Association between long working hours and diet quality and patterns: A latent profile analysis of a nationally representative sample of Korean workers.

BACKGROUND: Long working hours are associated with cardiovascular and metabolic diseases. This study investigated the relationship between the working hours and dietary qualities and patterns in Korean workers. METHODS: Data from 24,523 workers were extracted from the Korea National Health and Nutrition Examination Survey, 2013-2021. The Korean Healthy Eating Index (KHEI), which ranges from 0 to 100, with a higher score indicating greater adherence to Korean dietary guidelines and superior dietary quality, was used for dietary assessment. We identified dietary patterns and classified workers using latent profile analysis. Logistic regressions were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Five distinct dietary patterns emerged: healthy diet (24.8%), low-vegetable diet (14.0%), average diet (7.8%), low-fruit diet (31.4%), and poor diet (22.0%). The mean KHEI score was 60.8, with the highest score observed in the healthy diet pattern (71.3) and the lowest, in the poor diet pattern (50.0). Compared with working 35-40 h/week, working ≥55 h/week was negatively associated with KHEI scores (ß: -1.08; 95% CI: -1.67, -0.49). Those working ≥55 h/week were less likely to have a healthy diet pattern (OR: 0.81; 95% CI: 0.72, 0.91) and more likely to have a low-fruit diet (OR: 1.36; 95% CI: 1.20, 1.55) or poor diet pattern (OR: 1.23; 95% CI: 1.05, 1.43) compared with those working 35-40 h/week. CONCLUSION: Long working hours are associated with undesirable dietary quality and patterns. Policy interventions aimed at enhancing dietary quality are needed to alleviate the health burdens associated with long working hours.

Interaction between old age and precarious employment on poor mental well-being in workers: Evidence from a nationally representative sample in Korea.

OBJECTIVE: This study examined the relationship between precarious employment (PE) and mental well-being, focusing on age-specific interactions. METHODS: Nationally representative Korean workers (N = 29,961) were surveyed between 2020 and 2021 to collect data on multidimensional PE (categorized as low, moderate, or high) and the WHO-5 well-being index. Workers' ages were classified as young (<35 years), middle-aged (35-54 years), and older (≥55 years). Logistic regression was performed to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). The interaction between PE and age on well-being was examined by including interaction terms in the regression models. RESULTS: The prevalence of poor well-being was 25%, 29%, and 39% for low, moderate, and high precariousness, respectively, whereas it was 26%, 30%, and 39% for young, middle-aged, and older workers, respectively. In the overall sample, the OR (95% CI) of the association between PE and poor well-being was 1.24 (1.17-1.32) for moderate and 1.54 (1.43-1.65) for high precariousness, compared with low precariousness. There was a significant interaction between old age and PE on the odds of poor well-being. Compared with young workers with low PE, middle-aged workers with high PE (OR: 1.85, 95% CI: 1.62-2.10) and older workers with high PE (OR: 2.10, 95% CI: 1.83-2.40) exhibited increased odds of having poor mental well-being. CONCLUSION: PE serves as a social determinant of older workers' psychological well-being. Policy interventions are required to protect older workers' psychological well-being.

Long working hours, work-life imbalance, and poor mental health: a cross-sectional mediation analysis based on the sixth Korean Working Conditions Survey, 2020-2021.

Background There has been growing concern about the negative mental health impact of long working hours and overwork. Our study examined how work-life imbalance (WLI) could be a mediator between working hours and poor mental well-being.Methods We included 34,968 individuals from a nationwide cross-sectional survey in Korea. Self-reported working hours per week was collected, and mental health was assessed by the WHO-5 Well-Being Index. Counterfactual-based mediation models were employed to disentangle the total effects into a direct effect (work hour - poor mental health) and an indirect effect (work hour - WLI - poor mental health).Results Out of 34,968 participants, 52.6% worked 35-40 h/week, 20.0% worked 41-48 h/week, 11.7% worked 49-54 h/week, and 15.6% worked ≥55 h/week. The odds ratios (ORs) of the total impact of working hours on poor mental health were 1.08 (95% CI: 1.01-1.16) for 41-48 h/week, 1.28 (1.17-1.39) for 49-54 h/week, and 1.60 (1.48-1.74) for ≥55 h/week in comparison to 35-40 h/week. The ORs of the indirect effects were 1.04 (1.03-1.05) for 41-48 h/week, 1.08 (1.07-1.09) for 49-54 h/week, and 1.14 (1.12-1.16) for ≥55 h/week, accounting for 51%, 31%, and 28% of the total effects.Conclusion: Our findings suggest that WLI can partially mediate the association of long working hours with mental health deterioration. Policy efforts are required to mitigate the adverse mental health effects of overwork.

Association between temporary employment and current smoking and change in smoking behaviors: A prospective cohort study from South Korea (2009-2018).

Background Previous studies have suggested that employment insecurity is associated with adverse health outcomes. We explored the association between temporary employment and smoking behaviors.Methods We analyzed 11,795 workers (51,867 observations) from the Korea Health Panel Study (2009-2018). Employment types were categorized as regular, fixed-term, or daily, based on the duration of labor contract. The outcomes were current smoking status and changes in smoking behavior (initiation or cessation) in the following year. Generalized estimating equations were used to estimate odds ratio (OR) and 95% confidence interval (CI).Results The proportions of fixed-term and daily workers were 41.2% and 16.4% for women and 23.6% and 12.4% for men, respectively. Temporary employment was associated with increased odds of current smoking, while also demonstrating prospective associations with changes in smoking behaviors. For instance, in prospective analyses, male workers with fixed-term and daily employments were associated with a decreased likelihood of smoking cessation (OR:0.77; 95% CI:0.65-0.91 for fixed-term employment and OR:0.66; 95% CI:0.52-0.83 for daily employment) in the following year compared to those with regular employment. Moreover, those experiencing consecutive temporary employment was most inversely associated with smoking cessation in both men (OR:0.56; 95% CI:0.44-0.71) and women (OR:0.37; 95% CI:0.16-0.85) compared to those experiencing consecutive regular employment. However, no clear association between temporary employment and smoking initiation was observed in both men and women.Conclusions Temporary employment is directly associated with current smoking and inversely associated with smoking cessation. Policies are needed to improve job insecurity among temporary employees.

Job dissatisfaction as a risk factor of depressive symptoms and suicidal ideation among female workers: evidence from a nationwide longitudinal study in South Korea.

This study aimed to investigate the relationship between job dissatisfaction (JD) and depressive symptoms and suicidal ideation among female workers. Additionally, it examined how the cumulative exposure to JD over multiple years can exacerbate the effect. We conducted our analyses on a nationwide sample of 6111 female workers from the Korean Longitudinal Survey of Women and Family (Waves 5-7). Depressive symptoms were measured using the 10-item version of the Centre for Epidemiologic Studies Depression Scale. JD was classified into quartiles (Q1-Q4), and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using generalised estimating equations. The overall prevalence of depressive symptoms and suicidal ideation among study participants was 13.9% and 2.4%, respectively. Our findings revealed that female workers with the highest level of JD (Q4) had a significantly greater risk of depressive symptoms (OR [95% CI]: 1.61 [1.37-1.89]) and suicidal ideation (OR [95% CI]: 2.08 [1.37-3.17]) after 2-year follow-up compared to those with the lowest level of JD (Q1). Consecutive exposure to JD over multiple years was also associated with depressive symptoms and suicidal ideation after a 2-year follow-up. For instance, women exposed to JD for three consecutive waves exhibited a high risk of depressive symptoms (OR [95% CI]: 1.61 [1.33-1.95]) and suicidal ideation (OR [95% CI]: 1.67 [1.04-2.70]). JD was positively associated with depressive symptoms and suicidal ideation. Our study suggests that JD is a risk factor for mental health problems in female workers.

Association between sickness presenteeism and depressive symptoms: a cross-sectional study using the 6th Korean working conditions survey.

PURPOSE: This study aimed to reveal the relationship of the days of experiencing sickness presentism and depressive symptoms among Korean workers. Sickness presenteeism which defined as the act of going to work despite being feeling unhealthy triggers various adverse effects on mental health, including increased risks of depression. Furthermore, Sickness presenteeism is a major social issue causing substantial socioeconomic costs. METHODS: The data of 25120 participants from sixth Korean Working Condition Survey was utilized in this cross-sectional study. Sickness presenteeism was defined using a self-reported questionnaire and depressive symptoms were assessed by WHO well-being index. Multivariate logistic regression analysis was conducted to calculate the odd ratios for depressive symptoms regarding the number of days experiencing sickness presenteeism. We calculated odds ratios (ORs) and 95% confidence interval (95% CI) for depressive symptoms after categorizing participants into three groups based on the duration of experiencing sickness presenteeism, using cut-off values of 3 and 5 days. RESULTS: Workers who have experienced sickness presenteeism for more than 5 days were at highest risk for depressive symptoms than referent group (OR 2.87; 95% CI 2.17-3.76 in male, OR 3.86; 95% CI 3.02-4.91 in female). Furthermore, there was a trend of increasing risk for depressive symptom as the duration of experiencing sickness presenteeism extended. CONCLUSION: This study presents the association between experiencing sickness presenteeism in the previous 12 months and depressive symptoms. Based on the results, we provide individual and organizational strategies of reducing sickness presenteeism. Also, screening for workers who have experienced sickness presenteeism are needed to ensure good mental health.

Association between constant connectivity to work during leisure time and insomnia: does work engagement matter?

PURPOSE: The influx of communication media to contemporary workplaces has exposed workers to be always connected to their work. Constant connectivity to work (CCW) refers to the condition in which workers are always connected to work, even during their non-work hours, and are not detached from the work situation. We investigated the association between CCW and insomnia and the moderating effect of work engagement. METHODS: A total of 29,512 nationally representative samples of workers in Korea were used. Insomnia was assessed by the Minimal Insomnia Symptom Scale. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). The additive interaction between CCW and low work engagement was estimated by calculating Relative Excess Risk due to Interaction (RERI). RESULTS: Exposure to CCW was related to insomnia (OR [95% CI] 1.33 [1.22-1.46]). Additionally, a significant negative interaction between CCW and work engagement was observed. The effects of CCW were mitigated in those with high work engagement. The OR of the combined effect of CCW exposure and low work engagement was 2.52 (95% CI 2.22-2.87). RERI between exposure to CCW and low work engagement was 0.69 (95% CI 0.38-0.99), indicating that there is a supra-additive interaction. CONCLUSION: Our study found that CCW is related to an increased risk of insomnia and that high work engagement can mitigate the effect of CCW. Our study suggests that improving work engagement and disconnecting from work outside of work hours can help protect employees' sleep quality.

Associations between precarious employment and smoking and regular exercise: Results from a Korean longitudinal panel study from 2005 to 2020.

We examined whether precarious employment (PE) is related to cigarette smoking and physical inactivity and whether a longer duration of PE intensifies the detrimental impact. Using Korean longitudinal panel data, 89,289 observations of 15,712 employees were analyzed. Mixed models were applied to estimate the odds ratio (OR) and 95% confidence intervals (CIs). We adjusted for time-varying characteristics of the participants (age, education, marital status, income, occupation, and working hours). ORs of associations between PE and current smoking were 1.09 (95% CI: 0.95-1.25) in men and 1.77 (1.03-3.05) in women. Also, ORs of associations between PE and regular exercise were 0.52 (0.46-0.58) in men and 0.95 (0.85-1.07) in women. Next, the longer the duration of PE was related to the higher the risk of current smoking and physical inactivity. For instance, over 6 years of PE was related to the highest risk of current smoking in men (1.80 [1.38-2.34]) and women (3.94 [1.25-12.44]). Also, over 6 years of PE was related to the lowest likelihood of regular exercise in men (0.47 [0.37-0.59]), but not in women (0.83 [0.65-1.06]). A longer duration of PE is also related to a change in health behaviors among men. Over 6 years of PE was associated with the highest risk of smoking initiation (2.02 [1.28-3.19]) and the lowest likelihood of exercise initiation (0.42 [0.32-0.55]) in men. However, a longer duration of PE was not associated with a change in health behaviors in women. Our findings highlight that PE have a detrimental impact on health behaviors.

Multidimensional typologies of precarious employment and their relationships with mental well-being in Korean wageworkers: A latent class analysis based on the Korean Working Conditions Survey (2020-2021).

BACKGROUND: Precarious employment (PE) has been conceptualized as having a multidimensional nature, and research addressing this topic in Asian countries is scarce. This study examined the typologies of PE and their relationships with mental health among Korean workers. METHODS: From October 2020 to April 2021, the Korean Working Conditions Survey was conducted on Korean wageworkers (weighted N = 38,347), representative of the nation. With theory-based operationalization of PE, we identified typologies and classified workers through latent class analysis. Logistic regression was performed to explore the association between PE typologies and mental health among workers, represented as odds ratio (ORs) and confidence intervals (CIs). RESULTS: Four distinct employment typologies emerged: (i) standard employment relationships (SER, 34.5%), (ii) moderate employment precariousness (MEP, 43.5%), (iii) underemployment (17.9%), and (iv) daily laborers (4.1%). Women were overrepresented in the MEP and underemployment types, while the SER type consisted of those with higher educational attainment and white-collar jobs. The OR (95% CI) of depression was 1.38 (1.27-1.50) for the MEP type, 1.48 (1.32-1.66) for the underemployment type, and 2.15 (1.85-2.51) for the daily laborers, compared to the SER type. For individual elements of PE, temporary employment, low wages, low-income predictability, and low involvement in work process were positively associated with depression, whereas part-time employment was negatively associated with depression. CONCLUSION: Employment insecurity, low material rewards, and a lack of rights and protection can contribute to the poor mental health of workers. Policy interventions are warranted to mitigate inequalities in employment quality among Korean workers.

Self-Esteem Trajectories After Occupational Injuries and Diseases and Their Relation to Changes in Subjective Health: Result From the Panel Study of Workers' Compensation Insurance (PSWCI).

BACKGROUND: Occupational injuries and diseases are life events that significantly impact an individuals' identity. In this study, we examined the trajectories of self-esteem among victims of occupational injury and disease and their relation to health. METHODS: The Panel Study of Workers' Compensation Insurance conducted annual follow-ups on workers who had experienced occupational injury or disease. A total of 2,000 participants, who had completed medical care, were followed from 2013 to 2017. Growth mixture modeling was utilized to identify latent classes in the self-esteem trajectory. Additionally, logistic regressions were conducted to explore the association between trajectory membership, baseline predictors, and outcomes. RESULTS: Three distinct trajectory classes were identified. Total 65.8% of the samples (n = 1,316) followed an increasing self-esteem trajectory, while 31.1% (n = 623) exhibited a constant trajectory, and 3.1% (n = 61) showed a decreasing trajectory. Individuals with an increasing trajectory were more likely to have a higher educational attainment (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.20-2.88), an absence of a moderate-to-severe disability rating (OR, 0.49; 95% CI, 0.25-0.96), no difficulty in daily living activities (OR, 0.81; 95% CI, 0.75-0.88), and were economically active (re-employed: OR, 2.46; 95% CI, 1.52-3.98; returned to original work: OR, 4.46; 9% CI, 2.65-7.50). Those with a decreasing self-esteem trajectory exhibited an increased risk of poor subjective health (OR, 1.89; 95% CI, 0.85-4.85 in 2013 to OR, 3.17; 95% CI, 1.04-13.81 in 2017), whereas individuals with an increasing trajectory showed a decreased risk (OR, 0.54; 95% CI, 0.43-0.68 in 2013 to OR, 0.44; 95% CI, 0.33-0.57 in 2017). CONCLUSION: Our findings emphasize the diversity of psychological responses to occupational injury or disease. Policymakers should implement interventions to enhance the self-esteem of victims.

Evaluation of Temporal Trends of Lead Exposure in Korean Workers Using Workplace Monitoring Data.

BACKGROUND: Lead, which is widely used in various industrial settings, is a major health hazard for manufacturing workers. Therefore, control of lead exposure has been implemented in an effort to prevent lead-related health problems. In this study, our aim was to evaluate temporal trends in occupational lead exposure in Korean lead workers using data from monitoring of workplace exposure. METHODS: A nationwide work environment monitoring database, data from a work environment monitoring institution, and data extracted from a review paper were utilized. Different versions of standard industrial classification codes were aligned with the 10th Korean Standard Industrial Classification, which is generally consistent with the 4th revision of the International Standard Industrial Classification. The multiple data sources were combined and temporal trends over the period from 1994-2021 were estimated. In addition, separate estimation of temporal trends in the storage battery manufacturing industry over the period from 1987-2021 was also performed. RESULTS: A total of 444,296 personal airborne lead measurements were used for the estimation process. The temporal trends in occupational exposure to lead declined by -6% annually over the study period. In particular, levels of lead exposure in the storage battery manufacturing industry showed a steeper decline of -12% annually. CONCLUSIONS: Findings of our study showed that occupational exposure to lead declined over the period from 1994 to 2021 in Korea. However, adverse effects of exposure to lead on health should be regarded with caution. The results will be useful in conduct of epidemiological studies examining lead-related effects on health.

Indoor exposure assessment for levels of dust mite and total volatile organic compounds (TVOCs) in living houses.

The purpose of this study is to measure the levels of dust mites (Dermatophagoides farina group 1 [Der f1] and Dermatophagoides pteronyssinus group 1 [Der p1]) and total volatile organic compounds (TVOCs) in the resident environments with living conditions such as the number of ventilation; the number of window, floor, and temperature; and relative humidity (RH) from vulnerable class in South Korea. Information on residents is designed to be prepared by residents on their general characteristics (daily residence time, heating and cooking type, and cleaning on the day of sampling). Dust mites levels ranged from 24.0 to 1087.5 ng/g with a mean of 215.4 ng/g for Der f1 and from 0.6 to 489.9 ng/g with a mean of 489.9 ng/g for Der p1. Total TVOC levels ranged from 15.3 to 1642.1 µg/m3 with a mean of 219.7 µg/m3. The correlation analysis showed a positive association between Der f1 levels and xylene levels in fall (r = 0.49, r < 0.05) of this study.

Association between levels of radon and bioaerosols (bacteria and fungi) by living conditions.

This study aimed to measure the levels of airborne radon Rn and bioaerosols - culturable airborne bacteria (CAB) and culturable airborne fungi (CAF)-in South Korea's residential environments, considering living conditions such as the number of ventilations, number of windows, floors, temperature, and relative humidity. . The range of Rn levels was 0.43-7.439 pCi/L with a median of 0.70 pCi/L. The CAB levels were 239-488 colony-forming unit (CFU)/m3 with a median of 309 CFU/m3, and CAF levels were 174-366 CFU/m3 with a median of 233 CFU/m3. Thus, this study found that semi-basement residential indoor environments negatively affected Rn and bioaerosol levels, and living in such residences resulted in high health condition scores on the bad side. Given the correlation between airborne Rn and bioaerosol levels, further large-scale studies are needed to identify more reliable and representative of research.

Association between the return-to-work hierarchy and self-rated health, self-esteem, and self-efficacy.

PURPOSE: This study aimed to examine whether change of employer and/or job upon return-to-work after work-related injuries and diseases is related to health outcomes; self-rated health, self-esteem, and self-efficacy were used as indicators. METHODS: Data from the Panel Study of Workers' Compensation Insurance in Korea were used. A total of 1,610 workers who had returned to work after work-related injuries and diseases were included. The workers were divided into four groups according to their return-to-work characteristics: same employer, same job (n = 660); same employer, different job (n = 57); different employer, same job (n = 318); and different employer, different job (n = 575). Self-rated health, Rosenberg Self-Esteem Scale, and Self-Efficacy Scale scores were used as outcome variables. Logistic regression analysis was used. RESULTS: Compared to workers who had returned to the same employer and same job, those who had returned to the same employer but a different job were less likely to report good self-rated health (odds ratio [OR] 0.54; confidence interval [CI] 0.30-0.97). Those returning to a different employer but the same job were less likely to report good self-rated health (0.47, 0.35-0.64) and high self-esteem (0.73, 0.55-0.96). Those returning to a different employer and different job were less likely to report good self-rated health (0.49, 0.38-0.63), high self-esteem (0.68, 0.54-0.86), and high self-efficacy (0.66, 0.52-0.83). CONCLUSIONS: Change of employer and/or job related to health outcomes. Returning to the same employer and same job should be set as a goal in the vocational rehabilitation process.

Impacts of Return-to-Work Type and Period on Job Retention in Workers with Occupational Injuries and Diseases.

BACKGROUND: Despite the necessity of job retention in achieving return-to-work (RTW) goals, many workers leave their jobs after returning to work. The objective of this study was to examine the impacts of RTW type and period on job retention in Korean workers with occupational injuries and diseases. METHODS: Data were derived from the Panel Study of Worker's Compensation Insurance, including data from 2,000 systemically sampled workers who had finished recuperation in 2012; three waves of survey data were included in the analyses. Workers who returned to work (n = 1,610) were included in the analysis of the relationship between RTW type and job retention, and 664 workers who returned to their original workplaces were included in the analysis of the relationship between RTW period and job retention. The participants completed a questionnaire, and administrative data were provided by workers' compensation insurance. RESULTS: A Cox proportional-hazards regression analysis showed an increased hazard ratio (HR) for non-retention of 2.66 (95% confidence interval, 2.11-3.35) in reemployed workers compared to that in workers returning to their original workplaces. Among workers returning to their original workplaces, HRs for non-retention were increased in workers with a RTW period of 13-24 months (3.03 [1.52-6.04]) and > 24 months (5.33 [2.14-13.25]) compared to workers with a RTW period of ≤ 3 months. CONCLUSION: RTW type and period were significantly related to job retention, suggesting that policies for promoting job retention rate should be implemented.

Risk factors of suicide attempt among people with suicidal ideation in South Korea: a cross-sectional study.

BACKGROUND: Suicide is a serious public health concern worldwide, and the fourth leading cause of death in Korea. Few studies have focused on risk factors for suicide attempt among people with suicidal ideation. The aim of the present study was to investigate the risk factors and develop prediction models for suicide attempt among people with suicidal ideation in the Korean population. METHOD: This study included 1567 men and 3726 women aged 20 years and older who had suicidal ideation from the Korea National Health and Nutrition Examination Survey from 2007 to 2012. Among them, 106 men and 188 women attempted suicide. Multivariate logistic regression analysis with backward stepwise elimination was performed to find risk factors for suicide attempt. Sub-group analysis, dividing participants into under 50 and at least 50 years old was also performed. RESULTS: Among people with suicidal ideation, age, education, cancer, and depressive disorder were selected as risk factors for suicide attempt in men. Age, education, national basic livelihood security, daily activity limitation, depressive disorder, stress, smoking, and regular exercise were selected in women. Area under curves of our prediction models in men and women were 0.728 and 0.716, respectively. CONCLUSIONS: It is important to pay attention to populations with suicidal ideation and the risk factors mentioned above. Prediction models using the determined risk factors could be useful to detect high-risk groups early for suicide attempt among people with suicidal ideation. It is necessary to develop specific action plans for these high-risk groups to prevent suicide.

The Association between Involuntary Smoking Exposure with Urine Cotinine Level and Blood Cadmium Level in General Non-Smoking Populations.

Unintentional environmental exposure to toxicants is associated with an aggravated health status of the general population. Involuntary smoking (IS) exposure is one of the main routes to involuntary toxicants exposure. However, few studies have attempted to understand the environmental cadmium exposure by IS exposure in the general, non-smoking population. The purpose of the current study was to examine the relationship between blood cadmium level and IS level according to gender and age. We used the Korea National Health and Nutrition Examination Survey (KNHANES) IV-VI data that included heavy metal and urine cotinine sampling with IS exposure history. The final analysis comprised 3,493 adults (1,231 males and 2,262 females) and 395 adolescents (210 males and 185 females). Linear regression was performed to estimate the association between self-reported IS exposure with urine cotinine level and blood cadmium level in non-smokers with gender and age group stratification. In final regression model, the effect values (B) (standard errors [SE]) between blood cadmium and urine cotinine level in men was 0.0004 (0.0001) and 0.0006 (0.0002) in adults and adolescents, the B (SE) in women was 0.0006 (0.0002) and 0.0016 (0.0006) in adults and adolescents. Our study revealed, for the first time, a significant association between blood cadmium and IS exposure in non-smokers. Greater efforts are needed to improve environmental justices of the general population from IS, considering the severe harmful effects of involuntary exposure to even a low level of cadmium.

The association between low blood lead levels and the prevalence of prehypertension among nonhypertensive adults in Korea.

OBJECTIVES: Low-level lead exposure has been associated with increases in blood pressure (BP) and impairment of the cardiovascular system. Prehypertension is not categorized as a disease currently; however, individuals with untreated prehypertension are known to be at increased risk of progression to hypertension and mortality caused by cardiovascular disease. We investigated the association between blood lead levels below the threshold for the harmful effects of lead and the prevalence of prehypertension in Korean adults. METHODS: A total of 8,493 participants (3,945 men and 4,548 women) were included in the current analysis, using data from the fourth, fifth, and sixth Korean National Health and Nutrition Examination Survey (KNHANES) in 2007-2013. Blood analysis, self-report questionnaires, and physical examinations were used to assess blood lead levels, BP, and medical history. Odds ratios (OR) and 95% confidence intervals (95% CI) for prehypertension were calculated using multiple logistic regression models. RESULTS: Compared to the first quartile (Q1) blood lead level (0.206-1.539 µg/dl), the ORs (95% CI) were 1.24 (1.04-1.48) in Q2, (1.540-2.056 µg/dl), 1.27 (1.06-1.52) in Q3, (2.057-2.716 µg/dl), and 1.30 (1.07-1.60) in Q4 (2.717-24.532 µg/dl) for the prevalence of prehypertension after adjusting for age, sex, morbidity status, socioeconomic status, and health behavioral variables. CONCLUSIONS: Our large, cross-sectional, nationwide study revealed that blood lead levels below the threshold for the harmful effects of lead were significantly associated with prehypertension. Am. J. Hum. Biol. 28:729-735, 2016. © 2016 Wiley Periodicals, Inc.

Metabolic outcomes of workers according to the International Standard Classification of Occupations in Korea.

BACKGROUND: Occupation influences the risk for developing chronic metabolic diseases. METHODS: We compared the prevalence of MetS by International Standard Classification of Occupations using the nationally representative data in Korea (KNHANES). We enrolled 16,763 workers (9,175 males; 7,588 females) who had measurements for the National Cholesterol Education Program criteria III and other variables. OR and 95%CIs for MetS and its components were estimated according to occupation using the multiple logistic regression models. RESULTS: The occupational groups with the highest age-standardized prevalence of MetS were lower skilled white-collar men (31.1 ± 2.4%) and green-collar women (24.2 ± 2.9%). Compared with the unskilled male blue-collar group, which had the lowest prevalence of MetS, the OR (95%CIs) of MetS in men were 1.77 (1.45-2.15) in higher skilled white-collar, 1.82 (1.47-2.26) in lower-skilled white-collar, 1.63 (1.32-2.01) in pink-collar and 1.37 (1.13-1.66) in skilled blue-collar workers in final logistic regression model. CONCLUSIONS: MetS and its components vary by occupational category and gender in ways that may guide health interventions. Am. J. Ind. Med. 59:685-694, 2016. © 2016 Wiley Periodicals, Inc.

Concealing Emotions at Work Is Associated with Allergic Rhinitis in Korea.

Concealing emotions at work can cause considerable psychological stress. While there is extensive research on the adverse health effects of concealing emotions and the association between allergic diseases and stress, research has not yet investigated whether concealing emotions at work is associated with allergic rhinitis. Allergic rhinitis is a common disease in many industrialized countries, and its prevalence is increasing. Thus, our aim was to determine the strength of this association using data from three years (2007-2009) of the 4th Korean National Health and Nutrition Examination Survey. Participants (aged 20-64) were 8,345 individuals who were economically active and who had completed the questionnaire items on concealing emotions at work. Odds ratio (OR) and 95% confidence intervals (95% CIs) were calculated for allergic rhinitis using logistic regression models. Among all participants, 3,140 subjects (37.6%) reported concealing their emotions at work: 1,661 men and 1,479 women. The OR (95% CIs) for allergic rhinitis among those who concealed emotions at work versus those who did not was 1.318 (1.148-1.512). Stratified by sex, the OR (95% CIs) was 1.307 (1.078-1.585) among men and 1.346 (1.105-1.639) among women. Thus, individuals who concealed their emotions at work were significantly more likely to have a diagnosis of AR in comparison to those who did not. Because concealing emotions at work has adverse health effects, labor policies that aim to reduce this practice are needed.