Environmental drivers of increased ecosystem respiration in a warming tundra

Arctic and alpine tundra ecosystems are large reservoirs of organic carbon1,2. Climate warming may stimulate ecosystem respiration and release carbon into the atmosphere3,4. The magnitude and persistency of this stimulation and the environmental mechanisms that drive its variation remain uncertain5-7. This hampers the accuracy of global land carbon-climate feedback projections7,8. Here we synthesize 136 datasets from 56 open-top chamber in situ warming experiments located at 28 arctic and alpine tundra sites which have been running for less than 1 year up to 25 years. We show that a mean rise of 1.4 °C [confidence interval (CI) 0.9-2.0 °C] in air and 0.4 °C [CI 0.2-0.7 °C] in soil temperature results in an increase in growing season ecosystem respiration by 30% [CI 22-38%] (n = 136). Our findings indicate that the stimulation of ecosystem respiration was due to increases in both plant-related and microbial respiration (n = 9) and continued for at least 25 years (n = 136). The magnitude of the warming effects on respiration was driven by variation in warming-induced changes in local soil conditions, that is, changes in total nitrogen concentration and pH and by context-dependent spatial variation in these conditions, in particular total nitrogen concentration and the carbon:nitrogen ratio. Tundra sites with stronger nitrogen limitations and sites in which warming had stimulated plant and microbial nutrient turnover seemed particularly sensitive in their respiration response to warming. The results highlight the importance of local soil conditions and warming-induced changes therein for future climatic impacts on respiration.

CLDN18: Clinical, Pathological, and Genetic Signatures with Drug Screening in Gastric Adenocarcinoma

INTRODUCTION

The CLDN18 gene, encoding claudin 18.1 and claudin 18.2, is a key component of tight junction strands in epithelial cells that form a paracellular barrier that is critical in Stomach Adenocarcinoma (STAD).

METHODS

Our study included 1,095 patients with proven STAD, 415 from The Cancer Genome Atlas (TCGA) cohort and 680 from the Gene Expression Omnibus database. We applied various analyses, including gene set enrichment analysis, pathway analysis, and in vitro drug screening to evaluate survival, immune cells, and genes and gene sets associated with cancer progression, based on CLDN18 expression levels. Gradient boosting machine learning (70% for training, 15% for validation, and 15% for testing) was used to evaluate the impact of CLDN18 on survival and develop a survival prediction model.

RESULTS

High CLDN18 expression correlated with worse survival in lymphocyte-poor STAD, accompanied by decreased helper T cells, altered metabolic genes, low necrosis-related gene expression, and increased tumor proliferation. CLDN18 expression showed associations with gene sets associated with various stomach, breast, ovarian, and esophageal cancers, while pathway analysis linked CLDN18 to immunity. Incorporating CLDN18 expression improved survival prediction in a machine learning model. Notably, nutlin-3a and niraparib effectively inhibited high CLDN18-expressing gastric cancer cells in drug screening.

CONCLUSION

Our study provides a comprehensive understanding of the biological role of CLDN18-based bioinformatics and machine learning analysis in STAD, shedding light on its prognostic significance and potential therapeutic implications. To fully elucidate the molecular intricacies of CLDN18, further investigation is warranted, particularly through in vitro and in vivo studies.

Associations between Peritonsillar Abscess and Deep Neck Infection in Chronic Periodontitis Patients: Two Nested Case-Control Studies Using a National Health Screening Cohort

Background/Introduction: Odontogenic infection is one of the main etiologies of deep neck infection (DNI). However, the relationship between chronic periodontitis (CP) and the incidence of DNI has not been examined. This study aimed to evaluate the incidence of DNI and peritonsillar abscess (PTA) after CP. Methods: The Korean National Health Insurance Service-National Sample Cohort 2002-2019 was used. In Study I, 4585 PTA patients were matched with 19,340 control I participants. A previous history of CP for 1 year was collected, and the odds ratios (ORs) of CP for PTA were analyzed using conditional logistic regression. In Study II, 46,293 DNI patients and 185,172 control II participants were matched. A previous history of CP for 1 year was collected, and conditional logistic regression was conducted for the ORs of CP for DNI. Secondary analyses were conducted in demographic, socioeconomic, and comorbidity subgroups. Results: In Study I, a history of CP was not related to the incidence of PTA (adjusted OR = 1.28, 95% confidence interval [CI] = 0.91-1.81). In Study II, the incidence of DNI was greater in participants with a history of CP (adjusted OR = 1.55, 95% CI = 1.41-1.71). The relationship between CP history and DNI was greater in groups with young, male, low-income, and rural residents. Conclusions: A prior history of CP was associated with a high incidence of DNI in the general population of Korea. Patients with CP need to be managed for the potential risk of DNI.

Investigating the Connection between Chronic Periodontitis and Parkinson's Disease: Findings from a Korean National Cohort Study

Recent research suggests a potential relevance between chronic periodontitis (CP) and Parkinson's disease (PD), raising concerns about comorbid PD among elderly CP patients. However, the epidemiologic basis for this association remains unclear. Employing a nested case-control design, this study explored the association between CP and subsequent PD occurrences in Korean adults, leveraging a validated national population-based dataset covering the period from 2002 to 2019. It included 8794 PD patients and 35,176 matched control individuals, established through propensity score matching for age, sex, residential area, and income. Baseline characteristics were compared using standardized differences, and logistic regression was employed to assess the impact of CP histories on PD likelihood while controlling for covariates. We performed a thorough examination of CP events within both 1-year and 2-year intervals preceding the index date, incorporating subgroup analyses. Our analysis revealed no statistically significant association between CP history and PD development overall. However, subgroup analysis revealed a slightly increased likelihood of PD development among CP individuals with a high disease burden (Charlson Comorbidity Index score ≥ 2). In conclusion, although our study did not find a significant overall association between CP history and PD development, the elevated likelihood of PD in subgroups with high disease burden may suggest that comorbidities influence PD probability among certain CP patients. Considering comorbid conditions in PD screening for some individuals with CP may be also important.

Associations between Chronic Kidney Disease and Migraine Incidence: Findings from a Korean Longitudinal Big Data Study

While headaches frequently occur in individuals with chronic kidney disease (CKD), there are few statistical evaluations of their connection to migraines in population-based studies. In this nationwide longitudinal follow-up study of Korean health examination data (2002-2019), a total of 15,443 participants with CKD and 61,772 matched controls were enrolled. We applied overlap-weighted Cox proportional hazard regression models to assess hazard ratios, examining the correlation between CKD and the development of migraines. After accounting for various factors, we observed a modest reduction of approximately 11% in the likelihood of migraine occurrence among CKD patients (95% confidence intervals = 0.81-0.97) during the 16-year monitoring period. Subgroup analysis revealed a significant association among specific demographic and health conditions, including individuals aged 70 or older, females, overweight individuals, nonsmokers, and those without hypertension or diabetes. Our research may indicate a potential relationship between CKD and the onset of migraines in Korean adults, suggesting a slight reduction in the probability of the occurrence of migraines among those with CKD. These findings emphasize the need for attentive follow-up and preventive management in individuals without the identified protective factors, particularly in male CKD patients under the age of 70 with hypertension.

Cancer-Associated Fibroblasts Together with a Decline in CD8+ T Cells Predict a Worse Prognosis for Breast Cancer Patients

BACKGROUND

Cancer-associated fibroblasts (CAFs) play a crucial role in tumor microenvironment regulation and cancer progression. This study assessed the significance and predictive potential of CAFs in breast cancer prognosis.

METHODS

The study included 1503 breast cancer patients. Cancer-associated fibroblasts were identified using morphologic features from hematoxylin and eosin slides. The study analyzed clinicopathologic parameters, survival rates, immune cells, gene sets, and prognostic models using gene-set enrichment analysis, in silico cytometry, pathway analysis, in vitro drug-screening, and gradient-boosting machine (GBM)-learning.

RESULTS

The presence of CAFs correlated significantly with young age, lymphatic invasion, and perineural invasion. In silico cytometry showed altered leukocyte subsets in the presence of CAFs, with decreased CD8+ T cells. Gene-set enrichment analysis showed associations with critical processes such as the epithelial-mesenchymal transition and immune modulation. Drug sensitivity analysis in breast cancer cell lines with varying fibroblast activation protein-α expression suggested that CAF-targeted therapies might enhance the efficacy of certain anticancer drugs including ARRY-520, ispinesib-mesylate, paclitaxel, and docetaxel. Integrating CAF presence with machine-learning improved survival prediction. For breast cancer patients, CAFs were independent prognostic markers for worse disease-specific survival and disease-free survival.

CONCLUSION

This study highlighted the significance of CAFs in breast cancer biology and provided compelling evidence of their impact on patient outcomes and treatment response. The findings offer valuable insights into the potential of CAFs as prognostic and predictive biomarkers and support the development of CAF-targeted therapies to improve breast cancer management.

Potential Molecular Markers Related to Lymph Node Metastasis and Stalk Resection Margins in Pedunculated T1 Colorectal Cancers Using Digital Spatial Profiling: A Pilot Study with a Small Case Series

There is a debate regarding the prediction of lymph node metastasis (LNM) in pedunculated T1 colorectal cancer (CRC). In this study with four cases of pedunculated T1 CRCs, we aimed to investigate gene expression variations based on the distance from the Haggitt line (HL) and identify potential molecular risk factors for LNM. By leveraging the Cancer Transcriptome Atlas and digital spatial profiling technology, we meticulously analyzed discrete regions, including the head, HL, proximal stalk region (300-1000 μm from HL), and distal stalk region (1500-2000 μm from HL) to identify spatially sequential molecular changes. Our findings showed significant overall gene expression variations among the head, proximal stalk, and distal stalk regions of pedunculated T1 CRCs compared to the control adenoma. Compared to LNM-negative T1 CRCs, LNM-positive T1 CRC showed that the expression of genes involved in immune-related pathways such as B2M, HLA-B, and HLA-E were significantly downregulated in the distal stalk region compared to the proximal stalk region. In summary, our results may tentatively suggest considering endoscopic resection of the stalk with a minimum 2000 μm margin from the HL, taking into account the gene expression alterations related to immune-related pathways. However, we acknowledge the limitations of this pilot study, notably the small case series, which may restrict the depth of interpretation. Further validation is imperative to substantiate these findings.

JAK2 Loss Arising From Tumor-Spread-Through-Air-Spaces (STAS) Promotes Tumor Progression by Suppressing CD8+ T Cells in Lung Adenocarcinoma: A Machine Learning Approach

BACKGROUND

Tumor spread through air spaces (STAS) is a recently discovered risk factor for lung adenocarcinoma (LUAD). The aim of this study was to investigate specific genetic alterations and anticancer immune responses related to STAS. By using a machine learning algorithm and drug screening in lung cancer cell lines, we analyzed the effect of Janus kinase 2 (JAK2) on the survival of patients with LUAD and possible drug candidates.

METHODS

This study included 566 patients with LUAD corresponding to clinicopathological and genetic data. For analyses of LUAD, we applied gene set enrichment analysis (GSEA), in silico cytometry, pathway network analysis, in vitro drug screening, and gradient boosting machine (GBM) analysis.

RESULTS

The patients with STAS had a shorter survival time than those without STAS (P < 0.001). We detected gene set-related downregulation of JAK2 associated with STAS using GSEA. Low JAK2 expression was related to poor prognosis and a low CD8+ T-cell fraction. In GBM, JAK2 showed improved survival prediction performance when it was added to other parameters (T stage, N stage, lymphovascular invasion, pleural invasion, tumor size). In drug screening, mirin, CCT007093, dihydroretenone, and ABT737 suppressed the growth of lung cancer cell lines with low JAK2 expression.

CONCLUSION

In LUAD, low JAK2 expression linked to the presence of STAS might serve as an unfavorable prognostic factor. A relationship between JAK2 and CD8+ T cells suggests that STAS is indirectly related to the anticancer immune response. These results may contribute to the design of future experimental research and drug development programs for LUAD with STAS.

Association between the Use of Proton Pump Inhibitors and Cardiovascular Diseases: A Nested Case-Control Study Using a National Health Screening Cohort

We investigated the association of proton pump inhibitor (PPI) use with the risk of stroke and ischemic heart disease (IHD). The Korean National Health Insurance Service-Health Screening cohort from 2002 to 2003, the participants of which were followed up until 2019, was used. In study I, 45,905 participants who were diagnosed with stroke were matched with 91,810 control I participants. The history of PPI medication was examined. In study II, 40,928 participants who were diagnosed with IHD were matched with 81,856 control II participants. In both study I and study II, the previous history of PPI medication was examined. A propensity score overlap-weighted multivariable logistic regression analysis was conducted to estimate the overlap-weighted odds ratios (ORs) of PPI use for stroke (study I) and IHD (study II). Current PPI use was linked with higher odds for stroke in study I. The odds for stroke were higher in groups with a longer duration of PPI use (OR = 0.96 [95% CI = 0.92-1.00] < 1.55 [1.50-1.61] < 1.62 [1.57-1.68] for < 30 days, 30 to 180 days, and ≥180 days of PPI use). Previous PPI use was linked with higher odds for IHD in study II. The odds for stroke were higher in groups with a longer duration of PPI use (OR = 1.13 [95% CI = 1.08-1.18] < 2.12 [2.04-2.21] < 2.60 [2.51-2.69] for <30 days, 30 to 180 days, and ≥180 days of PPI use). Current PPI medication is associated with a high risk of stroke and IHD. A longer duration of PPI medication was related to a higher risk of stroke and IHD. However, a prior history of PPI medication was not linked with a high risk of stroke or IHD.

Unlocking the Protective Potential of Upper Respiratory Infection Treatment Histories against Alzheimer's Disease: A Korean Adult Population Study

With increasing interest in the inflammation-pathogen infection hypothesis and its potential links to Alzheimer's disease (AD) development, there is growing consideration of using upper respiratory infection (URI) treatments as interventions for AD. This nested case-control study explored the potential association between prior URI histories and AD development in a Korean adult population using the national health screening cohort data (2002-2019). The study included 26,920 AD patients and 107,680 matched control individuals, focusing on those seeking respiratory treatment. Logistic regression analyses assessed the impact of URI histories and treatment on AD risk while adjusting for covariates. Our results revealed that over a 1-year period, individuals with URI histories (≥1, ≥2, or ≥3 instances) exhibited decreasing probabilities of developing AD, with risk reductions of 19%, 15%, and 12%, respectively. Expanding our investigation to a 2-year period consistently showed a 17% reduction in AD risk. This effect remained robust across diverse demographic groups and after adjusting for covariates, encompassing comorbidities, hypertension, hyperlipidemia, blood glucose levels, and lifestyle factors. Subgroup analyses further substantiated this association. In conclusion, our findings cautiously suggest a potential protective role of prior URI treatment histories in mitigating the risk of AD development.

Increased Risk of Benign Prostate Hyperplasia (BPH) in Patients with Gout: A Longitudinal Follow-Up Study Using a National Health Screening Cohort

A previous study reported a high risk of benign prostatic hyperplasia (BPH) in patients with gout. This study intended to evaluate the risk of BPH in gout patients. A total of 514,866 Korean National Health Insurance Service-Health Screening Cohorts were retrieved from 2002 to 2019. Among these individuals, 14,961 gout patients and 58,764 control participants were matched based on demographic factors. The incidence of BPH during the follow-up periods was collected for both the gout and control groups. The risk of BPH was analyzed using stratified Cox proportional hazard models, and hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. Secondary analyses were conducted based on demographic factors and comorbidities. The incidence of BPH was 23.40% in gout patients and 20.70% in control participants. In the adjusted model, the HR of BPH was 1.13-fold higher in gout patients than in the control group (95% CI = 1.09-1.18). Compared with the ≥60-year-old group, the <60-year-old group demonstrated a higher HR for BPH in gout patients (1.19 [1.13-1.24] vs. 1.07 [1.01-1.13]). The risk of BPH in gout patients was consistent according to various comorbidities. Patients with gout demonstrated a greater risk of BPH than participants without gout. The young adult population had a higher risk of BPH related to gout.

Gout and Migraines: Exploring the Complex Link in a 16-Year Longitudinal Study of the Korean Population

Despite the growing prevalence of gout and its associated health concerns as a chronic disorder, population-based studies on its link to migraines are scarce. We conducted a 16-year longitudinal study in a Korean population to investigate the relationship between gout and migraines, including different subtypes. We enrolled 23,137 patients with gout and matched them with 92,548 controls based on age, sex, income, and residence. Using Cox proportional hazards models, we calculated hazard ratios to assess the likelihood of migraines while considering relevant factors. During the follow-up, 1000 gout patients and 3214 controls experienced migraines. After adjusting for various factors, including demographics, health-related variables, and weight categories, the gout group had a 1.26-fold higher likelihood of developing migraines compared to the group without gout. This association was particularly strong for migraines without aura, while it was not significant for migraines with aura. In summary, our study reveals a significant link between gout and migraines in the Korean population, emphasizing the complex relationship among chronic disorders, with a specific focus on migraine subtypes.

Risk for Esophageal Cancer Based on Lifestyle Factors-Smoking, Alcohol Consumption, and Body Mass Index: Insight from a South Korean Population Study in a Low-Incidence Area

Esophageal cancer constitutes a global public health challenge. However, South Korean population-specific information on the association of lifestyle (smoking, alcohol consumption, and obesity status) with esophageal cancer risk is sparse. This nested case-control study analyzed the Korean national health screening cohort data (2002-2019) of 1114 patients with esophageal cancer and 4456 controls (1:4 propensity-score matched for sex, age, income, and residential region). Conditional and unconditional logistic regression analyses, after adjustment for multiple covariates, determined the effects of lifestyle factors on esophageal cancer risk. Smoking and alcohol consumption increased the esophageal cancer risk (adjusted odds ratio [95% confidence interval]: 1.37 [1.15-1.63] and 1.89 [1.60-2.23], respectively). Overweight (body mass index [BMI] ≥ 23 to <25 kg/m2), obese I (BMI ≥ 25 to <30 kg/m2), or obese II (BMI ≥ 30 kg/m2) categories had reduced odds of esophageal cancer (0.76 [0.62-0.92], 0.59 [0.48-0.72], and 0.47 [0.26-0.85], respectively). In the subgroup analyses, the association of incident esophageal cancer with smoking and alcohol consumption persisted, particularly in men or those aged ≥55 years, whereas higher BMI scores remained consistently associated with a reduced esophageal cancer likelihood across all age groups, in both sexes, and alcohol users or current smokers. Underweight current smokers exhibited a higher propensity for esophageal cancer. In conclusion, smoking and alcohol drinking may potentially increase the risk, whereas weight maintenance, with BMI ≥ 23 kg/m2, may potentially decrease the risk, for esophageal cancer in the South Korean population. Lifestyle modification in the specific subgroups may be a potential strategy for preventing esophageal cancer.

Role of neutrophil extracellular traps in vascular access thrombosis in hemodialysis patients

BACKGROUND

A patent vascular access (VA) is a lifeline for hemodialysis (HD) patients. However, vascular access is prone to thrombosis, which, if left untreated, can lead to permanent VA loss and increased mortality. Neutrophil extracellular traps (NETs) are known to be involved in intravascular thrombosis. We evaluated the relationship between NETs and VA thrombosis and their impact on VA prognosis.

METHODS

A total of 189 patients with VA flow problems were enrolled. Among these, 93 patients underwent percutaneous transluminal angioplasty (PTA) for stenosis, and 96 patients underwent PTA with thrombectomy for thrombosis. Plasma nucleosome, myeloperoxidase-DNA complex, and von Willebrand factor (vWF) were measured as markers of circulating NETs and thrombosis risk, respectively. The primary outcome was permanent VA loss and the secondary outcome was recurrent thrombotic occlusion within 6 months. In addition, the presence of NETs in thrombi was evaluated by histopathological analysis.

RESULTS

Circulating nucleosome levels were closely associated with plasma vWF levels (r = 0.172, p = 0.025), and both were higher in thrombectomy cases than in PTA alone cases (nucleosome; 0.83 ± 0.70 vs. 0.35 ± 0.26, p < 0.001, vWF: 9.0 ± 7.6 vs. 7.3 ± 6.2, p = 0.038). The highest quartile of nucleosomes (Q4) was associated with an 18-fold increased rate of access thrombotic occlusion (p < 0.001). In addition, multivariate analysis showed that the rates of permanent access loss (HR 2.77, 95 % CI 1.35-5.77) and recurrent thrombosis (HR 2.35, 95 % CI 1.22-4.54) were much higher in patients with the Q4 nucleosome group than in those with Q1-3. In addition, higher neutrophil infiltration and NET expression in thrombi were also associated with poor VA prognosis.

CONCLUSIONS

Higher levels of circulating NETs and the amount of NET expression in thrombi may be associated with VA thrombosis and poor VA outcomes.

Dysregulated microRNA Expression Relevant to TERT Promoter Mutations in Tonsil Cancer-A Pilot Study

Tonsillar squamous cell carcinomas (TSCCs) exhibit high rates of human papillomavirus (HPV) positivity. The expression profiles of microRNA (miRNA), which are small RNA molecules that play pivotal roles in biological processes, in TSCC in relation to the HPV status and cancer-related genetic mutations are not well investigated. Herein, we expanded our previous research, which was focused on established clinicopathological and genetic mutational data, to profile miRNA expression in TSCC, aiming to identify clinically relevant targets for early diagnosis and therapeutic intervention. The miRNA profiles were analyzed using the nCounter Nanostring miRNA Expression assay in 22 surgically resected TSCC tissues and their contralateral normal tonsil tissues. The TERT promoter (TERTp) gene was the only relevant candidate gene associated with differentially expressed miRNAs in TSCC. Hierarchical clustering analysis revealed high expression levels of hsa-miR-1285-5p, hsa-miR-1203, hsa-miR-663a, hsa-miR-1303, hsa-miR-33a-5p, and hsa-miR-3615 coupled with low expression levels of hsa-miR-3182, hsa-miR-219a-2-3p, and hsa-miR-767-3p, which were associated with HPV-positive TSCC (p = 0.009). Functional enrichment analysis revealed that these dysregulated miRNAs tended to be involved in protein binding (molecular function) and cellular components (biological processes). Therefore, hsa-miR-1285-5p and hsa-miR-663a may be associated with HPV-positive TERTp-mutated tumors and may serve as potential treatment targets and biomarkers for early detection.

Changes in radiomic and radiologic features in meningiomas after radiation therapy

OBJECTIVES

This study evaluated the radiologic and radiomic features extracted from magnetic resonance imaging (MRI) in meningioma after radiation therapy and investigated the impact of radiation therapy in treating meningioma based on routine brain MRI.

METHODS

Observation (n = 100) and radiation therapy (n = 62) patients with meningioma who underwent MRI were randomly divided (7:3 ratio) into training (n = 118) and validation (n = 44) groups. Radiologic findings were analyzed. Radiomic features (filter types: original, square, logarithm, exponential, wavelet; feature types: first order, texture, shape) were extracted from the MRI. The most significant radiomic features were selected and applied to quantify the imaging phenotype using random forest machine learning algorithms. Area under the curve (AUC), sensitivity, and specificity for predicting both the training and validation sets were computed with multiple-hypothesis correction.

RESULTS

The radiologic difference in the maximum area and diameter of meningiomas between two groups was statistically significant. The tumor decreased in the treatment group. A total of 241 series and 1691 radiomic features were extracted from the training set. In univariate analysis, 24 radiomic features were significantly different (P < 0.05) between both groups. Best subsets were one original, three first-order, and six wavelet-based features, with an AUC of 0.87, showing significant differences (P < 0.05) in multivariate analysis. When applying the model, AUC was 0.76 and 0.79 for the training and validation set, respectively.

CONCLUSION

In meningioma cases, better size reduction can be expected after radiation treatment. The radiomic model using MRI showed significant changes in radiomic features after radiation treatment.

Alzheimer's Disease and Different Types of Cancer Likelihood: Unveiling Disparities and Potential Protective Effects in a Korean Cohort Study

The link between Alzheimer's disease and cancer risk is a concern in public health. However, research has yielded limited and sometimes contrasting results, suggesting the need for more validation. We analyzed a large cohort to examine the long-term association between Alzheimer's disease (AD) and the risk of developing cancer. In total, 24,664 AD patients and 98,656 control participants were selected from the National Health Insurance Cohort database of Korea, spanning from 2002 to 2019. Propensity score matching and overlap-weighted adjustment techniques were used to balance the standardized differences between the AD and control groups. The Cox proportional hazards model was applied to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for various cancers, considering relevant covariates. Results indicated that patients with AD had a significantly lower likelihood of overall malignancy (HR 0.63; 95% CI, 0.59-0.68) and each of the 10 site-specific cancers compared to the control group. Among these, pancreatic cancer (HR, 0.50) exhibited the strongest inverse association, followed by hepatic (HR, 0.60), gastric (HR, 0.63), kidney (HR, 0.63), lung (HR, 0.64), thyroid (HR, 0.65), colorectal (HR, 0.67), gallbladder and biliary duct (HR, 0.73), hematologic malignancy (HR, 0.73), and bladder cancers (HR, 0.76). This protective effect against certain organ-specific cancers persisted over the 16-year follow-up period, except for in kidney cancer and hematologic malignancies. The protective effect against specific cancer types (gastric, colorectal, lung, hepatic, and pancreatic) was more prominent in individuals aged 60 years and older, regardless of their sex. However, there were some variations in the specific types of cancer observed between males and females. In summary, Korean patients with AD had a lower risk of cancer, especially in individuals 60 years and older, during the 16-year follow-up period.

An elevated likelihood of stroke, ischemic heart disease, or heart failure in individuals with gout: a longitudinal follow-up study utilizing the National Health Information database in Korea

Objective

Accumulating evidence from other countries indicates potential associations between gout and cardiovascular diseases; however, the associations of gout with cardiovascular diseases, particularly stroke, ischemic heart disease, and heart failure, remain ambiguous in the Korean population. We hypothesized that individuals with gout are at a higher likelihood of stroke, ischemic heart disease, or heart failure. This study expands upon previous research by ensuring a comparable baseline between patient and control groups and analyzing 16 years of data derived from an extensive healthcare database.

Methods

We selected 22,480 patients with gout and 22,480 control individuals from the Korean National Health Insurance Service-Health Screening Cohort database (2002-2019), and matched them at a 1:1 ratio according to sex, age, income, and residence. A Cox proportional hazard model with weighted overlap was employed to examine the relationship between gout and the risk of stroke, ischemic heart disease, or heart failure after adjustment for several covariates.

Results

The incidences of stroke, ischemic heart disease, or heart failure in participants with gout were slightly higher than those in controls (stroke: 9.84 vs. 8.41 per 1000 person-years; ischemic heart disease: 9.77 vs. 7.15 per 1000 person-years; heart failure: 2.47 vs. 1.46 per 1000 person-years). After adjustment, the gout group had an 11% (95% confidence interval [CI] = 1.04-1.19), 28% (95% CI = 1.19-1.37), or 64% (95% CI = 1.41-1.91) higher likelihood of experiencing stroke, ischemic heart disease, or heart failure, respectively, than the control group.

Conclusion

The present findings suggest that individuals with gout in the Korean population, particularly those aged ≥ 60 years, were more likely to have stroke, ischemic heart disease, or heart failure.

Association between the Use of Statins and Brain Tumors

This study aimed to investigate the effects of statin use on the incidence of brain tumors. The Korean National Health Insurance Service-National Sample Cohort from 2005 to 2019 was used. The 1893 patients who were diagnosed with brain tumors were matched with 7572 control patients for demographic variables. The history of dyslipidemia was collected, and their history of prescription of statins before diagnosis of brain tumor was examined. The participants without dyslipidemia were set as a reference population. Then, the odds for brain tumors were analyzed in dyslipidemia patients without statin use, dyslipidemia patients who were prescribed statins for less than 365 days, and dyslipidemia patients who were prescribed statins for 365 days or more. Propensity score overlap weighted multivariable logistic regression analysis was used and adjusted for demographics and comorbidities. Secondary analyses were conducted according to types of statins, malignancy of brain tumors, and histories of demographics or comorbidities. A total of 11.78% of brain tumor patients and 10.95% of control participants had histories of statin use for 365 days or more. Dyslipidemia patients with 365 days or more duration of statin use demonstrated 1.22 times higher odds for brain tumors than normal participants (95% confidence intervals [CI] = 1.06-1.14, p = 0.007). Dyslipidemia patients with less than 365 days of statin use had higher odds of brain tumors than other groups (odds ratio = 1.60, 95% CI = 1.36-1.87, p < 0.001). The higher odds for brain tumors in short-term statin users (<365 days) than in long-term statin users (≥365 days) were consistent in secondary analyses according to types of statins, malignancy of brain tumors, and histories of demographics or comorbidities. Long-term statin use in dyslipidemia patients was related to a lower risk of brain tumors than short-term statin use in patients with dyslipidemia.

Chronic Periodontitis and the Potential Likelihood of Gastric Cancer: A Nested Case-Control Study in the Korean Population Utilizing a National Health Sample Cohort

There is limited information regarding the potential association between chronic periodontitis (CP) and gastric cancer, especially in the Korean population. This study aimed to explore this relationship. This nested case-control study analyzed data from 10,174 patients with gastric cancer and 40,696 controls from the Korean National Health Insurance Service-National Sample Cohort using propensity score matching. Standardized differences were used to compare baseline characteristics between study groups. Logistic regression analyses adjusted for confounders were conducted to assess the association between history of CP and gastric cancer occurrence. CP histories and comprehensive subgroup analyses in the 1- and 2-year periods preceding the index date were evaluated. Individuals with a history of CP within the 1-year and 2-year periods showed an increased likelihood of developing gastric cancer. Subgroup analyses consistently supported these findings in male participants aged <65 years and individuals with various income levels or living in residential areas. However, no significant associations were observed among participants aged ≥65 years. In conclusion, CP may be a potential risk factor for gastric cancer development in the Korean population. Regular screening for gastric cancer may be necessary for high-risk individuals, specifically men aged <65 years with a history of CP.

A higher probability of subsequent stroke and ischemic heart disease in migraine patients: a longitudinal follow-up study in Korea

BACKGROUND

Whether migraine is related to the risk of cardiovascular diseases (CVDs) remains unclear. Therefore, we conducted a longitudinal follow-up study to address the association between migraine and the development of CVDs in Korea.

METHODS

Using data from the national health screening cohort, we included 45,246 patients diagnosed with migraine between 2002 and 2019 and age-, sex-, income-, and residential region-matched nonmigraine participants at a ratio of 1:4. Participants with previous CVDs were excluded. Cox proportional hazards regression models were used to estimate the hazard ratios of three CVDs, stroke, ischemic heart disease, and heart failure, in patients with migraine after adjusting for potential cardiovascular risk factors.

RESULTS

The incidence rate differences of stroke, ischemic heart disease, and heart failure among patients with migraine were 2.61, 1.69, and 0.11, respectively. The probability of developing stroke and ischemic heart disease in patients with migraine was significantly higher than that in controls after controlling for multiple confounders (adjusted hazard ratio [HR] = 1.35, 95% confidence interval [CI] = 1.31-1.39 and adjusted HR = 1.31, 95% CI = 1.26-1.35, respectively). However, when compared with the patients without migraine, patients with migraine did not have an increased HR of developing heart failure (adjusted HR = 1.01, 95% CI = 0.95-1.08). The overall migraine group, as well as groups stratified by migraine subtypes with and without aura, each showed a significantly higher probability of subsequent stroke and ischemic heart disease than the control group.

CONCLUSIONS

Our longitudinal follow-up study demonstrated a significant association between the presence of migraine and the development of stroke and ischemic heart disease in Korea, even after adjusting for cardiovascular risk factors.

Longitudinal study of the inverse relationship between Parkinson's disease and cancer in Korea

Despite growing epidemiological evidence, the relationship between Parkinson's disease (PD) and cancer has not been conclusively demonstrated, and related studies are scarce in the Asian population. We aimed to determine the association between PD and subsequent development of various cancers from longitudinal data of a representative sample of Korean adults aged ≥40 years. We retrospectively identified 8381 patients diagnosed with PD from 2002 to 2019 using claims data among 514,866 people of random samples from the Korean National Health Insurance database. We sampled 33,524 age-, sex-, income-, and residential area-matched participants without PD from the same database. The longitudinal associations between PD and overall cancer, as well as 10 common types of cancer, were estimated using multivariable Cox proportional-hazards regression analysis. The adjusted hazard ratio (aHR) of all cancer types was 0.63 (95% confidence interval = 0.57-0.69) in patients with PD compared with matched controls. The aHRs of gastric, thyroid, colorectal, lung, hepatic, and pancreatic cancer and hematological malignancy were 0.69 (0.56-0.85), 0.60 (0.39-0.93), 0.56 (0.44-0.70), 0.71 (0.58-0.84), 0.64 (0.48-0.86), 0.37 (0.23-0.60), and 0.56 (0.36-0.87), respectively. The associations of bladder, gallbladder and biliary duct, and kidney cancer with PD were not statistically significant. Our findings show inverse associations between overall cancer and most cancer types in patients with PD. These inverse associations and their pathogeneses merit further investigation.

Exploring the Link between Chronic Kidney Disease and Parkinson's Disease: Insights from a Longitudinal Study Using a National Health Screening Cohort

Chronic kidney disease (CKD) and Parkinson's disease (PD) are common illnesses found in the geriatric population. A potential link between CKD and PD emergence has been hypothesized; however, existing conclusions are disputed. In this longitudinal research, we analyzed data acquired from the Korean National Health Insurance Service-Health Screening Cohort. The dataset comprised the health information of 16,559 individuals clinically diagnosed with CKD and 66,236 control subjects of comparable ages, all aged ≥40 years. These subjects participated in health examinations from 2002 to 2019. To assess the correlation between CKD and PD, we employed overlap-weighted Cox proportional hazard regression models. The unadjusted, crude hazard ratio for PD was greater in the CKD group than in the control group (crude hazard ration (HR) 1.20; 95% confidence interval (CI) = 1.04-1.39; p = 0.011). However, the Cox proportional hazard regression analysis, incorporating propensity score overlap weighting, revealed no significant discrepancy after considering confounding variables such as demographic factors, socio-economic status, lifestyle, and concurrent health conditions (adjusted HR (aHR), 1.09; 95% CI = 0.97-1.22; p = 0.147). Subgroup analyses showed a higher probability of PD development among certain CKD individuals, including those who resided in rural areas (aHR, 1.19; 95% CI = 1.03-1.37; p = 0.022), maintained a normal weight (aHR, 1.29; 95% CI = 1.08-1.56; p = 0.006), or had fasting blood glucose levels ≥100 mg/dL (aHR, 1.18; 95% CI = 1.00-1.39; p = 0.046). Therefore, these clinical or environmental factors may influence the incidence of PD in CKD patients. In conclusion, our results suggest that the general CKD population may not exhibit a greater propensity for PD than their non-CKD counterparts. However, this might be contingent upon specific lifestyle and comorbid conditions. Thus, certain lifestyle alterations could be crucial in mitigating the potential manifestation of PD in patients diagnosed with CKD.

Changes in the mean incidence and variance of orthopedic diseases before and during the COVID-19 pandemic in Korea: a retrospective study

BACKGROUND

During the coronavirus disease (COVID-19) pandemic, the amount of moderate- to high-intensity physical activity significantly decreased. Therefore, the epidemiology of musculoskeletal diseases could possibly have changed. We assessed changes in the incidence of and variance in non-traumatic orthopedic diseases before and after the COVID-19 pandemic in Korea.

METHODS

This study included data from the Korea National Health Insurance Service, which covers the entire Korean population (approximately 50 million), from January 2018 to June 2021. Using International Classification of Diseases, Tenth Revision codes, 12 common orthopedic diseases were evaluated, including cervical disc disorders, lumbar disc disorders, forward head posture, myofascial pain syndrome, carpal tunnel syndrome, tennis elbow, frozen shoulder, rheumatoid arthritis, gout, hip fracture, distal radius fracture, and spine fracture diseases. "Pre-COVID-19" was the period until February 2020, and "COVID-19 pandemic period" was the period starting March 2020. Differences in the mean incidence and variance of diseases before and during the COVID-19 pandemic were compared.

RESULTS

In most cases, the incidence of orthopedic diseases decreased at the beginning of the pandemic and then increased thereafter. Among the 12 diseases, the incidence of three diseases showed a statistically significant change. The incidence of myofascial pain syndrome (P < 0.001) was lower during the COVID-19 pandemic than during the pre-COVID-19 period. The incidences of frozen shoulder (P < 0.001) and gout (P = 0.043) were higher during the COVID-19 pandemic than during the pre-COVID-19 period. However, no statistical difference in disease variations was observed between the two periods.

CONCLUSIONS

The incidence of orthopedic diseases varied during the COVID-19 pandemic among the Korean population. Although the incidence of myofascial pain syndrome was lower, that of frozen shoulder and gout was higher during the COVID-19 pandemic than during the pre-COVID-19 period. No disease variations during the COVID-19 pandemic were found.

Relation of Statin Use with Esophageal Cancer

The present study evaluated the association of long-term statin use with the diagnosis and mortality of esophageal cancer in a Korean population. The Korean National Health Insurance Service-Health Screening Cohort from 2002 to 2019 was enrolled. Esophageal cancer patients were matched with control participants for demographic variables. The statin prescription histories were collected and grouped into <180 days, 180 to 545 days, and >545 days of duration. Propensity score overlap weighting was applied to minimize the bias between the esophageal cancer and control groups. The odds ratios (ORs) of the duration of statin use for esophageal cancer were analyzed using propensity score overlap weighted multivariable logistic regression analysis. The esophageal cancer group was classified as dead and surviving patients, and the ORs of the duration of statin use for the mortality of esophageal cancer were analyzed in an identical manner. Secondary analyses were conducted according to comorbid factors. Patients with esophageal cancer did not show lower odds for the duration of statin prescription in the overall study population (OR = 1.30, 95% CI = 1.03-1.65, p = 0.027 for 180 to 545 days and OR = 1.29, 95% CI = 1.08-1.55, p = 0.006 for >545 days). Subgroups of nonsmokers, past and current smokers, alcohol consumption ≥ 1 time a week, SBP < 140 mmHg and DBP < 90 mmHg, fasting blood glucose ≥ 100 mg/dL, total cholesterol ≥ 200 mg/dL, CCI score = 0, and nondyslipidemia history demonstrated low odds for the duration of statin prescription. Both types of statins, hydrophilic and lipophilic statins, were not related to a lower rate of esophageal cancer. The mortality of esophageal cancer was not associated with the duration of statin prescription. A subgroup with total cholesterol ≥ 200 mg/dL showed lower odds of statin prescription for mortality of esophageal cancer. The duration of statin prescription was not related to a lower rate or mortality of esophageal cancer in the adult Korean population.

Exploring the Link between Chronic Kidney Disease and Alzheimer's Disease: A Longitudinal Follow-Up Study Using the Korean National Health Screening Cohort

Chronic kidney disease (CKD) and Alzheimer's disease (AD) are common chronic diseases in the elderly population. Although a relationship between CKD and the occurrence of AD has been proposed, previous research results have been disputed, and further investigation is necessary to confirm this relationship. In this longitudinal follow-up study, we examined data from the Korean National Health Insurance Service-Health Screening Cohort, consisting of 15,756 individuals with CKD and 63,024 matched controls aged ≥40 years who received health check-ups between 2002 and 2019. Overlap-weighted Cox proportional hazard regression models were exploited to calculate hazard ratios (HRs) for the association between CKD and AD. During the monitoring period, individuals with CKD had a greater incidence of AD than those without CKD (15.80 versus 12.40 per 1000 person years). After accounting for various factors, CKD was significantly associated with a 1.14-fold increased likelihood of developing AD, with a 95% confidence interval ranging from 1.08 to 1.20. In subgroup analysis, this relationship persisted irrespective of age (≥70 or <70), sex, income, smoking status, alcohol consumption, place of residence, or fasting blood glucose level. Additionally, the association between CKD and AD was still evident among patients who were overweight or obese, those with normal blood pressure or cholesterol levels, and those without any other health conditions or with a CCI score of ≥2. These results suggest that CKD could increase the probability of developing AD in the Korean adult population irrespective of demographic or lifestyle conditions. This may make it challenging to predict AD in patients with CKD, emphasizing the importance of frequent AD screening and management.

Comparison between Two-Dimensional and Point Shear Wave Elastography Techniques in Evaluating Liver Fibrosis Using Histological Staging as the Reference Standard: A Prospective Pilot Study

Evaluation of hepatic fibrosis is essential to prevent liver-related morbidity and mortality. Although various types of ultrasound shear wave elastography (SWE) have been used and validated, there are limited studies on the relatively newer technique, two-dimensional SWE (2D-SWE). Therefore, this study aimed to compare the diagnostic performances of 2D-SWE and point SWE (p-SWE) for evaluating liver fibrosis using histology as the reference standard. To measure liver stiffness (LS) values, 87 patients underwent 2D-SWE and p-SWE using the same machine. Technical failures and unreliable measurements were also evaluated. The diagnostic performances of 2D-SWE and p-SWE were compared using area under the receiver operating characteristic (AUROC) curve analysis. No technical failures were observed in either method; however, unreliable measurements were less frequent in 2D-SWE (1/87 [1.1%]) than in p-SWE (8/87 [9.2%]) (p < 0.001). The AUROC of the LS values of 2D-SWE were significantly higher than those of p-SWE for diagnosing significant fibrosis (0.965 vs. 0.872, p = 0.022) and cirrhosis (0.994 vs. 0.886, p = 0.042). In conclusion, 2D-SWE is more reliable and accurate than p-SWE for diagnosing hepatic fibrosis.

DKK3 expression is associated with immunosuppression and poor prognosis in glioblastoma, in contrast to lower-grade gliomas

PURPOSE

We previously reported that expression of dickkopf-3 (DKK3), which is involved in the Wnt/β-catenin pathway, is significantly associated with prognosis in patients with glioblastoma multiforme (GBM). The aim of this study was to compare the association of DKK3 with other Wnt/β-catenin pathway-related genes and immune responses between lower grade glioma (LGG) and GBM.

METHODS

We obtained the clinicopathological data of 515 patients with LGG (World Health Organization [WHO] grade II and III glioma) and 525 patients with GBM from the Cancer Genome Atlas (TCGA) database. We performed Pearson's correlation analysis to investigate the relationships between Wnt/β-catenin-related gene expression in LGG and GBM. Linear regression analysis was performed to identify the association between DKK3 expression and immune cell fractions in all grade II to IV gliomas.

RESULTS

A total of 1,040 patients with WHO grade II to IV gliomas were included in the study. As the grade of glioma increased, DKK3 showed a tendency to be more strongly positively correlated with the expression of other Wnt/β-catenin pathway-related genes. DKK3 was not associated with immunosuppression in LGG but was associated with downregulation of immune responses in GBM. We hypothesized that the role of DKK3 in the Wnt/β-catenin pathway might be different between LGG and GBM.

CONCLUSION

According to our findings, DKK3 expression had a weak effect on LGG but a significant effect on immunosuppression and poor prognosis in GBM. Therefore, DKK3 expression seems to play different roles, through the Wnt/β-catenin pathway, between LGG and GBM.

Comparison of the Concordance of Allergic Diseases between Monozygotic and Dizygotic Twins: A Cross-Sectional Study Using KoGES HTS Data

Several epidemiological studies have demonstrated that genetic and environmental factors contribute to the development of allergic diseases. However, there is limited information on these factors in the Korean population. This study investigated the importance of genetic and environmental factors in allergic diseases, such as allergic rhinitis, asthma, allergic conjunctivitis, or atopic dermatitis, by comparing the disease incidence in Korean adult monozygotic and dizygotic twins. This cross-sectional study utilized data from 1296 twin pairs, including 1052 monozygotic and 244 dizygotic twins, aged over 20 years, from the Korean Genome and Epidemiology Study (2005-2014). The study utilized binomial and multinomial logistic regression models to compute odds ratios of disease concordance. The concordance rate (92%) of the presence or absence of atopic dermatitis in monozygotic twins was slightly higher than that in dizygotic twins (90.2%), which only had a borderline significance (p = 0.090). The concordance rates of other allergic diseases within monozygotic twins were lower compared to dizygotic twins (asthma, 94.3% vs. 95.1%; allergic rhinitis, 77.5% vs. 78.7%; allergic conjunctivitis, 90.6% vs. 91.8%), of which the differences were not statistically significant. Monozygotic twins had a higher proportion of cases in which both siblings had allergic diseases than dizygotic twins (asthma, 1.1% vs. 0.0%; allergic rhinitis, 6.7% vs. 3.3%; atopic dermatitis, 2.9% vs. 0.0%; allergic conjunctivitis, 1.5% vs. 0.0%), of which the differences were also not statistically significant. In conclusion, our results appear to indicate the relative importance of environmental factors over genetic factor in the development of allergic diseases in Korean adult monozygotic twins.

Possible Incidental Parkinson's Disease following Asthma: A Nested Case-Control Study in Korea

A connection between asthma and the occurrence of Parkinson's disease (PD) has been suggested, but the findings have been contentious and require verification. In this nested case-control study using data from the Korean National Health Insurance Service-Health Screening Cohort (2002-2019), which comprised 9029 participants with PD and 36,116 matched controls, we explored the relationship between asthma and incident PD. An overlap-weighted logistic regression model was used to measure the probability of asthma and PD. After adjusting for various covariates, we found that asthma was related to a 1.11-fold greater probability of PD (95% confidence interval: 1.06-1.16). A subgroup analysis showed that this effect was independent of age, sex, residential area, or alcohol consumption, and that it was still noticeable even among patients with a high income; those with a normal weight or obesity; those who were non-smokers or current smokers; and those with no history of chronic obstructive pulmonary disease, hypertension, hyperglycemia, hyperlipidemia, or anemia. Thus, these findings may indicate that asthma may slightly augment the likelihood of PD in the Korean adult population regardless of demographic or lifestyle factors, making it difficult to predict PD in asthma patients.

Association between Gallstone Disease and Statin Use: A Nested Case-Control Study in Korea

The correlation between statin use and the development of gallstone disease remains controversial. Existing data, primarily based on Caucasian populations, are biased, thus necessitating validation studies involving Asian cohorts. We conducted a nested case-control study using data from the Korean National Health Insurance Service Health Screening Cohort (2002-2019) to determine the likelihood of gallstone disease according to periods of previous statin use and type of statin. Among the 514,866 participants, 22,636 diagnosed with gallstones at ≥2 clinic visits (using the International Classification of Diseases, 10th revision, code K80) were matched 1:4 to 90,544 controls for age, sex, income, and residential area, and their statin prescription history for 2 years prior to the index date was examined. Propensity-score-weighted odds ratios (ORs) for gallstone disease were calculated using conditional logistic regression. Long-term use (>545 days) of any statin or lipophilic statins was associated with lower odds of incident gallstones (OR = 0.91, 95% confidence interval [CI] = 0.86-0.96, p < 0.001 and OR = 0.88, 95% CI = 0.83-0.93, p < 0.001, respectively) after adjusting for confounders. Short-term use (180-545 days) of any statin or hydrophilic statins was not statistically related to incident gallstones. In summary, prior statin medication, particularly long-term lipophilic statin use, may confer a preventive advantage against gallstone disease.

Different miRNAs Related to FBXW7 Mutations or High Mitotic Indices Contribute to Rectal Neuroendocrine Tumors: A Pilot Study

Recent studies suggest that miRNA may be involved in the development of rectal neuroendocrine tumors (NETs). We explored the frequency of clinicopathologically relevant mutations and miRNA expression in rectal NETs to examine molecular profiles related to prognosis and behavior. Twenty-four eligible specimens with endoscopically excised rectal NETs were selected. Next-generation sequencing and an miRNA expression assay were used to evaluate the expression profile relevant to common genetic mutations in rectal NETs. Kyoto Encyclopedia of Genes and Genomes analysis predicted that the possible target signaling pathways were correlated with dysregulated miRNAs. Nineteen rectal NETs harbored more than one mutation in the 24 cancer-related genes. Seven miRNAs (hsa-miR-769-5p, hsa-miR-221-3p, hsa-miR-34a-5p, hsa-miR-181c-5p, hsa-miR-1246, hsa-miR-324-5p, and hsa-miR-361-3p) were significantly down-regulated in tumors harboring the FBWX7 mutation. Unsupervised hierarchical clustering analysis showed that up-regulation of these seven miRNAs may result in high mitotic indices, indicating the role of miRNAs in tumor progression. Among the down-regulated miRNAs, hsa-miR-769-5p was strongly correlated with extracellular matrix–receptor interaction and lysine degradation. Among the clinicopathological factors, up-regulated hsa-miR-3934-5p was linked to an increased mitotic count. No change in miRNA expression was associated with a tumor size >1 cm, lymphovascular invasion, or Ki-67 index. In summary, we identified different miRNA signatures involved in FBXW7 mutations or high mitotic indices in rectal NETs, which may play a critical role in tumor behavior.

Low gamma-butyrobetaine dioxygenase (BBOX1) expression as a prognostic biomarker in patients with clear cell renal cell carcinoma: a machine learning approach

Gamma-butyrobetaine dioxygenase (BBOX1) is a catalyst for the conversion of gamma-butyrobetaine to l-carnitine, which is detected in normal renal tubules. The purpose of this study was to analyze the prognosis, immune response, and genetic alterations associated with low BBOX1 expression in patients with clear cell renal cell carcinoma (RCC). We analyzed the relative influence of BBOX1 on survival using machine learning and investigated drugs that can inhibit renal cancer cells with low BBOX1 expression. We analyzed clinicopathologic factors, survival rates, immune profiles, and gene sets according to BBOX1 expression in a total of 857 patients with kidney cancer from the Hanyang University Hospital cohort (247 cases) and The Cancer Genome Atlas (610 cases). We employed immunohistochemical staining, gene set enrichment analysis, in silico cytometry, pathway network analyses, in vitro drug screening, and gradient boosting machines. BBOX1 expression in RCC was decreased compared with that in normal tissues. Low BBOX1 expression was associated with poor prognosis, decreased CD8+ T cells, and increased neutrophils. In gene set enrichment analyses, low BBOX1 expression was related to gene sets with oncogenic activity and a weak immune response. In pathway network analysis, BBOX1 was linked to regulation of various T cells and programmed death-ligand 1. In vitro drug screening showed that midostaurin, BAY-61-3606, GSK690693, and linifanib inhibited the growth of RCC cells with low BBOX1 expression. Low BBOX1 expression in patients with RCC is related to short survival time and reduced CD8+ T cells; midostaurin, among other drugs, may have enhanced therapeutic effects in this context.

High PPFIA1 expression promotes cancer survival by suppressing CD8+ T cells in breast cancer: drug discovery and machine learning approach

BACKGROUND

PTPRF-interacting protein alpha 1 (PPFIA1) plays an important role as a regulator of cell motility and tumor cell invasion and is frequently amplified in breast cancer. The aim of this study was to investigate the clinicopathologic features, survival, anticancer immunities and specific gene sets related to high PPFIA1 expression in patients with breast cancer. We verified the importance of PPFIA1 and survival rates using machine learning and identified drugs that can effectively reduce breast cancer cells with high PPFIA1 expression.

METHODS

This study analyzed clinicopathologic factors, survival rates, immune profiles and gene sets according to PPFIA1 expression in 3457 patients with breast cancer from the Kangbuk Samsung Medical Center cohort (456 cases), Molecular Taxonomy of Breast Cancer International Consortium (1904 cases) and The Cancer Genome Atlas (1097 cases). We applied gene set enrichment analysis (GSEA), in silico cytometry, pathway network analyses, in vitro drug screening, and gradient boosting machine (GBM) analysis.

RESULTS

High PPFIA1 expression in breast cancer was associated with worse prognosis, with reduced tumor-infiltrating lymphocytes, especially CD8+ T cells, and increased PD-L1 expression. In pathway network analysis, PPFIA1 was linked directly to the tyrosine-protein phosphatase pathway and indirectly to immune pathways. The importance of PPFIA1's association with survival in GBM analysis was higher than that of perineural and lymphovascular invasion. In in vitro drug screening, expression of PPFIA1 on mRNA level positively correlated with sensitivity of cell lines to erlotinib.

CONCLUSION

High PPFIA1 in patients with breast cancer is related to poor prognosis and decreased anticancer immune response, and erlotinib may be promising for development of therapeutic approaches in patients with tumors overexpressing PPFIA1.

Computed tomography findings of thyroid hemiagenesis: differentiation from hemithyroidectomy

OBJECTIVES

Thyroid hemiagenesis is a rare congenital anomaly characterized by the lack of development of one thyroid lobe. The purpose of this study was to evaluate computed tomography (CT) findings of thyroid hemiagenesis and to establish useful CT criteria for differentiating thyroid hemiagenesis from the hemithyroidectomy state.

METHODS

The CT images of 11 patients with thyroid hemiagenesis were retrospectively reviewed and compared with those of 100 (49 left and 51 right) patients in a hemithyroidectomy state. Image analysis was performed according to the following CT parameters: (a) side of thyroid hemiagenesis, (b) edge of the medial end of the remnant thyroid gland, (c) location of the medial end of the remnant thyroid gland, expressed as the angle of the medial end and (d) any other thyroid abnormality observed during the initial examination.

RESULTS

The missing lobe occurred more often in the left than in the right lobe (72.7% vs. 27.3%) as well as concomitant isthmus agenesis (100% vs. 37.5%). The sharp edge of the medial end of the remnant thyroid gland was more common in thyroid hemiagenesis (64%) than in hemithyroidectomy (26%) (P = 0.0153). In left thyroid hemiagenesis, the angle of the medial end (63%) was more frequently >  + 30° than in hemithyroidectomy (0%) (P < 0.0001). Two patients presented with hypothyroidism; the remaining nine showed a normal thyroid function. The associated thyroid diseases were autoimmune thyroiditis (n = 1) and papillary thyroid carcinoma (n = 1).

CONCLUSIONS

The sharp edge of the medial end of the remnant thyroid gland and an angle of >  + 30° for the medial end in cases wherein the left lobe is absent are useful CT features for distinguishing thyroid hemiagenesis from hemithyroidectomy.

Potential Association of Osteoporosis and Not Osteoporotic Fractures in Patients with Gout: A Longitudinal Follow-Up Study

Health issues associated with gout and increased occurrence of osteoporosis or fractures have been raised; however, the results are elusive. Herein, we explored the possible link between gout and incident osteoporosis/osteoporotic fractures based on long-term follow-up nationwide data. This study enrolled 16,305 patients with gout and 65,220 controls who were matched by propensity score at a 1:4 ratio on the basis of sex, age, income, and residence from the Korean National Health Insurance Service-Health Screening Cohort database (2002−2015). A Cox proportional hazard model was employed to identify the relevance between gout and incident osteoporosis/fractures, following adjustment for various covariates. In the follow-up period, osteoporosis developed in 761 individuals with gout and 2805 controls (incidence rates: 8.0 and 7.3/1000 person-years, respectively), and each osteoporotic fracture in the distal radius (2.8 vs. 2.7/1000 person-years), hip (1.3 vs. 1.3/1000 person-years), and spine (4.5 vs. 4.5/1000 person-years) occurred in gout and control groups, respectively. After adjustment, the gout group presented an 11% higher development of osteoporosis (95% confidence interval = 1.02−1.20) than the controls (p = 0.011). Subgroup analyses maintained the augment of incident osteoporosis in sufferers with gout, particularly in either men or <60 years. However, no such relevance was identified between gout and incident osteoporotic fractures at any site. In conclusion, gout may result in a slightly elevated likelihood of developing osteoporosis, and not osteoporotic fractures, in the Korean population.

The association between hyperuricemia and cardiovascular disease history: A cross-sectional study using KoGES HEXA data

This cross-sectional study examines the association between hyperuricemia and cardiovascular diseases (CVDs). Data from the Korean Genome and Epidemiology Study from 2004 to 2016 were analyzed. Among the 173,209 participants, we selected 11,453 patients with hyperuricemia and 152,255 controls (non-hyperuricemia). We obtained the history of CVDs (stroke and ischemic heart disease [IHD]) from all participants. Crude and adjusted odds ratios (aORs) (age, income group, body mass index, smoking, alcohol consumption, anthropometry data, and nutritional intake) for CVDs were analyzed using a logistic regression model. Participants with hyperuricemia reported a significantly higher prevalence of stroke (2.4% vs 1.3%) and IHD (5.6% vs 2.8%) than controls did (P < .001). Participants with hyperuricemia had a significantly higher aOR for CVD than the controls. The aOR of hyperuricemia for stroke was 1.22 (95% confidence interval = 1.07-1.39, P = .004). When analyzed by subgroup according to age and sex, this result was only persistent in women. The aOR of hyperuricemia for IHD was 1.45 (95% confidence interval = 1.33-1.59, P < .001). In the subgroup analyses, the results were similar, except in young men. Hyperuricemia was significantly associated with CVD in the Korean population.

Associations between proton pump inhibitors and Alzheimer’s disease: a nested case–control study using a Korean nationwide health screening cohort

Background

Safety concerns against the use of proton pump inhibitors (PPIs) based on the risk of dementia, especially Alzheimer’s disease (AD), remain controversial. Here, we investigated the likelihood of AD depending on previous PPI exposure, use duration, and PPI generation.

Methods

This nested case–control study comprised 17,225 AD patients who were 1:4 matched with 68,900 controls for age, sex, income, and region of residence from Korean National Health Insurance Service-Health Screening Cohort data between 2002 and 2015 using propensity-score matching method. Conditional and unconditional logistic regression analyses were used to evaluate the effects of previous PPI use on AD adjusting for multiple covariates.

Results

Prior PPI use increased likelihood for AD in current and past PPI users (adjusted odds ratio 1.36 [95% confidence interval (CI) = 1.26–1.46] and 1.11 [95% CI = 1.04–1.18], respectively). Participants with either < 30 days, 30–90 days, or > 90 days of PPI prescription showed higher odds for AD (1.13 [95% CI = 1.07–1.19]; 1.18 [95% CI = 1.10–1.27]; 1.26 [95% CI = 1.16–1.36], respectively). Participants with either 1st-generation or 2nd-generation PPIs demonstrated higher incidences of AD in those with < 30 days (1.14 [95% CI = 1.07–1.22] and 1.13 [95% CI = 1.05–1.22], respectively), 30–90 days (1.19 [95% CI = 1.09–1.30] and 1.17 [95% CI = 1.05–1.29], respectively), or > 90 days (1.18 [95% CI = 1.07–1.30] and 1.27 [95% CI = 1.14–1.43], respectively) of prescription.

Conclusions

Prior PPI use, regardless of current or past exposure, duration of use, or use of 1st- or 2nd-generation PPIs, may increase likelihood of AD, providing supportive evidence of previous pharmacoepidemiologic studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13195-022-01032-5.

Comparison of the Concordance of Cardiometabolic Diseases and Physical and Laboratory Examination Findings between Monozygotic and Dizygotic Korean Adult Twins: A Cross-Sectional Study Using KoGES HTS Data

This study investigated the contribution of genetic and environmental factors to cardiometabolic diseases (CMDs) by comparing disease concordance in monozygotic and dizygotic twins. This cross-sectional study analyzed 1294 (1040 monozygotic and 254 dizygotic) twin pairs (>20 years) based on the Korean Genome and Epidemiology Study data (2005−2014). The odds ratios of disease concordance were calculated using binomial and multinomial logistic regression models. The occurrence of CMDs (hypertension, hyperlipidemia, type 2 diabetes, cerebral stroke, transient ischemic attack, and ischemic heart disease) and related physical and laboratory levels did not differ between the monozygotic and dizygotic twin groups. The odds for concordance of the presence/absence of CMDs and the likelihood of incident CMD within monozygotic twins were comparable to that of dizygotic twins. The absolute differences in hemoglobin A1c, insulin, low- and high-density lipoprotein cholesterol, total cholesterol, triglycerides, and systolic blood pressure were lower in monozygotic twins than in dizygotic twins. Absolute differences in fasting glucose and diastolic blood pressure did not differ between groups. Although baseline levels of several laboratory parameters related to CMD showed a strong likelihood of heritability in monozygotic twins, CMD phenotype appears to be largely affected by environmental factors.

Association between Migraines and Prior Proton Pump Inhibitor Use: A Nested Case-Control Study Using a National Health Screening Cohort

The effect of proton pump inhibitor (PPI) use on migraine risk remains controversial. We explored the odds of migraines in relation to prior PPI use and treatment duration. Data from the Korean National Health Insurance Service-Health Screening Cohort (2002−2015) were analyzed in this nested case-control study involving 28,159 participants with incident migraines and 112,636 controls (1:4 matched by sex, age, income, and residential region). The baseline covariates were balanced by performing propensity score overlap weighting-based adjustments, and the effect of prior PPI use (past vs. current) and treatment duration (<30 and 30−365 days vs. ≥365 days) on incident migraines was evaluated using logistic regression. In past and current PPI users, prior PPI use raised the likelihood of migraines (adjusted odds ratio [95% confidence interval]: 2.56 [2.36−2.79] and 4.66 [4.29−5.06], respectively). Participants who used PPI for <30, 30−365, or ≥365 days exhibited high odds of migraines (2.49 [2.29−2.72], 4.41 [4.05−4.79], and 4.14 [3.77−4.54], respectively). Incident migraines with or without aura also increased independently of PPI use history or duration. In summary, prior PPI use, irrespective of the elapsed time since use and the duration of use, is possibly associated with incident migraines with or without aura.

Somatic Mutations of TP53 Identified by Targeted Next-Generation Sequencing Are Poor Prognostic Factors for Primary Operable Breast Cancer: A Single-Center Study

Few studies have reported on the clinical utility of targeted next-generation sequencing (NGS) for breast cancer in Korea. We retrospectively reviewed the targeted NGS data of 219 patients with breast cancer who underwent surgical resection between August 2018 and April 2021. Here, we described the mutational profiles of breast cancer and examined their prognostic implications. The most frequently mutated gene was PIK3CA (n = 97/219, 44.3%), followed by TP53 (n = 79/219, 36.1%), AKT1 (n = 23/219, 10.5%), and GATA3 (n = 20/219, 9.1%). TP53 mutations were associated with aggressive histologic features. We followed up for 31 (range, 1-39) months and observed 11 (5.0%) recurrences: nine were TP53 mutant and two were TP53 wild-type. Multivariable analysis revealed that TP53 mutation was an independent prognostic factor for recurrence (p = 0.012). Although no drug is currently available for TP53 mutations, it is valuable to know the mutational status of TP53 for the precise management of breast cancer.

Changes in Otorhinolaryngologic Disease Incidences before and during the COVID-19 Pandemic in Korea

This study aimed to investigate the change in the incidence and variance of otorhinolaryngologic diseases during the coronavirus disease 19 (COVID-19) pandemic. The entire Korean population (~50 million) was evaluated for the monthly incidence of 11 common otorhinolaryngologic diseases of upper respiratory infection (URI), influenza, acute tonsillitis, peritonsillar abscess, retropharyngeal and parapharyngeal abscess, acute laryngitis and bronchitis, stomatitis and related lesions, acute sinusitis, rhinitis, otitis media, and dizziness from January 2018 through March 2021 using the International Classification of Disease (ICD)-10 codes with the data of the Korea National Health Insurance Service. The differences in the mean incidence of 11 common otorhinolaryngologic diseases before and during COVID-19 were compared using the Mann-Whitney U test. The differences in the variance of incidence before and during COVID-19 were compared using Levene's test. The incidence of all 11 otorhinolaryngologic diseases was lower during COVID-19 than before COVID-19 (all p < 0.05). The variations in disease incidence by season were lower during COVID-19 than before COVID-19 for infectious diseases, including URI, influenza, acute tonsillitis, peritonsillar abscess, retropharyngeal and parapharyngeal abscess, acute laryngitis and bronchitis, acute sinusitis, and otitis media (all p < 0.05), while it was not in noninfectious diseases, including stomatitis, rhinitis, and dizziness. As expected, the incidences of all otorhinolalryngolgic diseases were decreased. Additionally, we found that seasonal variations in infectious diseases disappeared during the COVID-19 pandemic, while noninfectious diseases did not.

Comparison of Concordance of Peptic Ulcer Disease, Non-Adenomatous Intestinal Polyp, and Gallstone Disease in Korean Monozygotic and Dizygotic Twins: A Cross-Sectional Study

Epidemiological studies have suggested the role of multiple genetic and environmental factors in the development of non-neoplastic gastrointestinal (GI) diseases; however, little information is available on these factors in the Korean population. Therefore, this cross-sectional study explored the effect of these factors by analyzing the concordance of several benign GI disorders in 525 monozygotic twins compared to that in 122 dizygotic twins aged >20 years from the Healthy Twin Study data of the Korean Genome and Epidemiology Study (2005-2014). Chi-square test, Wilcoxon rank-sum, and binomial and multinomial logistic regression models were used for statistical analysis. There was lack of concordance of gastric/duodenal ulcers and cholelithiasis/cholangitis between monozygotic twins compared to that in dizygotic twins, suggesting that environmental factors may mediate those concordant disease expressions in monozygotic twins. The concordance of intestinal polyps in monozygotic twins was 32% lower than that in dizygotic twins (p = 0.028), indicating that the effect of genetic factors on the risk for intestinal polyp development may be low. In conclusion, the lack or low concordance of several benign GI diseases between monozygotic and dizygotic twin groups suggests the relative importance of environmental factors, indicating that these are preventable diseases.

Association between metabolic syndrome and osteoporosis among adults aged 50 years and older: using the National Health Information Database in South Korea

This study aimed to examine the association between a history of metabolic syndrome (MetS) and osteoporosis with specific characteristics. The results showed that MetS was inversely associated with osteoporosis. In contrast, MetS was positively associated with osteoporosis in both obese men and postmenopausal obese women.

PURPOSE

Although several previous studies have investigated the association between MetS and osteoporosis, their findings remain controversial. This study aimed to examine the association between a MetS history and osteoporosis using a subset of data from a large, long-term, national database.

METHODS

This nested case-control study used the National Health Information Database (NHID) of the Korea National Health Insurance Service (NHIS) from 2009 to 2017. Osteoporosis (n = 459,771) and control (n = 459,771) participants were matched in a 1:1 ratio by age, gender, income, and region of residence. MetS was defined based on the modified National Cholesterol Education Program-Adult Treatment Panel III criteria. Crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for osteoporosis in patients with MetS and its components were analyzed using logistic regression. Subgroup analyses were performed according to the combination of gender, menopausal status, and obesity status.

RESULTS

The adjusted OR (95% CI) for osteoporosis in patients with MetS was 0.95 (0.94-0.96). This finding was consistent with the subgroup analyses in normal weight men, premenopausal (pre-MP) women with all obesity statuses, and postmenopausal (post-MP) underweight and normal weight women. In contrast, the opposite was observed for obese men (OR = 1.05, 95% CI = 1.01-1.09) and post-MP obese women (OR = 1.05, 95% CI = 1.01-1.08).

CONCLUSION

This study results suggested that MetS was associated with a low occurrence of osteoporosis. In contrast, MetS was associated with a high occurrence of osteoporosis in both obese men and post-MP obese women.

Differences in Nutritional Intake, Total Body Fat, and BMI Score between Twins

The present study aimed to investigate the coincidence of obesity and nutritional intake in monozygotic twins compared to dizygotic twins. The data from the Korean Genome and Epidemiology Study (KoGES) from 2005 through 2014 were analyzed. Participants ≥ 20 years old were enrolled. The 1006 monozygotic twins and 238 dizygotic twins were analyzed for differences in self-reported nutritional intake, total body fat, and body mass index (BMI) using a linear regression model. The estimated values (EV) with 95% confidence intervals (95% CI) of the difference in dietary intake, total body fat, and BMI score were calculated. The monozygotic twin group and the dizygotic twin group showed similar differences in nutritional intake, DEXA fat, and BMI (all p > 0.05). The differences in nutritional intake of total calories and carbohydrates were lower in the monozygotic twin group than in the dizygotic twin group (all p < 0.05). The differences in total body fat were lower in monozygotic twins than in dizygotic twins (adjusted EV = 2427.86 g, 95% CI = 1777.19−3078.53 and adjusted EV = 1.90%, 95% CI = 1.33−2.46). Monozygotic twins had more similar dietary habits for total calories and carbohydrate intake. Other nutritional factors did not show differential similarity between monozygotic and dizygotic twins. Total body fat was more concordant in monozygotic twins.

Association between Benign Paroxysmal Positional Vertigo and Previous Proton Pump Inhibitor Use: A Nested Case-Control Study Using a National Health Screening Cohort

The present nested case−control study evaluated the impact of previous proton pump inhibitor (PPI) prescription on the risk of benign paroxysmal positional vertigo (BPPV). A ≥40-year-old Korean population was included. A total of 34,441 patients with BPPV was matched with 137,764 comparison participants for demographic and socioeconomic factors. Previous histories of PPI use and PPI prescription dates were compared between the BPPV and comparison groups. The odds ratios (ORs) with 95% confidence intervals (CIs) of PPI use for BPPV were calculated using a logistic regression. The demographic and socioeconomic factors and comorbidities were adjusted in the adjusted model. Both current and past PPI users were associated with higher odds for BPPV than non-PPI users (adjusted OR (aOR) = 3.57, 95% CI = 3.33−3.83, and p < 0.001 for current PPI users and aOR = 1.76, 95% CI = 1.64−1.89, and p < 0.001 for past PPI users). In addition, longer dates of PPI use were related to higher odds for BPPV (aOR (95% CI) = 1.95 [1.81−2.10] for ≥1 day and <30 days of PPI prescription, <2.88 [2.68−3.10] for ≥30 days and <365 days of PPI prescription, and <3.45 [3.19−3.73] for ≥365 days of PPI prescription). PPI use was linked with an elevated risk of BPPV in the adult population. The odds for BPPV were higher in patients with a longer duration of PPI use.

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.