studies should aim to standardise methodology with more rigorous exclusion criteria to reproduce and define this association. NLR, PLR, WBC count, RDW and PDW do not show a reliable association with tinnitus.

Keywords:

• Mean platelet volume
• subjective tinnitus
• inflammation
• biomarker

Acknowledgements

Dr. John Knight, Associate Professor at Swansea University, has reviewed some of the numerical anomalies in studies and corroborated claims made in this review. This meta-analysis and scoping review was written in partial fulfilment of the requirements of the BSc Healthcare Science (Audiology) course at Swansea University and therefore received no funding.

Declaration

I declare that this meta-analysis and scoping review is an entirely original work written solely by its authors with no conflict of interest. This meta-analysis and scoping review, or any segment of it, has not been published previously. This work is solely the author’s except where referenced or stated otherwise. A version of this meta-analysis and scoping review was originally a dissertation submission for Swansea University’s BSc Healthcare Science (Audiology) course.

Raheel Ahmed Signed: Date: 02/07/2020

Disclosure statement

No potential conflict of interest was reported by the authors.