The menstrual cycle associated with insomnia in newly employed nurses performing shift work: a 12-month follow-up study.

PURPOSE: This study aimed to investigate whether insomnia among newly-employed shift-working nurses is associated with menstrual cycle irregularity. METHODS: We followed 287 nurses employed between 2015 and 2016 for 12 months. An Insomnia Severity Index (ISI) was completed to determine levels of insomnia 6 months after beginning work. At baseline and at 12-month follow-up, menstrual cycle information was obtained using clinical interviews. We analyzed baseline data separately by prevalence (participants with menstrual irregularity, n = 287) and incidence (participants with no reported menstrual irregularity, n = 238). RESULTS: In a multivariate logistic regression analysis, including age, body mass index, and physical activity, insomnia was associated with a 2.05-fold increase in the odds of newly developing menstrual cycle irregularity compared with not having insomnia [odds ratio (OR) 2.05, 95% confidence interval (CI) 1.12-3.77]. Insomnia was associated with a 3.05-fold increase in the prevalence of menstrual cycle irregularity compared with not having insomnia (OR 3.05, 95% CI 1.81-5.13). As the ISI score increased, both the incidence and prevalence odds of menstrual cycle irregularity tended to increase. CONCLUSIONS: Insomnia can induce menstrual cycle irregularity among nurses working shifts, and insomnia may have an important role in the pathway from shift work to menstrual dysfunction, aside from the possible effects of circadian rhythm disruption.

Coronary artery atherosclerosis associated with shift work in chemical plant workers by using coronary CT angiography.

OBJECTIVES: The aim of this study was to investigate whether shift work is related to elevated risk of coronary artery disease (CAD) by determining the coronary artery calcium (CAC) score and the presence of coronary artery stenosis by using coronary artery CT angiography (CCTA). METHODS: In this study, 110 male workers participated and underwent a CCTA examination for CAC scoring, which represents coronary artery plaque, and were evaluated for luminal stenosis. All of the participants were working in the same chemical plant, of whom 70 worked day shifts and 40 worked rotating shifts. RESULTS: In a multivariate logistic regression analysis, including age, smoking status, alcohol consumption, regular exercise and waist circumference, shift work was associated with a 2.89-fold increase in the odds of developing coronary plaque compared with day work (OR, 2.89; 95% CI 1.07 to 7.82). The association between shift work and coronary plaque was strong after adjustment for age, low-density lipoprotein cholesterol, hypertension and diabetes mellitus (OR, 2.92; 95% CI 1.02 to 8.33). In addition, the number of years of shift work employment was associated with coronary plaque. However, no association was found between shift work and coronary artery stenosis. CONCLUSIONS: Shift work could induce CAD onset via the atherosclerotic process, and shift work employment duration was associated with an increased risk of atherosclerosis in male workers.

The association between serum dehydroepiandrosterone sulfate (DHEAS) levels and job-related stress among female nurses.

BACKGROUND: Dehydroepiandrosterone sulfate (DHEAS) is an endogenous steroid hormone produced by the adrenal gland. DHEAS has been suggested to play a protective role against psychosocial stress. The aim of this study was to investigate the association between job-related stress and blood concentrations of DHEAS according to occupational stress factors among female nurses. METHODS: A cross-sectional study was conducted among 118 premenopausal nurses from 4 departments (operating room, emergency room [ER], intensive care unit, and ward) of a university hospital. Participants were all rotating night shift workers who have worked for over a year and mean age of 33.5 ± 4.8 years. Data from structured questionnaires including the Korean Occupational Stress Score, Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), and Pittsburgh Sleep Quality Index (PSQI) were used. RESULTS: In the high job-related stressor group, scores of BDI, BAI, and PSQI were significantly higher than low-stressor group. ER nurses had relatively more work-burden related stressors, but they had significantly lower levels of anxiety and depression than other groups. And, ER nurses showed higher levels of DHEAS than the other department nurses. The differences were significant (p = 0.003). Additionally, there was a statistically significant difference even after adjusting for factors that could affect level of DHEAS, such as age, body mass index, drinking, and physical activity (p = 0.039). CONCLUSIONS: This result suggests the possibility that DHEAS may play a role as a marker of proper stress management. The capacity to secrete DHEAS is not simply due to workload or job stressor but could be determined depending on how individuals and groups deal with and resolve stress. Proper resolution of stress may affect positive hormone secretion.

Acute radiation syndrome in a non-destructive testing worker: a case report.

BACKGROUND: In Korea, there were repeated radiation exposure accidents among non-destructive testing workers. Most of the cases involved local injury, such as radiation burns or hematopoietic cancer. Herein, we report a case of acute radiation syndrome caused by short periods of high exposure to ionizing radiation. CASE PRESENTATION: In January 2017, Korea Information System on Occupational Exposure (KISOE) found that a 31-year-old man who had worked in a non-destructive testing company had been overexposed to radiation. The patient complained of symptoms of anorexia, general weakness, prostration, and mild dizziness for several days. He was anemic. The venous injection areas had bruises and bleeding tendency. Blood and bone marrow testing showed pancytopenia and the patient was diagnosed with acute radiation syndrome (white blood cells: 1400/cubic mm, hemoglobin: 7.1 g/dL, platelets: 14000/cubic mm). He was immediately prohibited from working and blood transfusion was commenced. The patient's radiation exposure dose was over 1.4 Gy (95% confidence limits: 1.1-1.6) in lymphocyte depletion kinetics. It was revealed that the patient had been performing non-destructive tests without radiation shielding when working in high places of the large pipe surface. CONCLUSIONS: Exposure prevention is clearly possible in radiation-exposed workers. Strict legal amendments to safety procedures are essential to prevent repeated radiation exposure accidents.

Mercury poisoning in a fisherman working on a pelagic fishing vessel due to excessive tuna consumption.

OBJECTIVE: To report the case of a fisherman who developed chronic mercury poisoning due to excessive consumption of tuna while working on a pelagic fishing vessel. CASE REPORT: A 48-year-old male deep-sea fisherman developed paresthesia and pain in both legs while working at sea. He continued working for over 4 months on a pelagic fishing vessel but was eventually unable to function normally as his condition deteriorated. Upon arrival on land, he received specialist treatment, including imaging studies, for 2 months; however, the cause of the symptoms was not identified. An examination of his occupational history revealed that he had worked as a crew member on a pelagic fishing vessel catching tuna for the last 2 years and consumed tuna for two or more meals per day, every day. Two months after discontinuation of tuna consumption, he was tested for mercury. The result showed an elevated blood mercury level (BML) of 21.79 µg/l. Based on the half-life of mercury, the BML was evaluated as 38.70-53.20 µg/l when he was on board. Four months after discontinuing tuna consumption, his BML decreased to 14.18 µg/l, and the symptoms were almost ameliorated. The person responsible for preparing meals on a pelagic fishing ship should be aware that fish may contain high levels of heavy metals and should prepare meals for crew members according to the recommended levels. Crew members should also be aware that fish and shellfish may contain mercury, and hence, they should consume only an appropriate amount.

Insomnia and hearing impairment among occupational noise exposed male workers.

BACKGROUND: The aim of this study was to investigate the association between insomnia and hearing impairment among workers exposed to occupational noise. METHODS: This study included 809 male workers exposed to occupational noise. The participants underwent audiometric testing, and their insomnia was examined based on the Insomnia Severity Index test. Hearing impairment was defined as hearing threshold >25 dB hearing level in the range of 1-4 kHz. RESULTS: According to analysis of covariance, it was observed that pure tone audiometry thresholds at 1-2 kHz in the right ear and at 1 kHz in the left ear were significantly higher among workers with insomnia compared to those with no insomnia. Multiple logistic regression analysis of insomnia for hearing impairments was performed, which showed the odds ratio was 1.806 (95% confidence intervals: 1.022-3.188, p = 0.042) after adjustment for age, working period, noise level, snoring, use of protection devices, diabetes mellitus, hypertension, smoking, alcohol consumption, regular exercise, waist circumference, total cholesterol, triglyceride and high density lipoprotein cholesterol. CONCLUSION: Insomnia could be associated with hearing impairment in workers who are exposed to occupational noise. Additionally, insomnia may be associated with decreased hearing at low frequencies. Especially, more efforts are required to improve the quality of sleep for workers who are exposed to loud occupational noise. Further well- designed prospective studies are needed to clarify the relationship between insomnia and hearing impairment.

Comparison of anxiety and depression status between office and manufacturing job employees in a large manufacturing company: a cross sectional study.

BACKGROUND: The aim of this study was to investigate whether type of work is associated with anxiety and depression using the Hospital Anxiety and Depression Scale (HADS). Additionally, we investigated the impact of number of working hours on anxiety and depression. METHODS: A total of 1774 workers participated and completed the HADS to determine their levels of anxiety and depression. All subjects were employed at one of two manufacturing plants for the same company. Of all participants, 222 were employed in office jobs and 1552 in manufacturing jobs. RESULTS: Results of multivariate logistic regression analysis including age, sex, body mass index, smoking status, alcohol consumption, regular exercise, factory region, and working hours, indicated that employment in an office job was associated with a 2.17-fold increase in the odds of anxiety compared to a manufacturing job (odds ratio [OR] = 2.17; 95 % confidence interval [CI], 1.24-3.80). Office jobs were also associated with a 1.94-fold increase in the odds of depression (OR = 1.94; 95 % CI, 1.34-2.82). In addition, number of hours worked was significantly associated with depression, and working hours significantly modified the effect of office job employment on the risk of depression. CONCLUSIONS: Office job workers had higher levels of anxiety and depression than those working in manufacturing jobs. Our findings suggest that occupational physicians should consider the organizational risks faced by office job employees, and consider the differences in psychological health between office and manufacturing job workers when implementing interventions.

Case series of keratitis in poultry abattoir workers induced by exposure to the ultraviolet disinfection lamp.

BACKGROUND: An outbreak of eye diseases occurred among workers at a poultry abattoir in South Korea from December 2012 to June 2013. An epidemiological investigation of the causative agent was conducted. The workers were given a special health examination and workplace environmental monitoring was performed. Workers with ocular symptoms subsequently underwent an ophthalmic examination. CASE PRESENTAION: From a total of 41 workers, 26 (63.4 %) were diagnosed with keratoepitheliopathy by ophthalmic examination. Environmental monitoring of the workplace revealed that the ultraviolet (UV) apron-disinfection lamp had not been turning off at the set times, and so the workers' faces had been exposed to UV radiation. Effective radiation dose measurement showed a UV-B exposure of 7-30 µW/cm(2), and a UV-C exposure of 40-200 µW/cm(2); both values exceed the occupational exposure limits. The outbreak ceased after the lamp was repaired. CONCLUSIONS: This case shows that inappropriate use of the UV disinfection lamp can cause mass photokeratitis. In order to prevent this, the UV disinfection lamp must be checked regularly, workers must be educated on the health effects of UV radiation, and appropriate eye protection must be worn.

Serum prostate-specific antigen levels and type of work in tire manufacturing workers.

OBJECTIVES: This study measures serum prostate-specific antigen (PSA) levels in tire-manufacturing workers, and attempts to find occupational or non-occupational factors that related to their PSA levels. METHODS: A total of 1,958 healthy male workers (1,699 were production workers and 259 were office workers) took PSA measurement for analysis. RESULTS: After adjusting for age, body mass index, hypertension, regular exercise, alcohol drinking and smoking, which were significantly related to serum PSA levels or known related factors of serum PSA levels, the geometric mean PSA levels were significantly high in the office workers (p = 0.017), the older age group (p < 0.001), the group with hypertension (p = 0.046) and the group of individuals that do not exercise regularly (p = 0.015) and the office workers were more likely to have a serum PSA level of ≥4.0 (OR 7.73, 95% CI: 2.78-21.46) or 2.5 ng/mL (OR 2.74, 95% CI: 1.49-5.08). After stratifying by age and adjusting aforementioned covariates, office workers 50 years of age and older had the significantly higher geometric mean PSA levels (p = 0.017) and were more likely to have a serum PSA level of ≥4.0 ng/mL (OR 12.90, 95% CI: 3.65-45.64) or 2.5 ng/mL (OR 3.90, 95% CI: 1.64-9.25) than production workers 50 years of age and older. CONCLUSIONS: This study showed that serum PSA levels were significantly higher among the group with hypertension or the group of individuals that did not exercise regularly or group of office workers who were considered to have lesser physical activities.