This study aimed to investigate the effect of facing complaining customer and suppressed emotion at worksite on sleep disturbance among working population. We enrolled 13,066 paid workers (male = 6,839, female = 6,227, age < 65 years) in the 3rd Korean Working Condition Survey (2011). The odds ratio (OR) and 95% confidence intervals (CI) for sleep disturbance occurrence were calculated using multiple logistic regression models. Among workers in working environments where they always engage complaining customers had a significantly higher risk for sleep disturbance than rarely group (The OR [95% CI]; 5.46 [3.43–8.68] in male, 5.59 [3.30–9.46] in female workers). The OR (95% CI) for sleep disturbance was 1.78 (1.16–2.73) and 1.63 (1.02–2.63), for the male and female groups always suppressing their emotions at the workplace compared with those rarely group. Compared to those who both rarely engaged complaining customers and rarely suppressed their emotions at work, the OR (CI) for sleep disturbance was 9.66 (4.34–20.80) and 10.17 (4.46–22.07), for men and women always exposed to both factors. Sleep disturbance was affected by interactions of both emotional demands (engaging complaining customers and suppressing emotions at the workplace). The level of emotional demand, including engaging complaining customers and suppressing emotions at the workplace is significantly associated with sleep disturbance among Korean working population.
Dyssomnias ; Female ; Humans ; Korea* ; Logistic Models ; Male ; Occupational Exposure ; Odds Ratio ; Sleep Wake Disorders ; Workplace*

BACKGROUND: There is a lack of statistical analysis investigating the relationship between sleep problems and commute time in Korea. We aimed to analyze the association between representative health symptoms, sleep disturbances, and commute time according to working hours in Korea.METHODS: The 4th Korean Working Conditions Survey data were used for analysis, and unpaid family workers and workers who work fewer than three days in a week were excluded. Commute time, working hours, and sleep hours were assessed using self-reported questionnaires. Odds ratios (ORs) with 95% confidence intervals (CIs) for sleep problems were calculated using a multivariate logistic regression model with ≤10 min commute time as the reference group.RESULTS: Among a total of 28,804 workers (men = 14,945, women = 13,859), 2.6% of men and 3.2% of women experienced sleep problems. In both sexes, long commute time (51–60 minutes and >60 minutes) showed an increased OR [men, 2.03 (CI = 1.32–3.13) and 2.05 (CI = 1.33–3.17); women, 1.58 (CI = 1.05–2.39) and 1.63 (CI = 1.06–2.50), respectively]. In stratification analysis of working hours, long commute time (51–60 and > 60 minutes) showed an increased OR in men working >40 hours/week [2.08 (CI = 1.16–3.71) and 1.92 (CI = 1.08–3.41), respectively]. Furthermore, long commute time (41–50, 51–60, and >60 minutes) showed an increased OR in women working >40 hours/week [2.40 (CI = 1.27–4.55), 2.28 (CI = 1.25–4.16), and 2.19 (CI = 1.17–4.16), respectively]. Moreover, commute time >60 minutes showed an increased OR in women working ≤40 hours/week [1.96 (CI = 1.06–3.62)].CONCLUSION: This large cross-sectional study highlights that long commute time is related to sleep problems in both sexes. Shorter commute times and decreased working hours are needed to prevent sleep problems in workers.
Cross-Sectional Studies ; Female ; Humans ; Korea ; Logistic Models ; Male ; Odds Ratio

BACKGROUND: Health officers are an integral part of the occupational health service, and there have been studies to identify and improve the role of health officers in the workplace in order to improve the level of health care in the workplace. This study aimed to determine the contribution of health officers to the role of a health officer as prescribed by law and the percentage of health management work performed during work according to their qualifications. METHODS: Questionnaires were distributed to a total of 4584 workplaces where health officers were hired, and a total of 806 copies (17.58%) were returned. Of these, 336 questionnaires were finally analyzed, after excluding questionnaires missing the main variables. Using the data, the difference of role contributions and the percentage of health care work performed during the whole day according to the qualification of the health officer was analyzed. RESULTS: Nurses were highly rated in the field of medical care, and industrial hygienists and air environmental engineers were highly rated in terms of chemicals and risk factor management. The percentage of health care work performed during the whole day differed according to the size of the workplace and industrial classification, but it was generally the lowest among air environmental engineers. CONCLUSIONS: Health officers play a very different role in the workplace depending on their qualification, and they need support for areas of other qualification. In order to effectively manage the health of the staff at a workplace, it is necessary to consider the development of a support system for small- and medium-sized enterprises and adjust the conditions of employment of the health officer according to the law.
Classification ; Delivery of Health Care ; Employment ; Health Status ; Jurisprudence ; Occupational Health Services ; Risk Factors

BACKGROUND: The balance between self- and social identity on job value of Korean dance artists, considered as performing artists, was measured to investigate the relationship between balance and depressive symptoms. METHODS: Data of 139 dance artists were analyzed for depressive symptoms assessed by their responses to questionnaires from the Center for Epidemiologic Studies Depression (CESD) translated into Korean. The balance score of each aspect of social identity compared to that of self-identity on job value was measured and classified as lower, equal, or higher. Following a graphical approach, we performed locally weighted scatterplot smoothing algorithm, simple linear regression, and quadric equation regression. RESULTS: The mean of CESD was highest in the higher balance group and lowest in the lower balance group. There was a linear relationship between balance score and CESD regarding specific audience, unspecified audience, and unspecified public. Balance score showed no association with other aspects of social identity. In the balance score range of 1 or higher, it was associated with CESD with respect to artist colleague, unspecified audience, and unspecified public. CONCLUSIONS: Dance artists should maintain a balance between self- and social identity in job value to prevent depressive symptoms.
Dancing ; Depression ; Epidemiologic Studies ; Korea ; Linear Models ; Social Identification

PURPOSE: The prevalence of allergic diseases is known to be associated with both demographic and environmental factors. Herein, we aimed to determine significant factors associated with the prevalence of allergic diseases and with total immunoglobulin E (tIgE) and specific immunoglobulin E (sIgE) levels in Korea. METHODS: We analyzed unweighted data collected by the 2010 Korea National Health and Nutrition Examination Survey for 2,342 subjects who underwent serum tests for tIgE and sIgE to Dermatophagoides farinae, dog, and Blattella germanica, representing a sample of 16,003,645 citizens, by considering the sample weight and stratification. RESULTS: The overall prevalence of self-reported allergic diseases was 37.6%. The prevalence rates of allergic rhinitis and atopic dermatitis decreased with age, whereas the asthma prevalence was not affected by the age of the subjects. When analyzed according to the type of allergic diseases, the prevalence of self-reported allergic disease was significantly associated with various factors (e.g. age, occupation, living in urban areas, and depression). The tIgE level decreased with age, but later increased. Elevation of tIgE was significantly associated with male sex, type of occupation, obesity, and smoking status. However, the risk factors for the increased sIgE levels to each allergen were quite different. Sensitization to D. farinae was more likely in young subjects, whereas the prevalence of sensitization to B. germanica was significantly higher in subjects with male sex, residing in a house (houses), and with glucose intolerance. Finally, young age and the smoking status were significantly associated with sensitization to dog. CONCLUSIONS: Various demographic and environmental factors were significantly associated with the prevalence of self-reported allergic diseases and the levels of tIgE and sIgE to D. farinae, B. germanica, and dog in Korea.
Animals ; Asthma ; Demography ; Dermatitis, Atopic ; Dermatophagoides farinae ; Dogs ; Glucose Intolerance ; Humans ; Hypersensitivity ; Immunoglobulin E* ; Immunoglobulins ; Korea ; Male ; Nutrition Surveys ; Obesity ; Occupations ; Prevalence* ; Rhinitis, Allergic ; Risk Factors ; Smoke ; Smoking

BACKGROUND: Dipeptidyl peptidase-4 (DPP-4) inhibitor add-on therapy is a new option for patients with inadequately controlled type 2 diabetes who are taking combined metformin and sulfonylurea (SU). We evaluated the efficacy and safety of this triple therapy and the characteristics of rapid responders and hypoglycemia-prone patients. METHODS: We included 807 patients with type 2 diabetes who were prescribed a newly added DPP-4 inhibitor to ongoing metformin and SU in 2009 to 2011. Glycemia and other metabolic parameters at baseline, 12, 24, and 52 weeks, as well as episodes of hypoglycemia were analyzed. Rapid responders were defined as patients with > or =25% reduction in glycosylated hemoglobin (HbA1c) within 12 weeks. RESULTS: At baseline, while on the submaximal metformin and SU combination, the mean HbA1c level was 8.4%. Twelve weeks after initiation of DPP-4 inhibitor add-on, 269 patients (34.4%) achieved an HbA1c level < or =7%. Sixty-six patients (8.2%, 47 men) were rapid responders. The duration of diabetes was shorter in rapid responders, and their baseline fasting plasma glucose (FPG), HbA1c, C-peptide, and homeostasis model assessment of insulin resistance were significantly higher. Patients who experienced hypoglycemia after taking DPP-4 inhibitor add-on were more likely to be female, to have a lower body weight and lower triglyceride and FPG levels, and to have higher homeostasis model assessment of beta-cells. CONCLUSION: An oral hypoglycemic triple agent combination including a DPP-4 inhibitor was effective in patients with uncontrolled diabetes. Proactive dose reduction of SU should be considered when a DPP-4 inhibitor is added for rapid responders and hypoglycemia-prone patients.
Blood Glucose ; Body Weight ; C-Peptide ; Diabetes Mellitus, Type 2 ; Dipeptidyl-Peptidase IV Inhibitors ; Fasting ; Female ; Hemoglobin A, Glycosylated ; Homeostasis ; Humans ; Hypoglycemia ; Insulin Resistance ; Metformin* ; Sulfonylurea Compounds ; Triglycerides

PURPOSE: Endocrine-disrupting chemicals interfere with the endocrine system and therefore affect growth and pubertal progression. The study aim was to compare the growth and pubertal progression in wild-type female rats with different bedding types. METHODS: Twenty 5-week-old female wild-type Sprague Dawley rats were randomly assigned to two groups with different bedding types: one group received wood shaving bedding, while a second group received corncob bedding. We determined crown-rump length and body weight as anthropometric measurements and assessed the serum growth hormone (GH) and estradiol levels. The gh1 mRNA expression levels were compared using quantitative real time transcription polymerase chain reaction. The estrous cycle was evaluated by vaginal smear. RESULTS: The anthropometric measurements were not significantly different between the two groups. The mean relative expression of the gh1 gene was lower in the corncob bedding group than that in the wood shaving group (P=0.768). Meanwhile serum GH and estradiol were increased in the wood shaving bedding group; however this difference was not statistically significant. The time to first estrus and the length of the estrous cycle were increased in the corncob bedding group; the proportion of normal estrous cycles was also decreased. These findings indicate irregularities in the estrous cycle. CONCLUSION: Endocrine-disrupting chemicals in corncob bedding might be associated with time to first estrus and length of the estrous cycle. Therefore, the type of bedding should be considered as a factor affecting pubertal progression in rodents.
Adolescent ; Animals ; Bedding and Linens ; Body Weight ; Crown-Rump Length ; Endocrine Disruptors ; Endocrine System ; Estradiol ; Estrous Cycle ; Estrus ; Female ; Growth Hormone ; Humans ; Polymerase Chain Reaction ; Puberty ; Rats* ; Rats, Sprague-Dawley ; RNA, Messenger ; Rodentia ; Vaginal Smears ; Wood

BACKGROUND: We aim to discuss the overall effect of customer service manual (CSM) on service industry workers using Korean Working Condition Survey. METHODS: Out of 50,007 total survey participants, 11,946 customer service workers were included in the current study (5613 men, 6333 women). Answers to survey questions were used to define the use of CSM, emotional burden, emotional dissonance, engaging angry customers and other covariates. Emotional burden included either depressive event or stress level. Odds ratio (OR) with 95% confidence interval (95% CI) of experiencing emotional burden was calculated by logistic regression model. Interaction effect between CSM and engaging angry customer on emotional burden was also estimated. RESULTS: Out of 11,946 subjects, total of 3279 (27.4%) have experienced emotional burden. OR (95% CI) of experiencing emotional burden was 1.40 (1.19–1.64) in men and 1.25 (1.09–1.44) in women. There was gender difference in interaction effect between the use of CSM and engaging angry customers. In men, OR (95% CI) was 3.16 (1.38–7.23) with additive effect when always engaging angry customers with CSM compared to rarely engaging without CSM, while in women OR (95% CI) was 8.85 (3.96–19.75) with synergistic effect. Moreover, the risk of depressive event increased only in women with OR (95% CI) 2.22 (1.42–3.48). CONCLUSIONS: Our current study highlighted association between emotional burden and CSM in both men and women service workers. Furthermore, women were affected more severely by CSM. The results from current study suggest that CSM should be changed appropriately to benefit workers.
Female ; Humans ; Logistic Models ; Male ; Mental Health ; Odds Ratio

PURPOSE: Allergic diseases are triggered by Th2-mediated immune reactions to allergens and orchestrated by various immunological factors, including immune cells and cytokines. Although many reports have suggested that childhood is the critical period in the onset of allergic diseases and aging leads to alter the susceptibility of an individual to allergic diseases, age-related changes in various immunological factors in healthy individuals as well as their difference between healthy and allergic children have not yet been established. METHODS: We investigated the ratio of Th1/Th2 cells and the levels of 22 allergy-related cytokines across all age groups in individuals who were classified as clinically non-atopic and healthy. We also examined their differences between healthy and allergic children to evaluate immunological changes induced by the development of allergic diseases during childhood. RESULTS: The Th1/Th2 ratio rose gradually during the growth period including childhood, reaching peak values in the twenties-thirties age group. Th1/Th2 ratios were significantly lower in allergic children than in healthy controls, whereas 14 of 22 cytokines were significantly higher in allergic children than in healthy controls. On the other hand, there were no differences in Th1/Th2 ratios and cytokines between healthy and allergic adolescents. CONCLUSIONS: In this study, age-related changes in Th1/Th2 ratios were found in normal controls across all age groups, and decreases in Th1/Th2 ratio were observed with increasing of 14 cytokines in allergic children. The results of this study may be helpful as reference values for both monitoring immunological changes according to aging in healthy individuals and distinguishing between normal and allergic subjects in terms of immune cells and soluble factors.
Adolescent ; Aging ; Allergens ; Child ; Critical Period (Psychology) ; Cytokines ; Hand ; Humans ; Hypersensitivity ; Immunologic Factors* ; Reference Values

We evaluated the malignancy and nondiagnostic rates using fine needle aspiration cytology (FNAC) results in thyroid nodules smaller than 1 cm according to the subdivided size. We retrospectively reviewed the medical records of all subjects underwent FNAC from 2003 to 2009 in our hospital, and 2,756 patients of subcentimeter thyroid nodules with one or more suspicious sonographic features and 7,105 with nodule sized 1 cm or more were included. The malignancy rate was higher in those subcentimeter nodules with suspicious sonographic findings than the nodule sized 1cm or more (19.7% vs 7.8%, P < 0.001). We grouped the nodules based on size with mm interval and observed that the malignancy rate did not decrease but the nondiagnostic results increased its size decrement. When we divided the subjects arbitrarily into a 5 mm or smaller and a 6-9 mm sized group, nondiagnostic cytology findings were reported more frequently in the smaller group (24.3% vs 18.1%, P = 0.001), while the rate of "malignant" was similar (18.3% vs 15.5%, P = 0.123) and the rate of "suspicious for malignancy" was higher (6.8% vs 2.9%, P < 0.001). Therefore when we decide to perform FNAC or not in subcentimeter-sized nodules, we should consider sonographic findings and other clinical risk factors but not the nodular size itself.
Adult ; Biopsy, Fine-Needle ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Risk Factors ; Thyroid Gland/pathology/ultrasonography ; Thyroid Neoplasms/diagnosis/*pathology/*ultrasonography ; Thyroid Nodule/diagnosis/*pathology/*ultrasonography