Assessment of phthalate exposure at a fire site in Korean firefighters.

To determine phthalate exposure in 32 firefighters, the concentrations of urinary phthalate metabolites, immediately (exposure day) and three weeks (control day) after fire suppression, were compared. Mono-(2-ethyl-5-carboxypentyl) phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, mono-n-butyl phthalate (MBP), mono-n-benzyl phthalate (MBzP), and total phthalates (∑phthalates) levels, and creatinine-adjusted levels of MBP, MBzP, and ∑phthalates were significantly higher on exposure day than on control day. Phthalate concentration was significantly higher in firefighters who performed the fire extinguishing tasks (geometric mean [GM], 149.9 µg/L) than in those who performed other tasks (GM 70.8 µg/L) (p = .012). The GM concentration of firefighters who were active ≤ 50 m from the fire was 119.0 µg/L, and 37.6 µg/L for those who were > 50 m away (p = .012). The GM concentration was significantly different (p = .039) in firefighters with subjective symptoms after fire suppression (151.9 µg/L) compared to those without symptoms (81.6 µg/L). This study showed that firefighters were exposed to phthalate.

Posttraumatic stress disorder symptoms and neurocognitive functioning in fire fighters: The mediating role of sleep problems and resilience.

BACKGROUND: Firefighters are often exposed to terrible and dangerous scenes due to their duties, and thus have a high risk of developing posttraumatic stress disorder(PTSD). The purpose of the study is to examine the relationship between PTSD symptoms, sleep problems, resilience and neurocognitive functioning of firefighters, and to identify the sequential mediating effects of sleep problems and resilience on the relationship between PTSD symptoms and neurocognitive functioning (especially psychomotor speed and processing speed). METHODS: Data were collected from 325 firefighters in eight fire departments in four regions of Korea. Subjects performed neurocognitive function tests and completed the following questionnaires: Primary Care PTSD Screening, Pittsburgh Sleep Quality Index-K and Connor-Davidson Resilience Scale-2. The correlation and dual mediation effects were analysed using SPSS 22.0 program and PROCESS macro 3.4 program. RESULTS: PTSD symptoms, neurocognitive functioning, sleep problems and resilience were significantly correlated with each other. In the sequential mediation model, the relationship between PTSD and psychomotor speed/processing speed was sequentially mediated by sleep problems and resilience after adjusting for demographic variables. CONCLUSIONS: The PTSD symptoms of firefighters were related to a sequential link between sleep problems, low resilience and decreased neurocognitive function. These findings could serve as a basis for more effective and integrated interventional strategies for facilitating better neurocognitive functioning in firefighters.

Prenatal exposure to mixtures of heavy metals and neurodevelopment in infants at 6 months.

BACKGROUND: Exposure to mixture of neurotoxic metals such as lead, mercury and cadmium occurs at a specific point of time. When exposed to metal mixtures, one metal may act as an agonist or antagonist to another metal. Thus, it is important to study the effects of exposure to a combination of metals on children's development using advance statistical methods. OBJECTIVES: In this study, we explored the effects of prenatal metal exposure including lead, mercury and cadmium in early pregnancy (12-20 weeks), late pregnancy (>28 weeks), and at birth on neurodevelopment of infants at 6 months of age. METHODS: We included 523 eligible mother-child pairs from the mothers and children environmental health (MOCEH) study, a prospective birth cohort study in Korea. We used linear regression, Bayesian kernel machine regression (BKMR) and generalized additive models (GAM), to evaluate the effects of exposure to metal mixtures on neurodevelopment of infants aged 6 months. The Korean version of Bayley scale of infant and toddler development-II was used to measure the child's neurodevelopment. RESULTS: Linear regression models showed a significant negative effect of lead exposure during late pregnancy on the mental development index (MDI) [ß = -2.51 (-4.92, -0.10)] scores of infants aged 6 months following co-exposure to mercury. Further, linear regression analysis showed a significant interaction between late pregnancy lead and mercury concentrations. BKMR analysis showed similar results as those obtained in linear regression models. These results were also replicated in the GAM. Stratification analysis showed that greater than 50 percentile concentration of mercury in late pregnancy potentiated the adverse effects of lead in late pregnancy on MDI [ß = -4.33 (-7.66, -1.00)] and psychomotor development index (PDI) [ß = -5.30 (-9.13, -1.46)] at 6 months of age. Prenatal cadmium exposure did not show a significant association with MDI and PDI at 6 months in the linear regression or BKMR analysis. CONCLUSION: Based on all the statistical methods used, we demonstrated the effect of combined exposure to metals on the neurodevelopment of infants aged 6 months, with significant interaction between lead and mercury.

The relationship between the pattern of shift work and sleep disturbances in Korean firefighters.

PURPOSE: Sleep disturbances are prevalent in firefighters, but the relationship between patterns of shift work and sleep disturbances has not yet been investigated. Here, this relationship has been evaluated in Korean firefighters. METHODS: A cross-sectional study was conducted using an online questionnaire, which captured demographic, psychosocial and work-related characteristics. Sleep disturbance was assessed using the insomnia severity index (ISI). The relationship between insomnia and work-related factors (including type of shift work and the frequency of emergency events and off-duty work which means overtime work on off days) was analyzed. RESULTS: A total of 9810 firefighters completed the survey, representing approximately 21.5% of all Korean firefighters; data from 9738 subjects were included in the analysis. All firefighter roles were significantly associated with insomnia; the odds ratio (OR) was 2.456 (95% confidence interval [CI] 1.461-4.128) for fire suppression and 1.871 (95% CI 1.105-3.167) for the emergency medical services and rescue. However, the pattern of shift work did not show a statistically significant relationship. The OR increased along with the frequency of emergency events and off-duty work (p value for trend < 0.05). CONCLUSIONS: This study found a significant association between the frequency of emergency and off-duty work and insomnia in Korean firefighters, whereas the pattern of shift work showed no significant relationship. Therefore, measures to reduce the frequency of emergency and off-duty work are required to prevent sleep disturbances in firefighters.

Cohort profile: Beyond birth cohort study - The Korean CHildren's ENvironmental health Study (Ko-CHENS).

The Korean CHildren's ENvironmental health Study (Ko-CHENS) is a nationwide prospective birth cohort showing the correlation between the environmental exposures and the health effects to prevent the environmental diseases in children, and it provides the guidelines for the environmental hazardous factors, applying the life-course approach to the environmental-health management system. The Ko-CHENS consists of 5000 Core and 65,000 Main Cohorts. The children in the Core Cohort are followed up at 6 months, every year before their admission into the elementary school, and every 3 years from the first year after this admission. The children in the Cohort will be followed up through the data links (Statistics Korea, National Health Insurance Service [NHIS], and Ministry of Education). The individual biospecimens will be analyzed for 19 substances. The long-term-storage biological samples will be used for the further substance analysis. The Ko-CHENS will investigate whether the environmental variables including the perinatal outdoor and indoor factors and the greenness contribute causally to the health outcomes in the children and adolescents. In addition to the individual surveys, the assessments of the outdoor exposures and health outcomes will use the national air-quality monitoring data and claim data of the NHIS, respectively. The two big-data forms of the Ko-CHENS are as follows: The Ko-CHENS data that can be linked with the nationally registered NHIS health-related database, including the medical utilization and the periodic health screening, and the birth/mortality database in the Statistics; the other is the Big-CHENS dataset that is based on the NHIS mother delivery code, for which the follow-up of almost 97% of the total birth population is expected. The Ko-CHENS is a very cost-effective study that fully exploits the existing national big-data systems with the data linkage.

High Maternal Blood Mercury Level Is Associated with Low Verbal IQ in Children.

The objective of the present study was to investigate the relationship of IQ in children with maternal blood mercury concentration during late pregnancy. The present study is a component of the Mothers and Children's Environmental Health (MOCEH) study, a multi-center birth cohort project in Korea that began in 2006. The study cohort consisted of 553 children whose mothers underwent testing for blood mercury during late pregnancy. The children were given the Korean language version of the Wechsler Preschool and Primary Scale of Intelligence, revised edition (WPPSI-R) at 60 months of age. Multivariate linear regression analysis, with adjustment for covariates, was used to assess the relationship between verbal, performance, and total IQ in children and blood mercury concentration of mothers during late pregnancy. The results of multivariate linear regression analysis indicated that a doubling of blood mercury was associated with the decrease in verbal and total IQ by 2.482 (95% confidence interval [CI], 0.749-4.214) and 2.402 (95% CI, 0.526-4.279), respectively, after adjustment. This inverse association remained after further adjustment for blood lead concentration. Fish intake is an effect modifier of child IQ. In conclusion, high maternal blood mercury level is associated with low verbal IQ in children.

Effect of Breastfeeding Duration on Cognitive Development in Infants: 3-Year Follow-up Study.

We investigated the association between breastfeeding and cognitive development in infants during their first 3 years. The present study was a part of the Mothers' and Children's Environmental Health (MOCEH) study, which was a multi-center birth cohort project in Korea that began in 2006. A total of 697 infants were tested at age 12, 24, and 36 months using the Korean version of the Bayley Scales of Infant Development II (K-BSID-II). The use and duration of breastfeeding and formula feeding were measured. The relationship between breastfeeding and the mental development index (MDI) score was analyzed by multiple linear regression analysis. The results indicated a positive correlation between breastfeeding duration and MDI score. After adjusting for covariates, infants who were breastfed for ≥ 9 months had significantly better cognitive development than those who had not been breastfed. These results suggest that the longer duration of breastfeeding improves cognitive development in infants.

Maternal Stress and Depressive Symptoms and Infant Development at Six Months: the Mothers and Children's Environmental Health (MOCEH) Prospective Study.

Our objective is to evaluate the relationships between prenatal maternal stress and depressive symptoms, respectively, and infant neurodevelopment at 6 months, adjusted for heavy metals and oxidative stress. This research is a part of a multi-center birth cohort study in South Korea. Information on stress and depressive symptoms was collected during the first trimester using Psychosocial Well-Being Index Short Form (PWI-SF) and Center for Epidemiological Studies Depression Scale (CES-D). The Korean Bayley Scales of Infant Development-II assessment (BSID-II), which includes the standardized mental development index (MDI) and psychomotor developmental index (PDI), and Korean Ages & Stages Questionnaires (K-ASQ) were applied to infants at six months of age. A higher index score indicates better development. Among 641 babies, 320 were female (50%). Maternal PWI ≥ 29 (vs. PWI ≤ 18) during early pregnancy was associated with a decrease in MDI scores of 5.37 points (P = 0.02) after adjusting for socioeconomic factors. Maternal CES-D ≥ 26 (vs. CES-D ≤ 10) during early pregnancy was associated with a decrease in MDI scores of 8.18 points (P = 0.01). The associations remained significant even after adjustment for lead, cadmium, and MDA levels (P < 0.05). However, no association was found between maternal PWI/CES-D and PDI score. No interaction was observed between stress and lead exposure. We found an inverse association between prenatal maternal stress and depressive symptoms, and MDI scores in 6-month-old infants after adjustment for prenatal lead exposure, which is known to affect cognitive function negatively.

Epidemiologic characteristics of compensated occupational lung cancers among Korean workers.

An understanding of the characteristics of occupational lung cancer is important to establish policies that prevent carcinogen exposure and to compensate workers exposed to lung carcinogens. This study analyzed the characteristics of occupational lung cancers in workers who were compensated under the Industrial Accident Compensation Insurance Law between 1994 and 2011. A total of 179 occupational lung cancers were compensated. The main carcinogenic exposure was asbestos, followed by crystalline silica and hexavalent chromium. The mean exposure duration and latency were 19.8 and 23.2 yr. The most common industry was manufacturing, followed by construction and transportation. The most common occupation was maintenance and repair, followed by foundry work, welding, painting, and spinning or weaving. Although asbestos was predominant carcinogen, the proportion of these cases was relatively low compared to other developed countries. Proper surveillance system is needed to monitor occupational lung cancer and improve prevention measures.

Radon concentration and affecting environmental conditions in water-curtain heated cultivation facilities.

Farmers cultivate plants in the winter using water curtain cultivation (WCC) facilities by spraying groundwater to keep them warm. In this study, the WCC facilities exhibited high radon concentrations during winter. The risk varied significantly depending on the facility operation, peaking in the early morning and then decreasing upon ventilation. At all measurement sites, radon concentrations were low when groundwater was not used. Even during the period of facility groundwater use, if water vapor condensation does not occur, there is no significant difference from soil-only emissions. However, once water vapor condensation occurs, radon accumulates rapidly, depending on the degree of radon contamination in the groundwater. Because groundwater contamination varies according to dilution by regional rainfall or inflow from other regions due to groundwater movement, abnormal changes in radon content occur. We found that in the absence of water vapor condensation in the facility, all the radon emitted from the soil and groundwater quickly escaped to the atmosphere, resulting in significantly lower indoor radon concentrations. These findings pave the way for the development of new methods to mitigate radon in WCC facilities.

The Association between Social Support, Metabolic Syndrome, and Incidence of Cardio-Cerebrovascular Diseases in Older Adults: The ARIRANG Study.

PURPOSE: We investigated the association between social support, metabolic syndrome, and incident cardio-cerebrovascular disease (CCVD) in rural Koreans aged ≥50 years. MATERIALS AND METHODS: We conducted a prospective study using the Korean Genome and Epidemiology Study on Atherosclerosis Risk of Rural Areas in the Korean General Population (KoGES-ARIRANG) dataset. From the baseline of 5169 adults, 1682 participants were finally included according to the exclusion criteria. For outcomes, myocardial infarction, angina, and stroke were included. For independent variables, the social support score and metabolic syndrome were used. Descriptive statistics and multivariate logistic regression were performed to investigate the association among the variables. Paired t-test was conducted to analyze the longitudinal variation of social support scores. RESULTS: During the 6.37 years of median follow-up, 137 participants developed CCVD. The adjusted odds ratio (aOR) of metabolic syndrome with persistently high social support was 2.175 [95% confidence interval (CI): 1.479-3.119]. The aOR of metabolic syndrome with persistently low social support was 2.494 (95% CI: 1.141-5.452). The longitudinal variation of the social support score of persistently high social support group was increased significantly by 4.26±26.32. The score of the persistently low social support group was decreased by 1.34±16.87 with no statistical significance. CONCLUSION: The presence of metabolic syndrome increases the likelihood of developing onset CCVD. Within the metabolic syndrome positive group, when social support was persistently low, the cohort developed more cardio-cerebrovascular disease compared to the persistently higher social support group. The social support score of the persistently low social support group could be improved through proper intervention. To prevent CCVD, metabolic syndrome components and low social support should be improved in the study participants.

Association between prenatal exposure to cadmium and atopic dermatitis in infancy.

Our objective was to evaluate the relationship between intrauterine exposure to cadmium and the presence of atopic dermatitis in infants 6 months of age, adjusted for covariates including exposure to other heavy metals. The present research is a component of the Mothers' and Children's Environmental Health (MOCEH) study, a multi-center birth cohort project conducted in Korea. Study subjects were restricted to pregnant women in whom cadmium and lead levels were measured at delivery and whose infants were assessed for the presence of atopic disease at 6 months of age. The odds ratio (OR) for the presence of atopic dermatitis in 6-month-old infants whose cord blood had elevated cadmium levels, after adjustment for other covariates, was 2.350 (95% CI, 1.126-4.906). The OR for the presence of atopic dermatitis in infants whose cord blood had elevated lead levels was not significant. In the present study, the cord blood cadmium level was significantly associated with the presence of atopic dermatitis in 6-month-old infants; this was not true of the cord blood lead level. To the best of our knowledge, this is the first prospective study to show a relationship between prenatal exposure to cadmium and atopic dermatitis in infancy.

The Risk of Major Depressive Disorder Due to Cataracts among the Korean Elderly Population: Results from the Korea National Health and Nutrition Examination Survey (KNHANES) in 2016 and 2018.

Cataracts and major depressive disorder (MDD) both have high prevalence, representing for major health burdens globally. In this study, we examined the risk of MDD due to cataracts. Data from the 2016 to 2018 Korea National Health and Nutrition Examination Survey (KNHANES) were used, including 4122 participants. Logistic regression analysis was performed to evaluate the odds ratio for MDD in association with cataracts. Controlled variables were age, gender, smoking, dyslipidemia and mobility. Subgroup analysis was performed with stratification by gender. The results reveal that cataracts are significantly correlated with MDD. Elderly people with cataracts were found to be more likely to develop MDD compared to those without cataracts (adjusted odds ratio: 1.654; 95% CI = 1.197-2.286). In subgroup analysis, men (adjusted odds ratio: 2.631; 95% CI = 1.247-5.551) were found to be more likely to develop MDD than women (adjusted odds ratio: 1.510; 95% CI = 1.061-2.150). Cataracts may be a risk factor for MDD in the elderly, especially among the male population.

Risk of insomnia symptoms according to Work-Family Conflict by workers' characteristics.

Background: Work-Family Conflict means that the demands of work and family roles cannot be met simultaneously, so one cannot concentrate on one's work or family role. This conflict can negatively affect mental health and cause insomnia symptoms. Methods: This study was conducted on 20,442 subjects. Insomnia symptoms were assessed using the Minimal Insomnia Symptom Scale, and other variables were assessed using the questionnaire method. Logistic regression analyses were performed to evaluate the effect of Work-Family Conflict on insomnia symptoms, and subgroup logistic regression analyses were also performed. Results: The number of people with insomnia symptoms was 4,322 (15.1%). Compared with Low Work-Family Conflict, the odds ratios (ORs) for the risk of insomnia symptoms were 1.84 (95% confidence interval: 1.56-2.16) in High work-to-family conflict, 1.16 (1.02-1.32) in High family-to-work conflict, and 3.19 (2.87-3.55) in High Work-Family Conflict. The ORs were higher for men than women in High WFC but higher for women than men in High Work-Family Conflict. Conclusions: The risk of insomnia symptoms was highest in High Work-Family Conflict.

Statement by the Korean Society of Occupational and Environmental Medicine on the proposed reform of working hours in South Korea.

The current 52-hour workweek in South Korea consists of 40 hours of regular work and 12 hours of overtime. Although the average working hours in South Korea is declining, it is still 199 hours longer than the Organisation for Economic Co-operation and Development average of 1,716 hours per year. In view to this, the South Korean government has now proposed to reform the workweek, mainly intending to increase the workweek to 69 hours when the workload is heavy. This reform, by increasing the labor intensity due to long working hours, goes against the global trend of reducing work hours for a safe and healthy working environment. Long working hours can lead to increased cerebrovascular and cardiovascular diseases, industrial accidents, mental health problems, and safety accidents due to lack of concentration. In conclusion, the Korean government's working hour reform plan can have a negative impact on workers' health, and therefore it should be thoroughly reviewed and modified.

Cancer morbidity of professional emergency responders in Korea.

BACKGROUND: Many professional emergency responders (ERs) who belong to the Korean National Emergency Management Agency (NEMA) have been cross-trained and serve multiple roles. As such, firefighters and other ERs in Korea are exposed to similar occupational hazards. This study was conducted to estimate cancer morbidity in male ERs and compare that with Korean men. METHODS: The cohort was comprised of 33,416 male ERs working between 1980 and 2007, who were alive on December 31, 1995. Work histories were merged with the Korea National Central Cancer Registry (KNCCR) to assess cancer morbidity between 1996 and 2007. Standardized incidence ratios (SIRs) with reference to Korean men were analyzed. RESULTS: SIRs with reference to national cancer rates were not significantly decreased for overall cancer (SIR = 0.97, 95% CI = 0.90-1.08) in all ERs. However, colorectal (SIR = 1.35, 95% CI = 1.07-1.67), kidney (SIR = 1.59, 95% CI = 1.00-2.41), and bladder (SIR = 1.77, 95% CI = 1.08-2.73) cancer, and non-Hodgkin's lymphoma (SIR = 1.81, 95% CI = 1.12-2.76) morbidities were significantly increased among all ERs. In firefighters, significantly increased cancer types were as same as those of all ERs. In non-firefighter ERs, colorectal (SIR = 2.51, 95% CI = 1.20-4.61) and bone and articular cartilage cancers (SIR = 9.53, 95% CI = 1.07-34.41) were significantly higher than those of Korean men. CONCLUSIONS: Korean firefighters showed excess morbidity in several cancer types, including colorectal and urologic cancers, and non-Hodgkin's lymphoma, demonstrating similar trends to previous studies for firefighters conducted in other countries. Increased incidence in these cancer types suggests occupational exposure to carcinogens and shift work.

Low Contrast Visual Evoked Potentials for Early Detection of Optic Neuritis.

Optic neuritis (ON) detection is important for the early diagnosis and management of multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). However, the conventional high-contrast visual evoked potential (VEP) used for ON detection lacks sensitivity for identifying ON presenting as mild or unremarkable visual disturbance, which is common in first-episode ON. Therefore, this study aimed to investigate whether a change in contrast or check size improves the sensitivity of VEP to first-ever ON. In total, 60 patients with the demyelinating disease (29 MS and 31 idiopathic patients with ON) without ON or with first-ever ON at least 6 months prior and 32 healthy controls underwent neuro-ophthalmic evaluations. VEPs were induced using three pattern-reversal checkerboard stimuli having, respectively, 10% contrast with a check size of 32' (LC32 VEP), 100% contrast with a check size of 32' (HC32 VEP; conventional VEP), and 100% contrast with a check size of 16' (HC16 VEP). The receiver operating characteristic (ROC) curve analysis and area under the curve (AUC) were calculated to determine the most appropriate VEP method for detecting optic nerve involvement. The optimal cut-off point was determined using the Youden index (J-index). The McNemar test was used to determine whether dichotomous proportions were equivalent. In comparison with first-ever ON eyes (n = 39) and healthy eyes (n = 64), LC32 VEP showed the highest AUC for discriminating ON (0.750, p < 0.001; 0.730 for HC32 VEP, p < 0.001; 0.702 for HC16 VEP, p = 0.001). In the first-ever ON group, LC32 VEP and conventional HC32 VEP were abnormal in 76.9 and 43.6%, respectively (McNemar, p < 0.001), and combining these tests did not improve sensitivity. These indicate that LC32 VEP is the most sensitive method for detecting first-ever ON. Visual evoked potential with 10% contrast stimuli was superior to conventional VEP for detecting first-ever ON. Thus, adding these LC stimuli might be helpful in identifying optic nerve involvement in ON with mild or unremarkable visual impairment.

Biological monitoring for exposure assessment of volatile organic compounds by Korean firefighters at the fire site.

The VOCs and metabolites in urine for exposed VOCs were evaluated for firefighters who participated in the actual fire fighting to determine whether firefighters were exposed to hazardous chemicals, which is the basic data on cancer risk of firefighters. When the fire extinguishing time is long, the concentration of benzene, PHEMA, and toluene among VOCs and metabolites in the case of fire suppression, rescue, and fire investigation work, which is estimated that the exposure of hazardous substances generated from the fire site at the time of fire suppression was large, significantly increased. In the case where the number of urination is 2 or less, the concentration of TZCA, toluene, and benzene among VOCs and metabolites was significantly increased compared to the number of urinating more than 2 times. In the concentration of VOCs and metabolites in urine corrected with creatinine, the concentrations of toluene and PHEMA in urine were significantly higher. The concentration of PHEMA in urine was higher in the group who participated in the fire suppression for more than 11 hours (long time) than the group who participated in the fire suppression for a short time.

Association between sleep quality and type of shift work in Korean firefighters.

Background: Shift work that interferes with normal sleep patterns, is known to be a cause of sleep disturbance and has been studied through various occupational groups. However, it is not known which shift type is better for sleep health. Methods: This study included 568 firefighters. Sleep quality was evaluated using Pittsburgh Sleep Quality Index. Sleep quality was categorized into 2 groups; good quality (≤ 5 points) and poor quality (≥ 6 points). Demographic variables, depression, anxiety, type of shift, and job were collected by self-reported questionnaires. The χ2 test, t-test, and multiple logistic regression analysis were used to evaluate the effect of shift type on the sleep quality of firefighters. Results: Three hundred thirty-seven firefighters (59.3%) have poor sleep quality. Compared to day workers, the odds ratios (ORs) of poor sleep quality were 2.169 (95% confidence interval: 1.137-4.134) in 6-day cycle, 2.161 (1.150-4.062) in 9-day cycle, 1.805 (1.087-2.997) in 21-day cycle, and 1.485 (0.718-3.069) in 3-day cycle. The ORs of poor sleep quality were 1.697(1.021-2.823) in fire suppression and 2.325 (1.213-4.455) in emergency medical service compared to administration. Conclusions: All shift work type except for the 3-day cycle was associated with poor sleep quality compared to day work.

Variation in Genotype and DNA Methylation Patterns Based on Alcohol Use and CVD in the Korean Genome and Epidemiology Study (KoGES).

Alcohol consumption can increase the risk of chronic diseases, such as myocardial infarction, coronary artery disease, hyperlipidemia, and hypertension. We aimed to assess the association between genotype, DNA methylation patterns, alcohol consumption, and chronic diseases in Korean population. We analyzed 8840 subjects for genotypes and 446 for DNA methylation among the 9351 subjects from the Korean Genome and Epidemiology Study (KoGES). We further divided both groups into two sub-groups according to the presence/absence of chronic diseases. We selected genes whose methylation varied significantly with alcohol consumption, and visualized genotype and DNA methylation patterns specific to each group. Genome-wide association study (GWAS) revealed single nucleotide polymorphisms (SNPs) rs2074356 and rs11066280 in HECT domain E3 ubiquitin protein ligase 4 (HECTD4) to be significantly associated with alcohol consumption in both the presence. The rs12229654 genotype also displayed significantly different patterns with alcohol consumption. Furthermore, we retrieved differentially methylated regions (DMRs) from four groups based on sex and chronic diseases and compared them by drinking status. In genotype analysis, cardiovascular diseases (CVDs) showed a higher proportion in drinker than in non-drinker, but not in DMR analysis. Additionally, we analyzed the enriched Gene Ontology terms and Kyoto Gene and Genome Encyclopedia (KEGG) pathways and visualized the network, heatmap, and upset plot. We show that the pattern of DNA methylation associated with CVD is strongly influenced by alcoholism. Overall, this study identified genetic and epigenetic variants influenced by alcohol consumption and chronic diseases.