Association Between Hearing Loss and Cardiovascular Disease: A Meta-analysis

OBJECTIVE

Hearing loss (HL) has been postulated to be linked to cardiovascular diseases (CVDs) via vascular mechanisms, but epidemiological associations remain unclear. The study aims to clarify the association between HL and stroke, coronary artery disease (CAD), and any CVD.

DATA SOURCES

PubMed, Embase, and SCOPUS from inception until April 27, 2022.

REVIEW METHODS

Three blinded reviewers selected observational studies reporting stroke, CAD, and any CVD in patients with HL, compared to individuals without HL. We extracted data, evaluated study bias using the Newcastle-Ottawa scale, following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and a PROSPERO-registered protocol (CRD42022348648). We used random-effects inverse variance meta-analyses to pool the odds ratios (ORs) for the association of HL with stroke, CAD, and any CVD.

RESULTS

We included 4 cohort studies (N = 940,771) and 6 cross-sectional studies (N = 680,349). Stroke, CAD, and any CVD were all strongly associated with HL. The overall pooled OR of the association between HL and stroke was 1.26 (95% confidence interval [CI] = 1.16-1.37, I2  = 78%), and was 1.33 (95% CI = 1.12-1.58) and 1.29 (95% CI = 1.14-1.45) for low- and high-frequency HL, respectively. Minimal publication bias was observed, with minimal change to pooled effect size following trim and fill. Similarly, the pooled OR of the association between HL and CAD was 1.36 (95% CI = 1.13-1.64, I2  = 96%), while that between HL and any CVD was 1.38 (95% CI = 1.07-1.77, I2  = 99%).

CONCLUSION

Our findings suggest that HL and CVD are closely related. Physicians treating patients with HL should be cognizant of this association and view HL in the broader context of general health and aging.

Association of Hearing Aids and Cochlear Implants With Cognitive Decline and Dementia: A Systematic Review and Meta-analysis

Importance

Hearing loss is associated with cognitive decline. However, it is unclear if hearing restorative devices may have a beneficial effect on cognition.

Objective

To evaluate the associations of hearing aids and cochlear implants with cognitive decline and dementia.

Data Sources

PubMed, Embase, and Cochrane databases for studies published from inception to July 23, 2021.

Study Selection

Randomized clinical trials or observational studies published as full-length articles in peer-reviewed journals relating to the effect of hearing interventions on cognitive function, cognitive decline, cognitive impairment, and dementia in patients with hearing loss.

Data Extraction and Synthesis

The review was conducted in accordance with Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) reporting guidelines. Two authors independently searched the PubMed, Embase, and Cochrane databases for studies relating to the effect of hearing interventions on cognitive decline and dementia in patients with hearing loss.

Main Outcomes and Measures

Maximally adjusted hazard ratios (HRs) were used for dichotomous outcomes and ratio of means for continuous outcomes. Sources of heterogeneity were investigated using sensitivity and subgroup analyses, and publication bias was assessed using visual inspection, the Egger test, and trim and fill.

Results

A total of 3243 studies were screened; 31 studies (25 observational studies, 6 trials) with 137 484 participants were included, of which 19 (15 observational studies, 4 trials) were included in quantitative analyses. Meta-analysis of 8 studies, which had 126 903 participants, had a follow-up duration ranging from 2 to 25 years, and studied long-term associations between hearing aid use and cognitive decline, showed significantly lower hazards of any cognitive decline among hearing aid users compared with participants with uncorrected hearing loss (HR, 0.81; 95% CI, 0.76-0.87; I2 = 0%). Additionally, meta-analysis of 11 studies with 568 participants studying the association between hearing restoration and short-term cognitive test score changes revealed a 3% improvement in short-term cognitive test scores after the use of hearing aids (ratio of means, 1.03; 95% CI, 1.02-1.04, I2 = 0%).

Conclusions and Relevance

In this meta-analysis, the usage of hearing restorative devices by participants with hearing loss was associated with a 19% decrease in hazards of long-term cognitive decline. Furthermore, usage of these devices was significantly associated with a 3% improvement in cognitive test scores that assessed general cognition in the short term. A cognitive benefit of hearing restorative devices should be further investigated in randomized trials.

Associations of Hearing Loss and Dual Sensory Loss With Mortality: A Systematic Review, Meta-analysis, and Meta-regression of 26 Observational Studies With 1 213 756 Participants

IMPORTANCE

Hearing loss (HL) and dual sensory loss (DSL) are prevalent, disabling, and associated with numerous age-related health conditions, including dementia and frailty. To date, no evidence-based summary of their mortality risk is available.

OBJECTIVE

To clarify the epidemiological associations between HL/DSL and mortality.

DATA SOURCES

PubMed, Embase, and Cochrane Library, from inception until June 18, 2021.

STUDY SELECTION

Two blinded reviewers selected observational or interventional studies, published as full-length English articles in peer-reviewed journals, that reported the presence or severity of HL or DSL (ie, comorbid HL and vision loss), whether objectively measured or self-reported, in association with any mortality estimate, among adults 18 years and older.

DATA EXTRACTION AND SYNTHESIS

Two reviewers extracted data and evaluated study bias using the Newcastle-Ottawa Scale, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)/Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines and a PROSPERO-registered protocol. The analysis pooled maximally adjusted estimates using mixed-effects models, measured heterogeneity using I2, investigated sources of heterogeneity using meta-regression and subgroup meta-analyses, examined and adjusted for publication bias, performed influence and cumulative meta-analyses, and assessed evidence quality using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework.

MAIN OUTCOMES AND MEASURES

Hazard ratios (HRs) for all-cause, cardiovascular, or other mortality estimates.

RESULTS

This review included 14 retrospective and 12 prospective observational studies (1 213 756 participants) from 3220 records. Risk of bias was low to moderate; exclusion of 3 high-risk studies did not alter conclusions. Hearing loss was associated with excess all-cause mortality (HR, 1.13; 95% CI, 1.07-1.19; I2 = 77%; n = 21; 95% prediction interval [PI], 0.93-1.37) and cardiovascular mortality (HR, 1.28; 95% CI, 1.10-1.50; I2 = 60%; n = 6; 95% PI, 0.84-1.96), while DSL was associated with larger excess risks (all-cause: HR, 1.40; 95% CI, 1.30-1.51; I2 = 34%; n = 10; 95% PI, 1.18-1.66; cardiovascular: HR, 1.86; 95% CI, 1.31-2.65; I2 = 0%; n = 2), after adjustment for demographics and comorbidities. Prespecified meta-regression sufficiently explained heterogeneity, with longer follow-up duration weakening the pooled association, leaving low (29%) residual heterogeneity. Meta-regression among audiometric studies showed a dose-response association (doubling of HR per 30-dB increase in HL). Self-reported and audiometric effect sizes were similar, with lower heterogeneity in the latter. Associations were robust to trim-and-fill adjustment for publication bias and single-study influence and cumulative meta-analyses. Associations with accident/injury, cancer, and stroke mortality were inconclusive, with only 1 to 3 studies. Overall evidence quality was moderate.

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis, HL and DSL were associated with excess all-cause and cardiovascular mortality. Physicians caring for patients with HL should consider its relevance to general health and longevity.

Exploring the Clinical Utility of Gustatory Dysfunction (GD) as a Triage Symptom Prior to Reverse Transcription Polymerase Chain Reaction (RT-PCR) in the Diagnosis of COVID-19: A Meta-Analysis and Systematic Review

BACKGROUND

The diagnosis of COVID-19 is made using reverse transcription polymerase chain reaction (RT-PCR) but its sensitivity varies from 20 to 100%. The presence of gustatory dysfunction (GD) in a patient with upper respiratory tract symptoms might increase the clinical suspicion of COVID-19.

AIMS

To perform a systematic review and meta-analysis to determine the pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-) and diagnostic odds ratio (DOR) of using GD as a triage symptom prior to RT-PCR.

METHODS

PubMed and Embase were searched up to 20 June 2021. Studies published in English were included if they compared the frequency of GD in COVID-19 adult patients (proven by RT-PCR) to COVID-19 negative controls in case control or cross-sectional studies. The Newcastle-Ottawa scale was used to assess the methodological quality of the included studies.

RESULTS

21,272 COVID-19 patients and 52,298 COVID-19 negative patients were included across 44 studies from 21 countries. All studies were of moderate to high risk of bias. Patients with GD were more likely to test positive for COVID-19: DOR 6.39 (4.86-8.40), LR+ 3.84 (3.04-4.84), LR- 0.67 (0.64-0.70), pooled sensitivity 0.37 (0.29-0.47) and pooled specificity 0.92 (0.89-0.94). While history/questionnaire-based assessments were predictive of RT-PCR positivity (DOR 6.62 (4.95-8.85)), gustatory testing was not (DOR 3.53 (0.98-12.7)). There was significant heterogeneity among the 44 studies (I2 = 92%, p < 0.01).

CONCLUSIONS

GD is useful as a symptom to determine if a patient should undergo further testing, especially in resource-poor regions where COVID-19 testing is scarce. Patients with GD may be advised to quarantine while repeated testing is performed if the initial RT-PCR is negative.

FUNDING

None.

Time course and clinical characterization of cisplatin-induced ototoxicity after treatment for nasopharyngeal carcinoma in a South East Asian population

BACKGROUND

The purpose of this study was to characterize the clinical course of hearing loss in patients with nasopharyngeal carcinoma (NPC) and the clinical factors affecting its severity.

METHODS

The time course of hearing loss in patients with NPC was assessed using threshold shift from baseline and Common Terminology Criteria for Adverse Events (CTCAE) grade.

RESULTS

In the chemoradiotherapy (CRT) groups, the threshold shift was significantly higher from 3 months at 4 kHz (P = 2.30 × 10^-9 , concurrent CRT only) but not within 2 years posttreatment in the radiotherapy (RT) group. The CRT groups had worse CTCAE grades than the RT group (percentage of latest CTCAE grade ≥1: 64.9% vs 29.0%, respectively). Cumulative cisplatin dose and cochlear RT dose significantly affects threshold shifts, especially at high frequencies.

CONCLUSION

Although cisplatin led to high frequency hearing impairment from about 3 months posttreatment, RT conferred no significant hearing impairment in the first 2 years.

Possible influences of ginseng on the pharmacokinetics and pharmacodynamics of warfarin in rats

We evaluated the significance of a reported clinical case of drug-drug interaction between ginseng and warfarin using a robust pharmacokinetic/pharmacodynamic approach in a rat model. The influence of ginseng on the pharmacokinetics and pharmacodynamics of oral warfarin after a single dose (2 mg kg(-1)) and at steady state (0.2 mg kg(-1) daily x 6 days) was studied in male Sprague-Dawley rats. Prothrombin time was employed as a pharmacodynamic index. Warfarin plasma concentration and vitamin K content in the ginseng extract were assessed by validated HPLC assays. The pharmacokinetics of warfarin after a single dose were not altered in the presence of ginseng; peak plasma concentration (control 7.8+/-0.5; ginseng 7.3+/-2.5 microg mL(-1)), time to peak (control 2.6+/-1.0; ginseng 3.1+/-1.1 h), elimination half-life (control 14.3+/-5.8; ginseng 10.6+/-3.1 h), and oral clearance (control 17.5+/-3.3; ginseng 20.2+/-5.5 mL h(-1)) were not significantly different (P>0.05). Similarly, alterations in the pharmacokinetics of warfarin were not detected under the multiple dosing paradigm. Under both dosing conditions, ginseng also showed no significant impact on the pharmacodynamics of warfarin as assessed by the area under the prothrombin time vs time curve (multiple dosing; control 3776+/-619, ginseng 3830+/-362 sh) and maximum prothrombin time (control 57.2+/-11.8, ginseng 63.3+/-9.1 s). Furthermore, the content of vitamin K was undetectable in the ginseng decoction. In conclusion, current data obtained in the rat showed no significant impact of ginseng on the pharmacokinetics/pharmacodynamics of warfarin when they are concomitantly administered.

Malignant large-cell non-Hodgkin's lymphoma of the spleen

Primary malignant tumours of the spleen are rare, with non-Hodgkin's lymphoma being the most common. A case of malignant large-cell lymphoma of the spleen in a patient with unexplained splenomegaly, is presented. There are very few previous reports on this condition in the radiological literature. The sonographic, computed tomographic and angiographic findings are described, with a brief review of the literature on this condition. Although there are no specific radiological findings to diagnose this condition, it has to be considered in the differential diagnosis of a solitary lesion in the spleen.

Cavernous transformation of the portal vein--sonographic findings

Cavernous transformation of the portal vein may be seen following portal vein thrombosis. Ultrasound is a useful non-invasive procedure for demonstrating many abnormalities of the portal vein and surrounding structures. Two cases of cavernous transformation of the portal vein, diagnosed by ultrasonography, are presented.

A scanning and transmission electron microscopic study of the membranes of chicken egg

Questions regarding the structure of the inner and outer shell membranes of the chicken egg were addressed in this study by correlating observations from light microscopy and scanning and transmission electron microscopy. The egg membrane had a limiting membrane, which measured .9 to .15 microns in thickness and appeared to be a continuous and an impervious layer, but the shell membrane did not. Under the SEM, each membrane was seen to be made up of several fibre layers. In the tear preparations viewed under the SEM two layers were observed in the egg membranes and three to five layers in the shell membrane, with an apparent plane of cleavage between each layer. Each fibre was made up of a central core and an outer mantle layers. The central core was perforated by channels which measured .08 to 1.11 microns in diameter and ran longitudinally along the length of the fibre. Between the mantle layer and the fibre core was a gap or cleft measuring between .03 to .07 microns. The diameter of the fibres of the inner layer of the egg membrane ranged between .08 to .64 microns, whereas those of the outer layer of the same membrane ranged from .05 to 1.11 microns. Fibres in the shell membrane ranged from .11 to 4.14 microns diameter.