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Relationship between job stress and impaired fasting glucose in male steel industry workers: a cross-sectional study
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Original Article Relationship between job stress and impaired fasting glucose in male steel industry workers: a cross-sectional study
Hyun-Kyo Leeorcid, Inho Leeorcid, Jisuk Yunorcid, Yong-Jin Leeorcid, Eun-Chul Jangorcid, Young-Sun Minorcid, Soon-Chan Kwonorcid
Annals of Occupational and Environmental Medicine 2023;35:e12.
DOI: https://doi.org/10.35371/aoem.2023.35.e12
Published online: June 2, 2023

Department of Occupational and Environmental Medicine, Soonchunhyang University Cheonan Hospital, Cheonan, Korea.

Correspondence: Soon-Chan Kwon. Department of Occupational and Environmental Medicine, Soonchunhyang University Cheonan Hospital, 31 Suncheonhyang 6-gil, Dongnam-gu, Cheonan 31151, Korea. 91ksc@hanmail.net
• Received: February 8, 2023   • Revised: April 10, 2023   • Accepted: May 8, 2023

Copyright © 2023 Korean Society of Occupational & Environmental Medicine

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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  • Background
    The purpose of this study is to investigate the relationship between job stress and impaired fasting glycemia (IFG) of male workers in a manufacturing industry.
  • Methods
    Data were collected from 5,886 male workers in a manufacturing industry who participated in the medical examination from June 19 to August 14, 2020 through self-reported questionnaires. The general characteristics of the subjects, shift work, high blood pressure, dyslipidemia, and job stress were included. Job stress was measured using the Korean Occupational Stress Scale (KOSS) consisting of 8 items and 43 questions. Multivariable logistic regression analysis was used to investigate the IFG association with job stress.
  • Results
    Among the various factors that can cause job stress, only high job demand was associated with a risk of IFG (odds ratio, 1.43; 95% confidence interval, 1.13–1.82) especially in non-shift worker. For all other factors, no statistically significant results were obtained.
  • Conclusions
    In this study of male workers engaged in the Korean steel manufacturing industry, the 'job demand' item among job stress of non-shift worker was related to IFG.
Type 2 diabetes (T2DM), one of the most common chronic diseases, is a major public health problem in both developed and developing countries. Its incidence continues to increase.1,2 Epidemiological evidence has suggested that its incidence will continue to rise without effective prevention programs.3 Risk factors for T2DM include lifestyle factors such as obesity, low physical activity, and smoking in addition to aging. High blood pressure and low-density lipoprotein cholesterol rise are also widely known as risk factors for T2DM.4,5,6
Impaired fasting glycemia (IFG), a fasting blood glucose disorder and an intermediate condition between normal glucose metabolism homeostasis and diabetes, is thought to be a precursor to diabetes, although progression to an obvious disease is not certain.7 However, early detection of IFG might be important in that it is used as a risk indicator for future T2DM and cardiovascular disease (CVD).8
In addition to these risk factors, job stress is also emerging as a risk factor for T2DM.9 According to a demand-control model proposed by Karasek, job stress occurrence can be explained using two concepts: job control and job demand.10 Job control is a concept that measures workers' authority to exercise decision authority in the work process. Job demand is a concept to evaluate mental job needs. It is closely related to the overall production level of the workplace, that is, labor quantity and labor intensity.11 According to this model, job stress increases when workers are exposed to high job demands for a long time in a structure with a low job control.12
In people at risk of job-related stress, the imbalance in glucose metabolism can progress slowly over a long period of time.13 Recent studies have shown that high levels of stress in daily life, especially latent stress conditions such as exhaustion, are associated with T2DM.14,15 In addition, unfavorable conditions in the social environment, such as socioeconomic status and stressful working environment, are attracting attention as risk factors for T2DM.9,16
Although there are many physiological mechanisms by which job stress can impair glucose metabolism, it is commonly explained through autonomic nerves and hypothalamic pituitary adrenal axis (HPA-Axis).17 Constant exposure to stress can cause hyperstimulation of sympathetic nerves and the HPA-Axis.18 Abnormalities in the HPA-Axis due to hyperactivity of sympathetic nerves can cause CVD and cancer through various mechanisms such as increased cortisol in the blood, increased norepinephrine, and increased pulse rate.19,20,21 In addition, they affect the endocrine system, increasing insulin resistance and causing abnormal glucose metabolism.22 The sensory and endocrine systems operate around the autonomic nervous system, and stress affects these systems, resulting in complex reactions related to metabolism.23 As job demand increases, stress hormones such as cortisol and norepinephrine increase.24 These hormones reduce insulin secretion and promote glucose production and secretion, and these reactions can cause hyperglycemia or IFG.23,24
However, unlike known physiological mechanisms, research results on the association between T2DM and job stress are inconsistent. One study has found that among subjects classified by the Job Content Questionnaire (JCQ), those with high job stress are about 16% more likely to develop diabetes than those with low job stress.25 On the contrary, a meta-analysis conducted by Cosgrove et al.26 in 2012 showed that high psychological stress was not directly related to an increased risk of T2DM, showing inconsistent patterns. In a North American study of female nurses aged 29 to 46 years, job burden was not associated with the risk of T2DM,27 although other studies on female workers reported a link between job stress at work and T2DM.28
As such, there have been many studies on the relationship between T2DM and job stress.25,26,29 However, studies on the relationship between IFG, a pre-diabetes stage, and job stress have not been reported yet. In addition, no research has been conducted on such relationship using large-scale workplaces with more than 5,000 employees. Thus, the aim of this study was to determine the relationship between job stress and IFG in a single steel manufacturing workplace, focusing on the relationship between IFG and each item of KOSS. By examining the relationship between job stress and IFG, especially among “male” workers in Korea who have not been previously studied, we would like to provide insight to the relationship between job stress and IFG.
Study participants
This was a cross-sectional study. Participants aged 20 to 62 years were recruited based on regular annual worker checkups agreed by workers at a steel mill in Dangjin, Chungcheongnam-do, Rebublic of Korea. Medical checkups were conducted at a university hospital in Cheonan, Chungcheongnam-do, Korea. The examination has been conducted from June 29, 2020 to August 14, 2020. During this period, a total of 6,350 people were examined. A total of 111 women were excluded due to small sample size for gender-specific analysis. In addition, 353 patients with existing diabetes and those with a fast glucose level of 126 mg/dL or higher were excluded. Finally, a total of 5,886 male patients were analyzed.
Measurement

General and occupational characteristics

A structured questionnaire was used to collect information on age, body mass index (BMI), exercise, smoking, alcohol consumption, shift work history, and chronic diseases diagnosed by medical doctors (e.g., hypertension, dyslipidemia). In other words, information on general characteristics and occupational characteristics of subjects were obtained through specific questions presented in the special examination and shift work questionnaire.30,31 The age group was classified based on the age of 40, considering the increased risk of diabetes, metabolic disease, and metabolic syndrome factors with age and the significant difference in the distribution of IFG around the 30s and 40s in the study results. BMI was classified as “more than 25 kg/m2” and “less than 25 kg/m2”.32 Alcohol intake was classified as “people who do not drink,” “those who drink one to two times a week,” and “those who drink more than three times a week.” Smoking was classified as “current smokers,” “past smokers,” and “non-smokers.” Exercise was classified as “those who perform no exercise,” “those who exercise one to two times a week,” and “those who exercise more than three times a week.” Shift work was classified into “those who have work shifts” and “those who do not have work shifts”.33 Tenure was classified as ‘less than 5 years,’ ‘more than 5 years and less than 10 years,’ ‘more than 10 years and less than 15 years,’ and ‘more than 15 years.’ Hypertension was defined as systolic blood pressure of 140 mmHg or higher, diastolic blood pressure of 90 mmHg or higher, or taking high blood pressure drugs according to guidelines of the Korea Hypertension Association in 2018.34 Dyslipidemia was defined as total cholesterol of 240 mg/dL or more, a neutral fat of 200 mg/dL or more, a high-density cholesterol of 40 mg/dL or a low-density cholesterol of 160 mg/dL or more, or taking a dyslipidemia drug.35

Assessment of job stress

The Korean Occupaiotnal Stress Scale (KOSS) was developed in consideration of characteristics of Korean workers to evaluate job stress.36 KOSS was evaluated for validity and reliability based on 30,146 workers at workplaces nationwide. In a study that evaluated the reliability and validity of KOSS, KOSS showed a high correlation with the mental fatigue scale, the short form of psychosocial well-being index, and the job content questionnaire.37 KOSS consists of eight subscales and a total of 43 questionnaires, specifically consisting of physical environment, job demand, insufficient job control, interpersonal conflict, job insecurity, organizational system, lack of reward, and occupational climate. Each item uses a 4-point Likert scale. Total job stress score and lower category score of KOSS were converted to a 100-point system. Subjects were classified into a high-risk group if their KOSS scores were higher than top 25% Korean worker score (75% percentile) based on the KOSS reference value. They were classified into a low-risk group if their KOSS scores were less than top 25%.32

Impaired fasting glucose levels

Fasting blood samples were collected after at least 8 hours of fasting. Based on blood tests, fasting blood sugar levels ≤ 99 mg/dL were considered normal whereas fasting blood sugar levels ranging from 100 mg/dL to 125 mg/dL were considered IFG.
Statistical methods
After dividing the groups according to shift work, the prevalence of IFG by the potential confounders of the subjects was compared, and statistical significance was shown through the chi-square test. In addition, the mean value and high risk participants ratio by job stress subscale according to IFG were investigated. The mean value for each job stress subscale according to IFG was statistically verified through a Student’s t-test.
Logistic regression analyses were performed to investigate relationship between job stress and IFG according to shift work. The analysis models were as follows.
  • Model 1: crude

  • Model 2: Adjusted for Age, BMI

  • Model 3: Adjusted for Age, BMI, lifestyle characteristic (Alcohol consumption, Smoking, Regular exercise) and chronic diseases (such as hypertension and dyslipidemia)

Results are presented as odds ratio (OR) with 95% confidence interval (CI). Difference was considered statistically significant if p-value was less than 0.05. Statistical analysis was performed with SPSS 26.0 (IBM Corp., Armonk, NY, USA).
Ethics statement
This study was approved by the Institutional Review Board (IRB) of Soonchunhyang University Hospital, Cheonan (IRB No. 2022-12-040-002). The requirement of informed consent was waived due to its retrospective nature.
Characteristics and lifestyle
Table 1 shows the general characteristics of the study subjects according to the shift work. In the non-shift worker group, the incidence of IFG was higher in those over 40 years of age. On the other hand, in the shift worker group, when divided based on the age of 40, the group under the age of 40 (51.7%) had a slightly higher IFG incidence rate than the group over the age of 40 (48.3%). In the high BMI, the incidence of IFG was quite high for both shift workers and non-shift workers. Both shift workers and non-shift workers with hypertension and dyslipidemia had significantly higher IFG incidence rates. Significant differences in IFG incidence were observed in both groups in drinking and smoking. In the case of regular exercise, there was no statistically significant difference in the non-shift worker group, but in the shift worker group, the incidence of IFG was high in the group without exercise.
Table 1

Characteristics of study subjects by shift work

Variables Category Non-shift work (n = 2,686) Shift work (n = 3,200)
Non-IFG (n = 1,679) IFG (n = 1,007) p-valuea Non-IFG (n = 2,252) IFG (n = 948) p-valuea
Age (years) < 40 955 (56.9) 376 (37.3) < 0.001 1,636 (72.6) 490 (51.7) < 0.001
≥ 40 724 (43.1) 631 (62.7) 616 (27.4) 458 (48.3)
BMI < 25 789 (47.0) 350 (34.8) < 0.001 1,101 (48.9) 340 (35.9) < 0.001
≥ 25 890 (53.0) 657 (65.2) 1,161 (51.1) 608 (64.1)
HTN Yes 100 (6.0) 141 (14.0) < 0.001 77 (3.4) 103 (10.9) < 0.001
No 1,579 (94.0) 866 (86.0) 2,175 (96.6) 845 (89.1)
Dyslipidemia Yes 104 (6.2) 94 (9.3) 0.003 104 (4.6) 81 (8.5) < 0.001
No 1,575 (93.8) 913 (90.7) 2,148 (95.4) 867 (91.5)
Alcohol consumption (times/week) 0 445 (26.5) 216 (21.4) < 0.001 855 (38.0) 295 (31.1) < 0.001
1–2 1,058 (63.0) 607 (60.3) 1,145 (50.8) 513 (54.1)
≥ 3 176 (10.5) 184 (18.3) 252 (11.2) 140 (14.8)
Smoking Never 896 (53.4) 435 (43.2) < 0.001 1,307 (58.0) 470 (49.6) < 0.001
Past 452 (26.9) 331 (32.9) 499 (22.2) 266 (28.1)
Current 331 (19.7) 241 (23.9) 446 (19.8) 212 (22.4)
Regular exercise (times/week) 0 679 (40.4) 430 (42.7) 0.090 761 (33.8) 389 (41.0) < 0.001
1–2 476 (28.4) 303 (30.1) 655 (29.1) 283 (29.9)
≥ 3 524 (31.2) 274 (27.2) 836 (37.1) 276 (29.1)
BMI: body mass index; HTN: hypertension.
aCalculated by χ2 test.
Job stress of research subjects
Table 2 lists the KOSS score, KOSS reference value (75th percentile), and the number and proportion of participants classified as high risk. The total job stress score for KOSS was 44.71 ± 9.14 for the non-IFG group and 44.55 ± 8.69 for the IFG group. When comparing job stress scores by subclassification, the IFG group scored lower in Physical environment and Insufficient job control than the non IFG group, while the IFG group scored higher in Job demand than the group that did not (p < 0.001).
Table 2

Job stress levels of the participants by IFG (n = 5,886)

Subscales IFG(−) (n = 3,931) IFG(+) (n = 1,955) p-valueb
Mean ± SD Referencea High risk participants Mean ± SD Referencea High risk participants
Physical environment 51.02 ± 20.06 66.7 1,172 (29.8) 48.14 ± 20.38 66.7 498 (25.5) < 0.001
Job demand 40.67 ± 14.40 58.4 311 (7.9) 42.38 ± 14.28 58.4 195 (10.0) < 0.001
Insufficient job control 48.75 ± 12.14 60.1 382 (9.7) 47.49 ± 11.99 60.1 149 (7.6) < 0.001
Interpersonal conflict 35.44 ± 13.93 50.1 296 (7.5) 36.50 ± 12.58 50.1 162 (8.3) 0.005
Job insecurity 51.00 ± 12.76 61.2 521 (13.3) 51.05 ± 12.34 61.2 247 (12.6) 0.885
Organizational system 49.84 ± 16.18 62.0 698 (17.8) 49.81 ± 15.19 62.0 313 (16.0) 0.952
Lack of reward 44.79 ± 14.29 77.8 130 (3.3) 44.52 ± 13.66 77.8 46 (2.4) 0.490
Occupational climate 36.16 ± 15.48 50.1 410 (10.4) 36.42 ± 15.03 50.1 203 (10.4) 0.535
Total job stress score 44.71 ± 9.14 56.6 330 (8.4) 44.55 ± 8.69 56.6 143 (7.3) 0.504
Values are presented as number (%).
IFG: impaired fasting glycemia; IFG(−): IFG-negative group; IFG(+): IFG-positive group; SD: standard deviation.
aKorean Occupational Stress Scale reference value (75th percentile).
bCalculated by Student’s t-test.
Table 3 in appendix shows the KOSS score, the KOSS reference value (75th percentile), and the number and proportion of participants classified as high risk in the non-shift work group. The total job stress score for KOSS was 44.13 ± 8.79 for the non-IFG group and 43.82 ± 8.93 for the IFG group. Comparing job stress scores by subclassification, the IFG group scored lower in physical environment (p = 0.002) and Insufficient job control (p = 0.018) than the non IFG group, whereas the IFG group scored higher in job demand (p = 0.021).
Table 3

Job stress levels of the participants (non-shift work) by IFG (n = 2,686)

Subscales IFG(−) (n = 1,679) IFG(+) (n = 1,007) p-valueb
Mean ± SD Referencea High risk participants Mean ± SD Referencea High risk participants
Physical environment 44.86 ± 19.71 66.7 326 (19.4) 42.47 ± 19.77 66.7 175 (17.4) 0.002
Job demand 44.38 ± 14.36 58.4 200 (11.9) 45.72 ± 14.92 58.4 155 (15.4) 0.021
Insufficient job control 44.38 ± 10.82 60.1 75 (4.5) 43.36 ± 10.84 60.1 35 (3.5) 0.018
Interpersonal conflict 35.15 ± 13.43 50.1 113 (6.7) 35.65 ± 12.37 50.1 72 (7.1) 0.334
Job insecurity 50.35 ± 12.54 61.2 195 (11.6) 50.17 ± 12.46 61.2 122 (12.1) 0.726
Organizational system 49.91 ± 15.32 62.0 277 (16.5) 49.82 ± 14.95 62.0 154 (15.3) 0.872
Lack of reward 45.29 ± 14.15 77.8 53 (3.2) 44.84 ± 13.95 77.8 24 (2.3) 0.425
Occupational climate 38.68 ± 15.15 50.1 223 (13.3) 38.47 ± 15.24 50.1 129 (12.8) 0.731
Total job stress score 44.13 ± 8.79 56.6 127 (7.6) 43.82 ± 8.93 56.6 62 (6.2) 0.378
Values are presented as number (%).
IFG: impaired fasting glycemia; IFG(−): IFG-negative group; IFG(+): IFG-positive group; SD: standard deviation.
aKorean Occupational Stress Scale reference value (75th percentile).
bCalculated by Student’s t-test.
Table 4 in appendix shows the KOSS score, the KOSS reference value (75th percentile), and the number and proportion of participants classified as high risk in the shift worker group. The total job stress score for KOSS was 45.15 ± 9.36 for the non-IFG group and 45.32 ± 8.36 for the IFG group. Comparing the job stress scores by subclassification, there was no statistically significant difference in scores compared to the non-IFG group compared to the IFG group in all items.
Table 4

Job stress levels of the participants (Shift work) by IFG (n = 3,200)

Subscales IFG(−) (n = 2,252) IFG(+) (n = 948) p-valueb
Mean ± SD Referencea High risk participants Mean ± SD Referencea High risk participants
Physical environment 55.61 ± 19.06 66.7 846 (37.6) 54.17 ± 19.26 66.7 323 (34.1) 0.052
Job demand 37.90 ± 13.79 58.4 111 (4.9) 38.83 ± 12.65 58.4 40 (4.2) 0.075
Insufficient job control 52.01 ± 12.04 60.1 307 (13.6) 51.89 ± 11.59 60.1 114 (12.0) 0.801
Interpersonal conflict 35.65 ± 14.30 50.1 183 (8.1) 37.40 ± 12.75 50.1 90 (9.5) 0.001
Job insecurity 51.48 ± 12.91 61.2 326 (14.5) 51.98 ± 12.16 61.2 125 (13.2) 0.313
Organizational system 49.78 ± 16.80 62.0 421 (18.7) 49.81 ± 15.43 62.0 159 (16.8) 0.968
Lack of reward 44.41 ± 14.38 77.8 77 (3.4) 44.17 ± 13.34 77.8 22 (2.3) 0.662
Occupational climate 34.28 ± 15.46 50.1 187 (8.3) 34.25 ± 14.51 50.1 74 (7.8) 0.954
Total job stress score 45.15 ± 9.36 56.6 203 (9.0) 45.32 ± 8.36 56.6 81 (8.5) 0.626
Values are presented as number (%).
IFG: impaired fasting glycemia; IFG(−): IFG-negative group; IFG(+): IFG-positive group; SD: standard deviation.
aKorean Occupational Stress Scale reference value (75th percentile).
bCalculated by Student’s t-test.
Relationship between job stress and impaired fasting glucose
Table 5 shows the relationship between job stress and IFG by logistic regression analysis. Interestingly, for non-shift workers, the job demand subcategory showed an increase in IFG risk (Model 1, OR: 1.43, 95% CI: 1.13–1.82, p < 0.01; Model 2, OR: 1.42, 95% CI: 1.12–1.82, p < 0.01; Model 3, OR: 1.42, 95% CI: 1.11–1.81, p < 0.01). In the case of shift workers, on the other hand, all subcategories could not statistically confirm the relationship between job stress and IFG.
Table 5

ORs and 95% CIs for impaired fasting glycemia and job stress by shift work

Job stress Non-shift work (n = 2,686) Shift work (n = 3,200)
Model 1 Model 2 Model 3 Model 1 Model 2 Model 3
OR (95% CI) OR (95% CI) OR (95% CI) OR (95% CI) OR (95% CI) OR (95% CI)
Physical environment
Low risk 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference)
High risk 0.87 (0.70–1.06) 0.95 (0.76–1.17) 0.99 (0.80–1.23) 0.89 (0.75–1.05) 0.99 (0.84–1.18) 1.04 (0.87–1.23)
Job demand
Low risk 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference)
High risk 1.43 (1.13–1.82)** 1.42 (1.12–1.82)** 1.42 (1.11–1.81)** 0.96 (0.65–1.42) 0.95 (0.64–1.42) 0.92 (0.61–1.37)
Insufficient job control
Low risk 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference)
High risk 0.78 (0.51–1.20) 0.94 (0.61–1.46) 0.97 (0.62–1.51) 0.91 (0.72–1.17) 1.09 (0.85–1.40) 1.10 (0.85–1.42)
Interpersonal conflict
Low risk 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference)
High risk 1.13 (0.82–1.57) 0.92 (0.66–1.29) 0.89 (0.64–1.26) 1.33 (1.00–1.77) 1.18 (0.88–1.59) 1.19 (0.88–1.61)
Job insecurity
Low risk 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference)
High risk 1.09 (0.85–1.39) 1.03 (0.79–1.32) 0.95 (0.73–1.23) 0.96 (0.76–1.20) 0.94 (0.74–1.19) 0.90 (0.71–1.15)
Organizational system
Low risk 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference)
High risk 0.93 (0.83–1.19) 0.90 (0.70–1.15) 0.91 (0.71–1.17) 0.89 (0.71–1.12) 0.84 (0.66–1.06) 0.81 (0.64–1.04)
Lack of reward
Low risk 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference)
High risk 0.73 (0.43–1.25) 0.90 (0.52–1.55) 0.95 (0.55–1.65) 0.73 (0.43–1.24) 0.80 (0.47–1.37) 0.86 (0.50–1.47)
Occupational climate
Low risk 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference)
High risk 0.94 (0.73–1.21) 1.05 (0.81–1.36) 1.02 (0.79–1.33) 1.04 (0.76–1.41) 1.06 (0.77–1.45) 1.10 (0.80–1.51)
Total job stress score
Low risk 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference)
High risk 0.80 (0.59–1.10) 0.90 (0.65–1.25) 0.90 (0.64–1.25) 0.94 (0.72–1.24) 1.02 (0.77–1.34) 1.03 (0.78–1.36)
OR: odds ratio; CI: confidence interval; IFG: impaired fasting glycemia.
Model 1: crude; Model 2: adjusted for age, BMI; Model 3: adjusted for Model 2 + HTN, dyslipidemia, alcohol consumption, smoking, regular exercise.
**p < 0.01.
This study examined demographic characteristics and the correlation between job stress and IFG of male workers in a domestic steel manufacturing industry. Using KOSS, eight job stressors were investigated and the effect of each stressor on IFG was determined. Among these factors, job demand refers to the degree of burden on jobs. It was evaluated in detailed categories such as time pressure, disruption, increased workload, responsibility, excessive job burden, work family balance, and work multifunction.38
Among various factors that could cause job stress, psychological stress, especially stress due to high job demand, was related to an increased risk of IFG in non-shift worker group (Model 1, OR: 1.43).
Based on the correlation between the ‘job demand’ sub-scale items in KOSS and JCQ, it can be suggested that the demand-control model proposed by Karasek may be partially explained by KOSS.36 However, it should be noted that interpreting Karasek’s model solely based on KOSS is subjective and may involve logical leaps.
The results of this study are consistent with previous research on the increased risk and association between job-related high-risk groups (e.g., overwork) and T2DM, as well as studies on female workers in general evaluated using JCQ, suggesting a potential similar relationship with the results of this study which targeted male workers.26,28 Also this study confirmed a relationship between job demands and abnormal blood glucose levels, particularly IFG, only for non-shift worker in a group of male workers employed in a steel manufacturing plant, using KOSS as the job stress evaluation tool. This relationship has not been previously studied in this population.
Physiologically, IFG means that the liver's ability to regulate glucose metabolism has weakened due to a lack of insulin secretion or decreased sensitivity to insulin in the liver.39 Therefore, job stress, especially 'Job demand' in terms of IFG, a pre-stage of T2DM, means that excessive job demands have been associated with glycated metabolic abnormalities, which could increase the risk of developing T2DM, as well as CVDs, as suggested by previous studies.40 However, it should be noted that job demand is only one aspect of job-related stress and cannot solely determine an individual's stress level. In other words, this study is valuable from the perspective of preventing and preventing the progression to disease in that IFG is a pre-stage of diabetes.
It is well known that it is necessary to correct lifestyle factors such as proper diet and proper physical activity to prevent the progression of diabetes.41,42 However, evaluating various factors that can affect job stress while performing work, especially ‘job demand,’ as well as individual approaches through lifestyle factors correction, is important for IFG’s prevention in public health.43 Results of this study suggest that preventing job stress in companies through systematic approaches such as Employee Assistance Program (EAP) is necessary before IFG progresses to diabetes.44
What should be considered in the results of this study is that even though the “job demand” as a job stressor confirms the risk of IFG for non-shift workers, it cannot be confirmed for shift workers. Although many studies have been conducted on the link between diabetes, the link between IFG and night shift is still unclear, and risk factors including obesity, family history, high blood pressure, and cyclical rhythm disorders, which are known to directly affect diabetes, are higher risks for shift workers.45 In addition, considering that night work itself can also affect the factors affecting diabetes, it is a complex problem to determine how much risk the job demand can increase in IFG.45 In other words, further research is needed on the impact of job demand on Diabetes and IFG according to Karasek’s Job Demand-Control model model.46 It will also be important to develop research and surveys on shift workers by strengthening the current KOSS questionnaire.
Limitations of this study are as follows. First, it was difficult to accurately identify the causal relationship between variables in this study due to the nature of a cross-sectional study. In particular, unlike day workers, the lack of significant results in shift workers is a limitation of cross-sectional research that occurs because there is no data on shift workers despite other factors that can affect IFG. Second, since this study used only self-report data, there might be a possibility of response bias that might cause distorted results. Third, in this study, participants fasted for more than eight hours before blood collection, but it is difficult to accurately confirm this, the study was based on the results of one blood test, and no tests were conducted on variables that can provide information on blood sugar such as HbA1C. Fourth, it was difficult to generalize results of this study to other professional workers because the survey was conducted on manufacturing workers. Therefore, in future studies, it is necessary to comprehensively verify the effect of job stress exposure in consideration of work content and environment for workers engaged in various jobs. Further research should also consider different variables as the evaluation tool did not include stress causes other than personal personality items or jobs (such as family problems). Fifth, it was difficult to verify the influence of gender because subjects of this study were men with a very small number of women excluded. In the future, it is necessary to sufficiently recruit female subjects and conduct additional research. Lastly, KOSS was developed to understand the unique circumstances and working conditions of Korean workers and to identify factors contributing to job stress in that context.37,47 However, there are numerous survey tools available for evaluating job stress that have been developed and validated internationally, including the JCQ. These tools have been widely implemented in various countries and have been shown to possess high levels of reliability and validity.48 Although KOSS has been evaluated as an objective and valid measurement tool for assessing job stressors among Korean workers, it is essential to consider the potential benefits of employing other established job stress assessment tools. By doing so, we can ensure that the results of this study are strengthened and enhanced. Therefore, in order to determine how to improve the results of this study using these additional tools, it is necessary to evaluate the mental health effects caused by job stress, such as DASS (Depression Anxiety Stress Scales) and SCL-90-R (Symptom Checklist-90-Revised).
Therefore, in order to dig deeper into the causal relationship between stress level and IFG as well as job stress factors, more various measurement tools and methodologies will be needed, and these limitations will be considered in interpreting the results of this study. In addition, the top 25% of the previously suggested criteria were used in this study to compare high-risk and low-risk groups, but the previous criteria were for all workers at the beginning of the past study, so there is a limit to accurately explaining the current criteria. In this study, the quartile was classified and checked with job stress data, but it was only for specific steel manufacturing workers, and it was confirmed that the frequency was concentrated on a specific score as discrete data to select the standard value of 5,886. Therefore, it was determined that an investigation into the job stress standard in the future would be necessary. By using a variety of job stress assessment tools, we can gain a more comprehensive understanding of the job stress situation among Korean workers, which will ultimately lead to more effective strategies for managing and preventing job stress in the workplace.
Nevertheless, this study was meaningful in that it was conducted as a large-scale study analyzing more than 5,000 subjects in a single workplace. In addition, since few previous studies have verified the relationship between job stress and IFG, this study is meaningful in that it can lay the foundation for preventing and managing diabetes in advance.49
In this study of male workers engaged in the steel manufacturing industry in Korea, the item of ‘job demand’ among job stressor was related to IFG. In the future, more extensive research needs to be conducted considering effects of job stress on IFG not only for workers in the manufacturing industry, but also for white-collar works such as those who are office workers and professionals.
We would like to thank Harrisco (www.harrisco.net) for English language editing.

Funding: This work was supported by the Soonchunhyang University Research Fund.

Competing interests: The authors declare that they have no competing interests.

Author Contributions:

  • Conceptualization: Lee HK, Kwon SC.

  • Data curation: Lee HK, Lee YJ, Jang EC, Kwon SC, Min YS, Lee IH, Yun JS.

  • Formal analysis: Lee HK, Lee YJ, Jang EC, Kwon SC, Min YS, Lee IH, Yun JS.

  • Investigation: Lee HK, Lee IH, Yun JS, Kwon SC.

  • Writing - original draft: Lee HK.

  • Writing - review & editing: Kwon SC.

BMI

body mass index

CI

confidence interval

CVD

cardiovascular disease

HPA-Axis

hypothalamic pituitary adrenal axis

IFG

impaired fasting glycemia

IRB

Institutional Review Board

JCQ

Job Content Questionnaire

KOSS

Korean Occupational Stress Scale

OR

odds ratio

T2DM

type 2 diabetes
  • 1. Liu J, Ren ZH, Qiang H, Wu J, Shen M, Zhang L, et al. Trends in the incidence of diabetes mellitus: results from the Global Burden of Disease Study 2017 and implications for diabetes mellitus prevention. BMC Public Health 2020;20(1):1415. 32943028.ArticlePubMedPMCPDF
  • 2. Vijayakumar G, Manghat S, Vijayakumar R, Simon L, Scaria LM, Vijayakumar A, et al. Incidence of type 2 diabetes mellitus and prediabetes in Kerala, India: results from a 10-year prospective cohort. BMC Public Health 2019;19(1):140. 30704495.ArticlePubMedPMCPDF
  • 3. Forouhi NG, Wareham NJ. Epidemiology of diabetes. Medicine (Abingdon) 2014;42(12):698–702. 25568613.ArticlePubMedPMC
  • 4. Tuei VC, Maiyoh GK, Ha CE. Type 2 diabetes mellitus and obesity in sub-Saharan Africa. Diabetes Metab Res Rev 2010;26(6):433–445. 20641142.ArticlePubMed
  • 5. Giovannucci E, Harlan DM, Archer MC, Bergenstal RM, Gapstur SM, Habel LA, et al. Diabetes and cancer: a consensus report. Diabetes Care 2010;33(7):1674–1685. 20587728.PubMedPMC
  • 6. Long AN, Dagogo-Jack S. Comorbidities of diabetes and hypertension: mechanisms and approach to target organ protection. J Clin Hypertens (Greenwich) 2011;13(4):244–251. 21466619.ArticlePubMedPMC
  • 7. Santaguida PL, Balion C, Hunt D, Morrison K, Gerstein H, Raina P, et al. Diagnosis, prognosis, and treatment of impaired glucose tolerance and impaired fasting glucose. Evid Rep Technol Assess (Summ) 2005;(128):1–11.
  • 8. Tominaga M, Eguchi H, Manaka H, Igarashi K, Kato T, Sekikawa A. Impaired glucose tolerance is a risk factor for cardiovascular disease, but not impaired fasting glucose. The Funagata Diabetes Study. Diabetes Care 1999;22(6):920–924. 10372242.ArticlePubMedPDF
  • 9. Seeman TE, Crimmins E. Social environment effects on health and aging: integrating epidemiologic and demographic approaches and perspectives. Ann N Y Acad Sci 2001;954(1):88–117. 11797869.PubMed
  • 10. Baillien E, De Cuyper N, De Witte H. Job autonomy and workload as antecedents of workplace bullying: a two-wave test of Karasek’s Job Demand Control Model for targets and perpetrators. J Occup Organ Psychol 2011;84(1):191–208.Article
  • 11. Karasek RA Jr. Job demands, job decision latitude, and mental strain: Implications for job redesign. Adm Sci Q 1979;24(2):285–308.Article
  • 12. Demerouti E, Bakker AB, de Jonge J, Janssen PP, Schaufeli WB. Burnout and engagement at work as a function of demands and control. Scand J Work Environ Health 2001;27(4):279–286. 11560342.ArticlePubMed
  • 13. Yau YH, Potenza MN. Stress and eating behaviors. Minerva Endocrinol 2013;38(3):255–267. 24126546.PubMedPMC
  • 14. Tareen RS, Tareen K. Psychosocial aspects of diabetes management: dilemma of diabetes distress. Transl Pediatr 2017;6(4):383–396. 29184819.ArticlePubMedPMC
  • 15. Huth C, Thorand B, Baumert J, Kruse J, Emeny RT, Schneider A, et al. Job strain as a risk factor for the onset of type 2 diabetes mellitus: findings from the MONICA/KORA Augsburg cohort study. Psychosom Med 2014;76(7):562–568. 25102002.PubMed
  • 16. Link BG, Phelan J. Social conditions as fundamental causes of disease. J Health Soc Behav 1995;35(Spec No):80–94.Article
  • 17. Tsigos C, Chrousos GP. Hypothalamic-pituitary-adrenal axis, neuroendocrine factors and stress. J Psychosom Res 2002;53(4):865–871. 12377295.ArticlePubMed
  • 18. Sjörs Dahlman A, Jonsdottir IH, Hansson C. The hypothalamo-pituitary-adrenal axis and the autonomic nervous system in burnout. Handb Clin Neurol 2021;182:83–94. 34266613.PubMed
  • 19. Kivimäki M, Steptoe A. Effects of stress on the development and progression of cardiovascular disease. Nat Rev Cardiol 2018;15(4):215–229. 29213140.ArticlePubMedPDF
  • 20. Lagraauw HM, Kuiper J, Bot I. Acute and chronic psychological stress as risk factors for cardiovascular disease: insights gained from epidemiological, clinical and experimental studies. Brain Behav Immun 2015;50:18–30. 26256574.ArticlePubMed
  • 21. Penninx BW, Milaneschi Y, Lamers F, Vogelzangs N. Understanding the somatic consequences of depression: biological mechanisms and the role of depression symptom profile. BMC Med 2013;11(1):129. 23672628.ArticlePubMedPMCPDF
  • 22. Prpić-Križevac I, Canecki-Varžić S, Bilić-Ćurčić I. Hyperactivity of the hypothalamic-pituitary-adrenal axis in patients with type 2 diabetes and relations with insulin resistance and chronic complications. Wien Klin Wochenschr 2012;124(11-12):403–411. 22733309.ArticlePubMedPDF
  • 23. Cohen S, Janicki-Deverts D, Doyle WJ, Miller GE, Frank E, Rabin BS, et al. Chronic stress, glucocorticoid receptor resistance, inflammation, and disease risk. Proc Natl Acad Sci U S A 2012;109(16):5995–5999. 22474371.ArticlePubMedPMC
  • 24. Rosmond R, Dallman MF, Björntorp P. Stress-related cortisol secretion in men: relationships with abdominal obesity and endocrine, metabolic and hemodynamic abnormalities. J Clin Endocrinol Metab 1998;83(6):1853–1859. 9626108.ArticlePubMed
  • 25. Li W, Yi G, Chen Z, Dai X, Wu J, Peng Y, et al. Is job strain associated with a higher risk of type 2 diabetes mellitus? A systematic review and meta-analysis of prospective cohort studies. Scand J Work Environ Health 2021;47(4):249–257. 33404062.ArticlePubMedPMC
  • 26. Cosgrove MP, Sargeant LA, Caleyachetty R, Griffin SJ. Work-related stress and Type 2 diabetes: systematic review and meta-analysis. Occup Med (Lond) 2012;62(3):167–173. 22333189.ArticlePubMed
  • 27. Kroenke CH, Spiegelman D, Manson J, Schernhammer ES, Colditz GA, Kawachi I. Work characteristics and incidence of type 2 diabetes in women. Am J Epidemiol 2007;165(2):175–183. 17071844.ArticlePubMed
  • 28. Norberg M, Stenlund H, Lindahl B, Andersson C, Eriksson JW, Weinehall L. Work stress and low emotional support is associated with increased risk of future type 2 diabetes in women. Diabetes Res Clin Pract 2007;76(3):368–377. 17034894.ArticlePubMed
  • 29. Sui H, Sun N, Zhan L, Lu X, Chen T, Mao X. Association between work-related stress and risk for type 2 diabetes: a systematic review and meta-analysis of prospective cohort studies. PLoS One 2016;11(8):e0159978. 27513574.ArticlePubMedPMC
  • 30. Korean Industrial Health Association. Updated 2018]. Accessed January 12, 2023]. https://kiha21.or.kr/doc_download/special_ko_2018.pdf .
  • 31. Korean Industrial Health Association. Updated 2018]. Accessed January 12, 2023]. https://kiha21.or.kr/doc_download/night_ko_2018.pdf .
  • 32. Nam Y, Kwon SC, Lee YJ, Jang EC, Ahn SH. Relationship between job stress and functional dyspepsia in display manufacturing sector workers: a cross-sectional study. Ann Occup Environ Med 2018;30(1):62. 30364417.ArticlePubMedPMCPDF
  • 33. Ahn SH, Lee YJ, Jang EC, Kwon SC, Min YS, Ryu SH. A study of job stress, suicidal ideation and suicide attempts in display manufacturing workers: a cross-sectional study. Ann Occup Environ Med 2020;32:e16. 32676194.ArticlePubMedPMCPDF
  • 34. Lee HY, Shin J, Kim GH, Park S, Ihm SH, Kim HC, et al. 2018 Korean Society of Hypertension Guidelines for the management of hypertension: part II-diagnosis and treatment of hypertension. Clin Hypertens 2019;25(1):20. 31388453.ArticlePubMedPMCPDF
  • 35. Rhee EJ, Kim HC, Kim JH, Lee EY, Kim BJ, Kim EM, et al. 2018 guidelines for the management of dyslipidemia in Korea. J Lipid Atheroscler 2019;8(2):78–131. 32821702.ArticlePubMedPMCPDF
  • 36. Chang SJ, Koh SB, Kang D, Kim SA, Kang MG, Lee CG, et al. Developing an occupational stress scale for Korean employees. Korean J Occup Environ Med 2005;17(4):297–317.
  • 37. Choi YI, Kim EJ, Park EY. Validity of the Korean occupational stress scale in occupational therapists. J Korea Contents Association 2011;11(7):225–233.Article
  • 38. Kang DM, et al. Modern Understanding of Job Stress. 2nd ed. Seoul, Korea: Koryo Medical Book; 2016.
  • 39. Lewis GF, Carpentier A, Adeli K, Giacca A. Disordered fat storage and mobilization in the pathogenesis of insulin resistance and type 2 diabetes. Endocr Rev 2002;23(2):201–229. 11943743.ArticlePubMed
  • 40. Kivimäki M, Kawachi I. Work stress as a risk factor for cardiovascular disease. Curr Cardiol Rep 2015;17(9):74. 26238744.PubMedPMC
  • 41. Shrivastava SR, Shrivastava PS, Ramasamy J. Role of self-care in management of diabetes mellitus. J Diabetes Metab Disord 2013;12(1):14. 23497559.ArticlePubMedPMCPDF
  • 42. Gill JM, Cooper AR. Physical activity and prevention of type 2 diabetes mellitus. Sports Med 2008;38(10):807–824. 18803434.ArticlePubMed
  • 43. Toshihiro M, Saito K, Takikawa S, Takebe N, Onoda T, Satoh J. Psychosocial factors are independent risk factors for the development of Type 2 diabetes in Japanese workers with impaired fasting glucose and/or impaired glucose tolerance. Diabet Med 2008;25(10):1211–1217. 19046200.PubMedPMC
  • 44. Han K, Lee YJ, Kim J, Kim JH, Lee HJ. Effect of an employee assistance program (EAP) on reducing the risk of type 2 diabetes mellitus in Korea: A retrospective cohort study. J Occup Health 2019;61(1):72–80.
  • 45. Lee JY, Lee JW, Choi WS, Myong JP. Dose-response relationship between night work and the prevalence of impaired fasting glucose: the Korean worker’s special health examination for night workers cohort. Int J Environ Res Public Health 2021;18(4):1854. 33672896.ArticlePubMedPMC
  • 46. Toker S, Gavish I, Biron M. Job demand–control–support and diabetes risk: the moderating role of self-efficacy. Eur J Work Organ Psychol 2013;22(6):711–724.Article
  • 47. Kang SH, Boo YJ, Lee JS, Ji WB, Yoo BE, You JY. Analysis of the occupational stress of Korean surgeons: a pilot study. J Korean Surg Soc 2013;84(5):261–266. 23646310.ArticlePubMedPMC
  • 48. Karasek R, Brisson C, Kawakami N, Houtman I, Bongers P, Amick B. The Job Content Questionnaire (JCQ): an instrument for internationally comparative assessments of psychosocial job characteristics. J Occup Health Psychol 1998;3(4):322–355. 9805280.ArticlePubMed
  • 49. Karve A, Hayward RA. Prevalence, diagnosis, and treatment of impaired fasting glucose and impaired glucose tolerance in nondiabetic U.S. adults. Diabetes Care 2010;33(11):2355–2359. 20724649.ArticlePubMedPMCPDF

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        Relationship between job stress and impaired fasting glucose in male steel industry workers: a cross-sectional study
        Ann Occup Environ Med. 2023;35:e12  Published online June 2, 2023
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      Relationship between job stress and impaired fasting glucose in male steel industry workers: a cross-sectional study
      Relationship between job stress and impaired fasting glucose in male steel industry workers: a cross-sectional study
      VariablesCategoryNon-shift work (n = 2,686)Shift work (n = 3,200)
      Non-IFG (n = 1,679)IFG (n = 1,007)p-valueaNon-IFG (n = 2,252)IFG (n = 948)p-valuea
      Age (years)< 40955 (56.9)376 (37.3)< 0.0011,636 (72.6)490 (51.7)< 0.001
      ≥ 40724 (43.1)631 (62.7)616 (27.4)458 (48.3)
      BMI< 25789 (47.0)350 (34.8)< 0.0011,101 (48.9)340 (35.9)< 0.001
      ≥ 25890 (53.0)657 (65.2)1,161 (51.1)608 (64.1)
      HTNYes100 (6.0)141 (14.0)< 0.00177 (3.4)103 (10.9)< 0.001
      No1,579 (94.0)866 (86.0)2,175 (96.6)845 (89.1)
      DyslipidemiaYes104 (6.2)94 (9.3)0.003104 (4.6)81 (8.5)< 0.001
      No1,575 (93.8)913 (90.7)2,148 (95.4)867 (91.5)
      Alcohol consumption (times/week)0445 (26.5)216 (21.4)< 0.001855 (38.0)295 (31.1)< 0.001
      1–21,058 (63.0)607 (60.3)1,145 (50.8)513 (54.1)
      ≥ 3176 (10.5)184 (18.3)252 (11.2)140 (14.8)
      SmokingNever896 (53.4)435 (43.2)< 0.0011,307 (58.0)470 (49.6)< 0.001
      Past452 (26.9)331 (32.9)499 (22.2)266 (28.1)
      Current331 (19.7)241 (23.9)446 (19.8)212 (22.4)
      Regular exercise (times/week)0679 (40.4)430 (42.7)0.090761 (33.8)389 (41.0)< 0.001
      1–2476 (28.4)303 (30.1)655 (29.1)283 (29.9)
      ≥ 3524 (31.2)274 (27.2)836 (37.1)276 (29.1)
      SubscalesIFG(−) (n = 3,931)IFG(+) (n = 1,955)p-valueb
      Mean ± SDReferenceaHigh risk participantsMean ± SDReferenceaHigh risk participants
      Physical environment51.02 ± 20.0666.71,172 (29.8)48.14 ± 20.3866.7498 (25.5)< 0.001
      Job demand40.67 ± 14.4058.4311 (7.9)42.38 ± 14.2858.4195 (10.0)< 0.001
      Insufficient job control48.75 ± 12.1460.1382 (9.7)47.49 ± 11.9960.1149 (7.6)< 0.001
      Interpersonal conflict35.44 ± 13.9350.1296 (7.5)36.50 ± 12.5850.1162 (8.3)0.005
      Job insecurity51.00 ± 12.7661.2521 (13.3)51.05 ± 12.3461.2247 (12.6)0.885
      Organizational system49.84 ± 16.1862.0698 (17.8)49.81 ± 15.1962.0313 (16.0)0.952
      Lack of reward44.79 ± 14.2977.8130 (3.3)44.52 ± 13.6677.846 (2.4)0.490
      Occupational climate36.16 ± 15.4850.1410 (10.4)36.42 ± 15.0350.1203 (10.4)0.535
      Total job stress score44.71 ± 9.1456.6330 (8.4)44.55 ± 8.6956.6143 (7.3)0.504
      SubscalesIFG(−) (n = 1,679)IFG(+) (n = 1,007)p-valueb
      Mean ± SDReferenceaHigh risk participantsMean ± SDReferenceaHigh risk participants
      Physical environment44.86 ± 19.7166.7326 (19.4)42.47 ± 19.7766.7175 (17.4)0.002
      Job demand44.38 ± 14.3658.4200 (11.9)45.72 ± 14.9258.4155 (15.4)0.021
      Insufficient job control44.38 ± 10.8260.175 (4.5)43.36 ± 10.8460.135 (3.5)0.018
      Interpersonal conflict35.15 ± 13.4350.1113 (6.7)35.65 ± 12.3750.172 (7.1)0.334
      Job insecurity50.35 ± 12.5461.2195 (11.6)50.17 ± 12.4661.2122 (12.1)0.726
      Organizational system49.91 ± 15.3262.0277 (16.5)49.82 ± 14.9562.0154 (15.3)0.872
      Lack of reward45.29 ± 14.1577.853 (3.2)44.84 ± 13.9577.824 (2.3)0.425
      Occupational climate38.68 ± 15.1550.1223 (13.3)38.47 ± 15.2450.1129 (12.8)0.731
      Total job stress score44.13 ± 8.7956.6127 (7.6)43.82 ± 8.9356.662 (6.2)0.378
      SubscalesIFG(−) (n = 2,252)IFG(+) (n = 948)p-valueb
      Mean ± SDReferenceaHigh risk participantsMean ± SDReferenceaHigh risk participants
      Physical environment55.61 ± 19.0666.7846 (37.6)54.17 ± 19.2666.7323 (34.1)0.052
      Job demand37.90 ± 13.7958.4111 (4.9)38.83 ± 12.6558.440 (4.2)0.075
      Insufficient job control52.01 ± 12.0460.1307 (13.6)51.89 ± 11.5960.1114 (12.0)0.801
      Interpersonal conflict35.65 ± 14.3050.1183 (8.1)37.40 ± 12.7550.190 (9.5)0.001
      Job insecurity51.48 ± 12.9161.2326 (14.5)51.98 ± 12.1661.2125 (13.2)0.313
      Organizational system49.78 ± 16.8062.0421 (18.7)49.81 ± 15.4362.0159 (16.8)0.968
      Lack of reward44.41 ± 14.3877.877 (3.4)44.17 ± 13.3477.822 (2.3)0.662
      Occupational climate34.28 ± 15.4650.1187 (8.3)34.25 ± 14.5150.174 (7.8)0.954
      Total job stress score45.15 ± 9.3656.6203 (9.0)45.32 ± 8.3656.681 (8.5)0.626
      Job stressNon-shift work (n = 2,686)Shift work (n = 3,200)
      Model 1Model 2Model 3Model 1Model 2Model 3
      OR (95% CI)OR (95% CI)OR (95% CI)OR (95% CI)OR (95% CI)OR (95% CI)
      Physical environment
      Low risk1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)
      High risk0.87 (0.70–1.06)0.95 (0.76–1.17)0.99 (0.80–1.23)0.89 (0.75–1.05)0.99 (0.84–1.18)1.04 (0.87–1.23)
      Job demand
      Low risk1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)
      High risk1.43 (1.13–1.82)** 1.42 (1.12–1.82)** 1.42 (1.11–1.81)** 0.96 (0.65–1.42)0.95 (0.64–1.42)0.92 (0.61–1.37)
      Insufficient job control
      Low risk1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)
      High risk0.78 (0.51–1.20)0.94 (0.61–1.46)0.97 (0.62–1.51)0.91 (0.72–1.17)1.09 (0.85–1.40)1.10 (0.85–1.42)
      Interpersonal conflict
      Low risk1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)
      High risk1.13 (0.82–1.57)0.92 (0.66–1.29)0.89 (0.64–1.26)1.33 (1.00–1.77)1.18 (0.88–1.59)1.19 (0.88–1.61)
      Job insecurity
      Low risk1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)
      High risk1.09 (0.85–1.39)1.03 (0.79–1.32)0.95 (0.73–1.23)0.96 (0.76–1.20)0.94 (0.74–1.19)0.90 (0.71–1.15)
      Organizational system
      Low risk1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)
      High risk0.93 (0.83–1.19)0.90 (0.70–1.15)0.91 (0.71–1.17)0.89 (0.71–1.12)0.84 (0.66–1.06)0.81 (0.64–1.04)
      Lack of reward
      Low risk1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)
      High risk0.73 (0.43–1.25)0.90 (0.52–1.55)0.95 (0.55–1.65)0.73 (0.43–1.24)0.80 (0.47–1.37)0.86 (0.50–1.47)
      Occupational climate
      Low risk1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)
      High risk0.94 (0.73–1.21)1.05 (0.81–1.36)1.02 (0.79–1.33)1.04 (0.76–1.41)1.06 (0.77–1.45)1.10 (0.80–1.51)
      Total job stress score
      Low risk1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)
      High risk0.80 (0.59–1.10)0.90 (0.65–1.25)0.90 (0.64–1.25)0.94 (0.72–1.24)1.02 (0.77–1.34)1.03 (0.78–1.36)
      Table 1 Characteristics of study subjects by shift work

      BMI: body mass index; HTN: hypertension.

      aCalculated by χ2 test.

      Table 2 Job stress levels of the participants by IFG (n = 5,886)

      Values are presented as number (%).

      IFG: impaired fasting glycemia; IFG(−): IFG-negative group; IFG(+): IFG-positive group; SD: standard deviation.

      aKorean Occupational Stress Scale reference value (75th percentile).

      bCalculated by Student’s t-test.

      Table 3 Job stress levels of the participants (non-shift work) by IFG (n = 2,686)

      Values are presented as number (%).

      IFG: impaired fasting glycemia; IFG(−): IFG-negative group; IFG(+): IFG-positive group; SD: standard deviation.

      aKorean Occupational Stress Scale reference value (75th percentile).

      bCalculated by Student’s t-test.

      Table 4 Job stress levels of the participants (Shift work) by IFG (n = 3,200)

      Values are presented as number (%).

      IFG: impaired fasting glycemia; IFG(−): IFG-negative group; IFG(+): IFG-positive group; SD: standard deviation.

      aKorean Occupational Stress Scale reference value (75th percentile).

      bCalculated by Student’s t-test.

      Table 5 ORs and 95% CIs for impaired fasting glycemia and job stress by shift work

      OR: odds ratio; CI: confidence interval; IFG: impaired fasting glycemia.

      Model 1: crude; Model 2: adjusted for age, BMI; Model 3: adjusted for Model 2 + HTN, dyslipidemia, alcohol consumption, smoking, regular exercise.

      **p < 0.01.


      Ann Occup Environ Med : Annals of Occupational and Environmental Medicine
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