Hearing impairment and the risk of neurodegenerative dementia: A longitudinal follow-up study using a national sample cohort

A comprehensive evaluation on the associations between hearing and vision impairments and risk of all-cause and cause-specific dementia: results from cohort study, meta-analysis and Mendelian randomization study

BACKGROUND

Epidemiological studies show inconsistent links between hearing/vision impairment and dementia risk. Using multisource data, we investigated how single or combined sensory impairments relate to risks of all-cause and specific types of dementia.

METHODS

We employed a triangulation approach combining three methodologies. We analyzed 90,893 UK Biobank (UKB) adults to explore single and joint effects of hearing and vision impairments on all-cause and Alzheimer's disease (AD), vascular dementia (VD) and non-AD non-VD (NAVD). A meta-analysis of prospective studies involving 937,908 participants provided stronger evidence. Finally, we conducted Mendelian randomization (MR) analysis using genome-wide association studies from UKB (361,194 participants) and FinnGen (412,181 participants) to validate relationships between sensory impairments and dementia occurrence.

RESULTS

In the UKB cohort study, compared to participants with normal hearing, those in the mild and severe hearing impairment groups had progressively and significantly higher risk of all-cause dementia (mild: HR1.52, 95%CI 1.31-1.77; severe: HR1.80, 95%CI 1.36-2.38), AD (mild: HR1.63, 95%CI 1.30-2.04; severe: HR2.18, 95%CI 1.45-3.27), VD (mild: HR1.68, 95%CI 1.19-2.37; severe: HR1.47, 95%CI 1.22-1.78), and NAVD (mild: HR1.47, 95%CI 1.22-1.78; severe: HR1.98, 95%CI 1.43-2.75). Besides, vision impairment was associated with an increased risk of all-cause dementia (HR1.55, 95%CI 1.18-2.04) and NAVD (HR1.51, 95%CI 1.07-2.13). Furthermore, dual sensory impairment was associated with stepwise increased risks of all-cause and cause-specific dementia than single hearing or vision impairment. In the meta-analysis of 31 prospective cohort studies, risks of all-cause dementia and AD were elevated in participants with single hearing impairment (all-cause dementia: HR1.30, 95%CI 1.21-1.40; AD: HR1.30, 95%CI 1.21-1.40) and dual sensory impairment (all-cause dementia: HR1.63, 95%CI1.14-2.12; AD: HR 2.55, 95%CI 1.19-3.91), while single vision impairment only associated with higher risk of all-cause dementia (HR1.43, 95%CI 1.16-1.71) but not AD. Finally, the MR analysis revealed a significant association between hearing impairment and all-cause dementia (OR1.74, 95%CI 1.01-2.99), AD (OR1.56, 95%CI 1.09-2.23), and NAVD (OR1.14, 1.02-1.26), as well as vision impairment and NAVD (OR1.62, 95%CI 1.13-2.33).

CONCLUSIONS

Our findings showed significant associations between hearing and vision impairments and increased risks of all-cause and cause-specific dementia. Standardized hearing and vision assessment and intervention should be emphasized in dementia prevention strategies.

Association Between COPD and Hearing Loss

OBJECTIVE

The goal of the present study was to estimate the risk of hearing impairment in patients with COPD using huge nationwide population.

METHODS

A retrospective case-control study was performed using the National Health Insurance Database in South Korea from 2002 through 2019. Totally 614,370 COPD patients and matched 2,170,504 control participants were selected at a 1:4 ratio. Hearing impairment was defined based on the registered data in the Ministry of Health and Welfare of Korea with six levels of severity of hearing impairment. The propensity score was calculated, and overlap-weighted multinomial logistic regression was used to calculate the odds ratios of COPD for hearing impairment.

RESULTS

A total of 2.67% of COPD patients and 1.9% of control participants had hearing impairment. The COPD patients indicated 1.10-1.21 times higher odds for hearing impairment according to the severity of hearing impairment than the control group. In accordance with age and sex, the younger age group (<65 years old) and female group demonstrated higher odds for hearing impairment related to the presence of COPD. The high odds for hearing impairment in patients with COPD was consistent in all other subgroups, except for the underweight group.

CONCLUSIONS

COPD was associated with an increased risk of hearing impairment in the general population in Korea.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:4716-4722, 2024.

Hearing Loss and Associated 7-Year Cognitive Outcomes Among Hispanic and Latino Adults

Importance

Hearing loss appears to have adverse effects on cognition and increases risk for cognitive impairment. These associations have not been thoroughly investigated in the Hispanic and Latino population, which faces hearing health disparities.

Objective

To examine associations between hearing loss with 7-year cognitive change and mild cognitive impairment (MCI) prevalence among a diverse cohort of Hispanic/Latino adults.

Design, Setting, and Participants

This cohort study used data from a large community health survey of Hispanic Latino adults in 4 major US cities. Eligible participants were aged 50 years or older at their second visit to study field centers. Cognitive data were collected at visit 1 and visit 2, an average of 7 years later. Data were last analyzed between September 2023 and January 2024.

Exposure

Hearing loss at visit 1 was defined as a pure-tone average (500, 1000, 2000, and 4000 Hz) greater than 25 dB hearing loss in the better ear.

Main outcomes and measures

Cognitive data were collected at visit 1 and visit 2, an average of 7 years later and included measures of episodic learning and memory (the Brief-Spanish English Verbal Learning Test Sum of Trials and Delayed Recall), verbal fluency (word fluency-phonemic fluency), executive functioning (Trails Making Test-Trail B), and processing speed (Digit-Symbol Substitution, Trails Making Test-Trail A). MCI at visit 2 was defined using the National Institute on Aging-Alzheimer Association criteria.

Results

A total of 6113 Hispanic Latino adults were included (mean [SD] age, 56.4 [8.1] years; 3919 women [64.1%]). Hearing loss at visit 1 was associated with worse cognitive performance at 7-year follow-up (global cognition: β = -0.11 [95% CI, -0.18 to -0.05]), equivalent to 4.6 years of aging and greater adverse change (slowing) in processing speed (β = -0.12 [95% CI, -0.23 to -0.003]) equivalent to 5.4 years of cognitive change due to aging. There were no associations with MCI.

Conclusions and relevance

The findings of this cohort study suggest that hearing loss decreases cognitive performance and increases rate of adverse change in processing speed. These findings underscore the need to prevent, assess, and treat hearing loss in the Hispanic and Latino community.

Increased Risk of Dementia Following a Diagnosis of Hearing Impairment: A South Korean Nationwide Cohort Study

BACKGROUND

Among the older adults, hearing impairment is a common problem and may contribute to dementia.

OBJECTIVE

Therefore, we aimed to examine the association between hearing impairment and the risk of dementia among older adults in South Korea.

METHODS

Using the Korean National Health Insurance Service-Senior Cohort from 2005 to 2019, we collected data of 44,728 patients. Hearing impairment was determined using the national disability registry. Propensity score matching (1:1) was performed to match patients with and without hearing impairment (case: 22,364, control: 22,364). A Cox proportional hazards regression model was built to analyze the association between hearing impairment and dementia.

RESULTS

Patients with hearing impairment had a higher risk of dementia than those without hearing impairment (hazard ratio [HR] = 1.28, 95% confidence interval [CI] = 1.23-1.34). Assessing the degree of disability, both severe (HR = 1.25, 95% CI = 1.16-1.35) and mild conditions (HR = 1.29, 95% CI = 1.23-1.35) had an increased risk of dementia, respectively.

CONCLUSIONS

Older patients with hearing impairment exhibit an increased risk of dementia, thereby warranting a new approach to dementia care among these patients regardless of the degree of hearing impairment.

Dementia Incidence Rate Before and After Implementing the National Responsibility Policy for Dementia Care in Patients With Vascular Risk Factors in Korea

Background and Purpose

The National Responsibility Policy for Dementia Care was implemented in September 2017 in Korea. This study aimed to compare dementia incidence in Seoul and Gangwon-do before and after the implementation of this policy.

Methods

We extracted insurance claim data from the Korean Health Insurance Review and Assessment Service for people diagnosed with diabetes, hypertension, or dyslipidemia for the first time in Seoul and Gangwon-do, Korea. We defined two enrollment groups based on the policy implementation date: 1) January 1, 2015 to December 31, 2016 (Index 1, pre-implementation), and 2) January 1, 2017 to December 31, 2018 (Index 2, post-implementation). Each group was followed up for 1 year from the time of enrollment. Then, we calculated hazard ratios to compare the incidence of dementia between the two groups, and between Seoul and Gangwon-do.

Results

In Seoul, the incidence of dementia was significantly lower in Index 2 than in Index 1 (hazard ratio [HR], 0.926; 95% confidence interval [CI], 0.875-0.979). However, the incidence rate did not differ between the 2 groups (HR, 1.113; 95% CI, 0.966-1.281) in Gangwon-do. In Index 1, the incidence of dementia did not differ between Seoul and Gangwon-do (HR, 1.043; 95% CI, 0.941-1.156), but in Index 2, was significantly higher in Gangwon-do than in Seoul (HR, 1.240; 95% CI, 1.109-1.386).

Conclusions

After implementing the National Responsibility Policy for Dementia Care, the dementia incidence rate decreased significantly in Seoul, consistent with other studies, but not in Gangwon-do.

Vestibular cognition assessment system: Tablet-based computerized visuospatial abilities test battery

Introduction

The vestibular system is anatomically connected to extensive regions of the cerebral cortex, hippocampus, and amygdala. However, studies focusing on the impact of vestibular impairment on visuospatial cognition ability are limited. This study aimed to develop a mobile tablet-based vestibular cognitive assessment system (VCAS), enhance the dynamic and three-dimensional (3D) nature of the test conditions, and comprehensively evaluate the visuospatial cognitive ability of patients with vestibular dysfunction.

Materials and methods

First, the VCAS assessment dimensions (spatial memory, spatial navigation, and mental rotation) and test content (weeding, maze, card rotation, and 3D driving tests) were determined based on expert interviews. Second, VCAS was developed based on Unity3D, using the C# language and ILruntime hot update framework development technology, combined with the A* algorithm, prime tree algorithm, and dynamic route rendering. Further, the online test was built using relevant game business logic. Finally, healthy controls (HC) and 78 patients with vertigo (VP) were recruited for the VCAS test. The validity of VCAS was verified using the test results of random controls.

Results

In the weeding test, the HC group had a significantly longer span and faster velocity backward than did the VP group. In the 12 × 12 maze, statistically significant differences in step and time were observed between the two groups, with VP taking longer time and more steps. In the mental rotation task, no significant difference was observed between the two groups. Similarly, no significant difference was found in the performance of the two groups on maps 2, 3, and 4 in the 3D driving task.

Discussion

Thus, impaired visuospatial cognition in patients with vestibular dysfunction is primarily related to spatial memory and navigation. VCAS is a clinically applicable visuospatial cognitive ability test for VP.

Causes of Mortality in Korean Patients with Neurodegenerative Dementia

The prevalence of neurodegenerative dementia is increasing owing to the rapid growth of the older population. We investigated risks and causes of mortality in Korean patients with neurodegenerative dementia using data from the Korean Health Insurance Review and Assessment Service-National Sample Cohort with the aim to improve their care. From a pool of 1,125,691 patients, 11,215 patients aged ≥60 years who were diagnosed with dementia between 2002 and 2013 were examined along with 44,860 matched controls. A Cox proportional hazard model was used to calculate crude and adjusted hazard ratios (HRs). During the follow-up period, 34.5% and 18.8% of individuals in the neurodegenerative dementia and control groups, respectively, died (P < 0.001). The adjusted HR for mortality in the neurodegenerative dementia group was 2.11 (2.41 and 1.96 in men and women, respectively). Moreover, the adjusted HRs in patients with neurodegenerative dementia were 3.25, 2.77, and 1.84 for those diagnosed at ages 60–69, 70–79, and ≥80 years, respectively. The highest odds ratio for mortality was noted among patients with neurologic disease (15.93) followed by those with mental disease (4.89). These data show that the risk of mortality increased regardless of age and sex in Korean patients with neurodegenerative dementia.

The Occurrence of Alzheimer's Disease and Parkinson's Disease in Individuals With Osteoporosis: A Longitudinal Follow-Up Study Using a National Health Screening Database in Korea

Background: Public health concerns regarding the potential link between osteoporosis and the increased occurrence of Alzheimer’s disease (AD) and Parkinson’s disease (PD) have been raised, but the results remain inconsistent and require further validation. Here, we investigated the long-term relationship of osteoporosis with the occurrence of AD/PD using data from a large-scale nationwide cohort.

Methods: This longitudinal follow-up study included 78,994 patients with osteoporosis and 78,994 controls from the Korean National Health Insurance Service-Health Screening Cohort database (2002–2015) who were matched using propensity score matching at a 1:1 ratio based on age, sex, income, and residential area. A Cox proportional hazard model was used to assess the association between osteoporosis and the occurrence of AD/PD after adjusting for multiple covariates.

Results: During the follow-up period, AD occurred in 5,856 patients with osteoporosis and 3,761 controls (incidence rates: 10.4 and 6.8 per 1,000 person-years, respectively), and PD occurred in 1,397 patients and 790 controls (incidence rates: 2.4 and 1.4 per 1,000 person-years, respectively). The incidences of AD and PD were significantly higher in the osteoporosis group than in the matched control group. After adjustment, the osteoporosis group exhibited 1.27-fold and 1.49-fold higher occurrences of AD (95% confidence interval (CI) = 1.22–1.32) and PD (95% CI = 1.36–1.63) than the controls, respectively. The results of subgroup analyses supported the increased occurrence of AD and PD in patients with osteoporosis, independent of income, residential area, obesity, smoking, alcohol consumption, hyperlipidemia, hypertension, or blood glucose level.

Conclusion: Our results indicate that the presence of osteoporosis may increase the likelihood of developing two common neurodegenerative diseases in adults aged ≥40 years.

Medical Health Records-Based Mild Cognitive Impairment (MCI) Prediction for Effective Dementia Care

Dementia is a cognitive impairment that poses a global threat. Current dementia treatments slow the progression of the disease. The timing of starting such treatment markedly affects the effectiveness of the treatment. Some experts mentioned that the optimal timing for starting the currently available treatment in order to delay progression to dementia is the mild cognitive impairment stage, which is the prior stage of dementia. However, medical records are typically only available at a later stage, i.e., from the early or middle stage of dementia. In order to address this limitation, this study developed a model using national health information data from 5 years prior, to predict dementia development 5 years in the future. The Senior Cohort Database, comprising 550,000 samples, were used for model development. The F-measure of the model predicting dementia development after a 5-year incubation period was 77.38%. Models for a 1- and 3-year incubation period were also developed for comparative analysis of dementia risk factors. The three models had some risk factors in common, but also had unique risk factors, depending on the stage. For the common risk factors, a difference in disease severity was confirmed. These findings indicate that the diagnostic criteria and treatment strategy for dementia should differ depending on the timing. Furthermore, since the results of this study present new dementia risk factors that have not been reported previously, this study may also contribute to identification of new dementia risk factors.

Association between dementia and hepatitis B and C virus infection

ABSTRACT

Several viral infections are known to increase the risk of dementia through brain cell damage and systemic infection. The association between hepatitis B and C virus (HBV and HCV) infections and dementia was evaluated using a national sample cohort from South Korea. Using the national cohort study from the Korean National Health Insurance Service, we extracted data for patients with HBV or HCV infection and for matched control participants. The controls were matched to the patients according to age, sex, income, region of residence, and past medical histories. The incidence of HCV infection was higher in the dementia group (1.0% [113/11,228]) than in the control group (0.8% [364/44,912], P = .043). However, there was no difference in the incidence of HBV infection in the dementia and control groups. The adjusted odds ratio (OR) for HCV infection was 1.25 (95% confidence interval [CI] = 1.01-1.54, P = .043) in the dementia group. According to the subgroup analysis by sex, the adjusted ORs for HCV infection were 1.04 (95% CI = 072-1.49, P = .851) in men and 1.38 (95% CI = 1.06-1.79, P = .016) in women. We concluded that the incidence of HCV infection was higher (with a higher OR) in women with dementia than in matched control participants in South Korea.

Association between statin medication and hearing impairment in a national health screening cohort

This study aimed to investigate the association of previous stain use with hearing impairment in an adult population. Data from the ≥ 40-year-old population in the Korean National Health Insurance Service Health Screening Cohort were used. The hearing impairment group was classified based on the national registry of hearing-impaired persons. Control participants were randomly selected and matched for age, sex, income, and region of residence. The number of days of statin prescription during the 2 years before the diagnosis of hearing impairment was compared between the hearing impairment group and the control group using conditional logistic regression analysis. Additional analyses were conducted according to age and sex. The number of days of previous statin use was not different between the hearing impairment group and the control group (adjusted odds ratio [aOR] = 0.94, 95% confidence interval (CI) = 0.86-1.02, P = 0.118). According to age, in the ≥ 70-year-old group, those with hearing impairment had 11% lower rates of previous statin use than those in the control group (aOR = 0.89, 95% CI = 0.80-0.99, P = 0.039). According to sex, in the male group, 12% lower rates of previous statin use were observed among those with hearing impairment than among those in the control group (aOR = 0.88, 95% CI = 0.79-0.99, P = 0.037). Previous statin use might have an effect on reducing the prevalence of hearing impairment in elderly individuals and men.

Association between Proton Pump Inhibitors and Hearing Impairment: A Nested Case-Control Study

This study investigated the association of previous use of proton pump inhibitors (PPIs) with the rate of hearing impairment. The ≥40-year-old population in the Korean National Health Insurance Service-Health Screening Cohort was enrolled. The 6626 registered hearing-impaired patients were matched with 508,240 control participants for age, sex, income, region of residence, and index date (date of hearing impairment diagnosis). The prescription histories of PPIs were collected for 2 years before the index date. The odds ratios of the duration of PPI use for hearing impairment were analyzed using conditional logistic regression. Subgroups of age/sex and severity of hearing impairments were additionally analyzed for the relation of PPI use with hearing impairment. PPI use for 30-365 days was associated with a 1.65-times higher odds of hearing impairment (95% confidence interval (CI) = 1.47-1.86 for 30-365 days of PPI medication). PPI use for ≥365 days was also related to 1.52-times higher odds of hearing impairment (95% CI = 1.35-1.72, p < 0.001). All age and sex subgroups demonstrated a positive association between PPI use and hearing impairment. Severe hearing impairment showed consistently higher odds of a relation with PPI use. PPI use was associated with an increased rate of hearing impairment.

Hearing Impairment Increases Economic Inequality

Objectives

We evaluated changes in income levels in a hearing-impaired population.

Methods

The study subjects were selected from the Korean National Health Insurance Service-Health Screening Cohort data from 2002 to 2015 of Koreans ≥40 years old. In total, 5,857 hearing-impaired subjects were matched with 23,428 comparison participants. Differences between the initial income level and income levels at 1, 2, 3, 4, and 5 years post-enrollment were compared between the hearing-impaired and comparison groups. The interaction of time and hearing impairment/comparison was estimated.

Results

Both the hearing-impaired group and the comparison group showed increased income levels over time. In the hearing-impaired group, the income levels at 4 and 5 years post-enrollment were higher than the initial income level (each P<0.001). In the comparison group, the income levels of all the participants after 1–5 years were higher than the initial income level (each P<0.001). The interaction of time and hearing impairment was statistically significant (P=0.021).

Conclusion

The increase in income over time was relatively lower in the hearing-impaired adult population; therefore, the income gap widened between this population and the normal-hearing population.

Association between Previous Statin Use and Alzheimer's Disease: A Nested Case-Control Study Using a National Health Screening Cohort

A number of studies report the incidence of Alzheimer’s disease (AD) in patients taking statins, but the results are inconsistent. (1) Background: The present study investigated the cross-sectional association between previous statin use and the risk of AD development in Korean residents. (2) Methods: We used the Korean National Health Insurance Service-National Sample Cohort; 17,172 AD patients were matched by age, gender, income, and region of residence with 68,688 control participants at a ratio of 1:4. We used a multiple conditional logistic regression model to analyse the association between the number of days of statin use and AD occurrence. Further analyses were performed to identify whether this association is maintained for different ages, genders, socioeconomic status groups, and covariates. (3) Results: The odds ratio, which was adjusted for potential confounders, for the days of statin use per year in the AD group compared to the control group was 0.95 (95% confidence interval = 0.92–0.98; p = 0.003). The number of days of statin use in the AD group was significantly smaller in the subgroups of non-smokers and individuals with normal weight, alcohol consumption less than once a week, total cholesterol level below 200 mg/dL, systolic blood pressure below 140, diastolic blood pressure below 90, and fasting blood glucose below 100 mg/dL. (4) Conclusions: Our results suggest that statin use prevents the occurrence of AD. The effects of statin use in preventing AD may be greater in individuals at relatively low risk.

Benign Paroxysmal Positional Vertigo and the Increased Risk of Ischemic Stroke: A Nested Case-Control Study Using a National Cohort Sample

A recent population cohort study reported that benign paroxysmal positional vertigo (BPPV) was a risk factor for ischemic stroke. This study investigated the risk of ischemic and hemorrhagic strokes in patients with BPPV. A nested case-control study used the data from the Korean National Health Insurance Service-National Sample Cohort between 2002 and 2013. We used data of patients aged ≥50 years obtained from the Korean National Health Insurance Service-National Sample Cohort between 2002 and 2013. A total of 15,610 patients with ischemic stroke and 4,923 patients with hemorrhagic stroke were matched for age, sex, income, residential location, hypertension, diabetes, and dyslipidemia with 62,440 and 19,692 controls, respectively. History of BPPV was evaluated in the stroke and control groups. Crude and adjusted odds ratios (ORs) for stroke in patients with BPPV were analyzed using stratified logistic regression analysis. Subgroup analyses were performed for age and sex. Notably, 3.7% (572/15,610) of patients with ischemic stroke and 2.7% (1,702/62,440) of the control subjects reported a history of BPPV (P < 0.001). The adjusted OR for BPPV in patients with ischemic stroke was 1.35 (95% confidence interval (CI) 1.22-1.49, P < 0.001). Patients with ischemic stroke showed higher ORs for BPPV in the subgroup of women. Patients with hemorrhagic stroke did not show a high OR for BPPV. Ischemic stroke patients demonstrated the increased OR for BPPV in subjects aged ≥50 years old.

Altered sphingolipid function in Alzheimer's disease; a gene regulatory network approach

Sphingolipids (SLs) are bioactive lipids involved in various important physiological functions. The SL pathway has been shown to be affected in several brain-related disorders, including Alzheimer's disease (AD). Recent evidence suggests that epigenetic dysregulation plays an important role in the pathogenesis of AD as well. Here, we use an integrative approach to better understand the relationship between epigenetic and transcriptomic processes in regulating SL function in the middle temporal gyrus of AD patients. Transcriptomic analysis of 252 SL-related genes, selected based on GO term annotations, from 46 AD patients and 32 healthy age-matched controls, revealed 103 differentially expressed SL-related genes in AD patients. Additionally, methylomic analysis of the same subjects revealed parallel hydroxymethylation changes in PTGIS, GBA, and ITGB2 in AD. Subsequent gene regulatory network-based analysis identified 3 candidate genes, that is, SELPLG, SPHK1 and CAV1 whose alteration holds the potential to revert the gene expression program from a diseased towards a healthy state. Together, this epigenomic and transcriptomic approach highlights the importance of SL-related genes in AD, and may provide novel biomarkers and therapeutic alternatives to traditionally investigated biological pathways in AD.

Increased risk of herpes zoster in patients with psoriasis: A longitudinal follow-up study using a national sample cohort

BACKGROUND/OBJECTIVE

Although previous studies reported the relationship between psoriasis and herpes zoster, the number of study is not sufficient to support the conclusions. The purpose of this study was to evaluate the association between psoriasis and herpes zoster.

METHODS

The data of a nationally representative Korean cohort collected in the Korean Health Insurance Review and Assessment (HIRA) System from 2002 to 2013 were used. Psoriasis was defined ≥ 2 International Classification of Diseases 10^th revision (ICD-10) L40 codes. Among them, severe psoriasis was defined as psoriatic medication use, including acitretin, systemic corticosteroid, cyclosporine and methotrexate. Other psoriasis was defined as mild psoriasis. Herpes zoster was defined as ≥ 2 ICD-10 B02 codes or ≥ 1 B02 code with antiviral medication use. Psoriasis patients (n = 11 009) and control participants (n = 44 036) were matched 1:4 by age, sex, income and region of residence. A stratified Cox proportional hazard model was used stratified by age, sex, income and region of residence. Crude and adjusted hazard ratios (HRs) were calculated for the risk of herpes zoster in the total psoriasis group, mild psoriasis group, and severe psoriasis group and compared with those in each matched control group.

RESULTS

The HR for herpes zoster was higher in the psoriasis group than in control group (adjusted HR = 1.22, 95% CI = 1.12-1.33, P < 0.001). The findings were consistent between the mild psoriasis and severe psoriasis patients and their matched controls, and between male psoriasis patients in all age groups and their matched male controls.

CONCLUSIONS

Psoriasis may increase the risk of herpes zoster, especially in males.

Effects of hearing impairment and hearing aid use on the incidence of cognitive impairment among community-dwelling older adults: evidence from the Taiwan Longitudinal Study on Aging (TLSA)

Background

Previous studies have reported associations between hearing impairment (HI) and cognitive impairment, but the evidence is not conclusive while considering concurrent geriatric syndromes. Especially, evidence from previous studies rarely came from Asian studies. This study aimed to evaluate the independent effects of HI and hearing aid use on the incidence of cognitive impairment while considering most geriatric confounders.

Methods

This population-based, propensity-score matched cohort study used cohort from Waves IV–VII (1999–2011) survey of the Taiwan Longitudinal Study on Aging (TLSA). Cognitive impairment was identified based on Short Portable Mental Status Questionnaire (SPMSQ) scores. The hazard ratio (HR) was calculated using the Cox proportional hazard regression adjusting for age, sex, comorbidities, socioeconomic status, Center for Epidemiologic Studies Depression (CES-D) scores, the instrumental activities of daily living scale, mobility condition and quality of life. In addition, social support and participation were also considered as confounders in the analysis. To assess the robustness of our findings, we conducted a sensitivity analysis designed to access unmeasured confounding factors by calculating E-values.

Results

After 1:1 propensity-score matching, we included 709 participants in both the HI and non-HI groups with a mean age of 73.4 years and 39.4% of participants were female. The mean follow-up was 8.9 ± 3.9 years. The HI group had a higher incidence of cognitive impairment than the non-HI group (74.5% vs. 69.1%, respectively), with an adjusted HR of 1.16 (95% confidence interval [CI], 1.03–1.32) based on a 12-year follow up. The E-value was 1.45 for the estimate, which provided evidence for this study’s robustness. Although, a subgroup analysis showed that hearing aid use was associated with lower incidences of cognitive impairment (66.3% vs. 75.6%) when compared to non-users in the HI group, the adjusted HR of 0.82 (95% CI, 0.61–1.09) revealed no significant differences.

Conclusions

HI was an independent risk factor of incident cognitive impairment on top of concurrent geriatric syndromes. Early HI detection may thus be effective for preventing cognitive decline. Further studies are needed to evaluate the effect of hearing aid use on the prevention of cognitive decline.

Bidirectional association between asthma and otitis media in children

BACKGROUND

This study explored the reciprocal association between otitis media and asthma in children.

METHODS

The 2002-2013 Korean Health Insurance Review and Assessment Service-National Sample Cohort participants < 15 years old were used. In study I, 14,665 asthma patients from 2002 through 2005 were selected. The asthma patients were matched 1:1 with the control I group, and the occurrence of otitis media was followed until 2013. In study II, 27,043 otitis media patients from 2002 through 2005 were selected. The otitis media patients were matched 1:1 with the control II group, and the occurrence of asthma was followed until 2013. Stratified Cox proportional hazard models were used to analyze the hazard ratio (HRs) of asthma for otitis media (study I) and otitis media for asthma (study II).

RESULTS

The HR for otitis media was 1.46 in asthma patients (95% confidence interval [CI] = 1.40-1.52, P < 0.001). The HR for asthma was 1.43 in otitis media patients (95% confidence interval [CI] = 1.36-1.50, P < 0.001).

CONCLUSION

Asthma and otitis media have a bidirectional association in children.

Herpes Zoster Does Not Increase the Risk of Neurodegenerative Dementia: A Case-Control Study

OBJECTIVE

This study was conducted to evaluate the association between neurodegenerative dementia and herpes zoster infection (HZI) using a national sample cohort.

METHODS

From the national cohort study conducted by the Korean National Health Insurance Service, we extracted data for patients with neurodegenerative dementia and for 1:4 matched control participants and searched the patient histories for HZI.

RESULTS

The adjusted odds ratio (OR) for HZI was 0.90 (95% CI = 0.84-0.97) in the dementia group. According to the subgroup analysis, the adjusted OR for HZI was 0.91 (95% confidence interval [CI] = 0.83 -1.00) in the < 80 years old group, 0.88 (95% CI = 0.78 -1.00) in the ≥ 80 years old group, 0.77 (95% CI = 0.66-0.89) in men and 0.96 (95% CI = 0.88 -1.05) in women.

CONCLUSIONS

We concluded that HZI does not increase the risk of neurodegenerative dementia in individuals of any age or of either sex.

Psoriasis Increases the Risk of Sudden Sensorineural Hearing Loss: A Longitudinal Follow Up Study Using a National Sample Cohort

Psoriasis is a well-known immune-mediated disease. Its autoimmune pathophysiology is consistent with the immune-mediated systemic vascular hypothesis regarding the pathogenesis of sudden sensorineural hearing loss (SSNHL). The purpose of our study was to investigate whether psoriasis affects the prevalence of SSNHL in all age groups matched by age, sex, income, and region of residence. Korean Health Insurance Review and Assessment Service-National Patient Samples were collected from 2002 to 2013. A 1:4 matched psoriasis group (n = 12,864) and control group (n = 51,456) were selected. The crude (simple) and adjusted (Charlson comorbidity index) hazard ratios (HR) for psoriasis and SSNHL were analyzed using the stratified Cox proportional hazard model. The incidence of SSNHL was significantly higher in the psoriasis group than in the control group (0.5% vs. 0.4%, p = 0.004). Psoriasis increased the risk of SSNHL (adjusted HR = 1.44, 95% confidence interval (CI) = 1.09–1.90, p = 0.010). In the stratification analysis, the incidence of SSNHL was significantly higher in the 30–59-year-old group than other group SSNHL (adjusted HR = 1.50, 95% CI = 1.06–2.12, p = 0.023). In addition, SSNHL occurred significantly more frequently in men with psoriasis (adjusted HR = 1.70, 95% CI = 1.17–2.49, p = 0.006). Psoriasis increased the risk of SSNHL, and SSNHL was more prevalent in between the age of 30–59-year-olds and men with psoriasis.

Association of nephrolithiasis with the risk of cardiovascular diseases: a longitudinal follow-up study using a national health screening cohort

OBJECTIVES

The aim of this study was to explore the associations of stroke and ischaemic heart disease in patients with nephrolithiasis.

DESIGN

A longitudinal follow-up study.

SETTING

Data from the Korean National Health Insurance Service-Health Screening Cohort (2002-2013) were retrieved to identify the occurrence of nephrolithiasis.

PARTICIPANTS AND INTERVENTIONS

In total, 19 103 patients with nephrolithiasis were matched at a 1:4 ratio with control participants for age, sex, income and region of residence.

PRIMARY AND SECONDARY OUTCOME MEASURES

The occurrence of stroke and ischaemic heart disease was analysed in both patients with nephrolithiasis and control participants. The primary outcome was HRs of stroke and ischaemic heart disease in a stratified Cox proportional hazards model. Smoking, alcohol consumption, obesity and Charlson Comorbidity Index were adjusted for as covariates. Subgroup analyses according to age and sex were also performed.

RESULTS

Eight per cent (1615/19 103) of patients with nephrolithiasis and 7.2% (5476/76 412) of control participants had stroke. Nine per cent (1879/19 103) of patients with nephrolithiasis and 7.7% (5895/76 412) of control participants had ischaemic heart disease. Patients with nephrolithiasis had risks of stroke and ischaemic heart disease that were 1.18 times (95% CI=1.11 to 1.24) and 1.24 times (95% CI=1.18 to 1.31) those of the control participants, respectively. The age and sex subgroups showed consistent results.

CONCLUSIONS

Nephrolithiasis was associated with increased risks of stroke and ischaemic heart disease.

Mortality and cause of death in patients with tracheostomy: Longitudinal follow-up study using a national sample cohort

BACKGROUND

The purpose of this study was to evaluate the long-term mortality and cause of death in patients with tracheostomy.

METHODS

Data from the Korean National Health Insurance Service-Health Screening Cohort were collected from 2002 to 2013. A total of 2394 tracheostomy participants and 9536 control participants were included in this study. The crude and adjusted hazard ratios (HRs) for tracheostomy-associated mortality were analyzed. Subgroup analysis according to age and cause of death was analyzed.

RESULTS

The tracheostomy group showed a significantly higher rate of death (69.1%) than the nontracheostomy group (13.3%). The adjusted HR for mortality was 13.5 in the tracheostomy group. The most common cause of death after tracheostomy was a circulatory disease, followed by neoplasm, respiratory disease, and trauma.

CONCLUSIONS

Patients with tracheostomy had a significantly increased long-term mortality rate compared with patients with nontracheostomy. The circulatory disease was the most common cause of death following tracheostomy.

Bidirectional association between GERD and rheumatoid arthritis: two longitudinal follow-up studies using a national sample cohort

Several previous studies have suggested a relationship between GERD and RA. However, no study has investigated the bidirectional relationship between GERD and RA. This study aimed to evaluate the causal relationships between rheumatoid arthritis (RA) and gastroesophageal reflux disease (GERD). Participants aged ≥ 20 years old in the Korean Health Insurance Review and Assessment Service-National Sample Cohort from 2002 to 2013 were enrolled. In study I, 132,140 GERD participants were 1:2 matched with 264,280 control I participants. In study II, 6615 RA participants were 1:4 matched with 26,460 control II participants. Both control I and control II groups were matched with their study groups for age, sex, income, and region of residence. The occurrence of RA (study I) and GERD (study II) were followed up in both the study and control groups. The hazard ratios (HRs) of GERD for RA (study I) and of RA for GERD (study II) were analysed using stratified Cox-proportional hazards models. In study I, 0.8% (1,034/132,140) of the GERD group and 0.5% (1,290/264,280) of the control I group had RA (P < 0.001). The GERD group demonstrated a 1.49-fold higher adjusted HR than did the control I group (95% confidence interval (95% CI) = 1.37-1.62, P < 0.001). In study II, 22.5% (1,490/6,615) of the RA group and 15.2% (4,034/26,460) of the control II group had GERD (P < 0.001). The RA group showed a 1.46-fold higher adjusted HR than did the control II group (95% CI = 1.38-1.55, P < 0.001). GERD and RA have bidirectional associations in Korean adult population. Key Points • Several previous studies have suggested a relationship between gastroesophageal reflux disease (GERD) and rheumatoid arthritis (RA). • However, no study has investigated the bidirectional relationship between GERD and RA. • This is the first study to present a bidirectional relationship between GERD and RA. • GERD and RA have bidirectional relations with each other.

Conductive Hearing Loss Aggravates Memory Decline in Alzheimer Model Mice

The study of cognitive impairment associated with hearing loss has recently garnered considerable interest. Epidemiological data have demonstrated that hearing loss is a risk factor for cognitive decline as a result of aging. However, no previous study has examined the effect of hearing loss in patients with cognitive problems such as Alzheimer’s disease. Therefore, we investigated the effect of conductive hearing loss in an Alzheimer’s mouse model. Positron emission tomography (PET) and magnetic resonance imaging (MRI) were used to evaluate changes in glucose metabolism and gray matter concentrations in the 5xFAD Alzheimer’s Disease (AD) transgenic mouse model with and without conductive hearing loss (HL). Conductive hearing loss was induced using chronic perforation of the tympanic membrane. Behavioral data from the Y-maze and passive avoidance tests revealed greater memory deficits in the AD with HL (AD-HL) group than in the AD group. Following induction of hearing loss, lower cerebral glucose metabolism in the frontal association cortex was observed in the AD-HL group than in the AD group. Although lower glucose metabolism in the hippocampus and cerebellum was found in the AD-HL group than in the AD group at 3 months, the gray matter concentrations in these regions were not significantly different between the groups. Furthermore, the gray matter concentrations in the simple lobule, cingulate/retrosplenial cortex, substantia nigra, retrosigmoid nucleus, medial geniculate nucleus, and anterior pretectal nucleus at 7 months were significantly lower in the AD-HL group than in the AD group. Taken together, these results indicate that even partial hearing loss can aggravate memory impairment in Alzheimer’s disease.

Mortality and Cause of Death in Hearing Loss Participants: A Longitudinal Follow-up Study Using a National Sample Cohort

OBJECTIVE

The purpose of the present study was to estimate the risk of mortality in hearing loss subjects in accordance with the cause of death.

STUDY DESIGN

A longitudinal follow up study.

SETTING

Data from the Korean National Health Insurance Service-National Sample Cohort were collected from a period between 2002 and 2013.

PATIENTS AND INTERVENTION

The 4,606 severe and 1,007 profound hearing loss participants with 40 or more years old were 1:4 matched with control participants, respectively, for age, sex, income, and region of residence. The causes of death were grouped into 12 classifications.

MAIN OUTCOME MEASURES

The ratio of mortality was compared between the hearing loss and control group using a χ test or Fisher's exact test. In a Cox-proportional hazard model, age, sex, income, region of residence, and past medical histories were considered confounders.

RESULTS

The severe and profound hearing loss groups showed 4.07 (95% CI = 3.71-4.46, p < 0.001) and 4.22 times (95% CI = 3.52-5.05, p < 0.001) higher mortality ratios in the adjusted models, respectively. Both the severe and profound hearing loss groups showed higher mortality by infection, neoplasm, trauma, and metabolic, mental, circulatory, respiratory, and digestive diseases than control groups (p < 0.05). Among various causes of death, death by trauma revealed the highest odds ratios in both the severe and profound hearing loss groups.

CONCLUSION

Hearing loss was associated with a significant increase in mortality.

Association between neurodegenerative dementia and chronic rhinosinusitis: A nested case-control study using a national health screening cohort

The aim of this case-control study was to evaluate the association between chronic rhinosinusitis (CRS) and neurodegenerative dementia in a large representative Korean population. The ≥ 50-year-old population was selected from the Korean Health Insurance Review and Assessment Service - National Sample Cohort from 2002 to 2015. A total of 17,634 neurodegenerative dementia patients were matched in a 1:4 ratio with 70,536 control participants for age, sex, income, and region of residence. Neurodegenerative dementia was defined using the ICD-10 codes G30 and F00. CRS was identified based on the ICD-10 code J32. Among the cohort, we selected participants who were treated ≥ 2 times and those who underwent head and neck computed tomography. The odds ratio (OR) for CRS in patients with dementia was analyzed using a conditional logistic regression model. Subgroup analyses were conducted according to age and sex. There was no difference in the prevalence of CRS with/without nasal polyps between the dementia (1.1%) and control (1.2%) groups (P = .825). CRS with/without nasal polyps was not significantly associated with dementia (adjusted OR = 0.96, 95% CI = 0.82-1.13, P = .653). In the subgroup analyses according to age and sex, the adjusted ORs for CRS with/without nasal polyps were not higher in the dementia group than in the control group. Previous CRS was not associated with neurodegenerative dementia in the Korean population.

Peptic ulcer does not increase the risk of dementia: A nested case control study using a national sample cohort

Studies have shown that peptic ulcer disease (PUD) increases the risk of dementia via the mechanism of systemic inflammation. We examined the association between PUD and the risk of dementia using a population-based national sample cohort from South Korea.Using the national cohort study from the Korean National Health Insurance Service, we extracted data for patients with dementia (n = 11,434) and for 1:4 matched control participants (n = 45,736) and then analyzed the previous histories of PUD from 2002 to 2013 using conditional logistic regression analyses. The controls were matched to the patients according to age, sex, income, region of residence, and past medical history. Subgroup analyses were performed based on age and sex.There was no statistically significant difference in the incidence of PUD between the dementia and control groups (18.0% vs 17.4%, P = .107). The adjusted odds ratio (OR) for PUD was 0.92 (95% confidence interval [CI] = 0.88-0.97, P = .002). In the subgroup analysis based on age, the adjusted ORs for PUD were 0.93 (95% CI = 0.88-0.99) in the <80-year-old group and 0.90 (95% CI = 0.82-1.00) in the ≥80-year-old group (each P < .05). In the subgroup analysis based on sex, the adjusted ORs for PUD were 0.89 (95% CI = 0.81-0.97; P < .05) in men and 0.94 (95% CI = 0.89-1.00; P = .06) in women.PUD does not increase the risk of dementia at any age or in either sex after adjusting for age and the history of hypertension, diabetes mellitus, dyslipidemia, ischemic heart disease, stroke, and depression.

Increased risk of ischemic stroke in patients with Bell's palsy: A longitudinal follow-up study using a national sample cohort

OBJECTIVE

To investigate the association between Bell's palsy and stroke according to the different types of stroke, using a sample cohort based on the national Korean population.

METHODS

Individuals aged ≥ 20 years were collected from the Korean National Health Insurance Service National Sample Cohort between 2002 and 2013. We extracted the data for Bell's palsy patients (n = 3658) and 1:4 matched controls (n = 14,632) and analyzed the occurrence of hemorrhagic or ischemic stroke in both groups. Matching was performed on the basis of age, gender, income, and region of residence. For Bell's palsy, we included only participants who received the diagnosis (ICD-10 code, G510) 2 or more times via ambulatory visits for the same episode with steroid treatment. Patient admission histories were used to identify occurrences of hemorrhagic stroke (I60, I61 and I62) and ischemic stroke (I63). Adjusted hazard ratios were calculated using stratified Cox proportional hazard models for the Charlson comorbidity index and 95% confidence intervals (CIs). For the subgroup analyses, we divided the participants by age, sex, and each time period after the onset of Bell's palsy (≤1 year, 1 to 2 years, 2 to 3years, > 3years).

RESULTS

The risk of ischemic stroke was significantly increased in Bell's palsy patients compared to that in the controls (adjusted HR = 1.74, 95% CI = 1.38-2.19, P < 0.001). In the subgroup analyses, a significant association between two clinical disorders was observed in patients aged ≥ 50 years old, regardless of gender. The risk of ischemic stroke was significantly increased, especially within 2 years after Bell's palsy. In contrast, the risk of hemorrhagic stroke was not significantly increased.

CONCLUSION

There is an association of Bell's palsy with ischemic stroke but not with hemorrhagic stroke.

Bidirectional association between GERD and asthma in children: two longitudinal follow-up studies using a national sample cohort

BACKGROUND

The causal relationship between asthma and gastroesophageal reflux disease (GERD) is unknown in children.

METHODS

The Korean Health Insurance Review and Assessment Service-National Sample Cohort 2002-2013 was used. The population age <15 years was selected. In study I, 86,096 asthmatic children were 1:1 matched with 86,096 control I participants. In study II, 532 GERD children were 1:2 matched with 1064 control II participants. The stratified Cox proportional hazard ratios for GERD in patients with asthma (study I) and asthma in patients with GERD (study II) were analyzed.

RESULTS

In total, 0.7% (583/86,096) of the asthma group and 0.5% (430/86,096) of the control I group had GERD (P < 0.001). The asthma group demonstrated a 1.36 times higher HR for GERD than the control I group (95% CI = 1.20-1.54, P < 0.001). Subgroup analyses according to age and sex showed consistent results. In total, 15.0% (80/532) of the GERD group and 10.0% (106/1,064) of the control II group had asthma (P < 0.001). The GERD group showed a 1.62-fold higher HR for asthma than the control II group (95% CI = 1.21-2.18, P < 0.001).

CONCLUSION

GERD and asthma demonstrated a bidirectional relationship in children.

The Relation of Sudden Sensorineural Hearing Loss in Pediatric Patients With Recurrent Otitis Media: A Nested Case-control Study Using a National Sample Cohort

OBJECTIVE

The risk of sudden sensorineural hearing loss (SSNHL) was suggested to be increased in chronic otitis media patients. This study expanded previous findings by using pediatric patients with recurrent otitis media.

STUDY DESIGN

A nested case-control study.

SETTING

Participants in the Korean National Health Insurance Service-National Sample Cohort that were less than 15 years old from 2002 to 2004 were included.

PATIENTS

Overall, 24,226 patients with ≥ 5 instances of otitis media were 1:1 matched with a group controlled for age, sex, income, and region of residence.

MAIN OUTCOME MEASURE

The occurrence of SSNHL was followed until 2013. The hazard ratio (HR) for SSNHL was analyzed in the otitis media patients using a stratified Cox proportional hazard regression model. Matching variables were stratified. The histories of sinusitis and atopic dermatitis were adjusted. Subgroup analysis was performed according to age and sex.

RESULTS

Overall, 0.14% (33/24,226) of the otitis media group and 0.06% (14/24,226) of the control group had SSNHL (p = 0.006). The otitis media group had a higher adjusted HR for SSNHL than the control group (adjusted HR = 2.13, 95% CI = 1.13-4.02). According to age, the 10- to 14-year-old group showed a 9.07-fold higher HR for SSNHL than the control group (95% CI = 1.14-72.54). According to sex, the female group showed a 3.74-fold higher HR for SSNHL than the control group (95% CI = 1.24-11.29).

CONCLUSION

Recurrent otitis media in children was related to the onset of SSNHL.

Auditory and Olfactory Deficits in Essential Tremor - Review of the Current Evidence

Background:

Essential tremor (ET) is the most common adult movement disorder, characterized by several motor and increasingly well recognized non-motor symptoms. Sensory deficits, such as hearing impairment and olfactory dysfunction, are amongst them. This review analyzes the available evidence of these sensory deficits and their possible mechanistic basis in patients with ET.

Method:

A PubMed literature search on the topic was performed in the May 2019 database.

Results:

Nineteen articles on hearing impairment and olfactory dysfunction in ET patients were identified. The prevalence of hearing impairment is higher in ET patients than healthy controls or Parkinson disease. Cochlear pathologies are suggested as the underlying cause, but there is still a lack of information about retrocochlear pathologies and central auditory processing. Reports on olfactory dysfunction have conflicting results. The presence of mild olfactory dysfunction in ET was suggested. Conflicting results may be due to the lack of consideration of the disease’s heterogeneity, but according to recent data, most studies do not find prominent evidence of olfactory loss in ET.

Conclusion:

Although there is increasing interest in studies on non-motor symptoms in ET, there are few studies on sensory deficits, which are of particularly high prevalence. More studies are needed on to investigate the basis of non-motor symptoms, including sensory deficits.

Increased the risk of depression in patients with chronic rhinosinusitis without polyp: A longitudinal follow up study using a national sample cohort

Previous studies have reported that chronic rhinosinusitis (CRS) is closely related to depression. The present study aims to elucidate the association between CRS without nasal polyp and depression using a national sample cohort. Using the national sample cohort from Korean Health Insurance Review and Assessment Service, we matched patients with CRS (n = 21,707) to control participants (n = 86,828), at a ratio of 1:4, according to age, sex, household income, region of residence. The stratified Cox proportional-hazards model was used to evaluate the hazard ratio (HR) between CRS and depression. A subgroup analysis was performed according to age group and gender. The HR for depression was significantly higher in patients with CRS than in control participants (adjusted HR = 1.41, 95% confidence interval = 1.33-1.48) after adjustment for age, sex, household income, region of residence, and medical history. The risk of depression was also elevated in the subgroup analysis, regardless of age or gender. In conclusion, CRS was significantly associated with the increased risk of depression.

Impact of Hearing Aids on Poverty, Quality of Life and Mental Health in Guatemala: Results of a before and after Study

There are 466 million people globally with disabling hearing loss, many of whom can benefit from hearing aids. The aim of the study was to assess the impact of providing hearing aids on poverty, mental health, quality of life, and activities, among adults in Guatemala. A nonrandomised before and after study was conducted, with a comparison group to assess for secular trends. Adult cases with bilateral hearing impairment were identified within 150 km of Guatemala City, as well as age- and sex-matched comparison subjects without disabling hearing loss. All participants were interviewed with a semistructured questionnaire, and cases were offered hearing aids. Participants were reinterviewed 6–9 months later. We interviewed 135 cases and 89 comparison subjects at baseline and follow-up. At baseline, cases were poorer than comparison subjects with respect to individual income (p = 0.01), household income (p = 0.02), and per capita expenditure (PCE) (p = 0.003). After provision of hearing aids, median household income improved among cases (p = 0.03). In the comparison group, median individual income (p = 0.01) and PCE (p = 0.03) fell between baseline at follow-up. At follow-up, there were also improvements in productive time use, quality of life, and depressive symptoms among cases, but these were less apparent in the comparison group. In conclusion, this study has demonstrated a positive effect of hearing aids in improving quality of life, economic circumstances and mental health among Guatemalan adults.

Mood Disorders are Associated With Increased Risk of BPPV: A National Sample Cohort

OBJECTIVES

Few studies have reported that mood disorders increase the risk of benign paroxysmal positional vertigo (BPPV). The purpose of our study was to demonstrate whether the incidence of BPPV in those with mood disorders differs from that in a matched control group.

STUDY DESIGN

Nationwide cohort observational study.

METHODS

Korean Health Insurance Review and Assessment Service-National Patient Samples were collected from 2002 to 2013. A 1:4 matched mood disorder group (n = 59,340) and control group (n = 237,720) were selected. The crude and adjusted (cerebral stroke, ischemic heart disease, anxiety disorder, and osteoporosis histories) hazard ratios (HRs) for depression and BPPV were analyzed using a stratified Cox proportional hazard model. The results were stratified by age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia in these analyses.

RESULTS

The incidence of BPPV was significantly higher in the mood disorder group than in the control group (3.2% vs. 2.1%, P < .001). Mood disorder increased the risk of BPPV (adjusted HR = 1.31, 95% confidence interval [CI] = 1.23-1.39, P < .001). In subgroup analyses, the incidence of BPPV in all age groups and in both sexes was significantly higher in the mood disorder group than in the control group.

CONCLUSION

This population-based cohort study demonstrates that mood disorder was significantly associated with BPPV.

LEVEL OF EVIDENCE

N/A. Laryngoscope, 131:380-385, 2021.

The association between Bell's palsy and rheumatoid arthritis: A longitudinal study

This study aimed to evaluate the relationship between Bell's palsy and rheumatoid arthritis in a national sample cohort from Korea.Data were collected for individuals ≥20 years old from 2002 to 2013 in the Korean National Health Insurance Service-National Sample Cohort. We extracted data for patients with rheumatoid arthritis (n = 7628) and 1:4-matched controls (n = 30,512) and analyzed the occurrence of Bell's palsy in both groups. Matching was performed based on age, sex, income, and region of residence. Rheumatoid arthritis was diagnosed according to International Classification of Disease-10 (ICD-10) codes (M05-M06) and the prescription of biological agents and/or disease-modifying antirheumatic drugs. Bell's palsy patients were diagnosed according to ICD-10 code H912 and treatment ≥2 times with steroids. Adjusted hazard ratios (HRs) were calculated using stratified Cox proportional hazard models for the Charlson comorbidity index and 95% confidence intervals (CIs). Subgroup analyses based on age and sex were also performed.The rates of Bell's palsy were similar between the rheumatoid arthritis group (0.5% [38/7628]) and the control group, with no significant difference (0.4% [124/30,512], P = .270). The adjusted HR for Bell's palsy was 1.12 (95% CI, 0.78-1.62) in the rheumatoid arthritis group (P = .540). In the subgroup analyses according to age and sex, the relationship between Bell's palsy and rheumatoid arthritis did not reach statistical significance.The risk of Bell's palsy was not increased in patients with rheumatoid arthritis.

Reciprocal association between depression and peptic ulcers: Two longitudinal follow-up studies using a national sample cohort

This study was aimed to explore the bidirectional association between depression and peptic ulcers. The ≥20-year-old participants of the Korean National Health Insurance Service-National Sample Cohort from 2002 to 2013 were included in the study. In study I, 30,306 depression patients were 1:4 matched with 121,224 control I participants. In study II, 127,590 peptic ulcer patients were 1:1 matched with 127,590 control II participants. The stratified Cox-proportional hazards models were used to analyse the hazard ratio (HR) of depression for peptic ulcers (study I) and of peptic ulcers for depression (study II). A total of 8.9% (2,703/ 30,306) of depression patients and 7.3% (8,896/ 121,224) of patients in the control I group had peptic ulcers (P < 0.001). The depression group had an adjusted HR for peptic ulcers that was 1.14-fold higher than that of the control I group (95% confidence interval [95% CI] = 1.09–1.19, P < 0.001). A total of 6.4% (8,144/ 127,590) of peptic ulcer patients and 3.5% (4,515/127,590) of patients in the control II group had depression (P < 0.001). The peptic ulcer group had an adjusted HR for depression that was 1.68-fold higher than that of the control II group (95% CI = 1.62–1.74, P < 0.001). Depression and peptic ulcers exhibited a bidirectional relationship.

Auditory function and dysfunction: estrogen makes a difference

Estrogen is the major female hormone involved in reproductive functions, but it also exerts a variety of additional roles in non-reproductive organs. In this review, we highlight the preclinical and clinical studies that have pointed out sex differences and estrogenic influence on audition. We also describe the experimental evidences supporting a protective role of estrogen towards acquired forms of hearing loss. Although a high level of endogenous estrogen is associated with a better hearing function, hormonal treatments at menopause have provided contradictory outcomes. The various factors that are likely to explain these discrepancies include the treatment regimen as well as the hormonal status and responsiveness of the patients. The complexity of estrogen signaling is being untangled and many downstream effectors of its genomic and non-genomic actions have been identified in other systems. Based on these advances and on the common physio-pathological events that underlie age-related, drug or noise-induced hearing loss, we discuss potential mechanisms for their protective actions in the cochlea.

Bidirectional relation between depression and sudden sensorineural hearing loss: Two longitudinal follow-up studies using a national sample cohort

A few studies have explored the association between depression and sudden sensorineural hearing loss (SSNHL). This study was aimed to investigate the reciprocal relations between SSNHL and depression using a nationwide cohort of the Korean population. Subjects aged > 20 years from the Korean National Health Insurance Service-National Sample Cohort were enrolled from 2002 to 2013. In study I, a total of 60,178 depressed patients were matched 1:4 with 242,872 control I subjects. In study II, a total of 4,328 SSNHL patients were 1:4 matched with 17,312 control II subjects. They were matched for age, sex, income, and region of residence. The Charlson comorbidity index (CCI) was adjusted. Subgroup analysis was performed according to age and sex. The crude and adjusted CCI hazard ratios (HRs) of SSNHL in depressed patients (study I) and depression in SSNHL patients (study II) were analyzed using the stratified Cox proportional-hazard model. In study I, the depression group exhibited an elevated adjusted HR of SSNHL 1.16 times that of the control group (confidence interval [95% CI] = 1.02–1.31, P < 0.023). The middle-aged women subgroup demonstrated an increased risk of SSNHL within the depression group. In study II, the SSNHL group showed a higher adjusted HR of depression 1.29 times that of control II group (95% CI = 1.06–1.57, P = 0.010). The middle-aged women subgroup showed an elevated risk of depression in the SSNHL group. The risk of SSNHL was elevated in the depressed patients and the risk of depression was increased in the SSNHL patients.

Characteristics of Young-Onset and Late-Onset Dementia Patients at a Remote Memory Clinic

Background:

Young-onset dementia (YOD) is defined as the onset of dementia symptoms before the age of 65 years and accounts for 2–8% of dementia. YOD patients and their caregivers face unique challenges in diagnosis and management. We aimed to compare the characteristics of rural YOD and late-onset dementia (LOD) patients at a rural and remote memory clinic in Western Canada.

Methods:

A total of 333 consecutive patients (YOD = 61, LOD = 272) at a rural and remote memory clinic between March 2004 and July 2016 were included in this study. Each patient had neuropsychological assessment. Health, mood, function, behaviour and social factors were also measured. Both groups were compared using χ2 tests and independent sample tests.

Results:

YOD patients were more likely to be married, employed, current smokers and highly educated. They reported fewer cognitive symptoms, but had more depressive symptoms. YOD patients were less likely to live alone and use homecare services. YOD caregivers were also more likely to be a spouse and had higher levels of distress than LOD caregivers. Both YOD and LOD patient groups were equally likely to have a driver’s licence.

Conclusions:

Our findings indicate YOD and LOD patients have distinct characteristics and services must be modified to better meet YOD patient needs. In particular, the use of homecare services and caregiver support may alleviate the higher levels of distress found in YOD patients and their caregivers. Additional research should be directed to addressing YOD patient depression, caregiver distress and barriers to services.

Hepatitis virus B and C infections are associated with an increased risk of non-Hodgkin lymphoma: A nested case-control study using a national sample cohort

BACKGROUND

Hepatitis B virus (HBV) and hepatitis C virus (HCV) are suspected of being associated with non-Hodgkin lymphoma (NHL); however, persuasive data are lacking. Hence, a nested large-population case-control study was performed to investigate such associations in Koreans.

METHODS

Data were collected from 929 patients with NHL and 3716 healthy subjects, who were matched 1:4 for age, sex, income, and region of residence, from the Korean Health Insurance Review and Assessment Service-National Sample Cohort. The diagnoses of NHL and HBV/HCV infection were based on the International Classification of Diseases (version 10) codes. Conditional logistic regression models were used to assess odds ratios (ORs) for NHL with respect to HBV or HCV with adjustment for the Charlson comorbidity index.

RESULTS

HBV and HCV rates were higher in the NHL group (3.3% and 1.3%, respectively) than in the control group (0.9% and 0.3%, respectively; P < .001 for each). The adjusted OR of hepatitis infection in patients with NHL were 3.25 (95% confidence interval [CI] = 1.99-5.31) for HBV and 3.36 (95% CI = 1.51-7.46) for HCV (P < .001 for each). Subgroups categorized by age (<55 vs ≥55 years) or sex showed significantly higher adjusted ORs of HBV for NHL. Moreover, patients with NHL ≥ 55 years of age or those who were female showed significantly higher adjusted ORs of HCV; those <55 years or who were male also tended to have higher ORs of HCV.

CONCLUSION

Infection with either HBV or HCV is associated with NHL in Koreans.

Bidirectional association between asthma and migraines in adults: Two longitudinal follow-up studies

The objective of this study was to evaluate the bidirectional association between asthma and migraines using control subjects matched by demographic factors. The Korean Health Insurance Review and Assessment Service - National Sample Cohort from 2002 to 2013 was used. In study I, 113,059 asthma participants were matched with 113,059 control I participants. In study II, 36,044 migraine participants were matched with 114,176 control II participants. The hazard ratios (HRs) of migraines in the asthma patients (study I) and asthma in the migraine patients (study II) were analyzed using stratified Cox proportional hazard models after adjusting for depression and the Charlson comorbidity index. In study I, 5.3% (6,017/ 113,059) of the asthma group and 3.4% (3,806/ 113,059) of the control I group had migraines (P < 0.001). The asthma group demonstrated an adjusted HR of 1.47 for migraine (95% confidence interval (CI) = 1.41–1.53, P < 0.001). In study II, 15.4% (5,548/36,044) of the migraine group and 10.6% (15,271/144,176) of the control group had asthma (P < 0.001). The migraine group showed an adjusted HR of 1.37 for asthma (95% CI = 1.33–1.41, P value < 0.001). Asthma and migraines are reciprocally associated.

Evaluation of the increased risk of spine fracture in patients with mood disorder compared with matched controls: a longitudinal follow-up study using a national sample cohort in Korea

OBJECTIVE

To evaluate the risk of spine fracture in patients with mood disorder using a nationwide cohort.

DESIGN

A longitudinal follow-up study.

SETTING

Claims data for the population ≥20 years of age were collected from 2002 to 2013 for the Korean National Health Insurance Service-National Sample Cohort.

PARTICIPANTS

A total of 60 140 individuals with mood disorder were matched with 240 560 individuals (control group) for age, sex, income, region of residence and osteoporosis.

INTERVENTIONS

In both the mood disorder and control groups, the history of spine fracture was evaluated. The International Classification of Diseases 10th Revision codes for mood disorder (F31-F39) and spine fracture (S220 and S320) were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

The univariable and multivariable HRs and 95% CIs of spine fracture for patients with mood disorder were analysed using a stratified Cox proportional hazards model. Subgroup analyses were conducted according to the history of osteoporosis, age and sex.

RESULTS

Approximately 3.3% (2011/60 140) of patients in the mood disorder group and 2.8% (6795/240 560) of individuals in the control group had spine fracture (p<0.001). The mood disorder group demonstrated a higher adjusted HR for spine fracture than the control group (multivariable HR=1.10, 95% CI 1.04 to 1.15, p<0.001). The participants without osteoporosis showed a higher HR of mood disorder for spine fracture than the control participants (multivariable HR=1.25, 95% CI 1.14 to 1.37, p<0.001). According to age and sex, this result was consistent in subgroups of women aged 20-39 and 40-59 years and men aged ≥60 years.

CONCLUSION

The risk of spine fracture was increased in patients with mood disorder. The potential risk of spine fracture needs to be evaluated when managing patients with mood disorder.

Increased risk of lymphoid malignancy in patients with herpes zoster: a longitudinal follow-up study using a national cohort

Background

The association between herpes zoster and the risk of lymphoid neoplasms in Asian populations has not yet been established. We performed a longitudinal follow-up study using a nationwide cohort to assess the risk of lymphoid neoplasms arising after herpes zoster infection in the adult Korean population.

Methods

Data from participants ≥20 years of age who were registered in the Korean National Health Insurance Service-National Sample Cohort database between 2002 and 2013 were collected. We extracted the data of participants with herpes zoster (n = 59,495) as well as those of matched references at a ratio of 1:4 (n = 237,980) and investigated the subsequent occurrence of lymphoid neoplasms. A stratified Cox proportional hazards model was used to calculate unadjusted hazard ratios (HRs) as well as those adjusted for the Charlson comorbidity index score.

Results

The rate of lymphoid neoplasms was higher in the herpes zoster group (0.15% [90/59,495]) than in the reference group (0.08% [212/237,980], P < 0.001). The unadjusted and adjusted HRs of herpes zoster in patients with lymphoid neoplasms were 1.68 (95% confidence interval [CI] = 1.31–2.15) and 1.58 (95% CI = 1.23–2.02), respectively (P < 0.001 for both). On subgroup analyses according to age and sex, herpes zoster was associated with an increased risk of lymphoid neoplasms in all subgroups; the adjusted HRs were 1.53 (95% CI = 1.05–2.24) for patients < 60 years old, 1.58 (95% CI = 1.14–2.20) for patients ≥60 years old, 1.64 (95% CI = 1.16–2.31) for men, and 1.51 (95% CI = 1.06–2.16) for women (P < 0.05 for all). On subgroup analysis of lymphoid neoplasm subtypes, herpes zoster was associated with the risk of Hodgkin’s disease (adjusted HR: 3.23 [95% CI = 1.17–8.93]) and multiple myeloma/malignant plasma cell neoplasms (adjusted HR: 2.17 [95% CI = 1.33–3.54]) (P < 0.05 for both).

Conclusion

Herpes zoster is associated with lymphoid neoplasm development in the Korean population irrespective of age and sex. The risks of Hodgkin’s disease and plasma cell neoplasms are significantly elevated in patients with herpes zoster.

Association between depression and rheumatoid arthritis: two longitudinal follow-up studies using a national sample cohort

Objective

To investigate the bidirectional relation between RA and depression.

Methods

Data from the Korean Health Insurance Review and Assessment Service – National Sample Cohort from 2002 to 2013 were analysed. Patients ≥20 years of age were included. Study I was conducted with 38 087 depression patients and 152 348 matched control participants. Study II was conducted with 7385 RA patients and 29 540 matched control participants. Stratified Cox proportional hazards models were used to analyse the hazard ratios (HRs) for depression and RA (study I) and for RA and depression (study II). The data were adjusted by the Charlson comorbidity index; rheumatic disease was excluded. Subgroups were also analysed according to age and sex.

Results

A total of 0.7% (1260/38 087) of the depression group and 0.6% (883/152 348) of the control I group had RA (P = 0.02). The HR for RA in the depression group was not significantly higher than that in control I group. In study II, 5.5% (408/7385) of the RA group and 4.3% (1246/29 540) of the control II group presented with depression (P &lt; 0.001). The RA patients showed an adjusted depression HR that was 1.20 times higher (95% CI 1.07, 1.34; P = 0.002) than that of the control group. The &gt;30-years-old and women subgroups of RA patients showed higher depression HRs than the control subgroups.

Conclusion

RA increased the risk of depression; however, depression did not increase the risk of RA in the Korean adult population.

Bidirectional Association Between GERD and Asthma: Two Longitudinal Follow-Up Studies Using a National Sample Cohort

BACKGROUND

A relation between gastroesophageal reflux disease (GERD) and asthma has been suggested; however, causality has not been investigated.

OBJECTIVE

This study aimed to delineate the causal relation between GERD and asthma.

METHODS

Participants of the Korean National Health Insurance Service-National Sample Cohort 2002-2013 who were ≥20 years old were selected for this study. In study I, 116,502 patients with GERD were matched in a 1:2 ratio to 233,004 control I participants, and the hazard ratio (HR) of asthma in patients with GERD was analyzed. In study II, 104,146 patients with asthma were matched in a 1:1 ratio to 104,146 control II participants, and the HR for GERD in patients with asthma was analyzed. A stratified Cox-proportional hazards model was used. Subgroup analyses were performed according to age and sex.

RESULTS

In study I, 12.5% (14,595 of 116,502) of the GERD group and 7.8% (18,135 of 233,004) of the control I group presented asthma (P < .001). The GERD group demonstrated a 1.46-fold higher HR for asthma than the control I group (95% confidence interval [CI] = 1.42-1.49, P < .001). In study II, 16.9% (17,582 of 104,146) of the asthma group and 11.9% (12,393 of 104,146) of the control II group presented GERD (P < .001). The asthma group showed a 1.36-fold higher HR for GERD than the control II group (95% CI = 1.33-1.39, P < .001). All age and sex subgroups presented consistent results.

CONCLUSION

GERD and asthma had a bidirectional relation in the study population.

Increased risk of osteoporosis in patients with peptic ulcer: a follow-up study using a national sample cohort

We performed a nationwide, population-based cohort study to investigate the risk of osteoporosis in patients with peptic ulcer disease in South Korea and concluded that peptic ulcer disease is associated with an increased risk of osteoporosis.

PURPOSE

This study aimed to evaluate the association between peptic ulcer disease (PUD) and the occurrence of osteoporosis using a national sample cohort from South Korea.

METHODS

Using the national cohort study from the Korean National Health Insurance Service, we extracted data for patients with PUD (n = 50,002) and for 1:1 matched control participants (n = 50,002); we then analyzed the occurrence of osteoporosis from 2002 to 2013. The patients were matched according to age, sex, income, region of residence, and past medical history. A stratified Cox proportional hazards model was used to analyze the hazard ratios (HRs) and the 95% confidence intervals (CIs). Subgroup analyses were performed based on age and sex.

RESULTS

The adjusted HR for osteoporosis was 1.36 (95% CI = 1.33-1.40, P < 0.001) in the PUD group. In the subgroup analysis based on age and sex, the respective adjusted HRs of PUD for osteoporosis were 1.33 (95% CI = 1.21-1.47) in the < 65-year-old group of men and 1.42 (95% CI = 1.30-1.56) in the ≥ 65-year-old group of men (each P < 0.001). The respective adjusted HRs of PUD for osteoporosis were 1.34 (95% CI = 1.29-1.39) in the < 65-year-old group of women and 1.38 (95% CI = 1.33-1.47) in the ≥ 65-year-old group of women (each P < 0.001).

CONCLUSION

In the current nationwide cohort study, we found that PUD is associated with an increased risk of osteoporosis regardless of sex.