Depression, Stress, and Suicide in Korean Adults before and during the COVID-19 Pandemic Using Data from the Korea National Health and Nutritional Examination Survey

This study investigated changes in the prevalence of depression, stress, and suicidal attempts during the COVID-19 pandemic. The ≥19-year-old population in the Korea National Health and Nutrition Examination Survey in 2019 and 2020 was included. The histories of depression, stress, and suicidal attempts were compared between the 2019 and 2020 cohorts using multiple logistic regression analysis with complex sampling. The prevalence of depression was not significantly different between the 2019 and 2020 groups (4.1% vs. 4.5%, p = 0.326). The prevalence of stress and suicide attempts was also not significantly different between groups (all p > 0.05). The rates of depression, stress, and suicide attempts were not associated with the 2020 group compared to the 2019 group (all p > 0.05). The 19- to 39-year-old group in the 2020 group indicated a higher rate of depression (diagnosed by physicians) than the 19- to 39-year-old group in the 2019 group (adjusted odds ratio = 1.58, 95% confidence intervals = 1.00−2.50, p = 0.049). The risks of depression, stress, and suicidal attempts were not related to the COVID-19 pandemic in Korean adults. A young adult population demonstrated an increased risk of depression associated with the COVID-19 pandemic.

Physical Activity and Sedentary Time in Korean Adults before and during the COVID-19 Pandemic Using Data from the Korea National Health and Nutritional Examination Survey

Several recent studies suggested reduced physical activity (PA) related to the COVID-19 pandemic without consensus. This study investigated the changes in PA and sedentary time during the COVID-19 pandemic compared to before the COVID-19 era. The Korea National Health and Nutrition Examination Survey 2019 and 2020 were used. The ≥19-year-old population was examined in 2019 and 2020 for time spent engaging in high- and moderate-intensity PA and sedentary time. Based on the recommended level of PA by the World Health Organization, ≥75 min/wk of high PA and ≥150 min/of moderate PA were classified. A sedentary time of ≥120 min/d was selected. Multiple logistic regression analysis with complex sampling was conducted for ≥75 min/wk of high PA, ≥150 min/wk of moderate PA, and ≥120 min/d of sedentary time in the 2020 group compared to the 2019 group. The ≥75 min/wk high PA was not lower in the 2020 group than in the 2019 group (adjusted odds ratio (aOR) = 0.96, 95% confidence intervals (95% CIs) = 0.79–1.18, P = 0.696). The ≥150 min/wk of moderate PA was also not lower in the 2020 group (aOR = 1.12, 95% CI = 0.94–1.32, p = 0.201). However, the ≥150 min/wk of moderate PA in the female group was higher in the 2020 group than in the 2019 group (aOR = 1.29, 95% CI = 1.01–1.65, p = 0.042). Sedentary time ≥ 120 min/d was lower in the 2020 group (aOR = 0.35, 95% CI = 0.17–0.72, p = 0.005). This association was consistent in the 19–39-year-old and female group. In conclusion, during the COVID-19 pandemic, high and moderate PA were not decreased in Korean adults, while sedentary time was reduced.

Changes in the Incidence Rates of Gastrointestinal Diseases Due to the COVID-19 Pandemic in South Korea: A Long-Term Perspective

We investigated whether the coronavirus disease 2019 (COVID-19) pandemic, in conjunction with public health measures, influenced the incidence of gastrointestinal diseases according to age and sex during the pandemic. Changes in the monthly incidence rates (January 2018 to June 2021) of common gastrointestinal diseases were assessed using data from the Korean National Health Insurance Service by comparing the data of two periods: before COVID-19 (January 2018-February 2020) and during COVID-19 (March 2020-June 2021). The Mann-Whitney U test and Levene's test were used to compare the differences in the incidences before and during the pandemic. In the pandemic period, compared to in the pre-COVID-19 period, the incidence rates of ulcerative colitis, Crohn's disease, cholelithiasis, and esophageal reflux significantly increased, whereas those of infective enteritis and irritable bowel syndrome decreased, regardless of age or sex. There were no significant changes in the incidence rates of pancreatitis, acute appendicitis, liver cirrhosis, and hemorrhoids. No seasonal variations in gastrointestinal disease occurrence were observed. In conclusion, the COVID-19 pandemic may have had unprecedented and long-term impacts on the epidemiology of gastrointestinal disease. These changes may indicate a substantial future burden on healthcare resources during the recovery phase of the pandemic and thereafter.

Is the Number of Missing Teeth Associated With Mortality? A Longitudinal Study Using a National Health Screening Cohort

This study aimed to estimate the risk of mortality related to the number of missing teeth in a South Korean population. The ≥ 40-year-old population of the Korean National Health Insurance Service-Health Screening Cohort 2002–2003 was analyzed. Participants were selected from a total of 220,189 participants and included in groups of 0 teeth lost, 1–2 teeth lost, and ≥ 3 teeth lost. Among the total population, 17,211 participants were included in no missing teeth, 1–2 missing teeth, and ≥ 3 missing teeth and were randomly matched 1:1:1 for age and sex. Mortality from specific causes and all-cause mortality were compared among the groups. The hazard ratio (HR) of the number of missing teeth for all-cause mortality or each cause of mortality was analyzed using Cox proportional hazard models. According to the cause of death, the HRs for metabolic disease, digestive disease, and trauma were greater in the group with ≥ 3 missing teeth than in the no missing teeth group. The group with ≥ 3 missing teeth indicated a 1.19-fold higher HR for all-cause mortality than the no missing teeth group [95% confidence intervals (95% CIs) = 1.12–1.27, P < 0.001]. The group with 1- 2 missing teeth did not show a higher HR for all-cause mortality. In the group with 1–2 missing teeth, the HRs for mortality from mental disease and digestive disease were higher than those in the no missing teeth group. The group with 1–2 missing teeth did not show a higher HR for all-cause mortality. The number of missing teeth was linked with a higher risk of mortality. For specific causes of mortality, mortality from metabolic disease, digestive disease, and trauma was higher in the participants with the number of missing teeth.

Association between Thyroid Cancer and Weight Change: A Longitudinal Follow-Up Study

BACKGROUND

The purpose of this study was to evaluate body mass index (BMI) and systolic blood pressure (SBP)/diastolic blood pressure (DBP) between Korean adults who underwent thyroidectomy and comparison groups.

METHODS

Data were included from the Korean National Health Insurance Service-Health Screening Cohort (2002-2015). BMI and SBP/DBP were measured before thyroidectomy, 1 and 2 years after thyroidectomy (n = 1995 in study I, n = 2162 in study II), comparing 1:4 matched participants (n = 7980 in study I, n = 8648 in study II). The paired t-test and linear mixed model were used to identify the differences between groups.

RESULTS

DBP in both thyroid cancer II and comparison II group were significantly lower after thyroidectomy than before thyroidectomy. However, the interaction effect of thyroidectomy in study I and study II did not reach statistical significance.

CONCLUSION

BMI, SBP and DBP were not significantly different between the thyroidectomy group and the matched comparison group.

Association Between Meniere Disease and Migraine

Importance

A connection between Meniere disease (MD) and migraine has been proposed, but the temporal association remains unknown.

Objective

To examine the bidirectional association of MD with migraine.

Design, Setting, and Participants

This case-control study included participants 40 years or older from the Korean National Health Insurance Service Health Screening Cohort from 2002 to 2015.

Main Outcomes and Measures

A total of 6919 patients with MD were matched with 27 676 control participants without MD for age, sex, income, region of residence, and index date. The incidence of migraine was analyzed in the MD and matched groups using a stratified Cox proportional hazard regression model. In addition, 35 889 patients with migraine were matched with 71 778 control participants without migraine. The incidence of MD was analyzed using a stratified Cox proportional hazard regression model.

Results

Of 142 262 total participants, 94 611 (66.5%) were women. Migraine occurred in 695 of 6919 patients with MD (10.0%) and 970 of 27 676 matched control participants (3.5%). The MD group demonstrated a 2.22-fold higher risk of migraine than the matched control group (95% CI, 1.99-2.49). Meniere disease was present in 1098 of 35 889 patients with migraine (3.1%) and 781 of 71 778 matched control participants (1.1%). The migraine group had a 1.95-fold higher risk of MD than the matched control group (95% CI, 1.77-2.15).

Conclusions and Relevance

The results of this case-control study suggest that patients with MD had a greater risk of migraine occurrence. Furthermore, patients with migraine had a higher risk of MD. Based on the bidirectional association, therapeutics for migraine could potentially be applied to MD and vice versa.

Changes in the Mean of Medical Visits Due to Psychiatric Disease in Korean Children and Adolescents before and during the COVID-19 Pandemic

The COVID-19 pandemic has been suggested to have adverse impacts on psychiatric disorders. This study aimed to investigate the changes in medical visits due to a wide range of psychiatric disorders in children during the COVID-19 pandemic. The medical visits of all Korean children and adolescents (0−19 years old) due to the 12 following psychiatric disorders were investigated: autism; attention-deficit/hyperactivity disorder (ADHD); depressive disorder; bipolar disorder; primary insomnia; schizophrenia; panic disorder; hypochondriasis; posttraumatic stress disorder (PTSD); anxiety disorder; anorexia nervosa; and adephagia. The mean medical visits before and during the COVID-19 pandemic were compared. The mean number of clinical visits due to autism, ADHD, depressive disorder, bipolar disorder, panic disorder, hypochondriasis, PTSD, anxiety disorder, and anorexia nervosa was higher during the COVID-19 pandemic than before the COVID-19 pandemic (all p < 0.05). The higher mean number of medical visits due to psychiatric disorders was maintained in age and sex subgroups. The female and adolescent groups demonstrated a higher mean number of medical visits due to psychiatric disorders during the COVID-19 pandemic. The medical visits due to many psychiatric disorders were higher during the COVID-19 pandemic than before COVID-19 in children and adolescents in Korea. Women and adolescents were more susceptible to psychiatric disorders during the COVID-19 pandemic.

Association between Gout and Dyslipidemia: A Nested Case-Control Study Using a National Health Screening Cohort

The association between lipid levels and uric acid disorders remains controversial. We evaluated the association between dyslipidemia and gout in a large cohort from the Korean National Health Insurance Service-Health Screening Cohort. Among the 514,866 participants aged ≥40 years, 16,679 gout participants were selected and matched with 66,716 control participants for income, region of residence, sex, and age. We used the ICD-10 codes to define dyslipidemia (E78) and gout (M10) and diagnosis was confirmed when each was reported ≥2 times. The odds ratios (ORs) of dyslipidemia history were calculated using conditional logistic regression in crude, partial, and fully adjusted models. The days of statin use, systolic and diastolic blood pressure, fasting glucose level, total cholesterol, obesity, Charlson comorbidity index, alcohol consumption, and smoking were used as covariates. Patients with gout had a significantly higher dyslipidemia history than those without gout (33.1% vs. 24.0%, p < 0.001). The association was significant after adjustment (OR in partial adjusted model = 1.50, 95% confidence interval (CI) = 1.44−1.57; OR in fully adjusted model = 1.43, 95% CI = 1.37−1.49). These findings were consistent with the subgroup analysis. Our findings suggest that dyslipidemia history is more likely in patients with gout aged ≥40 years than in healthy controls among Korean population.

Association between statin use and Parkinson's disease in Korean patients with hyperlipidemia

INTRODUCTION

Findings on the association between statin therapy and Parkinson's disease (PD) occurrence have been inconsistent. This study aimed to identify the association between statin use and PD in participants with a history of hyperlipidemia or blood cholesterol >200 in a Korean population to exclude nonstatin users owing to normal lipid values.

METHODS

We conducted a nested case-control analysis using the Korean National Health Insurance Service-National Sample Cohort assessed between 2002 and 2015. We identified 3026 PD cases. A total of 12,104 controls were then individually matched by age, sex, income, and region of residence at a ratio of 1:4. Potential confounders comprised basic demographic factors, lifestyle factors, various medical conditions and comorbidities. A conditional/unconditional logistic regression method was applied.

RESULTS

Compared with statin use for <6 months, adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for 6-12 months of statin use and ≥12 months of statin use were 1.03 (0.92-1.15) and 1.61 (1.35-1.93) after adjustment for confounders, respectively (P = 0.664 and P < 0.001). In analyses according to statin solubility, only the association between lipophilic statin use for ≥12 months and PD maintained statistical significance, with an aOR of 1.64 (95% CI = 1.34-2.01, P < 0.001). These relations were consistent in subgroup analyses by covariates.

CONCLUSIONS

Statin use for more than 12 months was associated with a higher probability of PD in the Korean population with hyperlipidemia. This probability was significant for lipophilic statins but not hydrophilic statins.

Incident Rheumatoid Arthritis Following Statin Use: From the View of a National Cohort Study in Korea

Safety issues regarding the potential risk of statins and incident rheumatoid arthritis (RA) have been raised, but the existing data are largely based on Caucasian populations, and continue to have biases and require further validation in Asian populations. Here, we aimed to verify the risk of RA depending on the duration of previous statin use and statin types using a large-scale, nationwide database. This study enrolled 3149 patients with RA and 12,596 matched non-RA participants from the national health insurance database (2002−2015), and investigated their statin prescription histories for two years before the index date. Propensity score overlap-weighted logistic regression was applied after adjusting for multiple covariates. The prior use of any statins and, specifically, the long-term use of lipophilic statins (>365 days) were related to a lower likelihood of developing RA ((odds ratio (OR) = 0.73; 95% confidence intervals (CI) = 0.63−0.85, p < 0.001) and (OR = 0.71; 95% CI = 0.61−0.84, p < 0.001), respectively). Subgroup analyses supported these preventive effects on RA in those with dyslipidemia, independent of sex, age, smoking, alcohol use, hypertension, and hyperglycemia. Hydrophilic statin use or short-term use showed no such associations. Our study suggests that prior statin use, especially long-term lipophilic statin use, appears to confer preventive benefits against RA.

Longitudinal follow-up study of the association between statin use and chronic periodontitis using national health screening cohort of Korean population

Since a potential link between statins and the risk of adverse chronic periodontitis (CP) has been raised, we aimed to validate the association between statin use and the incidence of CP using nationwide cohort data. This longitudinal follow-up study included 169,381 patients prescribed statins who were matched with an equal number of controls using propensity scores from the Korean National Health Insurance Service-Health Screening Cohort database (2002–2015). A Cox proportional hazard model was used to assess the occurrence of CP following statin use after adjusting for multiple covariates. The occurrence of CP was significantly higher in patients who had long-term use (1–3 years, 3–5 years, or > 5 years) than with short-term use (≤ 1 year) of statins. After adjustment, statin users exhibited an occurrence of CP 1.32-fold higher (95% confidence interval 1.30–1.33) than that of the matched nonusers (incidence: 25.0 and 22.0 per 100 person-years, respectively). Subgroup analyses supported the adverse impact of statins on CP independent of age and gender. Statin user odds ratios for developing CP were higher compared to those of nonusers. This was consistent in individuals aged > 40 years in both genders, especially with long-term use.

The Influence of Prior Statin Use on the Prevalence and Exacerbation of Chronic Obstructive Pulmonary Disease in an Adult Population

Background

Statins have anti-inflammatory and antioxidant properties, and previous studies have reported the positive effects of statins on chronic obstructive pulmonary disease (COPD) outcomes. However, the effects of statins on the development and acute exacerbations of COPD remain unclear. Therefore, this study aimed to assess the relation between statin use and COPD occurrence in all participants and the link between statin use and COPD acute exacerbations in participants with COPD.

Methods

This case-control study comprised 26,875 COPD participants and 107,500 control participants who were 1:4 matched from the Korean National Health Insurance Service-Health Screening Cohort. Conditional logistic regression was used to evaluate the probability of COPD occurrence associated with previous statin use. In addition, unconditional logistic regression was employed to assess the risk of exacerbations related to statin use among COPD participants. These relations were estimated in subgroup analysis according to statin type (lipophilic vs. hydrophilic).

Results

The association between previous statin use and the occurrence of COPD did not reach statistical significance in the overall population (adjusted odds ratio [aOR] = 0.96, 95% confidence interval [CI] = 0.93–1.00, P = 0.059). However, statin use decreased the probability of exacerbations in participants with COPD (aOR = 0.79, 95% CI = 0.74–0.85, P &lt; 0.001). Lipophilic statins decreased the probability of exacerbations, whereas hydrophilic statins were not associated with a decreased likelihood of exacerbations (aOR = 0.78, 95% CI = 0.72–0.84, P &lt; 0.001 for lipophilic statins; aOR = 0.89, 95% CI = 0.78–1.02, P = 0.102 for hydrophilic statins).

Discussion

Statin use was not associated with the occurrence of COPD in the adult population. However, statin use was associated with a reduced probability of exacerbations in participants with COPD, with a greater risk reduction with lipophilic statin use.

Association between Thyroid Cancer and Breast Cancer: Two Longitudinal Follow-Up Studies Using a National Health Screening Cohort

Background: The purpose of this study was to evaluate the association between thyroid cancer and breast cancer. Methods: Data from the Korean National Health Insurance Service-Health Screening Cohort were collected from 2002 to 2013. In study I, 3949 thyroid cancer participants were 1:4 matched with 15,796 control I participants, and hazard ratios (HRs) with 95% confidence intervals (CIs) for breast cancer were evaluated using a stratified Cox proportional hazard model. In study II, 3308 breast cancer participants were 1:4 matched with 13,232 control II participants, and HRs with 95% CIs for thyroid cancer were assessed in the same way as in study I. In the subgroup analyses, associations were analyzed according to radioactive iodine (RAI) treatment and age (<60 years old and ≥60 years old). Results: The adjusted HR for breast cancer in the thyroid cancer group was 1.64 (95% CI = 1.13–2.39, p = 0.010). The adjusted HR for thyroid cancer in the breast cancer group was 1.91 (95% CI = 1.47–2.49, p < 0.001). In the subgroup analyses, the groups that were older and not treated with RAI treatment showed consistent results in study I, and the younger and older groups showed consistent results in study II. Conclusions: Based on this cohort study, breast and thyroid cancer have a reciprocal positive association.

The Association Between Thyroid Diseases and Alzheimer's Disease in a National Health Screening Cohort in Korea

OBJECTIVES

Thyroid dysfunction is linked to an increased risk of cognitive impairment. However, studies on the relationships between thyroid diseases and Alzheimer's disease (AD) have reported conflicting results. We investigated the associations between several thyroid diseases and AD in a nested case-control study.

METHODS

A total of 1,977 participants with AD were identified by claims data from 2002-2015 among a random sample of half a million people in the Korean National Health Insurance database. We recruited 16,473 age- and sex-matched (1:4 ratio) control participants and applied conditional logistic regression to estimate the relationships between thyroid diseases and AD, with adjustments for potential confounders, such as basic demographics, lifestyle factors, and various medical conditions or comorbidities.

RESULTS

The prevalence rates of hypothyroidism (odds ratio [OR]=1.14, 95% confidence interval [CI]=1.00-1.30), thyroiditis (OR=1.22, 95% CI=1.05-1.40), and hyperthyroidism (OR=1.13, 95% CI=1.01-1.28) were significantly higher in participants with AD than in control participants after adjustment for confounders.

CONCLUSION

In this large national sample, we found significant relationships between several thyroid diseases and AD. Despite of the need for further investigation, these findings could better support to appreciate the pathophysiology of AD.

Increased Risk of Temporomandibular Joint Disorder in Osteoporosis Patients: A Longitudinal Study

BACKGROUND

The objective of this study was to investigate the risk of temporomandibular joint disorder (TMD) in patients with osteoporosis.

METHODS

Data from the Korean National Health Insurance Service-Health Screening Cohort from 2002 to 2015 were collected. Participants ≥ 40 years old were enrolled, and the history of osteoporosis was evaluated. The 62,328 osteoporosis patients were matched for age, sex, income, and region of residence with 62,328 control participants. The occurrence of TMD was assessed in both the osteoporosis and control groups during the follow-up period. Stratified Cox proportional hazard analyses for TMD were conducted for the osteoporosis and control groups. The hazard ratios (HRs) of osteoporosis for TMD were further analyzed by age and sex subgroups.

RESULTS

A total of 1.2% (725/61,320) of the osteoporosis patients and 0.6% (339/61,320) of the control participants had TMD (P<0.001). Osteoporosis was associated with an elevated HR of TMD (adjusted HR=1.96, 95% CI=1.72-2.23, P<0.001). Among the age and sex subgroups, the < 60-year-old mal\e group demonstrated an adjusted HR of osteoporosis for TMD as high as 4.47 (95% CI=1.17-17.12, P=0.029). Other age and sex subgroups also showed a higher HR for TMD associated with osteoporosis (adjusted HR=2.30, 95% CI=1.90-2.78, P<0.001 for the ≥ 60-year-old female group).

CONCLUSION

Osteoporosis was related to a higher risk of TMD in the adult population. A prominent association of osteoporosis with TMD was noted in middle-aged men and older women.

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.

Association between Rheumatoid Arthritis and Meniere's Disease: A Longitudinal Follow-Up Study Using a National Health Screening Cohort

This study aimed to evaluate the impact of pre-existing rheumatoid arthritis (RA) on the occurrence of Meniere’s disease (MD). The 2002–2015 Korean National Health Insurance Service—Health Screening Cohort data were retrospectively analyzed. A total of 3038 participants with RA were matched with 12,152 control participants for demographic factors. The occurrence of MD was evaluated in both the RA and control groups. The hazard ratios (HRs) of RA for participants with MD were calculated using a stratified Cox proportional hazard model. Additionally, subgroup analyses were conducted. The rate of MD was not different between the RA and control groups (1.5% vs. 1.3%, standardized difference = 0.01). The HR was not higher in the RA group than in the MD group (adjusted HR = 1.03, 95% confidence interval = 0.73–1.44, p = 0.885). A higher HR of RA for participants with MD was found in the ≥60-year-old subgroup in the crude model but not in the adjusted model. An association between RA and MD was not found in any of the other subgroups. A previous history of RA was not related to an increased risk of MD.

Association between Osteoporosis and Previous Statin Use: A Nested Case-Control Study

The relationship between statin use and osteoporosis is controversial; therefore, this study aimed to investigate this association. The ≥40-year-old population of the Korean National Health Insurance Service Health Screening Cohort was enrolled. The 68,592 osteoporosis patients were matched 1:1 with control participants for age, sex, income, and region of residence using propensity score matching. The histories of statin use for two years before the diagnosis of osteoporosis (index date) in the osteoporosis and control groups were compared using conditional/unconditional logistic regression. An increased number of days of statin use was not associated with osteoporosis (adjusted OR (aOR) = 0.97, 95% confidence interval (95% CI) = 0.94–1.00, p = 0.052). In the subgroup analyses, a large number of days of statin use was related to a reduced rate of osteoporosis in the <60-year-old female group, while the opposite was true in the ≥60-year-old female group. Both lipophilic and hydrophilic statins were related to a decreased rate of osteoporosis in the <60-year-old female group. Lipophilic statins, but not hydrophilic statins, were associated with an increased rate of osteoporosis in the ≥60-year-old female group. Statin use showed different associations in middle-aged and elderly women.

Association between Temporomandibular Joint Disorder and Weight Changes: A Longitudinal Follow-Up Study Using a National Health Screening Cohort

This study aimed to investigate BMI changes following a temporomandibular joint disorder (TMJD) diagnosis. The Korean National Health Insurance Service-Health Screening Cohort from 2002 to 2015 was used. In Study I, 1808 patients with TMJD (TMJD I) were matched with 7232 participants in comparison group I. The change in BMI was compared between the TMJD I and comparison I groups for 1 year. In study II, 1621 patients with TMJD (TMJD II) were matched with 6484 participants in comparison group II participants. The change in BMI was compared between the TMJD II and comparison II groups for 2 years. In Study I, the BMI change was not associated with TMJD. In Study II, the BMI change was associated with TMJD in the interaction of the linear mixed model (p = 0.003). The estimated value (EV) of the linear mixed model was −0.082. The interaction was significant in women < 60 years old, women ≥ 60 years old, and the obese I category. TMJD was not associated with BMI changes after 1–2 years in the overall population. In women and obese patients, TMJD was associated with a decrease in BMI after 2 years.

Propranolol Inhibits the Proliferation of Human Glioblastoma Cell Lines through Notch1 and Hes1 Signaling System

Objective

The anti-tumor effect of the beta-adrenergic receptor antagonist propranolol in breast cancer is well known; however, its activity in glioblastoma is not well-evaluated. The Notch-Hes pathway is known to regulate cell differentiation, proliferation, and apoptosis. We investigated the effect of propranolol to human glioblastoma cell lines, and the role of Notch and Hes signaling in this process.

Methods

We performed immunohistochemical staining on 31 surgically resected primary human glioblastoma tissues. We also used glioblastoma cell lines of U87-MG, LN229, and neuroblastoma cell line of SH-SY5Y in this study. The effect of propranolol and isoproterenol on cell proliferation was evaluated using the MTT assay (absorbance 570 nm). The impact of propranolol on gene expression (Notch and Hes) was evaluated using real-time polymerase chain reaction (RT-PCR, whereas protein levels of Notch1 and Hes1 were measured using Western blotting (WB), simultaneously. Small interfering RNA (siRNA) was used to suppress the Notch gene to investigate its role in the proliferation of glioblastoma.

Results

Propranolol and isoproterenol caused a dose-dependent decrease in cell proliferation (MTT assay). RT-PCR showed an increase in Notch1 and Hes1 expression by propranolol, whereas WB demonstrated increase in Notch1 protein, but a decrease in Hes1 by propranolol. The proliferation of U87-MG and LN229 was not significantly suppressed after transfection with Notch siRNA.

Conclusion

These results demonstrated that propranolol suppressed the proliferation of glioblastoma cell lines and neuroblastoma cell line, and Hes1 was more closely involved than Notch1 was in glioblastoma proliferation.

High BMI1 Expression with Low CD8+ and CD4+ T Cell Activity Could Promote Breast Cancer Cell Survival: A Machine Learning Approach

BMI1 is known to play a key role in the regulation of stem cell self-renewal in both endogenous and cancer stem cells. High BMI1 expression has been associated with poor prognosis in a variety of human tumors. The aim of this study was to reveal the correlations of BMI1 with survival rates, genetic alterations, and immune activities, and to validate the results using machine learning. We investigated the survival rates according to BMI1 expression in 389 and 789 breast cancer patients from Kangbuk Samsung Medical Center (KBSMC) and The Cancer Genome Atlas, respectively. We performed gene set enrichment analysis (GSEA) with pathway-based network analysis, investigated the immune response, and performed in vitro drug screening assays. The survival prediction model was evaluated through a gradient boosting machine (GBM) approach incorporating BMI1. High BMI1 expression was correlated with poor survival in patients with breast cancer. In GSEA and in in silico flow cytometry, high BMI1 expression was associated with factors indicating a weak immune response, such as decreased CD8+ T cell and CD4+ T cell counts. In pathway-based network analysis, BMI1 was directly linked to transcriptional regulation and indirectly linked to inflammatory response pathways, etc. The GBM model incorporating BMI1 showed improved prognostic performance compared with the model without BMI1. We identified telomerase inhibitor IX, a drug with potent activity against breast cancer cell lines with high BMI1 expression. We suggest that high BMI1 expression could be a therapeutic target in breast cancer. These results could contribute to the design of future experimental research and drug development programs for breast cancer.

Abstract 2831: Exosome gene signatures characterize metastatic dynamicity

Early diagnosis and effective tumor monitoring can significantly alter clinical outcomes of ovarian cancer patients. Innovative tools are needed to enhance the sensitivity and specificity of current monitoring modalities. Extracellular vesicles, or exosomes, have shown to be promising conduits of diagnostic biomarkers to aid in tumor detection as evidenced by Exosome Diagnostics' new ExoDx Prostate (IntelliScore) test that uses exosomal markers to differentiate between benign prostate disease and early cancer (Tutrone, R., Donovan, M.J., Torkler, P. et al. Clinical utility of the exosome based ExoDx Prostate(IntelliScore) EPI test in men presenting for initial Biopsy with a PSA 2-10 ng/mL. Prostate Cancer Prostatic Dis 23, 607-614 (2020)). The potential of these vesicles however goes beyond simple diagnostic power of cancer detection. Due to the onco-specific contents packaged and the minimally invasive, low risk accessibility, exosomes have the capacity to be used as longitudinal monitoring tools to characterize early molecular changes at all stages of the disease. We hypothesized that the dynamicity of ovarian tumors during progression and metastatic development is reflected in exosomes. In order to test this we isolated exosomes and used qPCR to analyze exosomal gene signatures from a mouse model of ovarian cancer. SKOV3 ovarian cancer tumor cells were injected into mice and allowed to grow for 3 weeks. Plasma was collected from mice at 5-7 day increments and exosomes were extracted. Multiple established metastatic genes in ovarian cancer were evaluated and 4 genes, Lox, THBS1, TIMP3, and β-actin, were found to be differentially expressed in correlation with 3 translationally pertinent assessments: presence or absence of tumors, levels of metastatic burden, and longitudinal tumor progression. Gene expression patterns were compared with exosomal gene signatures extracted from human ovarian patient plasma and found to express similar patterns. These results support the diagnostic potential of using exosomal genetic signatures to detect early metastatic development and to facilitate longitudinal tracking of tumor progression.

Citation Format: Amber Gonda, Jay V. Shah, Jake N. Siebert, Nanxia Zhao, Mi Jung Kwon, Prabhas V. Moghe, Nicola Francis, Vidya Ganapathy. Exosome gene signatures characterize metastatic dynamicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2831.

Enzymatic characterization of a novel recombinant 1,3-α-3,6-anhydro-L-galactosidase specific for neoagarobiose hydrolysis into monosaccharides

Two GH117 family α-neoagarobiose hydrolases (GH117A α-NABH and GH117B α-NABH) from the freshwater agar-degrading Cellvibrio sp. KY-GH-1 were expressed and purified as recombinant His-tagged proteins using an Escherichia coli expression system to compare activities. The amino acid sequence of GH117A α-NABH (364 amino acids, 40.9 kDa) showed 35% identity with that of GH117B α-NABH (392 amino acids, 44.2 kDa). GH117A α-NABH, but not GH117B α-NABH, could hydrolyze neoagarobiose (NA2) into monosaccharides 3,6-anhydro-L-galactose (L-AHG) and D-galactose. The presence of GH117A α-NABH homologues in all of the agar-degrading bacteria aligned suggests that GH117A α-NABH hydrolyzing NA2 into L-AHG and D-galactose is an essential component of the agar-degrading enzyme machinery. For GH117A α-NABH-catalyzed hydrolysis, NA2 was the sole substrate among various neoagaro-oligosaccharides (NA2~NA18). GH117A α-NABH appeared to exist as a dimer, and optimal enzymatic temperature and pH were 35 °C and 7.5, respectively. GH117A α-NABH was stable up to 35 °C and at pH 7.5 and unstable beyond 35 °C and outside pH 7.0~7.5. The kinetic parameters K_m, V_max, k_cat, and k_cat/K_m for NA2 were 16.0 mM, 20.8 U/mg, 14.2 s^-1, and 8.9 × 10² s^-1 M^-1, respectively. Combined addition of 5 mM MnSO₄ and 10 mM tris(2-carboxyethyl)phosphine enhanced the enzyme activity by 2.4-fold. The enzyme-mediated hydrolysis of 5.0% NA2 into monosaccharide and purification of L-AHG from hydrolysis products by Sephadex G-10 column chromatography recovered ~ 192 mg L-AHG from 400 mg NA2 (~ 92% of the theoretical maximum yield). These results indicate that the recombinant GH117A α-NABH is NA2-specific and useful to produce L-AHG from NA2. KEY POINTS: • Recombinant GH117A α-NABH (364 aa, 40.9 kDa) purified from E. coli forms a dimer. • The enzyme hydrolyzes only NA2 among various neoagaro-oligosaccharides (NA2~NA18). • The enzyme completely hydrolyzes up to 5% NA2 into monomers under optimal conditions.

A pictorial review on clinicopathologic and radiologic features of duodenal gastrointestinal stromal tumors

Duodenal gastrointestinal stromal tumors (GISTs) are rare, and studies on their management are not sufficient. Owing to the complex anatomy of the duodenum and pancreatic head, GISTs can be misdiagnosed as pancreatic head tumors. Surgical resection is the first treatment for localized duodenal GISTs; thus, noninvasive imaging is important for the diagnosis and treatment of GISTs. Computed tomography, magnetic resonance imaging and endoscopic ultrasonography findings can be helpful for the diagnosis of duodenal GISTs and can help differentiate GISTs from other adjacent tumors.

Molecular risk markers related to local tumor recurrence at histological margin-free endoscopically resected early gastric cancers: A pilot study

Local recurrences in early gastric cancers (EGCs) after complete endoscopic submucosal dissection (ESD) remain problematic. Here, we investigated the spatially sequential molecular changes in various cancer-related proteins along the axis of the histologically clear but recurrent resection margins (TRM) to determine the appropriate tumor-free margin distance and potential molecular risk markers related to local recurrence. Five eligible patients with recurrent EGCs after complete ESD were selected from 548 EGC patients. The specimens, including recurrent resection margin axis, were divided into 5 zones. Digital spatial profiling assay was performed to quantify the expression level of 31 cancer-related proteins along each zone. p-Chk1 level was significantly reduced in TRM zone than non-recurrent resection margin. The expression of p44/42 ERK and p-Chk1 were significantly decreased along the lateral axis of the recurrent resection margin, with no significance toward the normal zone, which may suggest that p44/42 ERK and p-Chk1 may be involved in the recurrent side compared to non-recurrent margin. Although we could not evaluate more than 5.5 mm, the significant linear decreases in p44/42 ERK and p-Chk1 were maintained until at least 5.5 mm from the tumor zone in the TRM direction. We estimated the possible margin distance using scatterplots and linear regression analyses, which also showed the estimated distance more than 5.5 mm. In conclusion, the p-Chk1 and p44/42 ERK may be potential candidates of molecular risk markers that may be related to the local recurrence after complete ESD, and a tumor-free distance of 5.5 mm is not enough for safety margin.