Objectives: This study aimed to evaluate the potential interaction between kidney function and the non-linear association between serum calcium levels and cardiovascular disease (CVD) mortality. Methods: This study included 8927 participants enrolled in the Dong-gu Study. Albumin-corrected calcium levels were used and categorized into 6 percentile categories: <2.5th, 2.5-25.0th, 25.0-50.0th, 50.0-75.0th, 75.0-97.5th, and >97.5th. Restricted cubic spline analysis was used to examine the non-linear association between calcium levels and CVD mortality. Cox proportional hazard regression was used to estimate hazard ratios (HRs) for CVD mortality according to serum calcium categories. All survival analyses were stratified by the estimated glomerular filtration rate. Results: Over a follow-up period of 11.9±2.8 years, 1757 participants died, of whom 219 died from CVD. A U-shaped association between serum calcium and CVD mortality was found, and the association was more evident in the low kidney function group. Compared to the 25.0-50.0th percentile group for serum calcium levels, both low and high serum calcium tended to be associated with CVD mortality (<2.5th: HR, 6.23; 95% confidence interval [CI], 1.16 to 33.56; >97.5th: HR, 2.56; 95% CI, 0.76 to 8.66) in the low kidney function group. In the normal kidney function group, a similar association was found between serum calcium levels and CVD mortality (<2.5th: HR, 1.37; 95% CI, 0.58 to 3.27; >97.5th: HR, 1.65; 95% CI, 0.70 to 3.93). Conclusions We found a non-linear association between serum calcium levels and CVD mortality, suggesting that calcium dyshomeostasis may contribute to CVD mortality, and kidney function may modify the association.

Background and Objectives: The association between bilirubin and atrial fibrillation (AF) has been evaluated previously in observational studies but with contradictory results. This study evaluated the causal association between serum bilirubin level and AF using Mendelian randomization (MR) analysis. Methods: This cross-sectional study includes 8,977 participants from the Dong-gu Study.In the observational analysis, multivariate logistic regression was performed to evaluate the association between bilirubin and prevalent AF. To evaluate the causal association between bilirubin and AF, MR analysis was conducted by using the UGT1A1 rs11891311 and rs4148323 polymorphisms as instrumental variables. Results: Elevated serum bilirubin levels were associated with an increased risk for AF in observational analysis (total bilirubin: odds ratio [OR], 1.31; 95% confidence interval [95% CI], 1.15–1.48 per 1 standard deviation [SD]; direct bilirubin: OR, 1.31; 95% CI, 1.18–1.46 per 1 SD), whereas the genetically predicted serum bilirubin levels in MR analysis did not show this association (total bilirubin: OR, 1.02; 95% CI, 0.67–1.53 per 1 SD; direct bilirubin: OR, 1.03; 95% CI, 0.61–1.73 per 1 SD). Conclusions Genetically predicted bilirubin levels were not associated with prevalent AF.Thus, the observational association between serum bilirubin levels and AF may be noncausal and affected by reverse causality or unmeasured confounding.

Background and Objectives: Previous observational studies presented a positive association between alcohol and atrial fibrillation (AF). However, previous studies using genetic polymorphisms on the causal relationship between alcohol consumption and AF have reported conflicting results. This study aimed to evaluate the causality between alcohol consumption and AF using the aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism, which is the genetic variant with the most potent effect on drinking behavior. Methods: A total of 8,964 participants from the Dong-gu Study were included in the present study. The causal association between alcohol consumption and AF was evaluated through a Mendelian randomization (MR) analysis using the ALDH2 rs671 polymorphism as an instrumental variable. Results: No significant relationship between alcohol consumption and AF was found in the observational analysis. However, the genetic analysis using the ALDH2 polymorphism showed a significant association in men. In the MR analysis, genetically predicted daily alcohol consumption was positively related to AF. Conclusions MR analysis revealed a significant association between the amount of alcohol consumption and AF, which suggests that the association may be causal.

Purpose: Postoperative pain and delayed wound healing are the main complications following anal surgery associated with poor quality of life. Hyaluronic acid (HA) supports tissue regeneration and rapid wound healing by promoting cell proliferation and migration. We investigated the effects of HA on perianal wound healing in a rat model. Methods: Forty-eight 8-week-old Sprague-Dawley rats with perianal wounds created by biopsy punch were divided into 3 groups: simple dressing with gauze (control), dressing with topical HA film, and dressing with topical HA gel. HA agents were not reapplied postoperatively. Wound healing was evaluated by measuring the healed area, and histological analyses were randomly performed using hematoxylin and eosin and Masson trichrome staining. Results: Fewer mean days were required for complete wound healing in the HA film and HA gel groups than in the control group (11.6 vs. 11.9 vs. 13.8 days, respectively; P = 0.010). The healed area in the HA film group on day 11 was larger than that in the HA gel and control groups (80.2% vs. 61.9% vs. 53.2%, respectively; P < 0.001). Histologically, the HA film group showed accelerated reepithelialization, a rapid transition to lymphocyte-predominant inflammation, and increased fibroblastic proliferation and collagen deposition compared to the other groups. There was no treatment-related toxicity in the HA application groups. Conclusion Topical application of HA film to perianal wounds improves the wound healing rate in a rat model. This finding suggests a potential benefit of HA film application in promoting wound healing after anal surgery in humans.

Background: Several studies have reported conflicting results regarding the relationship between alcohol consumption and cortisol levels. However, the causality between alcohol consumption and cortisol levels has not been evaluated. Methods: This study examined 8,922 participants from the Dong-gu Study. The aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism was used as an instrumental variable for alcohol consumption. The association between the genetically predicted alcohol consumption and cortisol level was evaluated with Mendelian randomization (MR) using two-stage least squares regression. Results: Alcohol consumption was positively associated with the serum cortisol level in both sexes in the observational analysis. In the MR analysis, the genetically predicted alcohol consumption was positively related to the cortisol level in men, with cortisol levels increasing by 0.18 µg/dL per drink per day. However, there was no relationship in women in the MR analysis. Conclusion The predicted alcohol consumption according to the ALDH2 rs671 polymorphism was positively related to the cortisol levels, suggesting a causal relationship between alcohol consumption and cortisol levels.

Background: Several studies have reported conflicting results regarding the relationship between alcohol consumption and cortisol levels. However, the causality between alcohol consumption and cortisol levels has not been evaluated. Methods: This study examined 8,922 participants from the Dong-gu Study. The aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism was used as an instrumental variable for alcohol consumption. The association between the genetically predicted alcohol consumption and cortisol level was evaluated with Mendelian randomization (MR) using two-stage least squares regression. Results: Alcohol consumption was positively associated with the serum cortisol level in both sexes in the observational analysis. In the MR analysis, the genetically predicted alcohol consumption was positively related to the cortisol level in men, with cortisol levels increasing by 0.18 µg/dL per drink per day. However, there was no relationship in women in the MR analysis. Conclusion The predicted alcohol consumption according to the ALDH2 rs671 polymorphism was positively related to the cortisol levels, suggesting a causal relationship between alcohol consumption and cortisol levels.

BACKGROUND: Understanding the burden of disease is important to establish cost-effective treatment strategies and to allocate healthcare resources appropriately. However, little reliable information is available regarding the overall economic burden imposed by chronic obstructive pulmonary disease (COPD) in Korea. METHODS: This study is a multicenter observational research on the COPD burden in Korea. Total COPD costs were comprised of three categories: direct medical, direct non-medical, and indirect costs. For direct medical costs, institutional investigation was performed at 13 medical facilities mainly based on the claims data. For direct non-medical and indirect costs, site-based surveys were administered to the COPD patients during routine visits. Total costs were estimated using the COPD population defined in the recent report. RESULTS: The estimated total costs were approximately 1,245 million US dollar (1,408 billion Korean won). Direct medical costs comprised approximately 20% of the total estimated costs. Of these, formal medical costs held more than 80%. As direct non-medical costs, nursing costs made up the largest percentage (39%) of the total estimated costs. Costs for COPD-related loss of productivity formed four fifths of indirect costs, and accounted for up to 33% of the total costs. CONCLUSION: This study shows for the first time the direct and indirect costs of COPD in Korea. The total costs were enormous, and the costs of nursing and lost productivity comprised approximately 70% of total costs. The results provide insight for an effective allocation of healthcare resources and to inform establishment of strategies to reduce national burden of COPD.
Delivery of Health Care ; Efficiency ; Health Care Costs ; Humans ; Korea* ; Nursing ; Pulmonary Disease, Chronic Obstructive*

Diarrheagenic Escherichia coli (E. coli) is a main cause of diarrhea worldwide. This study reports the investigation on the occurrence of enterotoxigenic E. coli (ETEC) serotype O27:H7-associated foodborne gastrointestinal disease that occurred at two schools, one middle school and one high school, in Seoul, Korea in June 2015. The immediate government investigation in 1,216 students and 19 food handlers in these two schools revealed that 116 students, 32 students in the middle school and 84 students in the high school, and 2 food handlers, one from middle school and the other from high school, developed gastrointestinal illness symptoms including diarrhea. Following lab investigation identified 29 ETEC serotype O27:H7 strains, 27 from 116 students and 2 from 19 food handlers. Pattern of pulsed-field gel electrophoresis analysis of ETEC isolates suggested that ETEC serotype O27:H7 caused the diarrheal outbreak in June 2015 in Seoul, Korea was a specific clone. In addition, these ETEC serotype O27:H7 isolates were highly resistance to the several antibiotics. The results from the present study provide the evidence that ETEC serotype O27:H7 can be an important cause of domestic foodborne outbreak in Korea.
Anti-Bacterial Agents ; Clone Cells ; Diarrhea ; Electrophoresis, Gel, Pulsed-Field ; Enterotoxigenic Escherichia coli* ; Escherichia coli ; Gastrointestinal Diseases ; Humans ; Korea ; Seoul ; Serogroup

Many studies have investigated relationships between APOE genotype and bone mineral density (BMD). However, the results of these studies have been inconsistent. Few studies have been carried out in Asian populations. We studied the relationship of the APOE gene polymorphism and BMD in two large population-based studies. The datasets included the Dong-gu Study (3575 men and 5335 women) and the Namwon Study (2310 men, 3512 women). Lumbar spine and femoral neck BMD were measured by dual-energy X-ray absorptiometry. APOE genotypes were analyzed by polymerase chain reaction-restriction fragment length polymorphism. The APOE genotypes were classified into APOE E2 (E2/E2 and E2/E3), APOE E3 (E3/E3), and APOE E4 (E3/E4 and E4/E4). The genotype distribution of the study population was in Hardy-Weinberg equilibrium. There were no significant differences among APOE genotype groups in lumbar and femoral neck BMD in either cohort. Our data do not support the hypothesis that the APOE genotype is associated with BMD.
Absorptiometry, Photon ; Apolipoproteins E ; Asian Continental Ancestry Group ; Bone Density ; Cohort Studies ; Dataset ; Female ; Femur Neck ; Genotype ; Humans ; Jeollabuk-do ; Male ; Polymorphism, Genetic ; Spine

Low levels of vitamin D have been associated with increased cardiovascular disease risk. However, few studies have evaluated the association between vitamin D status and peripheral arterial disease (PAD). We therefore aimed to investigate whether low 25-hydroxyvitamin D (25(OH)D) levels were associated with increased risk of PAD in the Korean population. This cross-sectional study was conducted among 8,960 subjects aged 50 years or older without known myocardial infarction or stroke. PAD was defined by an ankle brachial blood pressure index <0.9. Multivariate logistic regression was used to evaluate the association between serum 25(OH)D levels and risk of PAD. Of the 8,960 subjects, 3.0% had PAD and the age and sex adjusted prevalence of PAD decreased with the increasing 25(OH)D quartile. After adjusting for potential confounders and parathyroid hormones, serum 25(OH)D levels were associated with a significantly decreased risk of PAD (OR for one SD increase, 0.98; 95% CI, 0.95-1.0, P for trend=0.040). Compared with the first 25(OH)D quartile, the odds of PAD were 0.86 (95% CI, 0.62-1.21), 0.67 (95% CI, 0.46-0.97), and 0.71 (95% CI, 0.49-1.04) for the second, third, and fourth quartiles, respectively. In this cross-sectional study, we found that low serum 25(OH)D levels were associated with an increased risk of PAD, independent of traditional cardiovascular risk factors and parathyroid hormone. Our findings suggest that low vitamin D levels may contribute to PAD in the Korean population.
Ankle ; Atherosclerosis ; Blood Pressure ; Cardiovascular Diseases ; Cross-Sectional Studies ; Logistic Models ; Myocardial Infarction ; Parathyroid Hormone ; Peripheral Arterial Disease ; Prevalence ; Risk Factors ; Stroke ; Vitamin D ; Vitamins