Diabetes mellitus and the incidence of hearing loss: a cohort study

Associations between diabetes mellitus and sensorineural hearing loss from humans and animal studies

There is controversy regarding the association and etiopathogenesis of diabetes mellitus (DM) and sensorineural hearing loss (SNHL). Some studies support that SNHL develops because of angiopathy and/or neuropathy caused by DM, but many of the findings have been inconsistent. This review aims to highlight a select number of studies that effectively describe the relationship between DM and SNHL, thus bringing more attention and awareness to this area of research. This review also describes animal models to understand better the mechanisms of DM contributing to SNHL in the inner ear. The goal of this narrative review is for researchers and healthcare professionals to further their understanding and investigation of the etiopathogenesis of both DM and SNHL, therefore leading to the development of effective treatments for diabetic patients displaying symptoms of SNHL.

Polygenic Risk Score Modifies the Association of HbA1c With Hearing Loss in Middle-Aged and Older Chinese Individuals: The Dongfeng-Tongji Cohort

OBJECTIVE

Evidence regarding the modifying effect of the polygenic risk score (PRS) on the associations between glycemic traits and hearing loss (HL) was lacking. We aimed to examine whether these associations can be influenced by genetic susceptibility.

RESEARCH DESIGN AND METHODS

This cross-sectional study included 13,275 participants aged 64.9 years from the Dongfeng-Tongji cohort. HL was defined according to a pure tone average >25 dB in the better ear and further classified by severity. Prediabetes and type 2 diabetes (T2D) were defined based on the 2013 criteria from the American Diabetes Association. A PRS was derived from 37 single nucleotide polymorphisms associated with HL. Multivariable logistic regression models were fitted to estimate the associations of PRS and glycemic traits with HL and its severity.

RESULTS

Elevated fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), and T2D were positively associated with higher HL risks and its severity, with odds ratios (ORs) ranging from 1.04 (95% CI 1.00, 1.08) to 1.25 (95% CI 1.06, 1.46). We also found significant interaction between HbA1c and PRS on risks of overall HL and its severity (P for multiplicative interaction <0.05), and the effects of HbA1c on HL risks were significant only in the group with high PRS. Additionally, compared with normoglycemia in the group with low PRS, T2D was associated with an OR of up to 2.00 and 2.40 for overall HL and moderate to severe HL, respectively, in the group with high PRS (P for additive interaction <0.05).

CONCLUSIONS

PRS modifies the association of HbA1c with HL prevalence among middle-aged and older Chinese individuals.

Association Between Hearing Loss, Asymmetric Hearing, and Postural Instability

OBJECTIVES

Recent studies have suggested that older adults with hearing loss (HL) are at a greater risk of postural instability than those with normal hearing. However, little is known regarding this association in middle-aged individuals. The relationships between HL laterality, asymmetric hearing, and posture control are similarly unclear. The purpose of this study was to investigate the effects of hearing status on postural control and to explore the dose-response relationship between the hearing threshold and postural instability risk in middle-aged adults.

DESIGN

This cross-sectional study included 1308 participants aged 40 to 69 years with complete audiometric and standing balance function data from the 2001-2004 National Health and Nutrition Examination Survey. Speech-frequency HL was defined as a pure-tone average at 0.5, 1, 2, and 4 kHz of >25 dB in the better-hearing ear; high-frequency HL was defined as a pure-tone average at 3, 4, and 6 kHz of >25 dB. Asymmetric hearing was defined as a difference in the pure-tone average >15 dB between ears. Postural instability was defined as participants ending the modified Romberg test in condition 4.

RESULTS

After adjustment for sociodemographic variables, lifestyle, and comorbidities, speech-frequency HL, except for unilateral HL, was associated with increased postural instability (mild HL: odds ratio [OR], 2.33; 95% confidence interval [CI], 1.25-4.35; moderate-to-severe HL: OR, 3.59; 95% CI, 1.61-8.03). Compared with individuals with normal bilateral hearing, participants with bilateral HL also showed a higher risk of postural instability (OR, 2.88; 95% CI, 1.61-5.14). The OR for postural instability among participants with asymmetric hearing compared with those with symmetric hearing was 2.75 (95% CI, 1.37-5.52). Furthermore, each 10 dB increase in the speech-frequency hearing threshold was associated with a 44% higher risk of postural instability.

CONCLUSIONS

Hearing loss is associated with poorer postural control. Individuals with asymmetric hearing have a higher postural instability risk compared with those with symmetric hearing. Further studies are needed to confirm these findings and the causality. Moreover, future studies are warranted to assess whether hearing aids are beneficial for the restoration of impaired balance functions.

Longitudinal urinary neopterin is associated with hearing threshold change over time in independent older adults

Low-grade chronic inflammation is associated with many age-related conditions. Non-invasive methods to monitor low-grade chronic inflammation may improve the management of older people at risk of poorer outcomes. This longitudinal cohort study has determined baseline inflammation using neopterin volatility in monthly urine samples of 45 independent older adults (aged 65-75 years). Measurement of neopterin, an inflammatory metabolite, enabled stratification of individuals into risk categories based on how often in a 12-month period their neopterin level was raised. Hearing was measured (pure-tone audiometry) at baseline, 1 year and 3 years of the study. Results show that those in the highest risk category (neopterin raised greater than 50% of the time) saw greater deterioration, particularly in high-frequency, hearing. A one-way Welch's ANOVA showed a significant difference between the risk categories for change in high-frequency hearing (W (3, 19.6) = 9.164, p = 0.0005). Despite the study size and duration individuals in the highest risk category were more than twice as likely to have an additional age-related morbidity than those in the lowest risk category. We conclude that volatility of neopterin in urine may enable stratification of those at greatest risk of progression of hearing loss.

Diabetes and long duration leading to speech-, low/mid-, and high- frequency hearing loss: current evidence from the China National Health Survey 2023

PURPOSE

To examine the effect of diabetes, duration of diabetes, and blood glucose on speech-, low/mid-, and high-frequency hearing loss.

METHODS

In this cross-sectional study, 2821 participants aged 20-87 years in the China National Health Survey were included. Diabetes was defined as valid fasting blood glucose (FBG) of ≥ 7.0 mmol/L, a self-reported history of diabetes or the use of anti-diabetic medications. Speech-(500, 1000, 2000, and 4000 Hz), low/mid- (500, 1000 and 2000 Hz), and high-frequency (4000, 6000, and 8000 Hz) hearing loss was defined as pure tone average of responding frequencies > 20 dB HL in the better ear, respectively.

RESULTS

In fully adjusted models, for speech-, low/mid-, and high-frequency hearing loss, compared with no diabetes, those with diabetes (OR[95%CI]: 1.44 [1.12, 1.86], 1.23 [0.94, 1.61], and 1.75 [1.28, 2.41], respectively) and with diabetes for > 5 years duration (OR[95%CI]: 1.63 [1.09, 2.42], and 1.63 [1.12, 2.36], 2.15 [1.25, 3.70], respectively) were at higher risk. High FBG level was associated with a higher risk of speech-, low/ mid-, and high-frequency hearing loss. And there were stronger associations between HL and diabetes, longer duration and higher in "healthier population" (no hypertension, no dyslipidemia and younger age).

CONCLUSION

Diabetes, longer duration, and higher FBG level were independently associated with hearing loss for speech-, low/mid- and high-frequency hearing loss, particularly in higher frequency and "healthier population". Paying more attention to hearing loss in those populations could lower the burden of hearing loss.

Effects of cooking with solid fuel on hearing loss in Chinese adults-Based on two cohort studies

The association between cooking fuel and hearing loss still needs more research to clarify, and two longitudinal cohort studies were explored to find if solid fuel use for cooking affected hearing in Chinese adults. The data from Chinese Health and Retirement Longitudinal Survey (CHARLS) and Chinese Longitudinal Healthy Longevity Survey (CLHLS) were analyzed. Participants (older than 18) without hearing loss at baseline and follow-up visits were included, which were divided into clean fuel and solid fuel groups. Hearing loss rate was from follow-up visits (both in year 2011) until the recent one (year 2018 in CHARLS and 2019 in CLHLS). Cox regressions were applied to examine the associations with adjustment for potential confounders. Fixed-effect meta-analysis was used to pool the results. A total of 9049 participants (average age 8.34 ± 9.12 [mean ± SD] years; 4247 [46.93%] males) were included in CHARLS cohort study and 2265 participants (average age, 78.75 ± 9.23 [mean ± SD] years; 1148 [49.32%] males) in CLHLS cohort study. There were 1518 (16.78%) participants in CHARLS cohort and 451 (19.91%) participants in CLHLS cohort who developed hearing loss. The group of using solid fuel for cooking had a higher risk of hearing loss (CHARLS: HR, 1.16; 95% CI 1.03-1.30; CLHLS: HR, 1.43; 95% CI 1.11-1.84) compared with the one of using clean fuel. Pooled hazard ratio showed the incidence of hearing loss in the solid fuel users was 1.17 (1.03, 1.29) times higher than that of clean fuel users. Hearing loss was associated with solid fuel use and older people were at higher risk. It is advised to replace solid fuel by clean fuel that may promote health equity.

Prevalence and Associated Factors of Sensorineural Hearing Impairment Among Patients with T2DM in Amhara Region, Northwest Ethiopia, 2022: A Multi-Centered Cross-Sectional Study

Background

Generally, people with type 2 diabetes mellitus in various countries experience a significant rate of sensorineural hearing impairment. Nonetheless, there is scant evidence of sensorineural hearing impairment among type 2 diabetes mellitus patients in Northwest Ethiopian. Therefore, the objective of this study was to evaluate the occurrence rate and contributing factors of sensorineural hearing impairment in type 2 diabetics at comprehensive and specialized referral hospitals in Northwest Ethiopia.

Methods

A facility-based cross-sectional study design was carried out from May 3, 2022, to June 14, 2022, on 846 study participants in Ethiopia, with a response rate of 99.65%. The research subjects were chosen by simple random sampling techniques. Data was gathered by using audiometric measurements and structured interview-administered questionnaires and then entered into EPI data version 4.6. Finally, it was exported to STATA 14 for analysis. Binary logistic regression, chi-square test, and odds ratio were done to verify the assumptions and degree of association. Ultimately, factors exhibiting a p-value < 0.05 with a 95% CI were regarded as significant predictors of hearing impairment.

Results

The magnitude of sensorineural hearing impairment in this investigation was 50.49% (95% CI: 45.67%, 55.26%). Factors significantly associated with sensorineural hearing impairment were age (AOR=1.10, 95% CI: 1.07, 1.14), hyperlipidemia (AOR=2.86, 95% CI: 1.05, 7.82), duration of diabetes (AOR=2.26, 95% CI: 1.26, 4.06), hypertension (AOR=1.94, 95% CI: 1.02, 3.69) and regular physical exercise (AOR=0.25, 95% CI: 0.09, 0.68).

Conclusions and Recommendations

In this study, relatively high rates of sensorineural hearing impairment were observed. Stakeholders should establish routine hearing screening, and participants will advise to incorporate regular physical exercise into their routines.

Sex differences in associated factors for age-related hearing loss

The prevalence and age of onset of hearing loss differ according to sex. This study aimed to identify associated factors for age-related hearing loss (ARHL) and determine whether there are differences between males and females regarding associated factors for ARHL. This cross-sectional study used data from adults who underwent medical examinations including hearing tests from 2011 to 2021. A total of 2,349 individuals were included. The study conducted sex-specific analyses using both univariate and multiple regression. Univariate analysis employed logistic regression, while multiple regression involved variable selection through the augmented backward elimination method. Separate multiple logistic regression analyses were conducted for each sex. In the univariate analysis, among males, age, underweight, alcohol consumption, weight, and height exhibited statistical significance. Among females, age, hypertension, diabetes, dyslipidemia, obesity, sarcopenia, weight, height, age at menarche, and duration of hormone exposure were found to be significant factors. However, in the multiple logistic regression model for males, underweight, and smoking emerged as significant, while in females, age, weight, obesity, and age at menarche retained their significance. We found that there are different associated factors for ARHL in each sex. Assessment and counseling for smoking, obstetric history, underweight, and obesity may be beneficial in managing patients with ARHL.

Establishing multifactorial risk factors for adult-onset hearing loss: A systematic review with topic modelling and synthesis of epidemiological evidence

BACKGROUND

This systematic review explores the multifaceted nature of risk factors contributing to adult-onset HL. The objective was to synthesise the most recent epidemiological evidence to generate pooled proportional incidences for the identified risk factors.

METHODS

We conducted an extensive search of electronic databases (MEDLINE, EMBASE, and psychINFO) for studies providing epidemiological evidence of risk factors associated with hearing loss. Topic modelling using Latent Dirichlet Allocation (LDA) was first conducted to determine how many risk factor themes were available from the papers. Data were analysed by calculating the pooled proportional incidence using a meta-analysis of proportions.

RESULTS

From the 72 studies reviewed, six key risk factor themes emerged through LDA topic modelling. The review identified ototoxicity, primarily caused by cancer treatments and antibiotics, infectious diseases like COVID-19, occupational noise exposure, lifestyle factors, health conditions, biological responses, and age progression as significant risk factors for HL. The highest proportional incidence was found with cancer-related ototoxicity at 55.4% (95%CI: 39.0-70.7), followed closely by ototoxicity from infectious diseases at 50.0% (95%CI: 28.5-71.5). This high proportional incidence suggests the need to explore less destructive therapies and proactively monitor hearing function during treatments.

CONCLUSIONS

The findings of this review, combined with the synthesis of epidemiological evidence, enhance our understanding of hearing loss (HL) pathogenesis and highlight potential areas for intervention, thereby paving the way for more effective prevention and management of adult-onset hearing loss in our ageing global population.

Cardiometabolic diseases according to the type and degree of hearing loss in noise-exposed workers

Background

This study aimed to determine the association between cardiometabolic diseases, including metabolic syndrome, hypertension, and diabetes, and the type and degree of hearing loss in noise-exposed workers.

Methods

A total of 237,028 workers underwent air conduction pure tone audiometry in 2015 to assess their health and diagnose cardiometabolic diseases. The study defined metabolic syndrome, hypertension, and diabetes using blood pressure, fasting blood sugar, cholesterol, and triglyceride levels. Mid-frequency hearing loss was defined as ≥ 30 dB at 2,000 Hz, whereas high-frequency hearing loss was ≥ 40 dB at 4,000 Hz. The average air conduction hearing thresholds at these frequencies were used to determine hearing loss degrees.

Results

The odds ratio (OR) of combined exposure to noise and night-shift work in all cardiometabolic diseases was higher than that of noise exposure alone. The risk of cardiometabolic diseases was dose-response, with higher hearing loss causing higher ORs. The ORs of hypertension compared with the normal group were 1.147 (1.098-1.198), 1.196 (1.127-1.270), and 1.212 (1.124-1.306), and those of diabetes were 1.177 (1.119-1.239), 1.234 (1.154-1.319), and 1.346 (1.241-1.459) for mild, moderate, and moderate-severe hearing loss, respectively.

Conclusions

Workers who are exposed to noise tend to demonstrate high risks of hearing loss and cardiometabolic diseases; thus, bio-monitoring of cardiometabolic diseases, as well as auditory observation, is necessary.

Non-invasive blood glucose monitoring technology in diabetes management: review

Diabetes is one of the leading non-communicable diseases globally, adversely impacting an individual's quality of life and adding a considerable burden to the healthcare systems. The necessity for frequent blood glucose (BG) monitoring and the inconveniences associated with self-monitoring of BG, such as pain and discomfort, has motivated the development of non-invasive BG approaches. However, the current research progress is slow, and only a few BG self-monitoring devices have made considerable progress. Hence, we evaluate the available non-invasive glucose monitoring technologies validated against BG recordings to provide future research direction to design, develop, and deploy self-monitoring of BG with integrated emerging technologies. We searched five databases, Embase, MEDLINE, Proquest, Scopus, and Web of Science, to assess the non-invasive technology's scope in the diabetes management paradigm published from 2000 to 2020. A total of three approaches to non-invasive screening, including saliva, skin, and breath, were identified and discussed. We observed a statistical relationship between BG measurements obtained from non-invasive methods and standard clinical measures. Opportunities exist for future research to advance research progress and facilitate early technology adoption for healthcare practice. The results promise clinical validity; however, formulating regulatory guidelines could foresee the deployment of approved non-invasive BG monitoring technologies in healthcare practice. Further, research prospects are there to design, develop, and deploy integrated diabetes management systems with mobile technologies, data analytics, and the internet of things (IoT) to deliver a personalised monitoring system.

Clinical Observations in Patients With Cystic Fibrosis-Related Diabetes and Self-Reported Ototoxicity Symptoms

PURPOSE

Persons with cystic fibrosis (PwCF) are at high risk for ototoxicity due to the routine use of intravenous aminoglycoside (IV-AG) antibiotics in respiratory infection management. Additionally, factors that contribute to ototoxicity-related symptom development and severity in PwCF are unknown. Given the increased risk of ototoxicity in people with diabetes, we explored the association between cystic fibrosis-related diabetes (CFRD) and self-reported ototoxicity symptoms (tinnitus and vestibular problems) in PwCF treated with aminoglycosides.

METHOD

PwCF (N = 39; 25 females, 14 males; Mage = 30.1 years, SD = 10.3) were recruited from the Cystic Fibrosis Care Center at Oregon Health & Science University. Patients completed the validated questionnaires to ascertain their experiences with ototoxicity-related symptoms of tinnitus and balance function. The diagnosis of CFRD, including oral glucose tolerance testing (OGTT), insulin treatment, hemoglobin A1c, and cumulative IV-AG treatment history, was obtained through a medical chart review. Participants were classified into three groups based on their medical diagnoses via OGTT: normal glucose tolerance (NGT; control; n = 16), abnormal glucose tolerance (AGT; n = 9), and CFRD (n = 14). Participants in each group were further classified based on survey outcomes for ototoxicity-related symptoms.

RESULTS

There was a trend toward a higher proportion of patients with CFRD reporting tinnitus compared to the AGT and NGT groups, but did not meet statistical significance (X2 = 2.24, p = .13). Approximately, 43% of patients with CFRD reported experiencing clinically significant tinnitus lasting > 3 min compared to 11% in the AGT group and 13% in the NGT group (X2 = 3.751, p = .05). Cumulative IV-AG exposure tended to be higher in CFRD compared to other groups. High balance function was generally reported in all groups.

CONCLUSIONS

Patients with CFRD have greater ototoxicity-related symptoms. Further investigation of the relationship between CF-related comorbidities and the risk of developing ototoxicity-related symptoms is warranted to improve the detection and management of ototoxicity in PwCF.

Association between HbA1c and hearing loss: a tertiary care center-based study

The purpose of this study was to investigate the correlation between glycated hemoglobin (HbA1c) levels and hearing loss (HL) using data from a tertiary hospital. Our hypothesis regarding the relationship between HL and HbA1c levels was that elevated HbA1c levels are associated with an increased risk of HL. We retrospectively reviewed the medical charts of patients diagnosed with sensorineural HL or diabetes between 2006 and 2021 at the Catholic Medical Center (CMC). Data were collected from the CMC's Clinical Data Warehouse. Participants were selected from patients who were prescribed pure-tone audiometry and an HbA1c blood test. The survey was completed for 5287 participants. The better ear pure-tone audiometry (PTA) for air conduction thresholds at 500, 1000, 2000, and 4000 Hz was calculated. Sensorineural HL was defined as a better ear PTA of 25 dB or higher. We used the HbA1c level as a diagnostic criterion for diabetes. The following criteria were used to define the HbA1c level: normal, HbA1c level below 5.6%; prediabetes, level between 5.6 and 6.4%; and diabetes, level of 6.5% or more. Among 5287 participants, 1129 were categorized as normal, 2119 as prediabetic, and 2039 as diabetic. The diabetic group was significantly older (p < 0.05). The PTA also significantly deteriorated in the diabetes group (p < 0.05). We analyzed the effects of age, sex, and HbA1c level on frequency-specific hearing using multiple regression. The hearing thresholds at all frequencies deteriorated significantly with increasing age and HbA1c level (p < 0.05). A case-control study was also performed to facilitate a comprehensive comparison between distinct groups. The participants were categorized into two groups: a case (PTA > 25 dB) and control group (PTA ≤ 25 dB), based on their PTA threshold of four frequencies. After adjusting for age and sex, we found no significant odds ratio (OR) of HL between the prediabetes group and the normal group. Notably, the OR of HL was significantly higher in the diabetes group with each PTA threshold and frequency. The 6.3% HbA1c level cutoff value was determined by analyzing the receiver operating characteristic curve for predicting hearing impairment > 25 dB. Diabetes was associated with hearing loss in all frequency ranges, particularly at high frequencies. Screening for HL is strongly recommended for patients with elevated HbA1c levels.

Evaluation of outcome of acoustic reflex tests in patients with type 2 diabetes mellitus: a cross-sectional study

PURPOSE

Type 2 diabetes mellitus (T2DM) may induce micro-vascular and macro-vascular changes that can lead to neuropathic changes which may affect the auditory pathway resulting in hearing loss. The study aims to evaluate the outcome of ipsilateral and contralateral acoustic reflex (AR) parameters and reflex decay tests (RDT) in patients with T2DM, and the relationship between average AR parameters, and duration and control of T2DM.

METHODS

An analytical cross-sectional study was conducted in a tertiary care setup in 126 subjects which included 42 subjects with T2DM between 30 and 60 years of age, age-matched with 84 non-diabetic subjects. The subjects were evaluated for pure tone average (PTA), speech identification score (SIS), AR parameters [acoustic reflex threshold (ART), acoustic reflex amplitude (ARA), acoustic reflex latency (ARL)] and RDT.

RESULTS

The subjects with T2DM showed increased PTA in both ears when compared to the subjects with no disease. No significant difference was found in the SIS between both groups. There was no significant difference in the ART and ARL between the two groups. There was a significant difference in the ipsilateral and contralateral ARA at 500 Hz, 1000 Hz and broadband noise (BBN) when compared between the diabetic and non-diabetic groups. No significant difference was found between average AR parameters and duration and control of T2DM.

CONCLUSION

T2DM increases hearing thresholds and reduces ipsilateral and contralateral AR at lower frequencies and BBN. Duration and control of T2DM do not affect the AR parameters.

Machine Learning Prediction of Objective Hearing Loss With Demographics, Clinical Factors, and Subjective Hearing Status

OBJECTIVE

Hearing loss (HL) is highly prevalent, yet underrecognized and underdiagnosed. Lack of standardized screening, awareness, cost, and access to hearing testing present barriers to HL identification. To facilitate prescreening and selection of patients who warrant audiometric evaluation, we developed a machine learning (ML) model to predict speech-frequency pure-tone average (PTA).

STUDY DESIGN

Cross-sectional study.

SETTING

National Health and Nutrition Examination Survey (NHANES).

METHODS

The cohort included 8918 adults (≥20 years) who completed audiometric testing with NHANES (2012-2018). The primary outcome measure was the prediction of better hearing ear speech-frequency PTA. Relevant predictors included demographics, medical conditions, and subjective assessment of hearing. Supervised ML with a tree-based architecture was used. Regression performance was determined by the mean absolute error (MAE) with binary classification assessed with area under the receiver operating characteristic curve (AUC).

RESULTS

Using the full set of predictors, the test set MAE between the ML-predicted and actual PTA was 5.29 dB HL (95% confidence interval [CI]: 4.97-5.61). The 5 most influential predictors of higher PTA were increased age, worse subjective hearing, male gender, increased body mass index, and history of smoking. The 5-factor abbreviated model performed comparably to the extended feature set with MAE 5.36 (95% CI: 5.03-5.69) and AUC for PTA > 25 dB HL of 0.92 (95% CI: 0.90-0.94).

CONCLUSION

The ML model was able to predict PTA with patient demographics, clinical factors, and subjective hearing status. ML-based prediction may be used to identify individuals who could benefit most from audiometric evaluation.

The Adverse Effects Profile of Teprotumumab

CONTEXT

Teprotumumab therapy for thyroid eye disease (TED) patients represents a major step forward. It targets and inhibits the insulin-like growth factor-1 receptor (IGF-1R), and its effectiveness is based on its interconnectedness with the thyrotropin receptor. However, IGF-1R has a ubiquitous expression and several adverse effects have been reported with teprotumumab use.

OBJECTIVE

Describing these adverse effects for better understanding is the purpose of this review.

METHODS

We reviewed the oncological studies in which teprotumumab was initially used. Subsequently we reviewed the clinical trials for TED and then the case series and case reports associated with teprotumumab use since it is US Food and Drug Administration approval (January 2020). We focused on common and/or serious adverse effects reported with the use of teprotumumab.

RESULTS

We described the common occurrence of hyperglycemia (10%-30% incidence), its risk factors and suggested management. Hearing changes are described, a broad spectrum from mild ear pressure to hearing loss (sensorineural mechanism). Risk factors, suggested monitoring, and possible upcoming therapies are reviewed. We also reviewed data on fatigue, muscle spasms, hair loss, weight loss, gastrointestinal disturbances, menstrual changes, and infusion reactions. We noted some discrepancies between adverse effects in oncological studies vs studies focused on TED, and we aimed to explain these differences.

CONCLUSION

The use of teprotumumab should consider patient's values and preferences in balancing the expected benefit with these potential risks. Future drugs targeting IGF-1R should investigate these adverse effects for a possible class effect. Combination therapies with different agents hopefully will be identified that maximize benefits and minimize risks.

The Association Between Midlife Leisure-Time Physical Activity and Hearing Loss in Late Life in the Atherosclerosis Risk in Communities Study

BACKGROUND

Hearing loss is highly prevalent in older ages and has several health consequences. Some cardiovascular risk factors are associated with worse hearing at older ages. Still, the role of midlife leisure-time physical activity (PA) as a risk factor for hearing loss is yet to be investigated.

METHODS

Among 3 198 participants of the Atherosclerosis Risk in Communities study, we investigated the associations of midlife and change from mid- to late-life PA (assessed via modified Baecke questionnaire) with hearing loss (audiometric battery [worse-ear pure-tone average, and speech-in-noise test]) at older ages. We used regression analyses, adjusted for demographics, medical conditions, and noise exposure, to estimate differences in hearing between those who met and did not meet PA recommendations at midlife and at late life.

RESULTS

A total of 1 386 (43.3%) participants met PA recommendations at midlife. These participants, compared to those who did not meet recommendations, had lower (better) pure-tone average by 1.51 (0.46, 2.55) decibels, identified 0.37 (0.01, 0.74) more words (better score) in the speech-in-noise test, and had a lower relative risk of having hearing loss at older ages (eg, relative risk ratio for severe hearing loss vs normal hearing = 0.70 [0.52, 0.95]). Similarly, those who persistently met PA recommendations from mid- to late life had, compared with those who did not, a better hearing at older ages.

CONCLUSIONS

Meeting PA public health recommendations in midlife and mid- to late life was associated with better hearing at older ages and reduced risk of hearing loss. Promoting adequate levels of PA may be an essential component of hearing care.

The association of sex steroid hormone concentrations with hearing loss: a cross-sectional study

BACKGROUND

Hearing loss is the most prevalent sensory disorder worldwide. Several studies have indicated that sex steroid hormone levels may be vital to hearing.

OBJECTIVE

We aimed to explore the associations between speech-frequency hearing loss and sex steroid hormones.

METHODS

We conducted a secondary analysis based on 3558 adult participants' data from the National Health and Nutrition Examination Survey (NHANES) from 2015 to 2016. We defined hearing loss as a pure-tone average (PTA) at 0.5, 1, 2, and 4 kHz ≥20 dB in the better ear. Multivariate logistic regression analysis was used to evaluate the association between sex steroid hormones and hearing loss risk. A nomogram model for the risk of hearing loss was constructed.

RESULTS

There were 560 (15.7%) cases who had hearing loss among the participants enrolled in this study. Participants with hearing loss had a higher total testosterone level and a lower estradiol level. Individuals with estradiol levels in the highest tertile still had lower hearing loss risks than those in the lowest tertile. Nevertheless, the total testosterone level had no influence on the risk of hearing loss.

CONCLUSION

Our research indicated that low estradiol concentrations were significantly associated with hearing loss, especially in menopausal women.

Obesity and risk of hearing loss in the middle-aged and elderly: a national cohort of Chinese adults

BACKGROUND

The relationship between obesity and hearing loss among the middle-aged and older population remained unclear. Moreover, few studies have focused on the impact of gender on this association.

METHODS

This cohort study extracted the data from the China Health and Retirement Longitudinal Study, a national survey of adults aged 45 years or over. Waist circumference was categorized into three groups: normal, pre-central obesity, and central obesity. We classified BMI into four categories: underweight, normal weight, overweight, and obese. The primary endpoint was the incidence of self-reported hearing loss.

RESULTS

Of the 14,237 participants, 1972 incidents of hearing loss were identified during a median 6.9 years of follow-up. The cumulative incidence of hearing loss was 13.9% (95% CI 13.3% -14.4%). Our study showed that central obesity was significantly associated with hearing loss (HR 0.84, 95%CI 0.75-0.94), and this relationship was more prominent in males (HR 0.76, 95%CI 0.63-0.91). Among male participants, the underweight group was at the highest risk of hearing loss (HR 1.39, 95%CI 1.08-1.79). Compared with the normal weight group, the adjusted HR for hearing loss in the obese groups was 0.69 (95%CI 0.51-0.94) among men. Among female participants, only the overweight group had a lower risk of hearing loss than the normal weight group (HR 0.83, 95%CI 0.71-0.96).

CONCLUSIONS

Being overweight and obese were significantly associated with a decreased risk of hearing loss, whereas being underweight was associated with an increased risk of hearing loss.

A new paradigm of hearing loss and preservation with cochlear implants: Learnings from fundamental studies and clinical research

In 2010 Cochlear initiated a coordinated preclinical research program to identify the factors and underlying mechanisms of acoustic hearing loss following cochlear implantation and device use. At its inception the program was structured around several major hypotheses implicated in the loss of acoustic hearing. The understanding of causes evolved over the course of the program, leading to an increased appreciation of the role of the biological response in post-implant hearing loss. A systematic approach was developed which mapped the cochlear implant journey along a timeline that considers all events in an individual's hearing history. By evaluating the available data in this context, rather than by discrete hypothesis testing, causative and associated factors may be more readily detected. This approach presents opportunities for more effective research management and may aid in identifying new prospects for intervention. Many of the outcomes of the research program apply beyond preservation of acoustic hearing to factors important to overall cochlear health and considerations for future therapies.

The neuroprotective and antidiabetic effects of trigonelline: A review of signaling pathways and molecular mechanisms

The global epidemic of diabetes has brought heavy pressure on public health. New effective anti-diabetes strategies are urgently needed. Trigonelline is the main component of fenugreek, which has been proved to have a good therapeutic effect on diabetes and diabetic complications. Trigonelline achieves amelioration of diabetes, the mechanisms of which include the modulation of insulin secretion, a reduction in oxidative stress, and the improvement of glucose tolerance and insulin resistance. Besides, trigonelline has been reported to be a neuroprotective agent against many neurologic diseases including Alzheimer's disease, Parkinson's disease, stroke, and depression. Concerning the potential therapeutic effects of trigonelline, comprehensive clinical trials are warranted to evaluate this valuable molecule.

Evaluation of Disturbances in Hearing, Tinnitus, and Dizziness as Signs of COVID-19 Infection

BACKGROUND

There have been reports and studies indicating audiovestibular disturbances in COVID-19 patients with variations in the percentage of sensorineural hearing loss (SNHL). The purpose of this study is to compare the incidence of newly diagnosed SNHL, sudden idiopathic hearing loss (SIHL), tinnitus, and vestibular disturbances between infected and uninfected patients, as well as to identify population groups at risk.

METHODS

This study used TriNetX to obtain statistics on COVID-19 (+) and COVID-19 (-) patients from 61 healthcare organizations. Propensity score with 1:1 matching was used to control confounding variables. This study evaluated the relative risk of developing audiovestibular disturbances up to 1 month after a COVID-19 test and further investigated the incidence in COVID-19 (+) subset groups.

RESULTS

Between COVID-19 (+) and COVID-19 (-) patients who had an audiogram, there was no statistically significant difference in SNHL or SIHL (SNHL: relative risk [RR] = 0.69, 95% confidence interval [CI] = 0.46-1.04; SIHL: RR = 1.00, 95% CI = 0.42-2.40). Race/ethnicity or specified comorbidity did not affect the incidence of SNHL or SIHL. There was a statistically significant difference in tinnitus and vestibular disturbances between the COVID-19 (+) and the COVID-19 (-) groups (RR = 1.29, 95% CI = 1.01-1.66; RR = 2.33, 95% CI = 2.19-2.48).

CONCLUSION

New onset hearing loss is not more common in patients with a positive COVID-19 test than those with a negative COVID-19 test. Audiologic evaluation is needed to verify reported hearing disturbances. Although statistically significant in specific population groups, tinnitus and vestibular disturbances may not be clinically significant due to the low incidence.

Relationship of cardiovascular disease risk and hearing loss in a clinical population

Hearing loss has been associated with individual cardiovascular disease (CVD) risk factors and, to a lesser extent, CVD risk metrics. However, these relationships are understudied in clinical populations. We conducted a retrospective study of electronic health records to evaluate the relationship between hearing loss and CVD risk burden. Hearing loss was defined as puretone average (PTA_0.5,1,2,4) > 20 dB hearing level (HL). Optimal CVD risk was defined as nondiabetic, nonsmoking, systolic blood pressure (SBP) < 120 and diastolic (D)BP < 80 mm Hg, and total cholesterol < 180 mg/dL. Major CVD risk factors were diabetes, smoking, hypertension, and total cholesterol ≥ 240 mg/dL or statin use. We identified 6332 patients (mean age = 62.96 years; 45.5% male); 64.0% had hearing loss. Sex-stratified logistic regression adjusted for age, noise exposure, hearing aid use, and body mass index examined associations between hearing loss and CVD risk. For males, diabetes, hypertension, smoking, and ≥ 2 major CVD risk factors were associated with hearing loss. For females, diabetes, smoking, and ≥ 2 major CVD risk factors were significant risk factors. Compared to those with no CVD risk factors, there is a higher likelihood of hearing loss in patients with ≥ 2 major CVD risk factors. Future research to better understand sex dependence in the hearing loss-hypertension relationship is indicated.

Association between individual, household, and area-level socioeconomic status indicators and sensorineural hearing loss in adults in southwest Iran: a population-based study

Introduction

Hearing loss is the fourth most common chronic disease, but studies on the relationship between hearing loss and socioeconomic factors are limited. We aimed to examine the association between hearing loss and socioeconomic factors among 35-70 year adults in southwest Iran.

Materials and methods

This population-based cross-sectional study was conducted in the baseline of Hoveyzeh cohort study in adults aged 35-70 in southwest Iran between 2017 and 2021. Information on socioeconomic factors, demographic characteristics, comorbidities, family history of hearing loss, and noise exposure was collected. We assessed the relationship between three levels of socioeconomic factors (individual, household, and area level) with sensorineural hearing loss (SNHL). Multiple logistic regression was used to adjust the potential confounders.

Results

Among a total of 1,365 assessed participants, 485 patients were diagnosed as having hearing loss, and the other 880 individuals were diagnosed without hearing loss, which is considered the case and the control group, respectively. At the individual level of socioeconomic, the odds of having hearing loss in the participants with high school education and diploma, [OR = 0.51 (95%CI:0.28-0.92)], and the individuals with university education [OR = 0.44 (95%CI:0.22-0.87)] were significantly lower than the illiterate participants. At the household socioeconomic level, the odds of having hearing loss were lower for those with poor [OR = 0.63 (95%CI:0.41-0.97)] and moderate [OR = 0.62 (95%CI:0.41-0.94)] wealth status vs. those with the poorest wealth status. In the area level socioeconomic, although the odds of hearing loss in the residents of affluent areas were slightly lower than the residents of deprived areas, there was no significant difference among the groups.

Conclusion

The individuals with hearing loss may have insufficient education and income.

Relationship between tinnitus and olfactory dysfunction: audiovisual, olfactory, and medical examinations

Introduction

Sensory dysfunctions and cognitive impairments are related to each other. Although a relationship between tinnitus and subjective olfactory dysfunction has been reported, there have been no reports investigating the relationship between tinnitus and olfactory test results.

Methods

To investigate the relationship between tinnitus and olfactory test results, we conducted sensory tests, including hearing and visual examinations. The subjects included 510 community-dwelling individuals (295 women and 215 men) who attended a health checkup in Yakumo, Japan. The age of the subjects ranged from 40 to 91 years (mean ± standard deviation, 63.8 ± 9.9 years). The participants completed a self-reported questionnaire on subjective tinnitus, olfactory function, and hearing function, as well as their lifestyle. The health checkup included smell, hearing, vision, and blood examinations.

Results

After adjusting for age and sex, the presence of tinnitus was significantly associated with subjective olfactory dysfunction, poor olfactory test results, hearing deterioration, vertigo, and headache. Additionally, high serum calcium levels and a low albumin/globulin ratio were significantly associated with low physical activity and nutrition. Women scored higher than men in olfactory and hearing examinations, but there was no gender difference in vision examinations.

Conclusion

Subjective smell dysfunction and poor smell test results were significantly associated with tinnitus complaints. Hearing and vision were associated even after adjusting for age and sex. These findings suggest that evaluating the mutual relationships among sensory organs is important when evaluating the influence of sensory dysfunctions on cognitive function.

Associations among Visual, Auditory, and Olfactory Functions in Community-Based Older Adults: The Atherosclerosis Risk in Communities (ARIC) Study

PURPOSE

Objective examination of relationships among visual, hearing, and olfactory function may yield mechanistic insights and inform our understanding of the burden of multiple-sensory impairments.

METHODS

This cross-sectional study capitalized on continuous measures of visual acuity (VA), contrast sensitivity, pure tone audiometry, Quick Speech-in-Noise (QuickSIN), and Sniffin' Sticks from a subset of ARIC participants at two community sites (EyeDOC Study, 2017-2019). Scales of all measures were aligned such that higher values indicated greater impairment. Intersensory bivariate associations were assessed graphically, and correlations assessed using Kendall's tau. Intersensory associations, independent of age, education, smoking, diabetes, and hypertension, were examined using linear regression. Analyses were stratified by community/race (Washington County/White vs Jackson/Black) and sex (men vs women) to explore community-sex heterogeneity.

RESULTS

We included 834 participants (mean age, 79 years); 39% were from Jackson and 63% females. We found weak intersensory correlations (tau generally ≤0.15). In the demographics-adjusted regression models, results were heterogeneous across communities and sex. Worse near VA, contrast sensitivity, and olfaction were associated with worse QuickSIN and worse near VA was associated with worse olfaction in some but not all community/race-sex groups (e.g., Jackson/Black women, 0.1 logMAR worse near VA was associated with 0.27 units increase in QuickSIN [95% confidence interval, 0.10-0.45]). Associations were modestly attenuated by adjustment for the shared risk factors of smoking, diabetes, and hypertension.

CONCLUSIONS

Visual dysfunction showed little or no association with hearing or olfaction impairments, suggesting a modest role for shared risk factors.

TRANSLATIONAL RELEVANCE

Visually impaired individuals have only a modestly higher risk of other sensory impairment.

Subclinical Hearing Deficits in Noise-Exposed Firefighters

Noise-induced hearing loss (NIHL) is the most prevalent occupational disease in the world and firefighters are at increased risk of NIHL due to their frequent exposure to hazardous levels of noise during service. Adverse effects of NIHL include acceleration of age-related hearing loss and an increased risk of cognitive decline. A critical challenge in addressing NIHL is the delayed clinical presentation of symptoms and lack of sensitive tools for early detection. To study the early clinical symptoms of NIHL in this high-risk group, we collected hearing function data including behavioral audiometric thresholds and distortion product otoacoustic emissions (DPOAEs) in 176 firefighters during annual physical assessments. Results revealed significant deficits in cochlear outer hair cell function in the presence of normal audiograms. Additionally, 55% of firefighters self-reported changes in hearing, while 20% self-reported concerns about their balance. This study is the first to characterize DPOAEs in firefighters who display decreased DPOAE amplitudes with increasing years in the fire service. These effects were observed even when controlling for hearing loss and age and are suggestive of a link between hearing loss and occupational exposure to hazardous noise.

Hearing Health Perceptions and Literacy Among Primary Healthcare Providers in the United States: A National Cross-Sectional Survey

OBJECTIVE

To characterize current awareness, perceptions, and literacy surrounding hearing loss among United States primary healthcare professionals.

STUDY DESIGN

National cross-sectional survey study.

SETTING

United States.

PARTICIPANTS

Four hundred six healthcare professionals.

RESULTS

Survey respondents included 205 primary care physicians and 201 nurse practitioners or physician assistants. When compared with 10 other common health conditions, only 1% of respondents ranked hearing loss as a "most important" health condition to manage. Less than half of providers reported recommending hearing testing for their patients at least once per year, whereas evaluation of blood pressure, total cholesterol, body mass index, and blood glucose levels are recommended at least annually by more than 80% of providers. Although 95% of respondents indicated that it is somewhat important or very important for patients to know the standard definition for normal hearing, only 57% of surveyed providers know of a standard definition themselves, and only 28% reported familiarity with the concept of "20/20 hearing." Conversely, more than 80% of respondents know the "normal" metric for blood pressure, total cholesterol, body mass index, blood glucose, and vision. Most respondents realize that hearing is important to overall health and hearing loss can impact personal safety, lead to social isolation, and negatively impact quality of life. Fifty-four percent also acknowledged a link between hearing loss and depression, but a majority were not very aware of the relationship of hearing loss to risk of falling and dementia, reduced income and job opportunities, and type 2 diabetes. Importantly, only 40% of providers believe hearing loss is treatable, and only 17% believe it is preventable.

CONCLUSION

Despite widespread literacy of what constitutes normal blood pressure, total cholesterol, body mass index, blood glucose, and vision metrics, healthcare providers exhibit a poor understanding of normal hearing levels. Few providers prioritize hearing health or regularly recommend for annual hearing evaluation. Most providers believe that options for people with hearing loss are limited, which may have important implications for prioritizing discussion of hearing loss with patients.

The Correlation of Signal to Noise Ratio Value on DPOAE with Malondialdehyde Levels in Rattus Norvegicus Diabetes Model

Introduction

The aim of this study was to determine the correlation of the signal-to-noise ratio (SNR) value on distortion product otoacoustic emissions (DPOAE) examination with malondialdehyde (MDA) levels in a diabetic rat model.

Materials and Methods

The subjects of this study were 25 rats. The samples were divided into 5 groups (days of confirmed diabetes): group 1 (control/non-treatment); group 2 (3 days); group 3 (6 days); group 4 (9 days); and group 5 (12 days). Samples that confirmed diabetes were assessed by DPOAE examination and subjected to MDA-level examination. The data were processed using SPSS and considered significant if p <0.05.

Results

The study showed a decrease in SNR values and an increase in MDA levels for the rats, which was confirmed by diabetes. The most significant result was shown by group 5, which compared to the other diabetes groups. A post hoc test showed the significant difference SNR value in each group (p<0.05); except for groups 1 and 2, the MDA levels showed significant differences for all groups. The Pearson correlation test showed a negative correlation between SNR values and MDA levels. A significant correlation between SNR values and MDA levels was found in group 5.

Conclusions

The study showed a correlation of SNR values from DPOAE examination to MDA levels in diabetes rats, indicating that there has been tissue damage (cochlea), which is characterized by a decrease in the SNR value.

Impaired auditory neural performance, another dimension of hearing loss in type-2 diabetes mellitus

AIM

to evaluate auditory performance in subjects with poorly controlled type-2 diabetes mellitus, using a simple test battery assessing sensitivity to pure tones and neuronal function.

METHODS

Enrolled subjects, aged between 23-79 years, reported several auditory dysfunctions. They were tested using pure-tone audiometry, otoacoustic emissions for cochlear-function evaluation, and measurement of middle-ear muscle-reflex thresholds in search of an auditory neuropathy.

RESULTS

Compared to the standard established for an age-matched normative population, the distribution of averaged pure-tone thresholds in enrolled subjects shifted by about one standard deviation with respect to the normal distribution, in line with past reports of mild sensorineural hearing impairment in diabetes, even though many diabetic subjects fell well within the normative interval of audiometric thresholds. Otoacoustic emissions showed that pure-tone thresholds correctly predicted the status of cochlear sensory cells that, by amplifying sound, ensure normal hearing sensitivity. Whereas the observed hearing losses should not have affected the acoustic levels above which the protective middle-ear muscle reflex is triggered by intense sounds, this reflex was undetectable in around 40% enrolled subjects, a marker of auditory neuropathy.

CONCLUSION

auditory-neural function should be evaluated to identify diabetic subjects whose hearing is impaired. Simple automatic tests are available for this purpose, for example middle-ear muscle reflex detection, which turns out to be more sensitive than the standard audiogram.

Hearing loss is associated with increased risk of incident stroke but not coronary heart disease among middle-aged and older Chinese adults: the Dongfeng-Tongji cohort study

Hearing loss has been associated with increased risk of cardiovascular disease (CVD) prevalence in cross-sectional studies. However, little is known about the prospective association between hearing loss and CVD incidence. We aimed to examine the associations of hearing loss with risk of incident CVD, coronary heart disease (CHD), and stroke in a Chinese population. We included 13,880 individuals aged 63.3 years from the Dongfeng-Tongji cohort study (2013-2018). Hearing loss was categorized into normal, mild, moderate, severe, or greater by the pure-tone average of thresholds at speech and high frequency in both ears. Cox proportional hazard models and linear regression models were used for multivariate longitudinal analyses. After multivariate adjustments, we observed suggestive dose-response associations of increased high-frequency hearing loss with elevated risk of CVD and stroke incidence. Compared with normal hearing loss at high frequency, those with moderate and severe or greater hearing loss had a 4% (95% CI: 0.92, 1.18) or 13% (95% CI: 0.98, 1.30) higher risk of CVD and 52% (95% CI: 1.06, 2.17) or 51% (95% CI: 1.03, 2.20) higher risk of stroke, while the associations were almost consistent across most subgroups. No significant associations were observed for CHD and high-frequency hearing loss, as well as CVD and speech-frequency hearing loss. In addition, higher high-frequency hearing loss was related to unfavorably altered lipid profiles and fasting glucose. Our data suggested that increased hearing loss might increase the risk of incident CVD and stroke among middle-aged and older Chinese, which was partially explained by altered CVD-related biomarkers.

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.

Hearing Dysfunction After Treatment With Teprotumumab for Thyroid Eye Disease

PURPOSE

To characterize the frequency, severity, and resolution of hearing dysfunction in patients treated with teprotumumab for thyroid eye disease (TED).

DESIGN

Prospective observational case series.

METHODS

Ophthalmic examination and adverse event assessment, including otologic symptoms, were performed at baseline, after infusions 2, 4, and 8, and at 6-month follow-up in consecutive patients who received at least 4 teprotumumab infusions. Laboratory test results were collected at baseline and during treatment. Audiometry, patulous eustachian tube (PET) testing, and otolaryngology evaluation were obtained for patients with new or worsening otologic symptoms, with a subset obtaining baseline and posttreatment testing.

RESULTS

Twenty-seven patients were analyzed (24 females, 3 males, average 56.3 years old). Twenty-two patients (81.5%) developed new subjective otologic symptoms, after a mean of 3.8 infusions (SD 1.8). At 39.2-week average follow-up after the last infusion, most patients with tinnitus (100%), ear plugging/fullness (90.9%), and autophony (83.3%) experienced symptom resolution, whereas only 45.5% (5 of 11) of patients with subjective hearing loss/decreased word comprehension experienced resolution. Six patients underwent baseline and posttreatment audiometry, 5 of whom developed teprotumumab-related sensorineural hearing loss (SNHL) and 1 patient also developed PET. Three of the 5 patients with teprotumumab-related SNHL had persistent subjective hearing loss at last follow-up. A prior history of hearing loss was discovered as a risk factor for teprotumumab-related SNHL (P = .008).

CONCLUSIONS

Hearing loss is a concerning adverse event of teprotumumab, and its mechanism and reversibility should be further studied. Until risk factors for hearing loss are better understood, we recommend baseline audiometry with PET testing and repeat testing if new otologic symptoms develop. Screening, monitoring, and prevention guidelines are needed.

Sex-specific associations between diabetes mellitus and hearing loss in the middle-aged and elderly: a national cohort study of Chinese adults

OBJECTIVE

To examine the association between diabetes and hearing loss and whether the association varied by sex.

METHODS

This cohort study based on nationally representative data from the China Health and Retirement Longitudinal Study included 16140 Chinese adults aged over 45 years between 2011 and 2018. Diabetes was identified by blood glucose, HbA_1c, and a self-reported diagnosis at baseline. The main outcome is self-reported incident hearing loss. Cox proportional hazards regression models were performed to estimate the risk of hearing loss.

RESULTS

We documented 2388 cases of hearing loss during a median 6.9 years of follow-up. The incidence rate was 29.64 (95% CI 28.07-31.29) per 1000 person-years in women and 25.23 (95% CI 23.77-26.78) per 1000 person-years in men. After adjustment, the HR of hearing loss associated with diabetes was 1.20 (95% CI 1.01-1.42) for women and 0.97 (95% CI 0.78-1.19) for men. Compared with poor control of blood sugar, the OR for hearing loss for women with good glycemic control was reduced from 5.08 (95%CI 1.31-19.66) to 1.26 (95%CI 0.69-2.28), and the corresponding OR for men was 1.65 (95% CI 0.61-4.44) to 0.50 (95%CI 0.18-1.38).

CONCLUSIONS

In conclusion, we identified a differential effect of sex on hearing loss risk with more pronounced effects for women. Our data suggest that good blood glucose control is helpful to prevent hearing loss.

Biguanide Pharmaceutical Formulations and the Applications of Bile Acid-Based Nano Delivery in Chronic Medical Conditions

Biguanides, particularly the widely prescribed drug metformin, have been marketed for many decades and have well-established absorption profiles. They are commonly administered via the oral route and, despite variation in oral uptake, remain commonly prescribed for diabetes mellitus, typically type 2. Studies over the last decade have focused on the design and development of advanced oral delivery dosage forms using bio nano technologies and novel drug carrier systems. Such studies have demonstrated significantly enhanced delivery and safety of biguanides using nanocapsules. Enhanced delivery and safety have widened the potential applications of biguanides not only in diabetes but also in other disorders. Hence, this review aimed to explore biguanides’ pharmacokinetics, pharmacodynamics, and pharmaceutical applications in diabetes, as well as in other disorders.

Self-Reported Sensory Impairments in Older Adults and their Association with Self-Rated Health and Mortality Outcomes

OBJECTIVES

This study assessed the relationship between self-reported impairments of vision, hearing, and dual sensory impairment, and change in self-rated health/mortality status over a 5-year period.

METHODS

Data came from the National Health and Aging Trends Study, a nationally representative survey of Medicare beneficiaries ages 65 and older. Analyses consisted of a series of ordinal logistic regressions stratified by sex.

RESULTS

For both women and men, self-reported sensory impairments were not statistical predictors of self-rated health/mortality, when other dimensions of health, such as physical functioning, participation, and activities of daily living functioning were included in models.

DISCUSSION

Understanding how self-reported sensory impairments impact self-rated health could assist in targeting rehabilitation strategies to older adults who experience sensory impairments.

Chronic Obstructive Pulmonary Disease is a Risk Factor for Sensorineural Hearing Loss: A US Population Study

OBJECTIVES

The goal of this study is to determine if chronic obstructive pulmonary disease (COPD) is associated with sensorineural hearing loss (SNHL) in a national database.

STUDY DESIGN

Cross-sectional study.

SETTING

National sample of the United States population.

PATIENTS

Adults with audiometric and spirometry data from the National Health and Nutrition Examination Study (NHANES) database.

INTERVENTIONS

None.

METHODS

A total of 2,464 adults with spirometry and audiometry data from the NHANES database (2009-2012) were studied. Outcome measures included hearing, measured by high-frequency pure tone average (HFPTA; 3, 4, 6, 8 kHz) and low-frequency pure tone average (LFPTA; .5, 1, 2 kHz) frequencies. SNHL was defined as a HFPTA or LFPTA threshold more than 25 decibels (dB) in the better ear. Multivariable regression analyses explored the association between hearing loss and COPD.

RESULTS

The prevalence of COPD was 19.8% in individuals with SNHL in the better ear and 4.7% in individuals with normal hearing (p < 0.001). Presence of COPD was associated with elevated hearing thresholds (worse hearing) at each individual frequency. The presence of COPD was independently associated with a 3.29 dB (95% CI: 1.48, 5.09) increase in HFPTA (p < 0.001), and 2.32 dB (1.13, 3.50) increase in LFPTA (p < 0.001) after controlling for medical, social, and environmental covariates. The presence of COPD was independently associated with a 1.85-fold (1.12, 3.06) increased odds of isolated low-frequency SNHL (p = 0.017).

CONCLUSIONS

COPD was independently associated with sensorineural hearing loss after controlling for multiple confounding factors. These results contribute to the evidence that COPD and pulmonary dysfunction can be comorbid with hearing decline.

Association Between Hearing Loss and Impaired Physical Function, Frailty, and Disability in Older Adults: A Cross-sectional Study

Importance

Several studies have examined the association between hearing loss (HL) and physical function, with inconsistent results. Few used pure-tone thresholds and considered possible confounders in the association.

Objective

To examine the association between hearing loss and impaired lower extremity function, frailty syndrome, and disability in older adults.

Design, Setting, and Participants

The Seniors-ENRICA-2 is a cohort study that was established in 2015-2017 in Spain. The present study was conducted from December 2015 to June 2017. Data were analyzed from January 2, 2021, to March 10, 2021. This cross-sectional analysis included 1644 community-dwelling individuals aged 65 years or older (range, 66-91 years) of both sexes. Participants had hearing threshold measurements and data on impaired lower extremity function, frailty syndrome, and disability.

Exposures

Hearing loss defined as pure-tone average greater than 40 dB HL in the better ear for standard frequency (0.5, 1, and 2 kHz), speech frequency (0.5, 1, 2, and 4 kHz), and high frequency (3, 4, and 8 kHz).

Main Outcomes and Measures

Impaired lower extremity function was defined with the Short Physical Performance Battery; the frailty syndrome was defined as having at least 3 of the 5 criteria, including weakness, slow walking speed, low physical activity, exhaustion, and weight loss; and disability in instrumental activities of daily living (IADL) was evaluated with the Lawton and Brody scale.

Results

Of the 1644 participants, 831 were men (50.5%); mean (SD) age was 73.8 (4.3) years. The prevalence of moderate HL was 13.6% at speech frequency. After adjustment for age, sex, lifestyle, comorbidities, impaired cognition, and social isolation, HL in standard frequency was associated with impaired lower extremity function, with an odds ratio (OR) of 2.20 (95% CI, 1.25-3.88); the corresponding estimate for the frailty syndrome was 1.85 (95% CI, 0.98-3.49) and for the IADL disability, was 2.25 (95% CI, 1.29-3.94). When considering speech frequency pure-tone average, HL was also associated with impaired function (OR, 2.59; 95% CI, 1.57-4.28), frailty syndrome (OR, 1.85; 95% CI, 1.06-3.22), and IADL disability (OR, 2.18; 95% CI, 1.32-3.60).

Conclusions and Relevance

In this cross-sectional analysis of data from the Seniors-ENRICA-2 cohort study, hearing loss was associated with impaired lower extremity function, frailty syndrome, and IADL disability. It may be useful to examine this association with the mechanisms elucidated in further studies.

Diabetes is a risk factor for hearing loss in older adults: Results of a community screening programme

OBJECTIVES

To investigate the association between diabetes mellitus (DM) and the prevalence and severity of hearing loss in a population of community-dwelling older adults in Singapore.

MATERIALS AND METHODS

This is a retrospective, cross-sectional study of 1787 adults aged 60-100 who had undergone a comprehensive audiological assessment in a community-based audiology clinic. Data extracted included their age, hearing profile, medical history, and comorbidities collected through verbal interview at the point of audiologic assessment. Multivariate linear regression and multivariate logistic regression were performed to investigate the relationship between DM and hearing loss.

RESULTS

The prevalence of DM in our studied population is 17.9%. After controlling for age, gender, race, hypertension, and hyperlipidaemia status, DM was found to be independently associated with at least moderate hearing loss (adjusted OR 1.3 [95% CI 1.06-1.59], p = .012). This was especially so in the younger (<70) age group (adjusted OR 1.7 [95% CI 1.18-2.44], p = .004).

CONCLUSION

DM is an independent risk factor for the presence of at least moderate hearing in community-dwelling seniors. Individuals aged <70 with DM should be screened for hearing loss to enable early intervention.

Impact of vision and hearing impairments on risk of cardiovascular outcomes and mortality in patients with type 2 diabetes: A nationwide cohort study

Aims/Introduction

The purpose of this study was to investigate the impact of vision and hearing impairments on the risk of adverse cardiovascular outcomes and mortality in patients with type 2 diabetes using a nationwide longitudinal cohort.

Materials and Methods

We enrolled 771,128 patients with type 2 diabetes who underwent the National Health Screening Program in 2009. We carried out Cox proportional hazards regression analyses to calculate the hazard ratios (HR) of myocardial infarction (MI), stroke, and mortality in those with or without vision and hearing impairments. Subgroup analyses of patients stratified by age, sex and diabetic retinopathy were carried out.

Results

Diabetes patients with either vision or hearing impairment showed higher risk of MI, stroke or death compared with those without. Among the combinations of impairments, patients with both vision and hearing impairments had the highest risk for MI (adjusted HR [aHR] 1.362, 95% confidence interval [CI] 1.252–1.481) and mortality (aHR 1.591, 95% CI 1.532–1.651). Those with only vision impairment showed higher risk of MI (aHR 1.324, 95% CI 1.275–1.375 and aHR 1.117, 95% CI 1.066–1.170, respectively), stroke (aHR 1.318, 95% CI 1.276–1.362 and aHR 1.134 95% CI 1.089–1.180, respectively) and mortality (aHR 1.417, 95% CI 1.390–1.446 and aHR 1.163, 95% CI 1.135–1.191, respectively) compared with those with only hearing impairment.

Conclusions

Vision and hearing impairments are independently important risk factors for adverse cardiovascular events and mortality in patients with type 2 diabetes. Vision and hearing impairments synergistically increased the risk of MI and all‐cause deaths, but not stroke. In addition, in patients aged <65 years, the HR of vision impairment was higher than those with vision and hearing impairments.

Diet Quality and the Risk of Impaired Speech Reception Threshold in Noise: The UK Biobank cohort

OBJECTIVE

Previous studies have examined the association between several diet quality indexes and risk of hearing loss, based on self-reported information or on audiometry test, with inconsistent results. However, the impact of healthy diets on the capacity to listening in noise, a proxy of disability due to hearing loss, is unknown. This research assessed the prospective association between five diet quality indexes and the speech reception threshold in noise in the UK Biobank study.

DESIGN

Prospective cohort with 105,592 participants aged ≥40 years. At baseline, adherence to the Mediterranean Diet Adherence Screener, the alternate Mediterranean Diet score, the Dietary Approaches to Stop Hypertension, the Alternate Healthy Eating Index-2010, and the healthful Plant-Based Diet Index were assessed. Functional auditory capacity was measured with a digit triplet test, and impairment was defined as a speech reception threshold in noise >-3.5 dB in any physical exam during the follow-up.

RESULTS

Over a median follow-up of 3.2 (SD: 2.1) years, 1704 participants showed impaired speech reception threshold in noise. After adjusting for potential confounders, the hazard ratios (95% confidence interval) of impairment per 1-SD increase in the Mediterranean Diet Adherence Screener, alternate Mediterranean Diet score, Dietary Approaches to Stop Hypertension, Alternate Healthy Eating Index-2010 and healthful Plant-Based Diet Index scores were, respectively, 0.98 (0.94 to 1.03), 1.01 (0.96 to 1.06), 1.02 (0.97 to 1.07), 1.01 (0.96 to 1.06), and 1.00 (0.96 to 1.05). Results were similar when analyses were restricted to those >60 years, with British ethnicity, without chronic disease, without tinnitus or with optimal cognitive function.

CONCLUSIONS

Adherence to a healthy diet did not show an association with the speech reception threshold in noise. More research is needed to identify the impact of individual foods or nutrients on this outcome.

Self-reported and cotinine-verified smoking and increased risk of incident hearing loss

We examined the associations of smoking status and urinary cotinine levels, an objective measure of smoking, with the development of new-onset HL. This cohort study was performed in 293,991 Korean adults free of HL who underwent a comprehensive screening examination and were followed for up to 8.8 years. HL was defined as a pure-tone average of thresholds at 0.5, 1.0, and 2.0 kHz ≥ 25 dB in both ears. During a median follow-up of 4.9 years, 2286 participants developed new-onset bilateral HL. Self-reported smoking status was associated with an increased risk of new-onset bilateral HL. Multivariable-adjusted HRs (95% CIs) for incident HL comparing former smokers and current smokers to never-smokers were 1.14 (1.004-1.30) and 1.40 (1.21-1.61), respectively. Number of cigarettes, pack-years, and urinary cotinine levels were consistently associated with incident HL. These associations were similarly observed when introducing changes in smoking status, urinary cotinine, and other confounders during follow-up as time-varying covariates. In this large cohort of young and middle-aged men and women, smoking status based on both self-report and urinary cotinine level were independently associated with an increased incidence of bilateral HL. Our findings indicate smoking is an independent risk factor for HL.

Modeling Hearing Loss Progression and Asymmetry in the Older Old: A National Population-Based Study

OBJECTIVE

The progression and asymmetry of age-related hearing loss has not been well characterized in those 80 years of age and older because public datasets mask upper extremes of age to protect anonymity. We aim to characterize the progression, severity, and asymmetry of hearing loss in those 80 years of age and older using a representative, national database.

METHODS

Cross-sectional, multicentered U.S. epidemiologic analysis using the National Health and Nutrition Examination Survey (NHANES) 2005 to 2006, 2009 to 2010, and 2011 to 2012 cycles. Subjects included noninstitutionalized, civilian adults aged 80 years and older (n = 621). Federal security clearance was granted to access publicly restricted age data. Outcome measures included pure-tone average (PTA) air conduction thresholds and the 4-frequency PTA.

RESULTS

Six hundred and twenty-one subjects were 80 years old or older (mean = 84.2 years, range = 80-104 years), representing 10,600,197 Americans. The average PTA was 38.9 dB (95% confidence interval [CI] = 37.8, 40.0). Hearing loss exhibited constant acceleration across the adult lifespan at a rate of 0.0052 dB/year2 (95% CI = 0.0049, 0.0055). This model predicted mean PTA within 2 dB of accuracy for most ages between 20 and 100 years. From age 80 years to approximately 100 years, the average PTA difference between the better and worse ear was 6.75 dB (95% CI = 5.8, 7.1). This asymmetry was relatively constant (i.e., nonsignificant linear regression coefficient of asymmetry over age = 0.07 [95% CI = -0.01, 0.2]).

CONCLUSION

Hearing loss steadily and predictably accelerates across the adult lifespan to at least age 100 years, becoming near universal. These population-level statistics will guide treatment and policy recommendations for hearing health in the older old.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:879-884, 2021.

Prevalence and incidence of hearing impairment among adults: a 13-year follow-up study

OBJECTIVE

The aim of this study was to investigate the prevalence and incidence of hearing impairment (HI) in a longitudinal setting among adults.

DESIGN

An unscreened, population-based epidemiological 13-year follow-up study. Study sample: 850 randomly sampled 54 to 66-year-old baseline participants, of whom 559 participated in the follow-up study at the age of 68 to 79 years. A questionnaire-based interview, an otological examination and pure-tone audiometry were performed.

RESULTS

The overall prevalence of HI was 70.3%, defined by better ear hearing level (BEHL)  ≥ 20 dB in the 0.5-4 kHz frequency range. The prevalence was higher among men (78.6%) than among women (63.7%). The overall incidence rate for HI was 45.8 per 1000 person years and the 13-year cumulative incidence was 60.9%. The incidence was higher among men and older participants.

CONCLUSION

HI is highly prevalent and incident among older adults in Northern Finland.

Association of Glycosylated Hemoglobin A1c Level With Sudden Sensorineural Hearing Loss: A Prospective Study

Glycosylated hemoglobin A1c (HbA1c) level has strong relevance to microvascular disorders, which are also thought to be the current main aspect of sudden sensorineural hearing loss (SSNHL), so we aim to elucidate the association of the HbA1c level with the severity, types, and prognosis of SSNHL. In this study, comparative analyses based on propensity score matching of the severity, types, and prognosis of SSNHL with the HbA1c level in 116 patients diagnosed as SSNHL were conducted, where they were divided into diabetes mellitus (DM) group and non-DM group. We finally found that, among patients with SSNHL, diabetic patients had a higher HbA1c level, more severe hearing loss, and poorer prognosis than non-diabetic patients. The HbA1c level was found to be significantly correlated with the severity and types of SSNHL, while no strong relevance was found between the higher HbA1c level and the poorer prognosis of SSNHL.

Association between frailty and risk of fall among diabetic patients

BACKGROUND

Several epidemiological studies have demonstrated the risk factors for fall, while few studies investigated the association between frailty and risk of fall in diabetic patients aged ≥45 years.

METHODS

In this multicity observational study, participants with type 2 diabetes aged ≥45 years were enrolled. Frailty status was measured by a frailty index (FI) of deficit accumulation. We used multivariable regression models to examine the relationship between frailty and fall in diabetic patients, and further investigated the associations between frailty and fall in varied subgroups.

RESULTS

A total of 2049 participants with type 2 diabetes were identified in our study. Our results showed a per-s.d. and a per-0.01 increment of FI were associated with an increased risk of fall, with a fully adjusted OR of 1.89 (95% CI: 1.50, 2.38), 1.06 (95% CI: 1.04, 1.09), respectively. The effects were magnified when frailty was considered as dichotomous, with an OR of 3.08 (95% CI: 2.18, 4.34). In further subgroup analyses, we found that the females, the older, rural residents, individuals with no sitting toilet, people with poor balance performance and those in poor health status were susceptible to fall. Especially, for the risk of fall in the older, a per-s.d. increase of FI corresponded to an OR of 2.46 (95% CI: 1.68, 3.62). When frailty was regarded as a binary variable, the effect increased to 4.62 (95% CI: 2.54, 8.38) in the older subgroup.

CONCLUSION

Frailty was associated with a higher risk of fall in people with type 2 diabetes, and the effects were higher in vulnerable groups. This evidence suggested that more attention should be paid to vulnerable groups for fall prevention.

Comparative Evaluation of Injection Dexamethasone and Oral Glycerol Versus Injection Dexamethasone Alone in the Treatment of Sudden Onset Sensorineural Deafness

OBJECTIVES

Our study was aimed at finding a definitive treatment protocol for the management of sudden sensorineural hearing loss (SSNHL) and to study the prognostic factors affecting it.

METHODS

This randomized clinical study was conducted on a total of 150 patients. All patients older than 10 years and presenting within 15 days of experiencing the symptom of SSNHL and with no known etiology were included. Patients were divided into 2 groups. In group I patients, we administered systemic steroids (injection dexamethasone 3 days, followed by oral deflazacort for 6 days) with liquid glycerol; and in group II, we administered systemic steroids alone (injection dexamethasone 3 days, followed by oral deflazacort for 6 days). The total time for which the treatment was instituted was 9 days and patients were assessed on the basis of their pure tone audiogram and speech discrimination score done at days 0, 3, 7, 21, and 42.

RESULTS

There were 77 males and 73 females. Vertigo (P value < .00) and diabetes mellitus (P value < .001) had a negative prognostic influence on the recovery rate in both the groups. The comparison revealed that group I (DG) in which patients received injection dexamethasone with oral glycerol had a higher recovery rate of 86.7% as compared to group II (D) patients, in which patients received injection dexamethasone alone (recovery rate = 48%; P = .000 highly significant).

CONCLUSIONS

Vertigo and diabetes mellitus play a negative role in the recovery of SSNHL. The novel treatment protocol we used in group I patients that is liquid glycerol and systemic steroids was significantly better and effective in treating SSNHL as compared to the group II treatment protocol of systemic steroids alone. Hence, we concluded that SSNHL is treatable that too with a good recovery rate.

Type 1 Diabetes Induces Hearing Loss: Functional and Histological Findings in An Akita Mouse Model

The relationship between type 1 diabetes and hearing loss is not well known, although based on many pathological studies, type 2 diabetes induced hearing loss is associated with microcirculation problems in the inner ear. The purpose of this study was to investigate the correlation between type 1 diabetes and hearing loss through hearing function and immunohistochemical analyses using type 1 diabetic Akita or wild-type (WT) mice. The Akita mice had a significant increase in hearing thresholds, blood glucose, and insulin tolerance compared to WT mice. Histological analysis showed that the loss of cells and damage to mitochondria in the spiral ganglion neurons of Akita mice were significantly increased compared to WT. Also, the stria vascularis showed decreased thickness, loss of intermediate cells, and disturbance in blood capillary shape in the Akita mice. Moreover, a reduction in type I, II, and IV fibrocytes and Na⁺/K⁺-ATPase α1 expression in spiral ligament was also observed. Cleaved caspase-3 expression was highly expressed in spiral ganglion neurons. In conclusion, hearing loss in type 1 diabetes is caused not only by ion imbalance and blood flow disorders of cochlear endolymph, but through the degenerative nervous system via apoptosis-mediated cell death.

The Association Between Glycolyzed Hemoglobin A1c and Hearing Loss in Diabetic Patients

Purpose

Our study aimed to determine the correlation between glycated hemoglobin (HbA1c) levels and the audiometric parameters in diabetic patients.

Methods

We included 724 patients (376 male, 348 female) in our outpatient clinic and created four groups by reference to the HbA1c values. The first group was 192 patients with an HbA1c value < 4.5, 176 patients with an HbA1c value between 4.5 - 5 as Group 2, 177 patients with an HbA1c value between 5 - 6 as Group 3, and 179 patients that had an HbA1c value greater than 6 as Group 4. The correlations between HbA1c values and median pure tone thresholds at 250, 500, 1,000, 2,000, 4,000, and 8,000 Hz, the speech recognition thresholds, and the speech discrimination scores were compared.

Results

The median speech recognition thresholds, speech discrimination scores, and the median pure-tone thresholds at 250, 500, 1,000, 2,000, 4,000, and 8,000 MHz in the left ear significantly differed in the fourth group (p < 0.001). Pure-tone thresholds at 500 Hz, 4,000 Hz, speech discrimination scores, and recognition thresholds in the right ear had a significant positive correlation in the fourth group (p < 0.001).

Conclusion

According to HbA1c levels, the severity of diabetes can affect high to all frequencies of hearing functions negatively. The follow-up of patients with higher levels of HbA1c should undergo audiological tests more regularly.