Association Between Nonoptimal Blood Pressure and Cochlear Function

Relationship between hypertension/blood pressure and hearing sensitivity among drivers: A correlation analysis

BACKGROUND

One of the most common chronic diseases is hypertension. The majority of research has linked hearing loss to hypertension. However, the relationship between hypertension and hearing is still unknown. The primary goal of the study is to investigate the effect of hypertension on hearing and to find out the association between blood pressure levels and auditory health in auto-rickshaw drivers.

MATERIALS AND METHODS

The study utilized 121 healthy professional auto-drivers between the age range of 25 and 55 years. Pure-tone audiometry (PTA) and extended high-frequency audiometry (EHFA) were used to determine the participants' hearing thresholds from 0.25 to 16 kHz. The cochlear hair cell functioning was evaluated using distortion-product otoacoustic emission (DPOAE) testing. Blood pressure (mmHg) measurements were categorized under hypertension stage (normal (120; <80); elevated (120-129; <80); hypertension - stage 1 (130-139; 80-89); hypertension - stage 2 (≥140; ≥90)).

RESULTS

The mean age of the study participants was 42.17 ± 9.03 years. The mean systolic and diastolic BP of all the study participants were 138.24 ± 19.73 (105-216) mmHg and 87.69 ± 12.14 (60-134) mmHg, respectively. BP levels were normal for 17.4% (N = 21) of the study participants, 21.5% (N = 26) had elevated blood pressure, 21.5% (N = 26) of the population falls under stage 1 hypertension, and 39.7% (N = 48) had stage 2 hypertension. Our study discovered a significant difference between main group effects and no significant difference between group interaction effects. Hearing thresholds were significantly higher in hypertensive participants compared to non-hypertensive participants. However, there was no statistically significant relationship between the two variables hypertension and hearing loss.

CONCLUSION

Implementing health promotion initiatives and raising awareness about hearing health could improve the quality of life for a high-risk occupational group of drivers.

Hypertension Associated With Hearing Loss and Tinnitus Among Hypertensive Adults at a Tertiary Hospital in South Africa

Introduction

Hypertension is one of the leading causes of morbidity and mortality worldwide, and has been associated with target organ damage. Effects of hypertension on the auditory system are varied and requires further investigation. This study aimed to investigate the association between hypertension and auditory deficits (hearing loss and tinnitus).

Methods

This study employed a cross-sectional study including 106 (54.7% female) hypertensive adults aged 18–55 years, and 92 (52.2% female) non-hypertensive sex- and age-matched adults residing in South Africa. A data extraction sheet was used to obtain hypertension information from participants' medical files, and to subjectively obtain tinnitus status and characteristics among participants. Participants' hearing sensitivity—including extended high frequencies (EHF)—were measured using a diagnostic audiometer. The χ2 test determined the difference in auditory deficit prevalence between the study groups. Logistic regression was used to identify predictor variables associated with auditory deficits in the hypertensive group.

Results

A hearing loss prevalence of 37.4% among hypertensive adults compared to 14.1% among the non-hypertensive group (P = 0.000, χ2 = 14.00) was found. The EHF pure-tone average among the hypertensive group was 44.1 ± 19.2 dB HL, and 20.0 ± 18.3 dB HL among the control group. Bilateral mild sensorineural hearing loss was the most common type of hearing loss among hypertensive adults. A higher prevalence of tinnitus (41.5%) was found in the hypertensive group compared to the control group (22.8%) (P = 0.008, χ2 = 7.09). In this study, 30.3% of hypertensive adults had tinnitus without hearing loss compared to 17.7% non-hypertensive adults. Factors associated with hearing loss included being between 50 and 55 years [adjusted Odds Ratio (AOR) = 3.35; 95% Confidence Interval (CI): 1.32–8.50; P = 0.011], having grade 2 hypertension (AOR = 4.18; 95% CI: 1.02–17.10; P = 0.048), and being on antihypertensive medication (AOR = 3.18; 95% CI: 1.02–9.87; P = 0.045). Tinnitus was associated with grade 3 hypertension (AOR = 3.90; 95% CI: 1.12–12.64; P = 0.033).

Conclusions

Our study showed that hypertensive adults had a higher proportion of hearing loss and tinnitus compared to non-hypertensive adults. Findings suggest an association between hypertension and auditory deficits, demonstrating a need for integration of hearing healthcare services for hypertension management.

Electrocochleography and Auditory Brainstem Responses in Persons with Non-Optimal Blood Pressure

BACKGROUND

Numerous cardiometabolic factors may underlie risk of hearing loss. Modifiable risk factors such as non-optimal blood pressure (BP) are of interest.

PURPOSE

To investigate early auditory evoked potentials (AEPs) in persons with nonoptimal BP.

RESEARCH DESIGN

A cross-sectional nonexperimental study was performed.

STUDY SAMPLE

Fifty-two adults (18-55 years) served as subjects. Individuals were classified as having optimal (systolic [S] BP < 120 and diastolic [D] BP < 80 mm Hg, n = 25) or non-optimal BP (SBP ≥=120 or DBP ≥=80 mm Hg or antihypertensive use, n = 27). Thirteen subjects had hypertension (HTN) (SBP ≥130 or DBP ≥80 mm Hg or use of antihypertensives).

DATA COLLECTION AND ANALYSIS

Behavioral thresholds from 0.25 to 16 kHz were collected. Threshold auditory brain stem responses (ABRs) were recorded using rarefaction clicks (17.7/second) from 80 dB nHL to wave V threshold. Electrocochleograms were obtained with 90 dB nHL 7.1/second alternating clicks and assessed for summating and compound action potentials (APs). Outcomes were compared via independent samples t tests. Linear mixed effects models for behavioral thresholds and ABR wave latencies were constructed to account for potential confounders.

RESULTS

Wave I and III latencies were comparable between optimal and non-optimal BP groups. Wave I was prolonged in hypertensive versus optimal BP subjects at stimulus level 70 dB nHL (p = 0.016). ABR wave V latencies were prolonged in non-optimal BP at stimulus level 80 dB nHL (p = 0.048) and in HTN at levels of 80, 50, and 30 dB nHL (all p < 0.050). DBP was significantly correlated with wave V latency (r = 0.295; p = 0.039). No differences in ABR amplitudes were observed between optimal and non-optimal BP subjects. Electrocochleographic study showed statistically comparable action and summating potential amplitudes between optimal and non-optimal BP subjects. AP latencies were also similar between the groups. Analysis using a set baseline amplitude of 0 μV showed that hypertensive subjects had higher summating (p = 0.038) and AP (p = 0.047) amplitudes versus optimal BP subjects; AP latencies were comparable.

CONCLUSION

Elevated BP and more specifically, HTN was associated with subtle AEP abnormalities. This study provides preliminary evidence that nonoptimal BP, and more specifically HTN, may be related to auditory neural dysfunction; larger confirmatory studies are warranted.