Obesity potentially protects against systemic bone loss in patients with rheumatoid arthritis treated with tumour necrosis factor inhibitors.

OBJECTIVES: We aimed to investigate how systemic bone metabolism was affected after 1 year of treatment with tumour necrosis factor (TNF) inhibitors in rheumatoid arthritis (RA) patients. METHODS: A total of 29 seropositive RA patients not treated for osteoporosis were enrolled and TNF inhibitors were administered for a year. Bone mineral density (BMD) at the lumbar spine, femur neck, and total hip was measured at baseline and 12 months after anti-TNF treatment. Blood samples were collected at baseline and 6 and 12 months after anti-TNF treatment and osteoclasts were cultured on bone slices. Weight was the strongest factor influencing systemic bone loss. Patients were categorised into two groups: obese (body mass index (BMI) ≥25 kg/m2) and non-obese (BMI <25 kg/m2). RESULTS: All patients showed decreased BMD at all sites. The obese group showed relatively little change in BMD, although the non-obese group showed significant decreases in BMD at all sites after 1 year of treatment with TNF inhibitors. Resorption pits created by osteoclasts decreased at 6 months and increased at 12 months in the non-obese group, while the obese group presented with steadily decreasing sizes of resorption pits at all-time points. Levels of receptor activator of nuclear factor kappa B ligand were significantly decreased at 12 months compared to baseline in the obese group, while they were increased in the non-obese group. CONCLUSIONS: One year of treatment with TNF inhibitors failed to halt systemic bone loss in RA patients, but obesity may have protective effects against bone loss.

Comparison of endoscopic papillary large balloon dilation with or without endoscopic sphincterotomy for the treatment of large bile duct stones.

BACKGROUND: Endoscopic papillary large balloon dilation (EPLBD) without prior endoscopic sphincterotomy (EST) produces excellent outcomes for the treatment of large common bile duct (CBD) stones. However, it remains unclear how the outcomes of EPLBD alone compare with those of EPLBD with EST. In this study, we assessed the safety and therapeutic outcomes of EPLBD with vs. without EST for the removal of large bile duct stones. METHODS: This prospective, multicenter study was conducted on 200 patients with bile duct stones of ≥ 10 mm in diameter. Patients were randomly assigned to an EPLBD alone group (n = 100) or an EPLBD with EST group (n = 100). These two groups were compared with respect to overall procedure-related adverse events, overall stone removal success rate, number of endoscopic sessions required for complete stone removal, need for mechanical lithotripsy, and total procedure time. RESULTS: The incidence of adverse events was not significantly different between the groups (EPLBD alone vs. EPLBD with EST: overall adverse events 6 % vs. 4 %, P = 0.75; pancreatitis 1 % vs. 3 %, P = 0.62). Overall success (P = 0.35), initial success (P = 0.28), and the need for mechanical lithotripsy (P = 0.39) were also similar between groups. Median total procedure time tended to be greater in the EPLBD alone group (20.5 minutes) than in the EPLBD with EST group (18 minutes; P = 0.08). CONCLUSION: The therapeutic outcomes and adverse events of EPLBD alone for the removal of large bile duct stones were comparable to those of EPLBD with EST.

Differences in suicidal behaviors between self-employed and standardly employed workers.

BACKGROUND: Although self-employed persons have greater autonomy, schedule flexibility, and control over their work than employees, they may be among the most vulnerable workers due to the lack of social benefits and protection from labor law and regulations. We compared suicidal behaviors between the self-employed and standardly employed workers. METHODS: This study used the 2008 Korean Community Health Survey data and included a total of 64 802 working population. Self-employed persons were classified into "small business self-employed persons" with zero to four employees and "middle to large business" with more than five employees. The outcomes were suicidal ideation and suicide attempts. RESULTS: Of the 64 802 participants, 40 422 were engaged in standard employment, and 24 380 were self-employed, with almost 90% (n = 21 970) being engaged in small businesses. Persons self-employed, compared with standard workers, were more likely to report suicidal ideation in both small (odds ratio [OR] = 1.25; 95% confidence interval [CI], 1.15-1.35) and middle to large businesses (OR = 1.32; 95% CI, 1.09-1.61). On the other hand, the likelihood for suicide attempt was only significant in persons self-employed in small businesses (OR = 1.67; 95% CI, 1.11-2.45). CONCLUSION: Self-employed persons were associated with greater odds of reporting suicidal behaviors than workers with standard employment. Among the self-employed, small business owners were particularly vulnerable to suicide attempts.

Determinants of Compliance of Travelers with Vaccination and Malaria Prophylaxis at a Travel Clinic.

BACKGROUND: Pre-travel medical consultation is essential to reduce health impairment during travel. Yellow fever vaccination (YFV) is mandatory to enter some endemic countries. In this study, we evaluated the factors that affect compliance with appropriate prevention of infectious diseases in travelers who visited clinic for YFV. METHODS: For this retrospective study, chart reviews for 658 patients who visited a travel clinic for YFV before travel were conducted. The period of this study was from January 2016 to September 2018. The associations between appropriate vaccination and factors such as travel duration, destination, time of visiting clinic before departure, and purpose of travel were analyzed. RESULTS: Among 658 patients who got YFV during the study period, 344 patients (52.3%) received additional vaccination or malaria prophylaxis following a physician's recommendation. Travelers who visited the clinic more than 21 days before departure were more compliant than those who visited 14 days or fewer before departure (odds ratio [OR], 1.90; 95% confidence interval [CI], 1.23-2.93; P = 0.004). Travelers visiting Africa were more compliant than were those traveling to South and Central America (OR, 1.97; 95% CI, 1.34-2.90; P = 0.001). Travelers in age groups of 40-49 years and over 70 years were less compliant than the 18-29 years old population (OR, 0.51; 95% CI, 0.28-0.93; P = 0.027 and OR, 0.19; 95% CI, 0.04-0.84; P = 0.03, respectively). Also, those who traveled for tour or to visit friends or relatives were more compliant than those who departed for business (OR, 0.77; 95% CI, 1.03-3.56; P = 0.04). CONCLUSION: For appropriate vaccination, pre-travel consultation at least 3 weeks before departure is crucial. Travelers should be aware of required vaccination and malaria prophylaxis before visiting South and Central America and Asia. Plans to enhance compliance of the elderly and business travelers should be contrived.

The effect of anti-TNF treatment on osteoblastogenesis in ankylosing spondylitis: the number of circulating osteoblast-lineage cells in peripheral blood decreased after infliximab therapy in patients with ankylosing spondylitis.

OBJECTIVES: The full effect of anti-TNF therapy on new bone formation is still in debate in spondylitis fields. We sought to obtain circulating osteoblast-lineage cells in peripheral blood from ankylosing spondylitis (AS) patients and healthy control subjects, and to evaluate the effect of before and after anti TNF-α therapy on osteoblastogenesis in patients with AS. METHODS: Sixteen male patients with AS slated for infliximab therapy and 19 controls were recruited. We cultured osteoblast-lineage cells from peripheral blood and measured the optical density of their Alizarin red S staining. We also measured serum P1NP (procollagen type 1 N-terminal propeptide) as an early osteoblast differentiation marker, osteocalcin as a late osteoblast differentiation marker, and inflammatory markers. RESULTS: There were significantly more circulating osteoblast-lineage cells in patients than in controls. The number of circulating osteoblast-lineage cells and optical density of Alizarin red S staining decreased 14 weeks after infliximab therapy (p=0.028); serum level of P1NP decreased, but that of osteocalcin increased (p=0.002 and 0.007, respectively). CONCLUSIONS: Our data reveals that first, the circulating osteoblast-lineage cells are recoverable and increased in AS patients, and also that they decrease after infliximab therapy; second, infliximab therapy resolves early inflammation, but allows mature osteoblast differentiation in late inflammation. The culture of osteoblast-lineage cells in peripheral blood may be a candidate for a new modality with which to study spondylitis and other autoimmune diseases.

Disparities in precarious workers' health care access in South Korea.

BACKGROUND: This study explored whether precarious workers have difficulties in health care access as compared with non-precarious workers. METHODS: The 2008 Korean Community Health Survey data were used for this study. Information was obtained on 51,322 participants (40,514 non-precarious workers and 10,808 precarious workers). Precarious workers were defined as part-time or contingent workers. RESULTS: Precarious workers had significantly higher risk of limited access to hospitals (OR = 1.14; 95% CI: 1.06-1.22) and dentists (OR = 1.28; 95% CI: 1.21-1.36) than non-precarious workers; disparities in doctor contacts among precarious workers were mostly linked to not having enough money. The risk of not receiving preventive care-medical checkups (OR = 0.52; 95% CI: 0.49-0.55) or cancer screenings (OR = 0.82; 95% CI: 0.77-0.86)-was also significantly elevated among precarious workers. CONCLUSION: We found that precarious workers had more difficulty accessing health care or receiving health checkups or cancer screenings than their non-precarious counterparts. Am. J. Ind. Med. 59:1136-1144, 2016. © 2016 Wiley Periodicals, Inc.

Precarious employment and the risk of suicidal ideation and suicide attempts.

OBJECTIVE: Although the effect of occupation or employment status on suicide risk is notable, there are few studies on the effect of precarious employment on suicide. We compared suicidal ideation and suicide attempts in precarious workers and their non-precarious counterparts using a representative sample from South Korea. METHOD: The 2008 Korean Community Health Survey data were used for this study. Information was obtained on 52,161 participants (41,063 employees with non-precarious work and 11,098 employees with precarious work). The outcome of the logistic regression model was the presence of suicidal thoughts and attempts, and the independent variables were the demographics, socioeconomic status, and health status. RESULTS: Employees with precarious work were more likely to exhibit suicidal ideation (OR=1.41; 95% CI, 1.28-1.55) and suicide attempts (OR=1.52; 95% CI, 1.02-2.27) than employees with non-precarious work. After controlling for income and education (Model 2) depressive feelings (Model 6), compared with unadjusted model, remained significant but the odds ratio was largely attenuated, indicating a strong association between suicidal risk and socioeconomic and feelings of depression. CONCLUSION: Precarious workers had a higher risk of suicidal ideation and suicide attempts than non-precarious workers. Our study suggests that precarious employment is an important risk for suicide.

Workplace injustice and self-reported disease and absenteeism in South Korea.

BACKGROUND: This study investigated whether experience of workplace injustice was associated with self-reported occupational health using a nationally representative sample of Korean workers. METHODS: We used the first wave of the Korean Working Conditions Survey (KWCS) and included 7,007 wage employees as the study population. Workplace injustice included the experience of discrimination, violence, or harassment, and occupational health was measured as self-reported health problems and absenteeism. Personal, occupational, and job-related characteristics were included as covariates. RESULTS: An average of 7.2% of workers reported experiencing at least one workplace injustice over the past 12 months. Female workers were significantly more likely to experience age and gender discrimination, and unwanted sexual attention than male workers. Both male and female workers who experienced any workplace injustice (i.e., discrimination, harassment, or violence) reported approximately two- to threefold increased risk for physical and mental health problems (i.e., backaches, muscular pain, stomach pain, overall fatigue, headaches, anxiety/depression, sleeping problems, and injury) and absenteeism due to accidents or due to health problems. CONCLUSION: Perceived injustice at work was significantly associated with an increased risk of occupational disease and absenteeism for Korean wage employees.

Digital thermography of the fingers and toes in Raynaud's phenomenon.

The aim of this study was to determine whether skin temperature measurement by digital thermography on hands and feet is useful for diagnosis of Raynaud's phenomenon (RP). Fifty-seven patients with RP (primary RP, n = 33; secondary RP, n = 24) and 146 healthy volunteers were recruited. After acclimation to room temperature for 30 min, thermal imaging of palmar aspect of hands and dorsal aspect of feet were taken. Temperature differences between palm (center) and the coolest finger and temperature differences between foot dorsum (center) and first toe significantly differed between patients and controls. The area under curve analysis showed that temperature difference of the coolest finger (cutoff value: 2.2℃) differentiated RP patients from controls (sensitivity/specificity: 67/60%, respectively). Temperature differences of first toe (cutoff value: 3.11℃) also discriminated RP patients (sensitivity/specificity: about 73/66%, respectively). A combination of thermographic assessment of the coolest finger and first toe was highly effective in men (sensitivity/specificity : about 88/60%, respectively) while thermographic assessment of first toe was solely sufficient for women (sensitivity/specificity: about 74/68%, respectively). Thermographic assessment of the coolest finger and first toe is useful for diagnosing RP. In women, thermography of first toe is highly recommended.

Association between Work-related Communication Devices Use during Work Outside of Regular Working Hours and Depressive Symptoms in Wage Workers.

Background: This study aimed to investigate the relationship between work-related communication devices use during work outside of regular working hours and depressive symptoms in wage workers. Methods: Data from 50,538 workers aged 15 years or older who had participated in the 6th Korean Working Condition Survey (KWCS) were used. The final sample was 32,994 wage workers. The questionnaire asked the respondents how often they used communication devices for work during work outside of regular working hours. Depressive symptoms were assessed using WHO-5 Well-Being Index. Multiple logistic regression analysis was used to analyze the association between work-related communication devices use during work outside of regular working hours and depressive symptoms. Results: The rate of depressive symptoms was highest among workers who did not use work-related communication devices during work outside of regular working hours. After adjusting for socio-demographic and work-related factors, the odds ratio of depressive symptoms among workers who used communication devices when working outside of regular working hours was 1.20 (95% CI: 1.09-1.32); the odds ratio of depressive symptoms in the group not using communication devices for free-time work was 1.66 (95% CI: 1.37-2.00), which was higher than that of the reference group, that is, workers who did not work outside of regular working hours, and was statistically significant. Conclusion: Regardless of whether work-related communication devices are used, working outside of regular working hours increases depressive symptoms. The use of work-related communication devices during work outside of regular working hours can reduce the rate of depressive symptoms.

Effect of job satisfaction on depression after adjusting for satisfaction with other life domains.

Background: Studies on the association between job satisfaction and depression have often been reported. However, no study has examined how job satisfaction impacts depression while considering satisfaction with other aspects of life. In this study, we evaluated the effect of job satisfaction on depression after adjusting for satisfaction with other domains of life. Methods: We used data from the 16th wave of the Korean Welfare Panel Study. A total of 3568 current employees without depression who completed a survey were included. Depression was measured using the abbreviated version of the CES-D scale. Various types of satisfaction, including job satisfaction, were measured using single-item questions and a 5-point Likert scale. The association between job satisfaction and depression after considering satisfaction with other life domains was analyzed using a multiple logistic regression model. Results: Crude models showed a significant association between job satisfaction and depression in males (odds ratio [OR]: 7.90; 95% confidence interval [CI]: 4.11-15.23) and females (OR: 7.12; 95% CI: 4.40-11.50). When adjusted for sociodemographic factors, health-related factors, and work-related factors, the association remained significant in males (OR: 6.20; 95% CI: 3.10-12.41) and females (OR: 6.28; 95% confidence interval (CI): 3.79-10.40). However, when satisfaction with other life domains was included, the association remained significant only in females (OR: 3.55; 95% CI: 1.93-6.50). Conclusions: This study shows an association between job satisfaction and depression in Korean employees. However, when satisfaction with other life domains was considered, this association remained significant only in women. Regular screening of job satisfaction should be considered as a means of preventing and managing depression among female employees.

Risk factors for long-term outcomes after initial treatment in hepatolithiasis.

Hepatobiliary complications, such as stone recurrence, recurrent cholangitis, liver abscess, secondary biliary cirrhosis, and cholangiocarcinoma may occur after treatment for hepatolithiasis. However, few previous studies have addressed the risk factors and long-term outcomes after initial treatment. Eighty-five patients with newly diagnosed hepatolithiasis, actively treated for hepatolithiasis, constituted the cohort of this retrospective study. Patients were treated by hepatectomy or nonoperative percutaneous transhepatic cholangioscopic lithotomy. Long-term complications, such as recurrent cholangitis, liver abscess, secondary biliary cirrhosis, and cholangiocarcinoma, and their relationships with clinical parameters were analyzed. The mean follow-up period was 57.4 months. The overall hepatobiliary complication rate after the treatment was 17.6%. Multivariate analysis of suspected risk factors showed that complications were associated with age (HR, 1.046; CI, 1.006-1.089), bile duct stricture (HR, 4.894; CI, 1.295-18.495), and residual stones (HR, 3.482; CI, 1.214-9.981). In conclusion, several long-term hepatobiliary complications occur after hepatolithiasis treatment, and regular observation is necessary in patients with concomitant biliary stricture or residual stones.

The relationship between working time mismatch and depression according to actual hours worked.

OBJECTIVES: The effect of the combination of working hours and working time mismatch on depression is unknown. This study was undertaken to confirm the relationship between working time mismatch and depression with respect to hours worked. MATERIAL AND METHODS: The data of 45 514 adult workers that participated in the 6th Korean Working Conditions Survey (KWCS-VI 2020) were reviewed. Depression was defined using the World Health Organization 5 Well-Being Index (WHO-5) cut-off score of 50. Working time mismatch was defined as a difference between actual and desired working hours. To identify associations between working hour mismatch and depression according to weekly hours worked, stratification analysis was conducted by dividing the study subjects into 3 groups based on actual hours worked weekly (<40 h, 40-<52 h, or ≥52 h). Multiple logistic regression analysis adjusted for potential confounders was performed to calculate odds ratios of depression. RESULTS: In the <40 h, 40-<52 h, and ≥52 h groups, the odds ratios (OR) of working more hours than desired were 1.51, 95% CI: 1.20-1.92 (<40 h), 1.70, 95% CI: 1.58-1.84 (40-<52 h), and 1.55, 95% CI: 1.41-1.69 (≥52 h), respectively, compared to a matched actual versus desired working hours group (the matched group). On the other hand, the odds ratios of working fewer hours than desired were 1.17, 95% CI: 1.07-1.27 (<40 h), 1.38, 95% CI: 1.20-1.60 (40-<52 h), and 1.98, 95% CI: 1.24-3.17 (≥52 h), respectively. The risk of depression was found to increase significantly with working time mismatch within all 3 working hour groups. CONCLUSIONS: Working time mismatch increases the risk of worker depression regardless of hours worked. Int J Occup Med Environ Health. 2023;36(6):788-97.

Occupational stress changes and new-onset depression among male Korean manufacturing workers.

Background: Studies on the association between occupational stress and depression have been frequently reported. However, the cross-sectional designs of studies limited insight into causal associations. In this study, we investigated the longitudinal association between occupational stress and new-onset depression among employees in a single manufacturing plant. Methods: The annual health checkup data of employees at a manufacturing plant in Korea were collected. A total of 1,837 male employees without depression who completed a health checkup during two consecutive years were included. Occupational stress was measured using a short form of the Korea Occupational Stress Scale (KOSS-SF), and depression was assessed using a Patient Health Questionnaire-2. The association between occupational stress change over the two years and newly developed depression was investigated using two logistic regression models. Results: Across all sub-factors of KOSS-SF, employees who reported increased occupational stress had a higher risk of new-onset depression. Newly developed depression was significantly associated with job demand (odds ratio [OR]: 4.34; 95% confidence interval [CI]: 2.37-7.96), job insecurity (OR: 3.21; 95% CI: 1.89-5.48), occupational climate (OR: 3.18; 95% CI: 1.91-5.31), lack of reward (OR: 2.28; 95% CI: 1.26-4.12), interpersonal conflict (OR: 2.14; 95% CI: 1.18-3.86), insufficient job control (OR: 1.93; 95% CI: 1.05-3.56), and the organizational system (OR: 1.84; 95% CI: 1.01-3.36). Conclusions: For every sub-factor of the KOSS-SF, occupational stress increase and persistent high stress were associated with the risk of developing new-onset depression. Among the seven sub-factors, job demand had the most significant effect. Our results show that occupational stress should be managed to promote employee mental healthcare.

The relationship between fatigue and sickness absence from work.

Background: Although many studies have been conducted on worker fatigue and sickness absence, the association between fatigue and sickness absence is unclear in Korean workers. This study was conducted to investigate the effect of worker fatigue on future sickness absence. Methods: The study was conducted on workers who received medical check-ups at a university hospital for two consecutive years (2014-2015). During check-ups in the first year, the Fatigue Severity Scale (FSS) was used to assess fatigue levels, and during check-ups in the second year, sickness absence was surveyed to determine whether they had been absent from work due to physical or mental illness during previous 12 months. The χ2 test was used to analyze relationships between sociodemographic and occupational characteristics, fatigue levels, and sickness absence. Odds ratios (ORs) were calculated by logistic regression analysis controlled for confounding factors. Results: A total of 12,250 workers were included in the study, and 396 (3.2%) workers experienced more than one day of sickness absence during the study period. Adjusted ORs for sickness absence were 3.35 (95% confidence interval [CI]: 2.64-4.28) in the moderate-fatigue group and 6.87 (95% CI: 4.93-9.57) in the high-fatigue group versus the low-fatigue group. For men in the moderate- and high-fatigue groups, adjusted ORs for sickness absence were 3.40 (95% CI: 2.58-4.48) and 8.94 (95% CI: 6.12-13.07), and for women in the moderate- and high-fatigue groups, adjusted ORs for sickness absence were 2.93 (95% CI: 1.68-5.10) and 3.71 (95% CI: 1.84-7.49), respectively. Conclusions: Worker fatigue is associated with sickness absence during the following 12 months, and this association appears to be stronger for men than women. These results support the notion that sickness absence can be reduced by evaluating and managing work-related fatigue.

Is endoscopic ultrasound needed as an add-on test for gallstone diseases without choledocholithiasis on multidetector computed tomography?

BACKGROUND: Choledocholithiasis commonly occurs in patients with symptomatic cholelithiasis. Although the recently developed multidetector computed tomography (MDCT) scan enhances the ability to diagnose choledocholithiasis, this technique is considered to have some limitations for evaluating the common bile duct (CBD). AIM: The purpose of this study was to evaluate the necessity for performing endoscopic ultrasound (EUS) as an add-on test to detect choledocholithiasis in patients who were diagnosed with gallstone disease without choledocholithiasis based on MDCT. METHODS: Three hundred twenty patients with gallstone disease and no evidence of CBD stones according to MDCT underwent EUS between March 2006 and April 2011. If CBD stones were suspected based on the EUS results or clinical symptoms, a final diagnosis was obtained by endoscopic retrograde cholangiopancreatography (ERCP). The patients' medical records were retrospectively analyzed based on clinical symptoms, biochemical findings, and results of the imaging studies. RESULTS: CBD stones were not detected with MDCT in 41 (12.8 %) out of 320 patients with gallstone disease. The causes for these discrepancies could be attributed to small stone size (n = 19, 46.3 %), isodensity (n = 18, 43.9 %), impacted stones (n = 1, 2.4 %), and misdiagnosis (n = 3, 7.3 %). If EUS were used as a triage tool, unnecessary diagnostic ERCP and its complications could be avoided for 245 (76.6 %) patients. CONCLUSIONS: MDCT may not be a primary technique for detecting CBD stones. EUS should be performed instead as an add-on test to evaluate the CBD for patients with gallstone-related disease. In particular, EUS should be routinely recommended for patients with abnormal liver enzyme levels, pancreatitis, and dilated CBD.

Dickkopf-1 level is lower in patients with ankylosing spondylitis than in healthy people and is not influenced by anti-tumor necrosis factor therapy.

(1) To compare the serum levels of Dickkopf-1 (DKK-1) and bone biomarkers in patients with ankylosing spondylitis (AS) and healthy controls. (2) To examine the effects of anti-tumor necrosis factor-α (TNF-α) therapy for 3 months on bone biomarkers in patients with AS. We measured the levels of DKK-1, osteocalcin, osteoprotegerin, and C-terminal telopeptide of type I collagen (CTX-1) in patients with AS and in healthy controls at baseline and 3 months after initiating anti-TNF-α therapy in AS patients. Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores were also measured before and after anti-TNF-α therapy in AS patients. Serum levels of DKK-1 were significantly lower in the AS patients than in the controls (P < 0.0001). Osteocalcin and osteoprotegerin levels were significantly higher in the AS patients than in the controls (P < 0.0001). Serum levels of DKK-1 were not changed after the 3-month anti-TNF-α therapy. Osteocalcin level increased (P < 0.0001), osteoprotegerin level and BASDAI scores decreased (P = 0.025 and P < 0.0001, respectively) significantly after the 3-months anti-TNF-α therapy. Serum DKK-1 level was lower in patients with AS than in healthy controls and did not change after 3 months of anti-TNF-α therapy in the AS patients despite the marked improvement in BASDAI scores. These findings suggest the low serum DKK-1 level is related to the pathogenesis of new bone formation in AS, which is resistant to TNF-α blocking therapy.

Estimation of maximal oxygen uptake without exercise testing in Korean healthy adult workers.

Maximal oxygen uptake is generally accepted as the most valid and reliable index of cardiorespiratory fitness and functional aerobic capacity. The exercise test for measuring maximal oxygen uptake is unsuitable for screening tests in public heath examinations, because of the potential risks of exercise exertion and time demands. We designed this study to determine whether work-related physical activity is a potential predictor of maximal oxygen uptake, and to develop a maximal oxygen uptake equation using a non-exercise regression model for the cardiorespiratory fitness test in Korean adult workers. Study subjects were adult workers of small-sized companies in Korea. Subjects with history of disease such as hypertension, diabetes, asthma and angina were excluded. In total, 217 adult subjects (113 men of 21-55 years old and 104 women of 20-64 years old) were included. Self-report questionnaire survey was conducted on study subjects, and maximal oxygen uptake of each subject was measured with the exercise test. The statistical analysis was carried out to develop an equation for estimating maximal oxygen uptake. The predictors for estimating maximal oxygen uptake included age, gender, body mass index, smoking, leisure-time physical activity and the factors representing work-related physical activity. The work-related physical activity was identified to be a predictor of maximal oxygen uptake. Moreover, the equation showed high validity according to the statistical analysis. The equation for estimating maximal oxygen uptake developed in the present study could be used as a screening test for assessing cardiorespiratory fitness in Korean adult workers.

Impacts of presenteeism on work-related injury absence and disease absence.

Background: Many studies have been conducted on presenteeism and absenteeism, but the relationship between presenteeism and absenteeism is unclear. This study was undertaken to investigate the effect of presenteeism on future absenteeism. Methods: This study was conducted on non-white collar workers that underwent general health examinations in 2014 and 2015. We asked subjects to fill out a questionnaire about their experiences of presenteeism for the past one year in 2014. In 2015, it was checked whether the same subjects had any experience of absence from work due to injury or disease during the past year. The χ2 test was used to analyze relationships between sociodemographic and occupational characteristics, presenteeism, and absence. Odds ratios (ORs) were calculated by logistic regression analysis controlled for confounding factors. Results: A total of 12,572 workers were included in the study. For workers who experienced presenteeism, the OR for injury absence was 2.705 (95% confidence interval [CI]: 2.044-3.581), and the OR for disease absence was 4.906 (95% CI: 3.996-6.024) after adjusting for sociodemographic and occupational confounding factors. For men that experienced presenteeism, the OR for injury absence was 3.035 (95% CI: 2.258-4.081), and the OR for disease absence was 5.508 (95% CI: 4.340-6.989). For women that experienced presenteeism, the OR for injury absence was 1.322 (95% CI: 0.577-3.028), which was not significant, and the OR for disease absence was 3.629 (95% CI: 2.405-5.475). Conclusions: This study suggests that presenteeism can influence future absenteeism. The effect of presenteeism may depend on cause of absence. Men who experienced presenteeism showed greater effects on injury and disease absence than women. For women, experience of presenteeism had a significant effect on disease absence but not on injury absence.

Employment Status Change and New-Onset Depressive Symptoms in Permanent Waged Workers.

BACKGROUND: This study aimed to investigate the relationship between changes in employment status and new-onset depressive symptoms through a one-year follow-up of permanent waged workers. METHODS: We analyzed the open-source data from the Korea Welfare Panel Study. Using the 2017 data, we selected 2,314 permanent waged workers aged 19 to 59 years without depressive symptoms as a base group. The final analysis targeted 2,073 workers who were followed up in 2018. In 2018, there were five categories of employment status for workers who were followed up: permanent, precarious, unemployed, self-employed, and economically inactive. Multiple logistic regression was used to determine the association between employment status change and new-onset depressive symptoms. RESULTS: Adjusted multiple logistic regression analysis showed that among male workers, workers who went from permanent status to being unemployed (odds ratio: 4.50, 95% confidence interval: 1.19 to 17.06) and from permanent status to being precarious workers (odds ratio: 3.15, 95% confidence interval: 1.30 to 7.65) had significantly high levels of new-onset depressive symptoms compared with those who retained their permanent employment status. There were no significant increases in new-onset depressive symptoms of male workers who went from permanent status to being self-employed or economically inactive. On the other hand, no significant differences were found among female workers. CONCLUSION: Our study suggests that the change of employment status to precarious workers or unemployment can cause new-onset depressive symptoms in male permanent waged workers.