Ambient particulate matter and surrounding greenness in relation to sleep quality among pregnant women: A nationwide cohort study

Background

Particulate air pollution and residential greenness are associated with sleep quality in the general population; however, their influence on maternal sleep quality during pregnancy has not been assessed.

Objective

This cross-sectional study investigated the individual and interactive effects of exposure to particulate matter (PM) air pollution and residential greenness on sleep quality in pregnant women.

Methods

Pregnant women (n = 4933) enrolled in the Korean Children's Environmental Health Study with sleep quality information and residential address were included. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). The average concentrations of PM (PM2.5 and PM10) during pregnancy were estimated through land use regression, and residential greenness in a 1000 m buffer area around participants' residences was estimated using the Normalized Difference Vegetation Index (NDVI1000-m). Modified Poisson regression models were used to estimate the associations between PM and NDVI and poor sleep quality (PSQI >5) after controlling for a range of covariates. A four-way mediation analysis was conducted to examine the mediating effects of PM.

Results

After adjusting for confounders, each 10 μg/m3 increase in PM2.5 and PM10 exposure was associated with a higher risk of poor sleep quality (relative risk [RR]: 1.06; 95% confidence interval [CI]: 1.01, 1.11; and RR: 1.09; 95% CI: 1.06, 1.13, respectively), and each 0.1-unit increase in NDVI1000-m was associated with a lower risk of poor sleep quality (RR: 0.97; 95% CI: 0.95, 0.99). Mediation analysis showed that PM mediated approximately 37%-56% of the association between residential greenness and poor sleep quality.

Conclusions

This study identified a positive association between residential greenness and sleep quality. Furthermore, these associations are mediated by a reduction in exposure to particulate air pollution and highlight the link between green areas, air pollution control, and human health.

Lung Cancer in Ever- and Never-Smokers: Findings from Multi-Population GWAS Studies

BACKGROUND

Clinical, molecular, and genetic epidemiology studies displayed remarkable differences between ever- and never-smoking lung cancer.

METHODS

We conducted a stratified multi-population (European, East Asian, and African descent) association study on 44,823 ever-smokers and 20,074 never-smokers to identify novel variants that were missed in the non-stratified analysis. Functional analysis including expression quantitative trait loci (eQTL) colocalization and DNA damage assays, and annotation studies were conducted to evaluate the functional roles of the variants. We further evaluated the impact of smoking quantity on lung cancer risk for the variants associated with ever-smoking lung cancer.

RESULTS

Five novel independent loci, GABRA4, intergenic region 12q24.33, LRRC4C, LINC01088, and LCNL1 were identified with the association at two or three populations (P < 5 × 10-8). Further functional analysis provided multiple lines of evidence suggesting the variants affect lung cancer risk through excessive DNA damage (GABRA4) or cis-regulation of gene expression (LCNL1). The risk of variants from 12 independent regions, including the well-known CHRNA5, associated with ever-smoking lung cancer was evaluated for never-smokers, light-smokers (packyear ≤ 20), and moderate-to-heavy-smokers (packyear > 20). Different risk patterns were observed for the variants among the different groups by smoking behavior.

CONCLUSIONS

We identified novel variants associated with lung cancer in only ever- or never-smoking groups that were missed by prior main-effect association studies.

IMPACT

Our study highlights the genetic heterogeneity between ever- and never-smoking lung cancer and provides etiologic insights into the complicated genetic architecture of this deadly cancer.

Mortality Burden Due to Short-term Exposure to Fine Particulate Matter in Korea

OBJECTIVES

Excess mortality associated with long-term exposure to fine particulate matter (PM2.5) has been documented. However, research on the disease burden following short-term exposure is scarce. We investigated the cause-specific mortality burden of short-term exposure to PM2.5 by considering the potential non-linear concentration-response relationship in Korea.

METHODS

Daily cause-specific mortality rates and PM2.5 exposure levels from 2010 to 2019 were collected for 8 Korean cities and 9 provinces. A generalized additive mixed model was employed to estimate the non-linear relationship between PM2.5 exposure and cause-specific mortality levels. We assumed no detrimental health effects of PM2.5 concentrations below 15 μg/m3. Overall deaths attributable to short-term PM2.5 exposure were estimated by summing the daily numbers of excess deaths associated with ambient PM2.5 exposure.

RESULTS

Of the 2 749 704 recorded deaths, 2 453 686 (89.2%) were non-accidental, 591 267 (21.5%) were cardiovascular, and 141 066 (5.1%) were respiratory in nature. A non-linear relationship was observed between all-cause mortality and exposure to PM2.5 at lag0, whereas linear associations were evident for cause-specific mortalities. Overall, 10 814 all-cause, 7855 non-accidental, 1642 cardiovascular, and 708 respiratory deaths were attributed to short-term exposure to PM2.5. The estimated number of all-cause excess deaths due to short-term PM2.5 exposure in 2019 was 1039 (95% confidence interval, 604 to 1472).

CONCLUSIONS

Our findings indicate an association between short-term PM2.5 exposure and various mortality rates (all-cause, non-accidental, cardiovascular, and respiratory) in Korea over the period from 2010 to 2019. Consequently, action plans should be developed to reduce deaths attributable to short-term exposure to PM2.5.

Relationship of bisphenol A substitutes bisphenol F and bisphenol S with adiponectin/leptin ratio among children from the environment and development of children cohort

BACKGROUND

Bisphenol A (BPA) is known as an obesogenic endocrine disruptor. Bisphenol S (BPS) and F (BPF) are substitutes that have recently replaced BPA.

OBJECTIVES

To investigate the relationships of urinary bisphenols (BPA, BPS and BPF) with adiposity measurements (obesity, BMI z-score, and fat mass), serum adipokine levels (adiponectin and leptin), and adiponectin/leptin ratio (A/L ratio) in 6- and 8-year-old children.

METHODS

A total of 561 children who participated in the Environment and Development of Children cohort (482 and 516 children visited at age 6 and 8, respectively) at Seoul National University Children's Hospital during 2015-2019 were included. Urinary BPA levels were log-transformed. BPS levels were categorized into three groups (non-detected, lower-half, and higher-half of detected), and BPF levels were classified into two groups (non-detected and detected).

RESULTS

The urinary BPS higher-half group had a higher BMI z-score (β = 0.160, P= 0.044), higher fat mass (β = 0.104, P< 0.001), lower adiponectin concentration (β =- 0.069, P< 0.001), higher leptin concentration (β = 0.360, P< 0.001), and lower A/L ratio (β =- 0.428, P< 0.001) compared with the non-detected group. The urinary BPF-detected group had a higher fat mass (β = 0.074, P< 0.001), lower adiponectin concentration (β =- 0.069, P< 0.001), higher leptin concentration (β = 0.360, P< 0.001), and lower A/L ratio (β =- 0.428, P< 0.001) compared with the non-detected group. The BPA levels showed no consistent associations with outcomes, except for isolated associations of BPA at age 6 with a higher BMI z-score at age 6 (P= 0.016) and leptin at age 8 (P= 0.021).

CONCLUSIONS

Increased exposure to BPS and BPF is associated with higher fat mass and leptin concentration, lower serum adiponectin, and lower A/L ratio in children. These findings suggest potential adverse effects of BPA substitutes on adiposity and adipokines. No consistent association of BPA exposure with outcomes could be partly explained by the decreasing BPA levels over time.

Infantile allergic diseases: a cohort study prenatal fish intake and mercury exposure context

BACKGROUND

Allergic diseases (ADs) have been increasingly reported in infants and children over the last decade. Diet, especially the inclusion of fish intake, may help to lower the risk of ADs. However, fish also, can bioaccumulate environmental contaminants such as mercury. Hence, our study aims to determine what effects the type and frequency of fish intake have on ADs in six-month-old infants, independently and jointly with mercury exposure.

METHODS

This study is part of the prospective birth cohort: Mothers and Children's Environmental Health (MOCEH) study in South Korea. Data was collected on prenatal fish intake, prenatal mercury concentration and ADs for infants aged six months for 590 eligible mother-infant pairs. Logistic regression analysis was conducted to evaluate the risk of prenatal fish intake and mercury concentration on ADs in infants. Finally, interaction between fish intake and mercury concentration affecting ADs in infants was evaluated. Hazard ratios of prenatal fish intake on ADs in 6 month old infants were calculated by prenatal mercury exposure.

RESULTS

Logistic regression analysis showed that white fish (OR: 0.53; 95% CI 0.30-0.94; P < 0.05) intake frequency, once a week significantly decreased the risk of ADs in infants. Stratification analysis showed that consuming white fish once a week significantly reduced the hazard of ADs (HR: 0.44; 95% CI 0.21-0.92; P < 0.05) in infants in the high-mercury (≥ 50th percentile) exposure group.

CONCLUSION

The result indicates that prenatal white fish intake at least once a week reduces the risk of ADs in infants, especially in the group with high prenatal mercury exposure.

CYP2A6 Activity and Cigarette Consumption Interact in Smoking-Related Lung Cancer Susceptibility

Cigarette smoke, containing both nicotine and carcinogens, causes lung cancer. However, not all smokers develop lung cancer, highlighting the importance of the interaction between host susceptibility and environmental exposure in tumorigenesis. Here, we aimed to delineate the interaction between metabolizing ability of tobacco carcinogens and smoking intensity in mediating genetic susceptibility to smoking-related lung tumorigenesis. Single-variant and gene-based associations of 43 tobacco carcinogen-metabolizing genes with lung cancer were analyzed using summary statistics and individual-level genetic data, followed by causal inference of Mendelian randomization, mediation analysis, and structural equation modeling. Cigarette smoke-exposed cell models were used to detect gene expression patterns in relation to specific alleles. Data from the International Lung Cancer Consortium (29,266 cases and 56,450 controls) and UK Biobank (2,155 cases and 376,329 controls) indicated that the genetic variant rs56113850 C>T located in intron 4 of CYP2A6 was significantly associated with decreased lung cancer risk among smokers (OR = 0.88, 95% confidence interval = 0.85-0.91, P = 2.18 × 10-16), which might interact (Pinteraction = 0.028) with and partially be mediated (ORindirect = 0.987) by smoking status. Smoking intensity accounted for 82.3% of the effect of CYP2A6 activity on lung cancer risk but entirely mediated the genetic effect of rs56113850. Mechanistically, the rs56113850 T allele rescued the downregulation of CYP2A6 caused by cigarette smoke exposure, potentially through preferential recruitment of transcription factor helicase-like transcription factor. Together, this study provides additional insights into the interplay between host susceptibility and carcinogen exposure in smoking-related lung tumorigenesis.

SIGNIFICANCE

The causal pathway connecting CYP2A6 genetic variability and activity, cigarette consumption, and lung cancer susceptibility in smokers highlights the need for behavior modification interventions based on host susceptibility for cancer prevention.

Developing a national surveillance system for stroke and acute myocardial infarction using claims data in the Republic of Korea: a retrospective study

BACKGROUND

Limited information is available concerning the epidemiology of stroke and acute myocardial infarction (AMI) in the Republic of Korea. This study aimed to develop a national surveillance system to monitor the incidence of stroke and AMI using national claims data.

METHODS

We developed and validated identification algorithms for stroke and AMI using claims data. This validation involved a 2-stage stratified sampling method with a review of medical records for sampled cases. The weighted positive predictive value (PPV) and negative predictive value (NPV) were calculated based on the sampling structure and the corresponding sampling rates. Incident cases and the incidence rates of stroke and AMI in the Republic of Korea were estimated by applying the algorithms and weighted PPV and NPV to the 2018 National Health Insurance Service claims data.

RESULTS

In total, 2,200 cases (1,086 stroke cases and 1,114 AMI cases) were sampled from the 2018 claims database. The sensitivity and specificity of the algorithms were 94.3% and 88.6% for stroke and 97.9% and 90.1% for AMI, respectively. The estimated number of cases, including recurrent events, was 150,837 for stroke and 40,529 for AMI in 2018. The age- and sex-standardized incidence rate for stroke and AMI was 180.2 and 46.1 cases per 100,000 person-years, respectively, in 2018.

CONCLUSION

This study demonstrates the feasibility of developing a national surveillance system based on claims data and identification algorithms for stroke and AMI to monitor their incidence rates.

Association of postnatal exposure to mixture of bisphenol A, Di-n-butyl phthalate and Di-(2-ethylhexyl) phthalate with Children's IQ at 5 Years of age: Mothers and Children's environmental health (MOCEH) study

Early childhood is important for neurodevelopment, and exposure to endocrine disruptors such as bisphenol A (BPA) and phthalates in this period may cause neurodevelopmental disorders and delays. The present study examined the association between exposure to mixtures of BPA and three metabolites of phthalates in early childhood and IQ at 5 years of age. The Mother and Children's Environmental Health (MOCEH) study is a prospective birth cohort study conducted in Korea with 1751 pregnant women enrolled from 2006 to 2010. After excluding those without relevant data, 47 children were included in the final analysis. We measured children's urinary concentrations of metabolites of endocrine-disrupting chemicals (Bisphenol A, mono-(2-ethyl-5-oxohexyl) phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate and mono-(2-ethyl-5-butyl) phthalate) at ages of 24 and 36 months. We evaluated the children's IQ with the Korean Wechsler Intelligence Test at the age of 5 years. After adjusting for potential confounders, a multiple linear regression was conducted to examine the associations between individual endocrine-disrupting chemicals and the IQ of the children. Weighted Quantile Sum (WQS) regression and quantile-based g-computation were used to assess the association between IQ at age 5 and exposure to mixtures of BPA and phthalates. In the single-chemical analyses, mono-(2-ethyl-5-butyl) phthalate exposure at 36 months was adversely associated with children's IQ (β = -4.93, 95% confidence interval (CI): -9.22, -0.64). In the WQS regression and quantile-based g-computation analyses, exposure to the mixture of BPA and phthalates was associated with lower IQ [β = -9.13 (P-value = 0.05) and β = -9.18 (P-value = 0.05), respectively]. The largest contributor to the overall association was exposure to mono-(2-ethyl-5-butyl) phthalate at 36 months. In the present study, postnatal exposure to mixtures of BPA and three metabolites of phthalates was associated with decreased IQ of children at age 5.

Effects of iodine status on thyroid volume and goiter in children living in an iodine-replete area

Objective

Adequate iodine intake is essential for growing children, and thyroid volume (Tvol) is considered as an indicator of iodine status. We investigated Tvol and goiter using ultrasonography (US) and their association with iodine status in 228 6-year-old children living in Korea.

Methods

Iodine status was assessed using urine iodine concentration (UIC) and categorized as deficient (<100 μg/L), adequate (100-299 μg/L), mild excess (300-499 μg/L), moderate excess (500-999 μg/L), and severe excess (≥1000 μg/L). Tvol was measured using US, and a goiter on the US (goiter-US) was defined as Tvol greater than 97th percentile value by age- and body surface area (BSA)-specific international references.

Results

The median Tvol was 2.4 mL, larger than the international reference value (1.6 mL). The age- and BSA-specific goiter-US rates were 25.9% (n = 59) and 34.6% (n = 79), respectively. The prevalence of excess iodine was 73.7% (n = 168). As iodine status increased from adequate to severe excess, the goiter-US rate significantly increased (P for trend <0.05). The moderate and severe iodine excess groups showed higher risk of goiter-US (adjusted odds ratio (aOR) = 3.1 (95% CI: 1.1-9.2) and aOR = 3.1 (95% CI: 1.2-8.3), respectively; age-specific criteria) than the iodine-adequate group.

Conclusions

Excess iodine was prevalent in Korean children, and their Tvol was higher than the international reference values. Goiter rate was associated with iodine excess, which significantly increased in the moderate and severe iodine excess groups. Further studies are warranted to define optimal iodine intake in children.

Increased breast cancer incidence among nurses in a tertiary university hospital in South Korea

Background

A series of breast cancer cases were recently reported in a tertiary university hospital in South Korea. Nurses are generally exposed to risk factors for breast cancer such as night shift work, antineoplastic agents, and job strain. However, the epidemiological evidence of excess incidence among nurses remains lacking. This study aims to investigate the excess incidence of breast cancer among nurses in a tertiary university hospital and provide epidemiological evidence of occupational risk factors.

Methods

A retrospective cohort was developed using personnel records of female workers in the nursing department who worked from January 2011 to June 2021 in a tertiary university hospital in South Korea. Sick leave records were used to identify cases of breast cancer. The standardized incidence ratio of breast cancer among nurses was compared to the general population.

Results

A total of 5,509 nurses were followed up for 30,404 person-years, and 26 breast cancer cases were identified. This study revealed a significantly increased breast cancer incidence among all included nurses, with a standardized incidence ratio of 1.65 (95% confidence interval [CI]: 1.08-2.41), compared to the general population. Workers, who handle antineoplastic agents in their representative department and current and/or former department, had significantly elevated breast cancer standardized incidence ratios of 2.73 (95% CI: 1.008-5.94) and 3.39 (95% CI: 1.46-6.68), respectively.

Conclusions

This study provides significant evidence of increased breast cancer risk among nursing staff in a hospital setting, particularly those who handle antineoplastic drugs. Measures that reduce exposure to risk factors should be implemented, especially anticancer drugs, to protect healthcare professionals. Further research at a national level that focuses on healthcare workers is necessary to validate breast cancer incidence and its contributing factors.

Mosaic Chromosomal Alterations Are Associated With Increased Lung Cancer Risk: Insight From the INTEGRAL-ILCCO Cohort Analysis

INTRODUCTION

Mosaic chromosomal alterations (mCAs) detected in white blood cells represent a type of clonal hematopoiesis (CH) that is understudied compared with CH-related somatic mutations. A few recent studies indicated their potential link with nonhematological cancers, especially lung cancer.

METHODS

In this study, we investigated the association between mCAs and lung cancer using the high-density genotyping data from the OncoArray study of INTEGRAL-ILCCO, the largest single genetic study of lung cancer with 18,221 lung cancer cases and 14,825 cancer-free controls.

RESULTS

We identified a comprehensive list of autosomal mCAs, ChrX mCAs, and mosaic ChrY (mChrY) losses from these samples. Autosomal mCAs were detected in 4.3% of subjects, in addition to ChrX mCAs in 3.6% of females and mChrY losses in 9.6% of males. Multivariable logistic regression analysis indicated that the presence of autosomal mCAs in white blood cells was associated with an increased lung cancer risk after adjusting for key confounding factors, including age, sex, smoking status, and race. This association was mainly driven by a specific type of mCAs: copy-neutral loss of heterozygosity on autosomal chromosomes. The association between autosome copy-neutral loss of heterozygosity and increased risk of lung cancer was further confirmed in two major histologic subtypes, lung adenocarcinoma and squamous cell carcinoma. In addition, we observed a significant increase of ChrX mCAs and mChrY losses in smokers compared with nonsmokers and racial differences in certain types of mCA events.

CONCLUSIONS

Our study established a link between mCAs in white blood cells and increased risk of lung cancer.

Association between early-childhood exposure to perfluoroalkyl substances and ADHD symptoms: A prospective cohort study

There is evidence that exposure to perfluoroalkyl substances (PFAS) is associated with attention-deficit/hyperactivity disorder (ADHD) symptoms. Previous studies have focused on prenatal exposure to PFAS, and only few studies have examined the associations of early-childhood exposure, especially at low exposure levels. This study explored the association between early-childhood exposure to PFAS and ADHD symptoms later in childhood. In 521 children, we measured the serum levels of six PFAS in peripheral blood at the ages of 2 and 4 years, including perfluorooctanoate (PFOA), perfluornonanoicacid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonate (PFOS). The ADHD Rating Scale IV (ARS) was utilized to measure ADHD traits at 8 years of age. We explored the relationship between PFAS and ARS scores using Poisson regression models after adjusting for potential confounders. Levels of exposure to individual PFAS and the summed value were divided into quartiles to examine possible nonlinear relationships. All six PFAS exhibited inverted U-shaped curves. Children in the 2nd and 3rd quartile levels of each PFAS showed higher ARS scores than those in the1^st quartile level. Below the 3rd quartile of the summed levels of six PFAS (ΣPFAS), a doubling of the ΣPFAS was associated with an 20.0 % (95 % CI: 9.5 %, 31.5 %) increase in ADHD scores. However, at the age of 4 years, none of the evaluated PFAS exhibited linear or nonlinear associations with the ARS scores. Thus, school-aged children may be vulnerable to the neurotoxic effects of exposure to PFAS at age 2 that contribute to ADHD, particularly at low to mid-levels.

The effect of residential greenness during pregnancy on infant neurodevelopment using propensity score weighting: A prospective mother-infant paired cohort study

BACKGROUND

While prior studies have suggested an association between green spaces and infant neurodevelopment, the causal effect of green space exposure during pregnancy has not been fully investigated. This study aimed to identify with causal inference the effect of exposure to residential greenness during pregnancy on infants' mental-psychomotor development and the role of maternal education in modifying this association.

METHODS

We prospectively collected data of pregnant women and their infants from Mothers and Children Environmental Health cohort study. Based on residential addresses, we compiled information on the percent of green space using different buffer distances (100 m, 300 m, and 500 m) and air pollution (PM_2.5). Infant neurodevelopment was measured at 6 months of age using the Korean Bayley Scales of Infant Development II Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI). Generalized propensity scores (GPSs) were estimated from machine-learning (ML) algorithms. We deduced causal inference through GPS adjustment and weighting approaches. Further analyses confirmed whether the association was altered by maternal academic background.

RESULTS

A total of 845 mother-infant pairs from the cohort study were included. We found that exposure to green spaces was robustly associated with infants' mental development. For example, an increase in % green space within 300 m increased the MDI by 14.32 (95 % confidence interval [CI], 3.44-25.2) in the weighting approach. Additionally, the association was even more noticeable for mothers with college degrees or above: an increase in % green space within 300 m increased the MDI by 23.69 (95 % CI, 8.53-38.85) and the PDI by 22.45 (95 % CI, 2.58-42.33) in the weighting approach. This association did not appear in mothers without college degrees.

CONCLUSION

Exposure to green spaces during pregnancy showed a beneficial relationship with infant mental development. Maternal academic background could modify the impact of green space exposure on infant neurodevelopment.

Genome-wide association study of lung adenocarcinoma in East Asia and comparison with a European population

Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (Pinteraction = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications.

Urinary Phthalate Metabolites and Slow Walking Speed in the Korean Elderly Environmental Panel II Study

BACKGROUND

Previous epidemiological studies have suggested that phthalate exposure may contribute to neurocognitive and neurobehavioral disorders and decreased muscle strength and bone mass, all of which may be associated with reduced physical performance. Walking speed is a reliable assessment tool for measuring physical performance in adults age 60 y and older.

OBJECTIVE

We investigated associations between urinary phthalate metabolites and slowness of walking speed in community-dwelling adults ages 60-98 y.

METHODS

We analyzed 1,190 older adults [range, 60-98 y of age; mean±standard deviation (SD) , 74.81±5.99] from the Korean Elderly Environmental Panel II study and measured repeatedly up to three times between 2012 and 2014. Phthalate exposure was estimated using the following phthalate metabolites in urine samples: mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono-n-butyl phthalate (MnBP), mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), and mono-benzyl phthalate (MBzP). Slowness was defined as a walking speed of <1.0meter/second. We used logistic and linear regression models to evaluate the association between each urinary phthalate metabolite and slowness or walking-speed change. We also used Bayesian kernel machine regression (BKMR) to examine overall mixture effects on walking speed.

RESULTS

At enrollment, MBzP levels were associated with an increased odds of slowness [odds ratio (OR) per doubling increase: 1.15, 95% confidence interval (CI): 1.02, 1.30; OR for the highest vs. lowest quartile: 2.20 (95% CI: 1.12, 4.35) with p-trend across quartiles=0.031]. In longitudinal analyses, MEHHP levels showed an increased risk of slowness [OR per doubling increase: 1.15 (95% CI: 1.02, 1.29), OR for the highest vs. lowest quartile: 1.47 (95% CI: 1.04, 2.06), p- trend=0.035]; whereas those with higher MnBP showed a reduced risk of slowness [OR per doubling increase: 0.84 (95% CI: 0.74, 0.96), OR in the highest (vs. lowest) quartile: 0.64 (95% CI: 0.47, 0.87), p-trend=0.006]. For linear regression models, MBzP quartiles were associated with slower walking speed (p-trend=0.048) at enrollment, whereas MEHHP quartiles were associated with slower walking speed, and MnBP quartiles were associated with faster walking speed in longitudinal analysis (p-trend=0.026 and <0.001, respectively). Further, the BKMR analysis revealed negative overall trends between the phthalate metabolite mixtures and walking speed and DEHP group (MEHHP, MEOHP, and MECPP) had the main effect of the overall mixture.

DISCUSSION

Urinary concentrations of prevalent phthalates exhibited significant associations with slow walking speed in adults ages 60-98 y. https://doi.org/10.1289/EHP10549.

DNA methylation is associated with prenatal exposure to sulfur dioxide and childhood attention-deficit hyperactivity disorder symptoms

Epigenetic influence plays a role in the association between exposure to air pollution and attention deficit hyperactivity disorder (ADHD); however, research regarding sulfur dioxide (SO₂) is scarce. Herein, we investigate the associations between prenatal SO₂ exposure and ADHD rating scale (ARS) at ages 4, 6 and 8 years repeatedly in a mother-child cohort (n = 329). Whole blood samples were obtained at ages 2 and 6 years, and genome-wide DNA methylation (DNAm) was analyzed for 51 children using the Illumina Infinium HumanMethylation BeadChip. We analyzed the associations between prenatal SO₂ exposure and DNAm levels at ages 2 and 6, and further investigated the association between the DNAm and ARS at ages 4, 6 and 8. Prenatal SO₂ exposure was associated with ADHD symptoms. From candidate gene analysis, DNAm levels at the 6 CpGs at age 2 were associated with prenatal SO₂ exposure levels. Of the 6 CpGs, cg07583420 (INS-IGF2) was persistently linked with ARS at ages 4, 6 and 8. Epigenome-wide analysis showed that DNAm at 6733 CpG sites were associated with prenatal SO₂ exposure, of which 58 CpGs involved in Notch signalling pathway were further associated with ARS at age 4, 6 and 8 years, persistently. DNAm at age 6 was not associated with prenatal SO₂ exposure. Changes in DNAm levels associated with prenatal SO₂ exposure during early childhood are associated with increases in ARS in later childhood.

Abstract WP40: Development Of The System For National Statistics Of Stroke And Acute Myocardial Infarction Using Claims-based Algorithms In Korea

Background: The epidemiology of stroke and acute myocardial infarction (AMI) in Korea is limited by inaccurate methods for estimating incidence. Therefore, this study aimed to build the system for national statistics of stroke and AMI in Korea using claims-based identification algorithms.

Methods: We identified stroke and AMI using the claims-based algorithms based on the 2018 National Health Insurance Service (NHIS) data. The identification algorithms were validated using investigation of medical records of the sampled cases including the patient groups and the control groups based on a 2-stage stratified sampling method. The sampled cases were divided into 6 strata according to regions (capital and non-capital) and types of centers (tertiary hospitals, general hospitals, and hospitals). Based on the medical records results, we calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), and weighted PPV and weighted NPV were calculated by applying strata-specific sampling rates. The incidence rate of stroke and AMI is the number of new cases of stroke and AMI, including recurrent events, which was calculated by applying the algorithms using weighted PPV and NPV to the claims data.

Results: In total, 2,200 cases (1,086 cases in stroke [578 patients and 508 controls] and 1,114 cases in AMI [520 patients and 594 controls]) were sampled after applying algorithms for review of hospital records. In hospital record reviews, the stroke algorithm had 95.2% sensitivity, 99.6% specificity, 89.3% PPV, and 99.8% NPV, and AMI algorithms showed 97.7% sensitivity, 99.9% specificity, 90.0% PPV, and 99.9% NPV. We identified 94,994 stroke and 33,834 AMI cases including recurrent events using validated identification algorithms in 2018. The age- and sex-standardized incidence rate of stroke was 175.7 cases per 100,000 person-years and the incidence rate of AMI was 49.3 cases per 100,000 person-years in 2018.

Conclusion: We developed the national statistical system to estimate the incidence of stroke and AMI using validated claims-based algorithms in Korea. By using this system, we expect that it will be possible to conduct nationwide epidemiological research and improve acute cardiovascular care in Korea.

Working From Home, Work-Life Balance, and Depression/Anxiety Among Korean Workers in the COVID-19 Pandemic Period: A Mediation Analysis

OBJECTIVE

We aimed to investigate the association between working from home (WFH), depression/anxiety, and work-family conflict (WFC) among Korean workers during the COVID-19 pandemic.

METHODS

We surveyed a total of 1074 workers online. Depression and anxiety were measured using the Centre for Epidemiologic Studies Depression Scale (CES-D) and Beck Anxiety Inventory (BAI). Mediating effects of WFC on the relationship between WFH and depression/anxiety were examined.

RESULTS

The WFH group had higher depression and anxiety scores than the daily commuting group. As WFC increased, the CES-D and BAI scores also increased. A possible mediating effect of WFC on the relationship between WFH and high CES-D and BAI scores was found.

CONCLUSION

We observed a significant difference in depression/anxiety between WFH and daily commute workers, which was mediated by WFC, especially for young, child-growing, and precarious workers.

Association of paternal cadmium and other heavy metal exposure to birth outcomes using propensity score matching

BACKGROUND

Human exposure to cadmium has various effects on health, especially on male reproductive organs. Although it is widely known that prenatal maternal cadmium exposure can affect birth outcomes, the effect of paternal exposure to cadmium remains unclear.

OBJECTIVES

This study aimed to evaluate the effect of paternal cadmium exposure on fetal growth by considering maternal cadmium exposure and exposure to other heavy metals, namely mercury and lead.

METHODS

The Mothers and Children's Environmental Health (MOCEH) study is a prospective birth cohort study in Korea. Overall, 1313 families (father-mother-child triple) without child abnormalities and who completed paternal whole blood cadmium assessments were included in this study. Families were divided into two subgroups based on the blood sampling periods, namely early and late pregnancy. Subjects were selected as follows: one family triple with a high level of paternal cadmium and two triples with low levels of paternal cadmium, using the method of propensity score matching. And linear regression analyses were performed.

RESULTS

The group with high paternal cadmium exposure (80% or more; 1.93 μg/L) had lower birth weight infants compared to the group with low cadmium concentrations (β(se) = -0.21(0.10); p-value = 0.0283). After stratification by infant sex, prenatal paternal cadmium exposure significantly reduced the birth weight of females in subgroups of different sampling times, namely early pregnancy (β(se) = -0.52 (0.22); p-value = 0.0170) and late pregnancy (β(se) = -0.43 (0.18); p-value = 0.0160). Finally, after performing propensity score matching in the early pregnancy measurement group, it was found that the prenatal exposure of father to cadmium significantly reduced birth weight in females (β(se) = -0.72(0.25); p-value = 0.0047).

CONCLUSION

This study assessed the effect of paternal cadmium exposure on birth outcomes in family units consisting of a father, mother, and child. Prenatal paternal cadmium exposure negatively affected birth weight, especially that of female, considering covariates and other heavy metals exposure, namely mercury and lead.

Relationship of iodine excess with thyroid function in 6-year-old children living in an iodine-replete area

BACKGROUND

Adequate iodine intake is essential for growing children, as both deficient and excessive iodine status can result in thyroid dysfunction. We investigated the iodine status and its association with thyroid function in 6-year-old children from South Korea.

METHODS

A total of 439 children aged 6 (231 boys and 208 girls) were investigated from the Environment and Development of Children cohort study. The thyroid function test included free thyroxine (FT4), total triiodothyronine (T3), and thyroid-stimulating hormone (TSH). Urine iodine status was evaluated using urine iodine concentration (UIC) in morning spot urine and categorized into iodine deficient (< 100 μg/L), adequate (100-199 μg/L), more than adequate (200-299 μg/L), mild excessive (300-999 μg/L), and severe excessive (≥ 1000 μg/L) groups. The estimated 24-hour urinary iodine excretion (24h-UIE) was also calculated.

RESULTS

The median TSH level was 2.3 μIU/mL, with subclinical hypothyroidism detected in 4.3% of patients without sex differences. The median UIC was 606.2 μg/L, with higher levels in boys (684 μg/L vs. 545 μg/L, p = 0.021) than girls. Iodine status was categorized as deficient (n = 19, 4.3%), adequate (n = 42, 9.6%), more than adequate (n = 54, 12.3%), mild excessive (n = 170, 38.7%), or severe excessive (n = 154, 35.1%). After adjusting for age, sex, birth weight, gestational age, body mass index z-score, and family history, both the mild and severe excess groups showed lower FT4 (β = - 0.04, p = 0.032 for mild excess; β = - 0.04, p = 0.042 for severe excess) and T3 levels (β = - 8.12, p = 0.009 for mild excess; β = - 9.08, p = 0.004 for severe excess) compared to the adequate group. Log-transformed estimated 24h-UIE showed a positive association with log-transformed TSH levels (β = 0.04, p = 0.046).

CONCLUSION

Excess iodine was prevalent (73.8%) in 6-year-old Korean children. Excess iodine was associated with a decrease in FT4 or T3 levels and an increase in TSH levels. The longitudinal effects of iodine excess on later thyroid function and health outcomes require further investigation.

Association of long-term exposure to PM2.5 and survival following ischemic heart disease

BACKGROUND

Numerous studies have suggested that long-term exposure to particulate matter ≤2.5 μm (PM_2.5) may cause cardiovascular morbidity and mortality. However, susceptibility among those with a history of ischemic heart disease is less clearly understood. We aimed to evaluate whether long-term PM_2.5 exposure is related to mortality among patients with ischemic heart disease.

METHODS

We followed up 306,418 patients hospitalized with ischemic heart disease in seven major cities in South Korea between 2008 and 2016 using the National Health Insurance Database. We linked the modeled PM_2.5 data corresponding to each patient's administrative districts and estimated hazard ratios (HRs) of cause-specific mortality associated with the long-term exposure to PM_2.5 in time-varying Cox proportional hazard models after adjusting for individual- and area-level characteristics. We also estimated HRs by sex, age group (65-74 vs. ≥75 years), and household income.

RESULTS

Of the patients with ischemic heart disease, mean age at the discharge was 76.8 years, and 105,913 died during a mean follow-up duration of 21.4 months. The HR of all-cause mortality was 1.10 [95% confidence intervals (CI): 1.07, 1.14] per 10 μg/m³ increase in a 12-month moving average PM_2.5. The HRs of cardiovascular, stroke, and ischemic heart disease were 1.17 (95% CI: 1.11, 1.24), 1.17 (95% CI: 1.06, 1.30), and 1.25 (95% CI: 1.15, 1.35), respectively. The subgroup analyses showed that participants aged 65-74 years were more susceptible to adverse effects of PM_2.5 exposure. We did not observe any differences in the risk by sex and household income.

CONCLUSION

Mortality from all-cause and cardiovascular disease following hospitalization due to ischemic heart disease was higher among individuals with greater PM_2.5 exposure in seven major cities in South Korea. The result supports the association of long-term exposure to air pollution with poor prognosis among patients with ischemic heart disease.

The association between occupational stress level and health-related productivity loss among Korean employees

OBJECTIVES

Occupational stress management is particularly important for successful business operations, since occupational stress adversely affects workers' health, eventually lowering their productivity. Therefore, this study aimed to investigate the correlation between occupational stress and health-related productivity loss (HRPL) among Korean workers.

METHODS

In 2021, 1,078 workers participated in a web-based questionnaire survey. HRPL was measured using the Work Productivity and Activity Impairment Questionnaire, and occupational stress was measured using the Korean Occupational Stress Scale-Short Form. The occupational stress level was divided into tertiles (low, intermediate, and high), and the low occupational stress group was used as the reference group. Using a generalised linear model, differences in labour productivity loss according to the level of occupational stress were tested after adjusting for demographic characteristics such as age, gender, education level, household income, occupation, and underlying medical conditions.

RESULTS

Non-parametric regression analysis of HRPL according to occupational stress showed a direct association between occupational stress and HRPL. A statistically significant difference was observed in HRPL between participants with intermediate and high occupational stress and those with low occupational stress.

CONCLUSIONS

Our results support the hypothesis that high occupational stress is associated with decreased labour productivity.

Association between sickness presenteeism and depressive symptoms in Korean workers during the COVID-19 pandemic: A cross-sectional study

BACKGROUND

During the COVID-19 pandemic, Korean workers have reported various types of sickness presenteeism (SP: continuing to attend work during illness). Understanding SP through mental health perspectives will help to make practical strategy for better working conditions. We examined the association between SP and depression among Korean workers during the COVID-19 pandemic in relation with the socioeconomic and lifestyle factors.

METHODS

Data from the 2020 Korean Community Health Survey were used as a representative nationwide sample dataset. We surveyed the experience of depression in the last two weeks from individuals who worked more than a week recently. We investigated the associations between SP and depressive symptoms. Depressive symptoms were scored using the Patient Health Questionnaire-9 (PHQ-9). Logistic regression analysis was performed to examine the significance of the associations.

RESULTS

Analysis of the data obtained from 84,514 participants revealed that 1700 (2.2 %) participants reported experiencing depressive symptoms in 2020. Employees with SP showed higher association with depressive symptoms than employers or self-employed individuals (OR = 2.18, 95 % CI: 1.85, 2.56 among employees vs. OR = 1.76, 95 % CI: 1.29, 2.40 among employers or self-employed individuals).

CONCLUSION

SP has become more prominent during the COVID-19 pandemic. A protective strategy against SP among vulnerable workers is necessary for a healthier and safer society.

Effects of short-term exposure to air pollution on hospital admissions for autism spectrum disorder in Korean school-aged children: a nationwide time-series study

OBJECTIVES

This study explored the effects of short-term exposure to air pollution on hospital admissions for autism spectrum disorder (ASD), a proxy for symptom aggravation, among Korean children aged 5-14 years.

DESIGN

Time-series study.

SETTING, PARTICIPANTS AND OUTCOME MEASURES

We used data from the National Health Insurance Service (2011-2015). Daily concentrations of fine particulate matter (PM_2.5), nitrogen dioxide (NO₂) and ozone (O₃) levels in each region were used as exposures. ASD cases were defined based on a principal admission diagnosis of the claims data. We applied distributed lag non-linear models and a generalised difference-in-differences method to the quasi-Poisson models to estimate the causal effects of air pollution for up to 6 days. We also performed weighted quantile sum regression analyses to assess the combined effects of air pollution mixtures.

RESULTS

PM_2.5 levels at lag day 1, NO₂ levels at lag day 5 and O₃ levels at lag day 4 increased the risks of hospital admissions for ASD (relative risk (RR)=1.17, 95% CI 1.10 to 1.25 for PM_2.5; RR=1.09, 95% CI 1.01 to 1.18 for NO₂ and RR=1.03, 95% CI 1.00 to 1.06 for O₃). The mean daily count of hospital admissions for ASD was 8.5, and it would be 7.3, 7.8 and 8.3 when the PM_2.5 levels would be decreased by 10.0 µg/m³, NO₂ by 10 ppb and O₃ by 10 ppb, respectively. The weighted quantile sum index, constructed from PM_2.5, NO₂ and O₃ levels, was associated with a higher risk of hospital admissions for ASD (RR 1.29, 95% CI 1.14 to 1.46), where NO₂ was found to contribute to the effects most (the weight of 0.80).

CONCLUSIONS

These results emphasise that reduction of air pollution exposure should be considered for ASD symptom management, with important implications for the quality of life and economic costs.

Genome-wide interaction analysis identified low-frequency variants with sex disparity in lung cancer risk

Differences by sex in lung cancer incidence and mortality have been reported which cannot be fully explained by sex differences in smoking behavior, implying existence of genetic and molecular basis for sex disparity in lung cancer development. However, the information about sex dimorphism in lung cancer risk is quite limited despite the great success in lung cancer association studies. By adopting a stringent two-stage analysis strategy, we performed a genome-wide gene-sex interaction analysis using genotypes from a lung cancer cohort including ~ 47 000 individuals with European ancestry. Three low-frequency variants (minor allele frequency < 0.05), rs17662871 [odds ratio (OR) = 0.71, P = 4.29×10-8); rs79942605 (OR = 2.17, P = 2.81×10-8) and rs208908 (OR = 0.70, P = 4.54×10-8) were identified with different risk effect of lung cancer between men and women. Further expression quantitative trait loci and functional annotation analysis suggested rs208908 affects lung cancer risk through differential regulation of Coxsackie virus and adenovirus receptor gene expression in lung tissues between men and women. Our study is one of the first studies to provide novel insights about the genetic and molecular basis for sex disparity in lung cancer development.

Cross-ancestry genome-wide meta-analysis of 61,047 cases and 947,237 controls identifies new susceptibility loci contributing to lung cancer

To identify new susceptibility loci to lung cancer among diverse populations, we performed cross-ancestry genome-wide association studies in European, East Asian and African populations and discovered five loci that have not been previously reported. We replicated 26 signals and identified 10 new lead associations from previously reported loci. Rare-variant associations tended to be specific to populations, but even common-variant associations influencing smoking behavior, such as those with CHRNA5 and CYP2A6, showed population specificity. Fine-mapping and expression quantitative trait locus colocalization nominated several candidate variants and susceptibility genes such as IRF4 and FUBP1. DNA damage assays of prioritized genes in lung fibroblasts indicated that a subset of these genes, including the pleiotropic gene IRF4, potentially exert effects by promoting endogenous DNA damage.

Associations between Dietary Intake and Attention Deficit Hyperactivity Disorder (ADHD) Scores by Repeated Measurements in School-Age Children

Attention deficit hyperactivity disorder (ADHD) is a common psychiatric disorder in school-age children and adolescents. However, the reported associations between ADHD and single nutrient intake are inconsistent. The aim of the study was to investigate the relationships between dietary intake changes and the prevalence of ADHD over time with repeat measurements using data from the Children Health and Environment Research (CHEER). To assess changes over time, we used data obtained in 2006 and 2008 (Phases ₁ and ₂). In this study, there were 2899 children aged 8 years or older in Phase ₁ and 2120 children aged 9 years or older in Phase ₂ from Korea, and the ADHD scores and dietary intake of 1733 children in Phases ₁ and ₂ were used in the final analysis. The YN group refers to children whose disease had improved in Phase ₂, and the NY group refers to children diagnosed with ADHD in Phase ₂. A notable within-group result was the increase in vegetable protein (p = 0.03) in the YN group. A between-group comparison showed that significant changes in nutrient intake could be confirmed most in the NY group, and the YN group tended to have a lower nutrient intake than the NY group. In the correlation of changes in nutrient intake and three subtypes (combined, AD, and HD), the total fat (p = 0.048) and animal protein (p = 0.099) showed a positive correlation with the prevalence of AD. Vegetable iron (p = 0.061 and p = 0.044, respectively), zinc (p = 0.022 and p = 0.007, respectively), vegetable protein (p = 0.074), and calcium (p = 0.057) had inhibitory effects on ADHD and its subtype. In conclusion, management of dietary and nutritional status should be considered to ameliorate ADHD and its subtypes in school-age children, and these relationships require further exploration in other settings.

Relationship between bisphenol A, bisphenol S, and bisphenol F and serum uric acid concentrations among school-aged children

Background

Hyperuricemia has a suspected relationship with hypertension, metabolic syndrome, kidney disease, and cardiovascular disease. Endocrine disruptors may affect uric acid metabolism; however, few epidemiologic studies have been performed in children regarding newly developed bisphenol A (BPA) substitutes. We evaluated the associations between BPA, bisphenol S (BPS), and bisphenol F (BPF) exposure and serum uric acid concentrations in 6-year-old Korean children.

Methods

From the Environment and Development of Children cohort study, six-year-old children (N = 489; 251 boys) who underwent an examination during 2015–2017 were included. Anthropometry, questionnaires, and biological samples were evaluated. BPA, BPS, and BPF levels were measured from spot urine samples, and log-transformed or categorized into groups for analysis. We constructed linear regression models adjusting for age, sex, urinary creatinine levels, body mass index z-scores, and estimated glomerular filtration rates.

Results

Mean serum uric level was 4.2 mg dL^-1 (0.8 SD) without sex-differences. Among the three bisphenols, higher BPS exposure was associated with increased serum uric acid concentrations (P-value for trend = 0.002). When BPS levels were categorized into three groups (non-detection < 0.02 μg L^-1 vs. medium BPS; 0.02–0.05 μg L^-1 vs. high BPS ≥ 0.05 μg L^-1), the high BPS group showed higher serum uric acid concentrations (by 0.26 mg dL^-1, P = 0.003) than the non-detection group after adjusting for covariates, which was significant in boys but not girls.

Discussions

Urinary BPS levels was positively associated with serum uric acid concentrations in 6-year-old children, and the association was more pronounced in boys. Considering the increasing use of BPS and concerning effect of hyperuricemia on health outcomes, their positive relationship should be investigated further.

Predicting High Blood Pressure Using DNA Methylome-Based Machine Learning Models

DNA methylation modification plays a vital role in the pathophysiology of high blood pressure (BP). Herein, we applied three machine learning (ML) algorithms including deep learning (DL), support vector machine, and random forest for detecting high BP using DNA methylome data. Peripheral blood samples of 50 elderly individuals were collected three times at three visits for DNA methylome profiling. Participants who had a history of hypertension and/or current high BP measure were considered to have high BP. The whole dataset was randomly divided to conduct a nested five-group cross-validation for prediction performance. Data in each outer training set were independently normalized using a min–max scaler, reduced dimensionality using principal component analysis, then fed into three predictive algorithms. Of the three ML algorithms, DL achieved the best performance (AUPRC = 0.65, AUROC = 0.73, accuracy = 0.69, and F1-score = 0.73). To confirm the reliability of using DNA methylome as a biomarker for high BP, we constructed mixed-effects models and found that 61,694 methylation sites located in 15,523 intragenic regions and 16,754 intergenic regions were significantly associated with BP measures. Our proposed models pioneered the methodology of applying ML and DNA methylome data for early detection of high BP in clinical practices.

Prenatal exposure to phthalate and decreased body mass index of children: a systematic review and meta-analysis

Phthalates are well-known endocrine-disrupting chemicals. Many detrimental health effects of phthalates were investigated, but studies on the association of phthalates with obesity in children showed inconsistent results. Thus, this systematic review and meta-analysis were performed to clarify whether prenatal and postnatal exposures to phthalates are associated with physical growth disturbances in children. We performed the systematic review and meta-analysis following the PRISMA 2020 statement guidelines, and found 39 studies that met our inclusion criteria, including 22 longitudinal and 17 cross-sectional studies. We observed a significant negative association between the prenatal exposure to DEHP and the body mass index (BMI) z-score of the offspring (β = - 0.05; 95% CI: - 0.10, - 0.001) in the meta-analysis, while no significant association between the prenatal exposure to DEHP and the body fat percentage of the offspring was observed (β = 0.01; 95% CI: - 0.41, 0.44). In the systematic review, studies on the association between phthalates exposure in childhood and obesity were inconsistent. Prenatal exposure to phthalates was found to be associated with decreased BMI z-score in children, but not associated with body fat percentage. Our findings suggest that phthalates disturb the normal muscle growth of children, rather than induce obesity, as previous studies have hypothesized.

Pre- and postnatal exposure to multiple ambient air pollutants and child behavioral problems at five years of age

Ambient air pollution is emerging as a risk factor for adverse neurological symptoms and early childhood diseases. This study aimed to evaluate the association between pre- and postnatal exposure to air pollutants and childhood behavior by using MOCEH prospective birth cohort data. In total, 353 mother-child pairs at birth, who completed child behavioral assessments using the Korean version of the Child Behavior Checklist at five years of age, were included in the study. Multivariate linear regression (MLR) for single pollutant and Bayesian kernel machine regression (BKMR) for multiple pollutants were conducted. MLR analysis showed that air pollutant exposures during the first trimester were significantly associated with the internalizing problems score after adjusting for covariates. The estimates were 0.19 (0.05-0.32) per 1 μg/m³ increase in PM_2.5, 0.13 (0.04-0.22) per 1 μg/m³ increase in PM₁₀, and 0.20 (0.02-0.37) per 1 ppb increase in NO₂. The BKMR model analysis revealed that the overall effects of multiple air pollutants during the first trimester of pregnancy and 0-6 months of the infantile period were significantly associated with behavioral problems. Boys showed a stronger associations than girls. Taken together, these results showed that the first trimester of pregnancy and 0-6 months of the infantile period were important for air pollutant exposure because exposure at these periods was associated with behavioral problems in 5-year-old children. Future efforts are required to control air pollution levels and reduce the health burden of vulnerable populations, including pregnant women and children.

Association of bisphenol A, bisphenol F, and bisphenol S with ADHD symptoms in children

BACKGROUND

Bisphenol A (BPA) has been linked to attention-deficit/hyperactivity disorder (ADHD) symptoms, but the neurotoxic effects of bisphenol substitutes such as bisphenol F (BPF) and S (BPS) have not been well investigated. We investigated the associations between BPA, BPF, and BPS with ADHD symptoms at multiple time points in children.

METHODS

The levels of BPA (at ages 4, 6, and 8), BPF (at ages 6 and 8), and BPS (at ages 6 and 8) were measured in 619 children. Because of the low detection frequency of BPF and BPS levels, participants were divided into categories (<or ≥ limit of detection (LOD) for BPF; < LOD, ≥ LOD and < median, or ≥ median for BPS). ADHD symptoms were assessed using the ADHD Rating Scale IV (ARS). The relationship between bisphenols and ARS scores was analyzed using Poisson regression models, and generalized additive models and piecewise regression models were further explored for BPA.

RESULTS

BPA was detected in most participants (>97%), whereas BPF and BPS were less frequently detected (age 6: 17.5% for BPF and 42.0% for BPS; age 8: 51.6% for BPF and 73.3% for BPS). Doubling in BPA levels was associated with increased ARS scores by 4.7% (95% confidence intervals [CI]: 0.5, 9.2) at age 6. The association was greater with BPA levels higher than 3.0 μg/g creatinine (24.2% [95% CI: 15.5, 33.6] increase). The BPF ≥ LOD group had 10.8% (95% CI: 1.2, 21.4) higher ARS scores than the BPF < LOD group. The BPS ≥ median group had 11.4% (95% CI: 2.0, 21.7) higher ARS scores than the BPS < LOD group.

CONCLUSION

All bisphenols, in particular those at or above the LOD or median levels, were associated with ADHD symptoms at age 6. Further prospective studies are warranted to determine causal inference.

The association of prenatal and childhood pyrethroid pesticide exposure with school-age ADHD traits

BACKGROUND

Pyrethroid insecticides are commonly used in residential settings, and their use has increased rapidly. Although research has been scarce, they have been reported to be associated with impaired neurodevelopment. Moreover, susceptible exposure windows and the long-term effects of pyrethroids have not been investigated. We examined the association between pyrethroid exposure and attention-deficit/hyperactivity disorder (ADHD) symptoms over time, with exposure windows spanning from the prenatal period to school-age.

METHODS

Using 524 mother-child pairs, we measured urinary concentrations of 3-phenoxybenzoic acid (3-PBA), a major pyrethroid metabolite, and asked parents to fill-out the ADHD Rating Scale IV (ARS). We used Poisson regression to identify the susceptible periods of pyrethroid exposure, by correlating various 3-PBA exposure windows (prenatal, ages 2, 4, 6 and 8) with ADHD symptoms at ages 6 and 8.

RESULTS

Doubling of prenatal and age 2 3-PBA concentrations was associated with increased ADHD symptoms at age 6 (2.7% change, 95% confidence interval [CI]: 0.3, 5.2; 5.2% change [95% CI: 0.5, 10.2], respectively). The 3-PBA concentrations at age 4 and age 6 were linked with ADHD symptoms at age 8 (2.7% change [95% CI: 0.3, 5.3]; 3.3% change [95% CI: 0.2, 6.4], respectively). There were no clear sex-specific patterns in association.

DISCUSSION

Both prenatal and early-childhood exposure to 3-PBA were found to be associated with ADHD symptoms. Exposure during pregnancy, and at ages 2 to 6 were found to be susceptible periods for pyrethroid neurotoxicity at ages 6 and 8.

General public’s perspectives on telemedicine during the COVID-19 pandemic in Korea: an analysis of the nationwide survey

OBJECTIVES

We investigated the awareness, experience, approval, intention to use, and the desired type of telemedicine among Korean general public.

METHODS

From November to December 2020, we conducted an online self-reported survey on awareness, experience, approval, and intent to use telemedicine services among Korean residents aged 20 years or older. A total of 2,097 participants completed the survey.

RESULTS

Of the 2,097 participants, 1,558 (74.3%) were aware of, 1,198 (57.1%) approved of, and 1,474 (70.3%) had the intention to use telemedicine. Participants from regions other than the Seoul metropolitan area and Daegu–Gyeongbuk Province (adjusted odds ratio [aOR], 1.29; 95% confidence interval [CI], 1.02 to 1.63), households with a monthly household income of US$6,000 or more (aOR, 1.44; 95% CI, 1.01 to 2.08), participants who had a college/university or associate’s degree (aOR, 1.35. 95% CI, 1.04 to 1.75) or a master’s degree or above (aOR, 1.73; 95% CI, 1.20 to 2.50), and housewives (aOR, 1.30; 95% CI, 1.03 to 1.64) had higher odds of approval. Elderly participants, those with a chronic disease (aOR, 1.26; 95% CI, 1.04 to 1.54), those who had experienced delays of healthcare services (aOR, 1.94; 95% CI, 1.27 to 2.96), and those who had experience with telemedicine (aOR, 4.28; 95% CI, 1.69 to 10.82) were more likely to intend to use telemedicine services. Regarding types of telemedicine, teleconsultation between doctors showed the highest approval rate (73.1%).

CONCLUSIONS

In the context of the coronavirus disease 2019 pandemic, more than 70% of participants had already used or intended to use telemedicine at some point. Groups with a substantial need for telemedicine were more in favor of telemedicine.

Body Mass Index Changes and Insulin Resistance at Age 4: A Prospective Cohort Study

OBJECTIVES

The objective of this study is to investigate whether body mass index (BMI) changes are associated with fasting glucose and insulin resistance (IR) in early childhood.

METHODS

From the Environment and Development of Children (EDC) cohort, 334 children who visited at ages 2 and 4 were included in this study. Height and weight were measured at ages 2 and 4, and fasting glucose and insulin were assessed at age 4. Homeostatic model assessment of insulin resistance (HOMA-IR) was calculated as insulin (μIU/ml) × glucose (mg/dl)/405. The BMI Z-score [BMI (Z)] quartiles for each age group were defined as Q4, ≥75th percentile; Q2-3, 25th to 75th percentile; and Q1, <25th percentile. Glucose, insulin, and the HOMA-IR were compared between groups according to the change in BMI (Z) from age 2 to 4.

RESULTS

Children who stayed in Q4 at both ages had higher fasting glucose (92.2 vs. 88.0 and 87.1 mg/dl), insulin (3.2 vs. 2.5 and 2.3 μIU/ml), and HOMA-IR (0.68 vs. 0.54 and 0.52) than children who stayed in Q1 or Q2-3 (all P<0.01). Children in Q4 at both ages had higher fasting glucose than children whose BMI (Z) increased from Q1 or Q2-3 to Q4 (92.2 vs. 87.3, P<0.001). The BMI (Z) category at age 2 of children who were in Q2-3 at age 4 did not affect glucose or IR at 4 years.

CONCLUSION

The group of children within the highest BMI (Z) quartile at both 2 and 4 years of age had higher fasting glucose and IR at age 4 than any other BMI (Z) change group.

Age-specific effects of ozone on pneumonia in Korean children and adolescents: A nationwide time-series study

OBJECTIVES

The aim of this study was to estimate the age-specific effects of 8-hour maximum ozone levels on pneumonia in children and adolescents.

METHODS

We performed quasi-Poisson regression analyses for individuals of 0-4 years, 5-9 years, 10-14 years, and 15-19 years of age using nationwide time-series data from the Korea (2011-2015). We constructed distributed lag linear models employing a generalized difference-in-differences method and controlling for other air pollutants.

RESULTS

A 10.0-parts per billion increase in 8-hour maximum ozone levels was associated with a higher risk of hospital admissions due to pneumonia at 0-4 (relative risk [RR], 1.02; 95% confidence interval [CI], 1.01 to 1.03) and 5-9 years of age (RR, 1.06; 95% CI, 1.04 to 1.08), but not at 10-14 (RR, 1.01; 95% CI, 0.98 to 1.04) or 15-19 years of age (RR, 1.01; 95% CI, 0.97 to 1.06). The association between ozone and hospital admissions due to pneumonia was stronger in cool seasons (from November to April) than in warm seasons (from May to October), but was similar between boys and girls.

CONCLUSIONS

Short-term exposure to ozone was associated with a higher risk of pneumonia at 0-4 years and 5-9 years of age, but not at 10-14 years or 15-19 years of age. Our findings can help identify vulnerable periods, determine the target populations for public health interventions, and establish air pollution standards.

The Effects of Social Activities and Living Arrangements on Cognitive Functions in Middle-aged and Elderly Adults: A Panel Study Using the 2006-2018 Korean Longitudinal Study of Aging

OBJECTIVES

Previous studies have shown that participation in social activities (SA) can prevent cognitive decline (CD) and that living arrangements (LA) can affect cognitive function. This study aimed to evaluate the effects of SA and LA on CD, as well as their interactions, using longitudinal data.

METHODS

Data were used from the 2006-2018 Korean Longitudinal Study for Aging, which followed 10 254 adults older than 45 years over a 12-year period. CD was defined as a ≥4-point score decrease in the Mini-Mental Status Exam over 2 years. We developed an extended Cox proportional hazards model for time-dependent covariates to estimate the hazard ratio (HR) of CD in 4 groups: (1) socially active and living with others, (2) socially active and living alone, (3) socially inactive and living with others (SILO), and (4) socially inactive and living alone (SILA). The model was stratified by gender and adjusted for important confounders.

RESULTS

The HR of CD was significantly higher in the SILO group in men (HR,1.36; 95% confidence interval [CI], 1.08 to 1.78) and in the SILA group in women (HR, 1.72; 95% CI, 1.08 to 2.75). However, the interaction term for gender was not significant.

CONCLUSIONS

Among socially inactive elderly adults, the HR of CD was elevated in men who lived with others and in women who lived alone, although the interaction term for gender was not significant. Socially inactive men who live with others and socially inactive women who live alone are particularly encouraged to participate in SA to prevent CD.

Prenatal and postnatal exposures to four metals mixture and IQ in 6-year-old children: A prospective cohort study in South Korea

BACKGROUND

Humans are exposed to a mixture of metals during their lifetime; however, evidence of neurotoxicity of such mixtures in critical time windows is still insufficient. We aimed to elucidate the associations of four metals mixture across multiple time points with children's intelligence quotient (IQ) in a prospective cohort study.

METHODS

Prenatal exposure and exposure at age 4 and 6 years to four types of blood metals, namely lead, mercury, cadmium, and manganese were quantified in 502 pregnant women and their children who participated in the Environment and Development Cohort study. Children' s IQ scores were assessed using the Wechsler Intelligence Scale at age 6. Bayesian kernel machine regression (BKMR), quantile g-computation models, and elastic net (ENET) models were used to assess the associations of their blood metals mixture with IQ scores.

RESULTS

Multivariate linear regression models indicated that postnatal blood manganese exposure at the age of 4 years was significantly negatively associated with children's IQ [β =  - 5.99, 95% confidence interval (CI): -11.37 to - 0.61]. In the multi-chemical BKMR and quantile g-computation model, statistically significant inverse associations were found between the mixture of prenatal and postnatal metals and children's IQ score (Difference in children' IQ per quartile increase: -2.83; 95% CI: -5.28, -0.38). Interestingly, we found that manganese levels at both age of 4 and 6 years were contributing factors to children's IQ in the mixture models, namely, BKMR, quantile g-computation, and ENET models.

CONCLUSIONS

Multi-pollutant mixtures of prenatal and postnatal exposures to four metals affected child IQ at 6 years of age. We found a relationship between manganese exposure at both age 4, and 6 years and children's IQ. Additional studies are warranted to confirm these associations and to control the exposure to different metals during pregnancy and preschool childhood.

Association of phthalate exposure with autistic traits in children

BACKGROUND

Phthalates are synthetic chemicals with endocrine-disrupting properties. They are reportedly associated with various neurotoxic outcomes. Studies on exposure to phthalates and children's autistic traits have shown inconsistent results with respect to sex and susceptible time periods. We investigated the association of phthalate exposure during the prenatal period and childhood with autistic traits over time using a birth cohort in South Korea.

METHODS

Five phthalate metabolites were measured during mid-term pregnancy and children's follow-up at ages of 4, 6, and 8 years among a total of 547 mother-child pairs. The social communication questionnaire (SCQ) was used to assess autistic traits of children at each time point. The relationship between phthalate metabolites and SCQ scores were analyzed by exposure windows and sex.

RESULTS

A 2.7 fold increase in di-(2-ethylhexyl) phthalate metabolite levels, mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) during pregnancy was associated with increased SCQ scores at 4 years by 8.5% (95% confidence intervals [CI]: 1.9%, 15.5%) and 7.4% (95% CI: 0.3%, 15.0%), respectively, but not at the age of 6 or 8 years. Moreover, MEHHP levels at ages of 4 and 8 years were associated with increased SCQ scores at 8 years by 9.9% (95% CI: 1.8%, 18.6%) and 9.6% (95% CI: 1.3%, 18.6%), respectively. Boys showed stronger associations between phthalate exposure and SCQ scores than girls.

CONCLUSION

The study suggested different susceptible time windows of phthalate exposure: exposure during pregnancy is associated with autistic traits in young children, whereas exposure during early childhood years leads to autistic traits in school-aged children, particularly boys.

Impact of the COVID-19 Pandemic on the Health Status and Behaviors of Adults in Korea: National Cross-sectional Web-Based Self-report Survey

Background

The COVID-19 pandemic has radically shifted living practices, thereby influencing changes in the health status and behaviors of every person.

Objective

The aim of this study was to investigate the impact of COVID-19 on the self-reported health status and health behaviors along with any associated factors in adults in the Republic of Korea wherein no stringent lockdown measures were implemented during the pandemic.

Methods

We conducted a web-based self-reported survey from November 2020 to December 2020. The study participants (N=2097) were identified through quota sampling by age, sex, and geographical regions among residents aged 19 years or older in Korea. The survey collected information on basic demographics, changes in self-reported health status, and health behaviors during the COVID-19 pandemic. Self-reported health status and health behaviors were categorized into 3 groups: unchanged, improved, or worsened. A chi-square test and logistic regression analyses were conducted.

Results

With regard to changes in the self-reported health status, the majority (1478/2097, 70.5%) of the participants reported that their health was unchanged, while 20% (420/2097) of the participants reported having worser health after the COVID-19 outbreak. With regard to changes in health behaviors, the proportion of participants who increased tobacco consumption was similar to that of those who decreased tobacco consumption (110/545, 20.2% vs 106/545, 19.5%, respectively), while the proportion of those who decreased their drinking frequency was more than twice as many as those who increased their drinking frequency (578/1603, 36.1% vs 270/1603, 16.8%, respectively). Further, those who decreased their exercising frequency were more than those who increased their exercising frequency (333/823, 15.9% vs 211/823, 10%, respectively). The factor that had the greatest influence on lifestyle was age. In the subgroup analysis, the group aged 20-29 years had the highest number of individuals with both a worsened (100/377, 26.5%) and an improved (218/377, 15.7%) health status. Further, individuals aged 20-29 years had greater odds of increased smoking (6.44, 95% CI 2.15-19.32), increased alcohol use (4.64, 95% CI 2.60-8.28), and decreased moderate or higher intensity aerobic exercise (3.39, 95% CI 1.82-6.33) compared to individuals aged 60 years and older. Younger adults showed deteriorated health behaviors, while older adults showed improved health behaviors.

Conclusions

The health status and the behavior of the majority of the Koreans were not found to be heavily affected by the COVID-19 outbreak. However, in some cases, changes in health status or health behavior were identified. This study highlighted that some groups were overwhelmingly affected by COVID-19 compared to others. Certain groups reported experiencing both worsening and improving health, while other groups reported unchanged health status. Age was the most influential factor for behavior change; in particular, the younger generation’s negative health behaviors need more attention in terms of public health. As COVID-19 prolongs, public health interventions for vulnerable groups may be needed.

Household insecticide use and urinary 3-phenoxybenzoic acid levels in an elder population: a repeated measures data

BACKGROUND

Pyrethroids are associated with adverse health consequences, even at low-dose exposures. However, there is limited evidence on pyrethroids exposure levels among vulnerable elder population and on their exposure sources.

OBJECTIVE

We tried to determine pyrethroids exposure levels among Korean elders and their exposure sources.

METHODS

We measured levels of 3-phenoxybenzoic acid (3-PBA), a pyrethroids metabolite, in urines repeatedly collected from 1239 Korean rural and urban elders; we also explored exposure sources for pyrethroids using questionnaire data.

RESULTS

Our participants had high levels of 3-PBA with 446 (36.0%) of elders with 3-PBA level over 2 ng/mL of 95th percentile of the German representative populations. After adjustment for sex, age, smoking status, visit episode, and surveyed season using linear mixed effect models, household insecticide spray use was significantly associated with 3-PBA level (β = 0.03 and p = 0.02) and the association was apparent only for females (β = 0.03 and p = 0.03). In the analyses for nonlinear relationships using generalized additive mixed models, there was a J-shape change in 3-PBA level by insecticide spray use (p < 0.01 both in total population and in females).

SIGNIFICANCE

Household insecticide spray was a predominant exposure source for pyrethroids at community level among Korean elders, warning more stringent control for frequently exposed environmental factors for pyrethroids including insecticide spray.

Joint association of prenatal bisphenol-A and phthalates exposure with risk of atopic dermatitis in 6-month-old infants

BACKGROUND

Prenatal exposure to bisphenol A (BPA) and phthalates could trigger immune response. Few studies have investigated the association between prenatal BPA and phthalate exposure and atopic dermatitis (AD) in infants.

OBJECTIVE

We aimed to clarify the joint association of prenatal exposure to BPA and phthalate metabolites with AD incidence in 6-month-old infants.

METHODS

We included 413 mother-child pairs from the Mothers and Children's Environmental Health (MOCEH) in a prospective birth cohort study. Maternal urinary BPA, mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP), and mono-n-butyl phthalate (MnBP) concentrations were measured during early and late pregnancy. We applied the Bayesian kernel machine regression (BKMR) with probit regression to estimate the association of BPA and phthalate metabolites with AD incidence after adjusting for potential confounders. Individual association was estimated by differences in predicted probabilities comparing each individual chemical concentration at 75th versus 25th percentiles, while other chemicals were set at their median. Overall joint effect was estimated by differences in predicted probabilities comparing all chemical concentrations at 75th versus 25th percentiles.

RESULTS

Individual effect of MEHHP in late pregnancy was strongly associated with incident AD [Difference: 0.244 (95% credible interval: -0.066, 0.554)] in the model including both early and late exposures. Furthermore, we confirmed overall joint association of urinary BPA and phthalate metabolites during pregnancy with a higher risk of AD [0.347 (0.168, 0.526) for late pregnancy exposure, and 0.307 (0.094, 0.521) for both early and late pregnancy]. Additionally, the joint association was more prominent among girls than that in boys.

CONCLUSIONS

The joint association of prenatal exposure to BPA and phthalates could be associated with the incident AD in 6-month-old infants. Further studies are needed to confirm the synergistic effect of BPA and phthalate exposures on AD in children.

Pulmonary function of healthy Korean children from three independent birth cohorts: Validation of the Global Lung Function Initiative 2012 equation

BACKGROUND AND OBJECTIVE

Global Lung Function Initiative (GLI) 2012 equations were developed to resolve the age-related disparity in interpreting spirometry results. Local validation of the equation is needed, especially in Northeast Asian children. This study evaluated the GLI equation in Korean children.

METHODS

Spirometry indices (FEV1, FVC, FEV1/FVC, and FEF25%-75%) and clinical information were gathered from three population-based birth cohorts. Predicted GLI reference values and z scores of spirometry results were calculated for 1239 healthy children. The mean, standard deviation of z scores were compared with the expected 0 and 1. Probabilities of falling below the lower limit of normal (LLN) (z score: -1.64) were compared with the expected value 5%. GLI z scores were assessed according to low (<-2), normal (≥-2 and ≤2), and high (>2) BMI z score groups.

RESULTS

Mean z scores significantly differed from 0 for FEV1/FVC in males (mean [95% confidence interval]: 0.18 [0.08, 0.27]) and forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) in females (-0.23 [-0.31, -0.15] and -0.26 [-0.36, -0.16], respectively). The standard deviation was larger than 1 for all variables in males and FVC and FEV1/FVC in females. The probability of falling below the LLN was significantly larger than 5% for FEV1 (12.13% [9.64, 14.77]), FVC (15.86% [13.06, 18.81]), and forced expiratory flow at 25%-75% of forced vital capacity (FEF25%-75%) (7.31% [5.29, 9.49]) in males and FVC (11.91% [9.40, 14.60]) in females. FEV1 and FVC z scores increased across low to high body mass index (BMI) groups, and FEV1/FVC decreased from low to high BMI groups.

CONCLUSION

GLI equations marginally differ from real-world values, which should be considered by pulmonologists in practice or research.

Particulate respirator use and blood pressure: A systematic review and meta-analysis

People use a particulate respirator in order to reduce exposure to ambient fine particulate matter (PM_2.5). Acute exposure to PM_2.5 is known to increase blood pressure. However, systematic reviews or meta-analyses on blood pressure-related benefits of using a particulate respirator is lacking. Therefore, we reviewed randomized crossover intervention studies on blood pressure-related effects of particulate matter respirator use. We conducted a literature review of articles found on Embase, Medline, and Cochrane library on August 31, 2020. The study outcomes were systolic and diastolic blood pressure and mean arterial pressure. A random-effect model was used in the meta-analysis. Subgroup analyses, based on age (adult < 60 years, elderly ≥ 60 years), personal PM_2.5 exposure levels (High: ≥ 25 μg/m³, Low: < 25 μg/m³), and types of monitoring methods (ambulatory and resting blood pressure) were conducted. We identified 297 references, and seven studies were included in our systematic review. None of the studies used a sham respirator as control and complete allocation concealment and blinding were impossible. The use of a particulate respirator was associated with a -1.23 mmHg (95% confidence interval (CI): -2.53, 0.07) change in systolic blood pressure and a -1.57 mmHg (95% CI: -3.85, 0.71) change in mean arterial pressure. There were significant heterogeneities and possibilities for publication bias. The subgroup analyses revealed that studies involving elderly individuals, those conducted in high PM_2.5 personal exposure, and those in which resting blood pressure was monitored demonstrated a larger decrease in blood pressure resulting from respirator use. Further intervention studies with a large sample size and subjects with diverse characteristics and different personal PM_2.5 levels may add the evidence to current literature.

Different Influence of Negative and Positive Spillover between Work and Life on Depression in a Longitudinal Study

Background

This study investigated the longitudinal associations between the degrees of positive and negative spillover in work–life balance (WLB) at baseline and reports of depressive mood at a 2-year follow-up in Korean women employees.

Methods

We used a panel study design data of 1386 women employees who participated in the Korean Longitudinal Survey of Women and Families in both 2014 and 2016. Depressive mood was measured using the “10-item Center for Epidemiologic Studies Depression Scale.” Associations between the positive and negative spillover in WLB at baseline and reports of new incidence of depressive mood at 2-year follow-up were explored using a multivariate logistic regression model.

Results

Negative spillover in WLB at baseline showed a significant linear association with reports of depressive mood at 2-yearfollow-up after adjusting for age, education level, marital status, number of children, and positive spillover (P = 0.014). The highest scoring group in negative spillover (fourth quartile) showed a significant higher odds ratio of 1.95 compared with the lowest scoring group (first quartile; P = 0.036).

Conclusion

Positive spillover in WLB showed a U-shaped association with depression. The degrees of positive and negative spillover in WLB among Korean women employees at baseline were associated with new incidence of depressive mood within 2 years. To prevent depression of female workers, more discrete and differentiated policies on how to maintain healthy WLB are required.

Empathy With Patients and Post-Traumatic Stress Response in Verbally Abused Healthcare Workers

OBJECTIVE

The current study examined the differential empathic capacity, post-traumatic symptoms, and coping strategies in healthcare workers (HCWs) according to the exposure of verbal or physical workplace violence (WPV).

METHODS

Using online survey, a total of 422 HCWs employed at a training general hospital of South Korea participated and completed self-reporting questionnaires including the WPV questionnaire with coping strategy, the Jefferson Scale of Physician Empathy.

RESULTS

Those who experienced either only verbal violence or both physical and verbal violence had lower Jefferson Scale of Physician Empathy scores (p<0.05). Posttraumatic stress symptom severity was higher among people who experienced verbal violence than physical violence. HCWs' exposure to verbal violence was associated with severe posttraumatic symptoms and a low level of empathy with patients (p<0.05). More than half of the victims of verbal violence responded that they did not take any action, receive organizational protection, or peer support, while most physically-abused HCWs received institutional intervention or help from others.

CONCLUSION

Our findings highlight the critical importance of reducing verbal violence, which may represent a larger psychological burden compared to physical violence, by actively implementing effective strategies and policies at the institutional level.

Childhood Obesity-Related Mechanisms: MicroRNome and Transcriptome Changes in a Nested Case-Control Study

Childhood obesity could contribute to adulthood obesity, leading to adverse health outcomes in adults. However, the mechanisms for how obesity is developed are still unclear. To determine the epigenome-wide and genome-wide expression changes related with childhood obesity, we compared microRNome and transcriptome levels as well as leptin protein levels in whole bloods of 12 obese and 24 normal children aged 6 years. miR-328-3p, miR-1301-3p, miR-4685-3p, and miR-6803-3p were negatively associated with all obesity indicators. The four miRNAs were also associated with 3948 mRNAs, and separate 475 mRNAs (185 among 3948 mRNAs) were associated with all obesity indicators. The 2533 mRNAs (64.2%) among the 3948 mRNAs and 286 mRNAs (60.2%) among the 475 mRNAs were confirmed as targets of the four miRNAs in public databases through miRWalk 2.0. Leptin protein was associated with miR-6803-3p negatively and all obesity indicators positively. Using DAVID bioinformatics resources 6.8, top three pathways for obesity-related gene set were metabolic pathways, pathways in cancer, and PI3K-Akt signaling pathway. The top three obesity-related disease classes were metabolic, cardiovascular, and chemdependency. Our results support that childhood obesity could be developed through miRNAs-related epigenetic mechanism and, further, these obesity-related epigenetic changes could control the pathways related with the development of various diseases.