The relationship between skeletal muscle mass and the KOSHA cardiovascular risk in obese male workers.

Background: Efforts for the prevention and management of cardiovascular diseases (CVDs) in workers have been actively pursued. Obesity is one of the important risk factors related to CVDs. Obesity has various metabolic characteristics, and some individuals can be metabolically healthy. Body composition including skeletal muscle mass is known to have protective effect in obesity. The study aims to investigate the association between skeletal muscle mass and Korea Occupational Safety and Health Agency (KOSHA) CVD risk among obese male manufacturing workers in Korea and to identify appropriate indicators of skeletal muscle mass for predicting risk of CVDs. Methods: The study was conducted on 2,007 obese male workers at a manufacturing industry aged more than 19 years. Skeletal muscle mass, skeletal muscle index (SMI), skeletal muscle mass percent (SMM%) and skeletal muscle to body fat ratio (MFR) were used to evaluate body composition and these indicators were divided into quartiles. The odds ratios (ORs) and 95% confidence intervals (CIs) for the KOSHA CVD risk groups according to quartiles of skeletal muscle mass indicators were estimated using ordinal logistic regression analysis. Results: The OR for the KOSHA CVD risk groups in the highest quartile of SMI was 1.67 (95% CI: 1.42-1.92), while the ORs for the KOSHA CVD risk groups in the highest quartiles of SMM%, SMM/body mass index (BMI), and MFR were 0.47 (95% CI: 0.22-0.72), 0.51 (95% CI: 0.05-0.76), and 0.48 (95% CI: 0.23-0.74), respectively. Conclusions: We found that high SMI increase the likelihood of high risk of CVDs, while high SMM%, SMM/BMI, and MFR lower the likelihood of high risk of CVDs. Accurate evaluation of skeletal muscle mass can help assess the cardiovascular risk in obese male workers.

Association between shift work and serum homocysteine level in female electronic manufacturing services workers.

Background: Shift work has been shown to increase the risk of cardiovascular disease (CVD) based on several evidences. The classic risk factors of CVD include age, hypertension, smoking, obesity and diabetes. Recently, the serum homocysteine level has been reported to be a valuable indicator of CVD risk. This study aimed to determine the variation in serum homocysteine level as a cardiovascular risk indicator among female workers according to shift work. Methods: The data of regular health examination of workers at an electronic manufacturing services company in Yeongnam region, South Korea in 2019 were examined in this study. The investigation was based on a cross-sectional study conducted on 697 female workers (199 day workers and 498 shift workers). The sociodemographic and biochemical characteristics were compared between day workers and shift workers. Through a logistic regression analysis, the odds ratio (OR) of the increased serum homocysteine level in relation to shift work was determined. Results: Compared to female day workers, female shift workers showed significantly higher level of serum homocysteine (8.85 ± 2.16 vs. 9.42 ± 2.04 µmol/mL; p = 0.001). The OR of day workers against shift workers was 1.81 (95% confidence interval [CI]: 1.25-2.63). With the adjustment of variables that may influence the level of serum homocysteine, the adjusted OR was 1.68 (95% CI: 1.09-2.60). Conclusions: The serum homocysteine level was significantly higher in shift workers than in day workers. It is thus likely to be a useful predictor of CVD in shift workers.

Association between coronavirus disease 2019-related workplace interventions and prevalence of depression and anxiety.

Background: Although coronavirus disease 2019 is causing a variety of psychological problems for workers, there are few longitudinal studies on changes in workers' mental health by workplace intervention. This study aimed to evaluate the change in the prevalence of depression and anxiety according to the active involvement of the workplace. Methods: This study was conducted on 1,978 workers at a workplace who underwent a health screening from January 2019 to August 2020, and classified depression and anxiety disorders using a self-report questionnaire. After the first pandemic, the company stopped health screening, took paid leave and telecommuting, and conducted interventions such as operating its own screening clinic. To see if this workplace intervention affects workers' mental health, we conducted generalized estimating equations to compare odds ratio (OR). Results: In the pre-intervention group, 384 people (16.86%) had depression, and 507 people (22.26%) had anxiety disorder. Based on the OR before intervention, the OR of depression decreased to 0.76 (0.66-0.87) and the OR of anxiety disorder decreased to 0.73 (0.65-0.82). Conclusions: As a result of this study, it was confirmed that workplace intervention was related to a decrease in depression and anxiety. This study provides basic data to improve workers' mental health according to workplace intervention, and further research is needed according to workplace intervention in the future.

Obesity Impairs Embryonic Myogenesis by Enhancing BMP Signaling within the Dermomyotome.

Obesity during pregnancy leads to adverse health outcomes in offspring. However, the initial effects of maternal obesity (MO) on embryonic organogenesis have yet to be thoroughly examined. Using unbiased single-cell transcriptomic analyses (scRNA-seq), the effects of MO on the myogenic process is investigated in embryonic day 9.5 (E9.5) mouse embryos. The results suggest that MO induces systematic hypoxia, which is correlated with enhanced BMP signaling and impairs skeletal muscle differentiation within the dermomyotome (DM). The Notch-signaling effectors, HES1 and HEY1, which also act down-stream of BMP signaling, suppress myogenic differentiation through transcriptionally repressing the important myogenic regulator MEF2C. Moreover, the major hypoxia effector, HIF1A, enhances expression of HES1 and HEY1 and blocks myogenic differentiation in vitro. In summary, this data demonstrate that MO induces hypoxia and impairs myogenic differentiation by up-regulating BMP signaling within the DM, which may account for the disruptions of skeletal muscle development and function in progeny.

Effects of work stress, sleep, and shift work on suicidal ideation among female workers in an electronics company.

BACKGROUND: Suicide is the leading cause of death in young adults in Korea. Stress in the workplace affects the suicide rate; young female workers are particularly vulnerable to adverse work environments. We investigated the relationships of shift work, sleep, and work stress to suicidal ideation. METHODS: This study used data from 508 female workers aged 22-40 years in an electronics company. Data on baseline characteristics, work patterns, sleep quality (using the Pittsburgh Sleep Quality Index), and work stress levels using the Korean Occupational Stress Scale (KOSS) were obtained from questionnaires. We examined associations between suicidal ideation and shift work, sleep quality, and KOSS scores. RESULTS: Suicidal ideation was significantly higher among shift workers (odds ratio [OR], 2.38; 95% confidence interval [CI], 1.31-4.32), those with poor sleep (OR, 2.84; 95% CI, 1.68-4.84), and those with high work stress (OR, 3.30; 95% CI, 1.82-6.00). Both 3 × 12 h shift workers (OR, 2.98; 95% CI, 1.35-6.57) and 4 × 8 h shift workers (OR, 2.14; 95% CI, 1.03-4.45) had increased suicidal ideation. High work stress (OR, 11.55; 95% CI, 2.93-45.48) had stronger associations with suicidal ideation than poor sleep (OR, 3.86; 95% CI, 1.21-12.33) in shift workers. The combined effect of poor sleep and high KOSS on suicidal ideation was stronger in shift workers (OR, 13.39; 95% CI, 3.22-55.62) than day workers (OR, 4.31; 95% CI, 1.03-18.01). CONCLUSIONS: Shift workers are more vulnerable than day workers to the combination of work stress and poor sleep quality as well as to work stress alone.

Relationship of shift work with endoscopic gastritis among workers of an electronics company.

Objectives The current study aimed to examine the cross-sectional association between shift work and gastritis using endoscopic evaluation. Methods We collected questionnaire data from 964 non-shift workers and 290 shift workers aged 22-40 years at an electronics company, comprising age, smoking status, alcohol consumption, physical activity, occupational stress, and gastrointestinal symptoms. We performed a gastroendoscopy of participants. Along with describing the gastroendoscopic results, we analyzed the correlations between gastritis and shift work using multiple logistic regression analysis. Results In terms of gastrointestinal symptoms, night shift workers complained more of indigestion than non-shift workers (P<0.01), and the rate of gastritis was higher. The odds of gastritis was significantly higher among shift workers after adjusting for covariates. The odds ratio (OR) for gastritis was 2.24 [95% confidence interval (CI) 1.47-3.43] in shift workers compared with non-shift workers. Among seven subtypes of gastritis, only superficial gastritis was significantly associated with shift work (OR 1.58, 95% CI 1.12-2.24). Conclusions We found that shift workers experience gastritis more than non-shift workers as well as more gastrointestinal symptoms, particularly indigestion. Using endoscopic findings, our study supports that shift work negatively affects the gastrointestinal system.

The effect of long working hours on cerebrovascular and cardiovascular disease; A case-crossover study.

BACKGROUND: This study investigated the relationship between weekly working hours and the occurrence of cerebro-cardiovascular diseases using a case-crossover study design. METHODS: We investigated average working hours during the 7 days before the onset of illness (hazard period) and average weekly working hours between 8 days and 3 months before the onset of cerebro-cardiovascular diseases (control period) for 1,042 cases from the workers' compensation database for 2009. RESULTS: Among all subjects, the odds ratio by conditional logistic regression for the risk of cerebro-cardiovascular diseases with a 10 hr increase in average weekly working hours was 1.45 (95% confidence interval [CI]: 1.22-1.72), a significant association. CONCLUSIONS: An increase in average weekly working hours may trigger the onset of cerebro-cardiovascular disease. Am. J. Ind. Med. 60:753-761, 2017. © 2017. Wiley Periodicals, Inc.

Health care strategy for ensuring work ability in an aging Korea.

The rapid aging trend in South Korea will cause a growing shortage of labor and decreasing quality of the labor force. The purpose of this commentary is to recommend a health care strategy to maintain and promote the work ability of employees in an aging Korea. Strategies to promote the work ability require the collaboration of governmental agencies at the central and local levels. First, the common goal should be the reinforcement of follow-up measure in general medical examinations and the promotion of healthy lifestyles for workers. Second, collaborating activities should be performed among the Worker's Health Center, the Health Promotion Center, and community health centers. In conclusion, health care strategies for ensuring the work ability in an aging Korea require the collaboration of governmental agencies at the central and local levels.

Effects of exercise and L-arginine intake on inflammation in aorta of high-fat diet induced obese rats.

PURPOSE: In the present study, we investigated the effect of exercise and arginine on the inflammatory makers and Cu-Mn superoxide dismutase (SOD) expression in the aortas of high-fat-induced obese rats. METHODS: Fifty 6-month-old male Sprague-Dawley rats were randomly assigned as follows: HF-Con: high-fat diet, HF-Ex: high-fat diet and exercise, HF-Ex+A: high-fat diet and combined exercise and arginine, HF-A: high-fat diet and arginine. The high-fat diet was fed for 12 weeks following 1 week of environmental adaptation with mixed solid chow. The rats performed treadmill exercise 6 times per week for 12 weeks at20 m/min for 60 min. L-argininewas mixed with saline and orally administered at 150 mg/kg once a day. Expressions of inflammatory markers (including NF- κB, TNF-α, COX-2) and SOD were evaluated using western blotting. RESULTS: NF-κB expression decreased significantly (p<0.05) in the HF-Ex group compared with HF-Con group, and we found additional effects(p<0.01) on NF-κB expression in HF-EX+A compared withHF-Ex. TNF-α expression decreased significantly (p<0.01) in HF-Ex, FH-Ex+A, and FH-A compared with HF-Con. In a similar trend with NF-κB expression, COX-2 expression decreased significantly in HF-Ex compared withHF-Con. In Cu-Mn SOD expression, there was no difference between HF and HF-Ex, but significant increases (p<0.01) inCu-Mn SOD werefound in HF-Ex+A and HF-A. CONCLUSION: Based on our results, treatment that combines exercise and arginine might be effective for modulatingvascular inflammation and oxidative stress in obesity.

The association between intraocular pressure and different combination of metabolic syndrome components.

BACKGROUND: Although the association between metabolic syndrome and intraocular pressure is well known, the relationship between the intraocular pressure and different combination of the components of metabolic syndrome has not been actively researched yet. The study aimed to investigate the relationship between the intraocular pressure and metabolic syndrome components with their different combinations. METHODS: Thirty-one thousand two hundred seventy one healthy people aged 19-79 who attended a community hospital for a health check-up between January 2011 and December 2013 were enrolled in the study. Subjects with a history of intraocular disease, at least in one eye and those receiving medical treatment for glaucoma were excluded. Metabolic syndrome was diagnosed following the criteria defined in Circulation 2009. RESULTS: Subjects with combination of three metabolic syndrome components of triglycerides, abdominal obesity, and fasting glucose had the highest intraocular pressure. And subjects with the combination of four components of blood pressure, high-density lipoproteins, triglycerides, fasting glucose had a significantly higher intraocular pressure than ones with the combination of all five metabolic syndrome components. CONCLUSIONS: The difference in the risk of high intraocular pressure according to the different combination of the metabolic syndrome components could be confirmed. If additional follow-up studies are conducted, the findings can be used as an indicator for predicting intraocular pressure increases in patients with metabolic syndrome.

The effect of organisational system on self-rated depression in a panel of male municipal firefighters.

OBJECTIVES: The present study evaluated the effects of job stress, including organisational system to self-rated depression through a panel study of male municipal firefighters in the Republic of Korea. METHODS: A panel of 186 municipal firefighters reported self-rated depressive symptoms according to the Beck Depression Inventory (BDI). The effects of job stress were evaluated using the Korea Occupational Stress Scale, taken one year earlier and classified by the median value. Panel members were classified into Depression or Control groups according to BDI scores, with a cut-off level of 'over mild depression' in a follow-up survey. RESULTS: The Depression group included 17 (9.1%) workers. Firefighters who scored high on occupational system had an 8.3 times greater risk of being assigned to the Depression group than those who had not (adjusted odds ratio [OR] = 8.03, 95% confidence interval (CI) = [1.73-37.22]). In contrast, job stress from a 'difficult physical environment' revealed negative risks related to being classified in the Depression group (AOR = 0.20, 95% CI = [0.04-0.92]). CONCLUSIONS: Although the healthy worker effect may be involved, job stress based on perceptions of organisational system was a strong risk factor for depression. A comprehensive approach should be considered that encompasses social issues when assessing or mental health in high-risk groups, as well as the practical issue of physiochemical hazards.