Relationship between increased carotid artery stiffness and idiopathic subjective tinnitus

The association between tinnitus and risk of cardiovascular events and all-cause mortality: insight from the UK Biobank

BACKGROUND

The potential influence of tinnitus on cardiovascular disease (CVD) and all-cause mortality has yet to be explored. We aim to examine the correlations between tinnitus and the risk of cardiovascular events and all-cause mortality.

METHODS

We conducted a prospective cohort study utilising data from the UK Biobank. The presence of tinnitus was evaluated through a questionnaire. The primary outcome was defined as a composition of cardiovascular events, including myocardial infarction (MI), stroke, and mortality from CVD, as well as all-cause mortality. Cox proportional hazard models were employed to examine the associations between tinnitus and both the primary outcome and its individual components. Sensitivity analyses were conducted to evaluate the robustness of the primary analysis.

RESULTS

A total of 140,146 participants were included in the study. The presence of tinnitus was found to be associated with a higher incident rate of the primary outcome (HR = 1.057, 95%CI: 1.017-1.099, p = 0.005), MI (HR = 1.139, 95%CI: 1.061-1.222, p < 0.001) and all-cause mortality (HR = 1.053, 95%CI: 1.003-1.105, p = 0.038) after adjusting for confounders. However, there was no significant association between tinnitus and stroke or mortality from CVD. Subgroup analysis revealed that the association between tinnitus and the primary outcome was significant in females, participants with abnormal BMI, and those without hearing difficulty, depression or anxiety. Sensitivity analyses yielded consistent results.

CONCLUSION

The findings from this study contribute to the existing body of evidence suggesting an association between tinnitus and an increased risk of cardiovascular events and all-cause mortality.

Tinnitus Is Marginally Associated with Body Mass Index, Heart Rate and Arterial Blood Pressure: Results from a Large Clinical Sample

INTRODUCTION

This study aimed to explore whether body mass index (BMI), systolic blood pressure (RR syst), diastolic blood pressure (RR diast) or heart rate (HR) are associated with tinnitus status and/or severity.

METHODS

To that end, we evaluated the influence of tinnitus status and Tinnitus Handicap Inventory (THI) score on BMI, RR syst, RR diast and HR by comparing data from a large sample of patients presenting to a specialized tertiary referral clinic (N = 1066) with data from a population-based control group (N = 9885) by means of linear models.

RESULTS

Tinnitus patients had a significantly lower BMI and higher RR syst, RR diast and HR than non-tinnitus patients; however, the contribution of the case-control status to R² was very small (0.1%, 0.7%, 1.4% and 0.4%, respectively). BMI had little predictive power for the THI score (higher BMI scores were related to higher THI scores; R² = 0.5%) and neither RR syst, RR diast, nor HR showed a statistically significant association with THI.

DISCUSSION

Our findings suggest that HR, RR and BMI are at most marginally associated with tinnitus status and severity.

The Role of Inflammation in Tinnitus: A Systematic Review and Meta-Analysis

Subjective tinnitus is the perception of sound without the presence of an external source. Increasing evidence suggests that tinnitus is associated with inflammation. In this systematic review, the role of inflammation in subjective tinnitus was studied. Nine animal and twenty human studies reporting inflammatory markers in both humans and animals with tinnitus were included. It was established that TNF-α and IL-1β are increased in tinnitus, and that microglia and astrocytes are activated as well. Moreover, platelet activation may also play a role in tinnitus. In addition, we elaborate on mechanisms of inflammation in tinnitus, and discuss potential treatment options targeting inflammatory pathways.

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

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.

A retrospective cross-sectional study on tinnitus prevalence and disease associations in the Dutch population-based cohort Lifelines

Tinnitus is a highly prevalent disorder with heterogenous presentation and limited treatment options. Better understanding of its prevalence and disease and lifestyle risk factor associations in the general population is necessary to identify the underlying mechanisms. To this end, we quantified the prevalence of tinnitus and identified disease and lifestyle risk factors associated with tinnitus within a general population cohort. For this study, we used the Lifelines population-based cohort study to perform a retrospective cross-sectional study. Lifelines is a large, multi-generational, prospective cohort study that includes over 167,000 participants (or 10% of the population) from the northern Netherlands. For this study, conducted between 2018 and 2021, data from the Lifelines population-based cohort study was used to perform a cross-sectional study. Adult participants (age ≥ 18 years) with data on tinnitus perception (collected once between 2011 and 2015) were included in this study. An elastic-net regression analysis was performed with tinnitus as the dependent variable and parameters of diseases and lifestyle risk factors (collected once between 2006 and 2014)-including hearing problems, cardiovascular disease, metabolic disorders, psychiatric disorders, thyroid disease, inflammatory disease, and functional somatic syndromes-as the independent variables. Among 124,609 participants, N = 8,011 (6.4%) reported perceiving tinnitus constantly (CT: constant tinnitus) and N = 39,625 (31.8%) reported perceiving tinnitus constantly or occasionally (AT: any tinnitus). Our analysis identified 38 parameters that were associated with AT and 48 parameters that were associated with CT. Our study identified established disease associates with tinnitus, including problems with hearing (OR 8.570 with CT), arrythmia (OR 1.742 with CT), transient ischemic attack (OR 1.284 with AT), diabetes mellitus (OR 1.014 with AT) and psychiatric disorders, including major depressive disorder (OR 1.506 with CT). Factors related to lifestyle associated with tinnitus included waist-hip ratio (OR 1.061 with CT) and smoking (OR 1.028 with AT). Novel disease associates with CT were identified for inflammatory diseases, including rheumatoid arthritis (OR 1.297) and ulcerative colitis (OR 1.588), thyroid disease (as evidenced by the use of thyroid medication) (OR 1.298), and functional somatic syndromes, including chronic fatigue syndrome (OR 1.568). In addition to validating established disease associates in a general population cohort, this study identified novel associations with tinnitus and several disease categories, including functional somatic syndromes, inflammatory diseases, and thyroid disease. Future work will be necessary to identify whether (common) mechanisms underly tinnitus and these associated disorders. Lifelines is an important new resource available for future studies investigating tinnitus in the general population.

Objective and Measurable Biomarkers in Chronic Subjective Tinnitus

Tinnitus is associated with increased social costs and reduced quality of life through sleep disorders or psychological distress. The pathophysiology of chronic subjective tinnitus, which accounts for most tinnitus, has not been clearly elucidated. This is because chronic subjective tinnitus is difficult to evaluate objectively, and there are no objective markers that represent the diagnosis or therapeutic effect of tinnitus. Based on the results of studies on patients with chronic subjective tinnitus, objective and measurable biomarkers that help to identify the pathophysiology of tinnitus have been summarized. A total of 271 studies in PubMed, 303 in EMBASE, and 45 in Cochrane Library were found on biomarkers related to chronic subjective tinnitus published until April 2021. Duplicate articles, articles not written in English, review articles, case reports, and articles that did not match our topic were excluded. A total of 49 studies were included. Three specimens, including blood, saliva, and urine, and a total of 58 biomarkers were used as indicators for diagnosis, evaluation, prognosis, and therapeutic effectiveness of tinnitus. Biomarkers were classified into eight categories comprising metabolic, hemostatic, inflammatory, endocrine, immunological, neurologic, and oxidative parameters. Biomarkers can help in the diagnosis, measure the severity, predict prognosis, and treatment outcome of tinnitus.

Is there an association between the parameters of arterial stiffness and tinnitus?

Background: Increasing arterial stiffness is associated with atherosclerosis and there is an association between atherosclerosis and tinnitus may occur.Objectives: The aim of this study was to investigate the relationship between arterial stiffness and tinnitus using the central pulse-wave analysis method.Methods: This prospective, single center study included 98 participants, comprising 49 patients diagnosed with subjective idiopathic tinnitus (Group 1) and a control group of 49 healthy subjects (Group 2). The Mobil-O-Graph 24 h Pulse wave analysis (PWA) Monitor (I.E.M. GmbH, Stolberg, Germany) was used to determine the arterial stiffness and cardiovascular hemodynamic parameters. Central pulse pressure (CPP), Augmentation index and pulse wave velocity (PWV) were obtained with the device.Results: No statistically significant difference was determined between Groups in respect of age, smoking and hypertension (p > .05). Statistically significantly higher Central Pulse Pressure (CPP) values and pulse wave velocity were higher in Group 1 compared to the control group (p < .005). No statistical variation was detected in terms of the augmentation index (18.5 ± 11.3 vs 16.7 ± 10.3, p = .543).Conclusion: Our results marked that arterial stiffness is associated with tinnitus. The relationship was examined via oscillometric method, which is simple to perform and has been recommended in guidelines for the determination of cardiovascular event risk.

Corticospinal excitability for flexor carpi radialis decreases with baroreceptor unloading during intentional co-contraction with opposing forearm muscles

Concurrent activation of antagonistic muscles (co-contraction) is used for stiffening a joint, whereas its neural control under hemodynamic stress (e.g., posture change, high gravity, and hemorrhage) is unknown. Corticospinal excitability during co-contraction may be altered with baroreceptor unloading due to potential modulations in spinal and/or inhibitory pathways (e.g., disynaptic group I inhibition and GABA-mediated intracortical inhibition). The purpose of this study was to understand the effect of baroreceptor unloading on corticospinal excitability during co-contraction in humans. Motor evoked potential and cortical silent period in a wrist flexor muscle were examined using transcranial magnetic stimulation in two groups of healthy young adults. All subjects performed isometric contraction of the wrist flexors (flexion) and co-contraction of the wrist flexors and extensors (co-contraction). Spinal disynaptic inhibition was also assessed with the ratio of H-reflex responses to unconditioned and conditioned electrical stimulations of the peripheral nerves for the muscles. In one of the groups, baroreflex unloading was induced by applying lower body negative pressure. There was no significant effect of baroreflex unloading on cortical silent period or H-reflex measure of disynaptic inhibition. With baroreflex unloading, motor evoked potential area in the flexor carpi radialis was decreased during co-contraction but not during flexion. The results indicated that baroreceptor unloading decreases corticospinal excitability during co-contraction of antagonistic muscles, apparently by influencing neural pathways that were not probed with cortical silent period or spinal disynaptic inhibition.

The association between tinnitus and the risk of ischemic cerebrovascular disease in young and middle-aged patients: A secondary case-control analysis of a nationwide, population-based health claims database

Background

Tinnitus and ischemic cerebrovascular disease (ICVD) may share common pathophysiologic mechanisms. Nevertheless, no studies have investigated whether tinnitus is associated with a higher risk of ICVD. The aim of this study was to evaluate the risk of ICVD among young and middle-aged patients with tinnitus.

Methods

Using the Taiwan’s National Health Insurance Research Database, we identified 3,474 patients 20–45 years old with incident ICVD diagnosed between January 1, 2000 and December 31, 2010 and 17,370 controls, frequency matched on age interval, sex, and year of the index date. Risk of ICVD associated with tinnitus was assessed using multiple logistic regression analyses.

Results

Tinnitus was significantly associated with a higher risk of incident ICVD among young and middle-aged patients (adjusted odds ratio [OR] 1.66, 95% confidence interval [CI] 1.34–2.04), adjusting for sex, age, and comorbidities. In addition, sex-stratified analysis showed that the associations were significant in both male (adjusted OR 1.55, 95% CI 1.16–2.07) and female patients (adjusted OR 1.77, 95% CI 1.30–2.41). Furthermore, tinnitus was significantly associated with a higher risk of ICVD in the 20.0–29.9 years (adjusted OR 4.11, 95% CI 1.98–8.52) and 30.0–39.9 years (adjusted OR 2.19, 95% CI 1.57–3.05) age groups, but not in the 40.0–45.0 years age group.

Conclusions

Tinnitus could be a novel risk factor or clinical indicator for young ischemic stroke, and further investigations are warranted.