Association between ergonomic risk exposures and insomnia symptoms: a mediation analysis of the 5th Korean working conditions survey.

BACKGROUND: This study investigates the relationship between ergonomic risk exposures and insomnia symptoms, using data representative of Korea's general working population. METHODS: Data from the 5th Korean Working Conditions Survey were used for this study. The eligible population (employees) for the current study was 37,026. Insomnia symptoms were estimated using the minimal insomnia symptom scale (MISS) questionnaire. Logistic regression analysis was conducted to explore the association between ergonomic risks and insomnia symptoms. RESULTS: All the investigated ergonomic risks increased odd ratios (ORs) for insomnia symptoms: Tiring or painful positions (OR, 1.64; 95% CI, 1.43-1.88); lifting or moving heavy loads (OR, 2.33; 95% CI, 1.99-2.71); long periods of standing (OR, 1.47; 95% CI, 1.29-1.69); and repetitive hand or arm movements (OR, 1.46; 95% CI, 1.29-1.67). The mediated proportion of musculoskeletal pain was 7.4% (95% CI, 5.81-10.13), and the mediated proportion of feeling of exhaustion was 17.5% (95% CI, 5.81-10.13). CONCLUSIONS: This study provides evidence for the relationship between ergonomic risks and insomnia symptoms, for which musculoskeletal pains and the feeling of exhaustion may be potential mediators.

Occupational risk factors associated with lower urinary tract symptoms among female workers: a systematic review.

A systematic review was performed aiming to identify the various occupational risk factors of lower urinary tract symptoms (LUTS) among female workers. A systematic, comprehensive literature search of PubMed, Embase and Cochrane Library databases was conducted to identify studies published until 24 November 2021, evaluating the possible occupational risk factors of LUTS among female workers. Two reviewers assessed all articles retrieved through a computerised search for eligibility using predetermined criteria. Data on the first author, publication year, country, study design, participants, identified occupational risk factors, outcome variables and main results were extracted from the selected articles. The Newcastle-Ottawa Quality Assessment Scale guidelines were adopted to estimate the quality scores. Overall, our search yielded a total of 16 articles suitable for review. The occupational risk factors identified in the studies were strenuous physical demand and activity, prolonged sitting, occupational stress, shift work, limited use of the toilet at work and other occupational environments (eg, an unclean and uncomfortable workplace, dangerous job and probability of accidents, feeling pressed for time and awkward position for long periods). The findings of this review may raise awareness regarding the risk of LUTS among female workers with these factors. From an occupational health perspective, the implementation of tailored prevention strategies based on these occupational factors may prevent female workers from developing LUTS. PROSPERO registration number CRD42022316728.

Association of sedentary work with colon and rectal cancer: systematic review and meta-analysis.

OBJECTIVES: There has been no research on sedentary behaviour in the occupational domain that occupies a large portion of the daily life. METHODS: We conducted a meta-analysis to investigate the association between sedentary work and colorectal cancer. We searched PubMed, Embase and Cochrane databases up to 12 August 2020 for peer-reviewed journal articles that assessed the association between sedentary work and colon or rectal cancer. Pooled estimates of ORs were obtained using random effects models. Statistical tests for publication bias, heterogeneity and sensitivity analysis were applied. RESULTS: Of the 5 381 studies initially identified, 23 studies with 64 reports were eligible for inclusion. Sedentary work significantly increased the risk of colon cancer (pooled OR=1.21, 95% CI 1.11 to 1.31, p value ≤0.0001) and rectal cancer (pooled OR=1.08, 95% CI 1.00 to 1.16, p value=0.0395). The adjustment for leisure time physical activity attenuated the association and made the risk estimates non-significant for sedentary behaviour, but the association was independent of sex, control of body mass index and assessment of sedentary behaviour. CONCLUSIONS: We found evidence of association between sedentary work and the risk of colon or rectal cancer. Limiting excessive sedentary work could be an important means of preventing colon and rectal cancer.

Occupational physical activity, not leisure-time physical activity, is associated with increased high-sensitivity C reactive protein levels.

OBJECTIVE: This study aims to explore the association between physical activity and high-sensitivity C reactive protein, based on different types of physical activity-occupational and leisure time. METHODS: Using cross-sectional data from the Korea National Health and Nutrition Examination Survey 2015-2018, we explored the association between different types of self-reported physical activity and high levels of high-sensitivity C reactive protein (>3 mg/L). We estimated the ORs for high-level high-sensitivity C reactive protein using multiple logistic regression models after adjusting for covariates from 12 970 eligible subjects (mean age 44.8). RESULTS: Compared with subjects who did not engage in moderate-to-vigorous level of occupational physical activity (OPA), the group that engaged in moderate-to-vigorous level of OPA showed a significantly high OR (1.32, 95% CI (1.03 to 1.69)), whereas the group that engaged in moderate-to-vigorous level of leisure-time physical activity (LPA) yielded a low OR (0.84, 95% CI (0.69 to 1.01)). The group that engaged in moderate-to-vigorous level of OPA but not LPA showed a significantly high OR (1.76, 95% CI (1.27 to 2.45)) compared with subjects who engaged in moderate-to-vigorous level of LPA but not in OPA. CONCLUSIONS: OPA is directly associated with high C reactive protein levels, suggesting that it increases the risk of inflammation.

Long work hours and decreased glomerular filtration rate in the Korean working population.

OBJECTIVES: We studied the association between long working hours and decreased kidney function, which was determined using estimated glomerular filtration rate (eGFR), among the working population in South Korea. METHODS: We analysed nationally representative cross-sectional data for 20 851 Korean workers ≥20 years of age. A negative binomial regression model was used to test differences in the prevalence of chronic kidney disease (eGFR <60 mL/min/1.73 m2) among workers divided into groups according to weekly working hours (<30, 30-40, 41-51 and ≥52 hours/week). Multivariate linear regression analysis was performed to investigate the association between weekly working hours and eGFR, with adjustments made for age, sex/gender, income, education, shift work, occupation, smoking, alcohol use, hypertension, diabetes mellitus, body mass index, systolic blood pressure, fasting blood glucose and total serum cholesterol. RESULTS: A 1-hour increase in weekly working hours was associated with 0.057 mL/min/1.73 m2 (95% CI 0.005 to 0.109) decrease in eGFR among participants who worked ≥52 hours/week. Among participants without hypertension or diabetes, a 1-hour increase in weekly working hours was significantly associated with 0.248 and 0.209 mL/min/1.73 m2 decrease in eGFR among participants who worked 30-40 hours/week and 41-51 hours/week, respectively. CONCLUSION: Long working hours are associated with decreased kidney function. We expect that our findings could call for more research regarding this association and provide policy-oriented perspectives.

Occupational post-traumatic stress disorder: an updated systematic review.

BACKGROUND: Although numerous studies on occupational post-traumatic stress disorder (PTSD) have been conducted prior to the 1950-2010 seminal systematic review by Skogstad et al., the prevalence, risk factors, and impact of this disorder following traumatic events in occupational settings remain unclear. This study aims to address this knowledge gap by reviewing the literature published after 2010. METHODS: We reviewed literature from databases such as PubMed and Google Scholar using PRISMA guidelines to identify studies that address occupational PTSD and examined the status (prevalence or incidence), the risk factors, and the health effects of PTSD among workers. RESULTS: In total, 123 articles were identified, and finally, 31 (25.2%) articles were selected after excluding duplicates. Various occupational traumatic physical events were reported such as natural or manmade disaster, explosion, accident, handling refugee corpses, or bullying at work. Risk of PTSD was closely associated with working conditions, severity of injury, history of mental disorder, occurrence of psychiatric symptoms at the time of the event, personality, interpersonal relationships, etc. Workers with PTSD were likely to experience a deterioration of physical and psychological health and impairment of social and occupational functioning. CONCLUSIONS: Our review suggests that many workers remain highly vulnerable to occupational PTSD and its consequences.

Effects of perceived job insecurity on depression, suicide ideation, and decline in self-rated health in Korea: a population-based panel study.

PURPOSE: To investigate the effects of job security on new development of depressive episode, suicide ideation, and decline in self-rated health. METHODS: Data from the Korea Welfare Panel Study from 2012 to 2015 were analysed. A total of 2912 waged workers self-assessed their depressive episode, suicide ideation, and health annually by answering the questionnaire. Participants were divided into three groups according to the level of job security: high, intermediate and low. To evaluate the influence of job security, we performed survival analysis after stratification by gender with adjustment for covariates. The result was further stratified by whether the respondent was the head of household. RESULTS: After adjusting for covariates, men in low job security group showed significantly higher hazard ratios (HRs) for depression (HR 1.27, 95% CI 1.01-1.60), suicide ideation (HR 3.25, 95% CI 1.72-6.16), and decline in self-rated health (HR 1.73, 95% CI 1.16-2.59). Women showed significantly higher HR of depression in the intermediate (HR 1.37, 95% CI 1.01-1.87) and low (HR 1.50, 95% CI 1.12-1.99) job security group. Male head of household with low job security showed significantly higher HR of depression, suicide ideation, and decline in self-rated health. Non-head-of-household women with intermediate and low job security showed higher risk of depression than those with high job security. CONCLUSIONS: We found that perceived job insecurity is associated with the new development of depressive episode, suicide ideation, and decline in self-rated health.

Adverse pregnancy outcomes in healthcare workers: a Korean nationwide population-based study.

PURPOSE: To assess female healthcare workers' pregnancy complications and outcomes including abortion, fetal screening abnormalities, intrauterine growth retardation (IUGR), and preterm labor using nationwide population data and compare these results with those of the general population in Korea. METHODS: Korean National Health Insurance (NHI) claim data was used. We choose 3 different reference groups for comparison: (1) dependents of employees insured by NHI, i.e. non-working women, (2) all insured employees, i.e. all working women, and (3) workers in the education division. To compare the groups, logistic regression was used for multivariate analysis after adjusting for age and income level. RESULTS: Overall, healthcare workers showed a higher adjusted OR (odds ratio) in almost all obstetrical consequences. Miscarriage, threatened abortion, preterm labor, fetal screening abnormalities, and IUGR showed a higher adjusted OR in the working group than in the non-working group. We also observed similar results in a comparison of both the working groups. Regarding workers in the education division, ORs for obstetrical outcomes were also high, except for preterm labor. CONCLUSIONS: Health care workers have a higher risk of adverse pregnancy outcomes such as miscarriage, IUGR, and fetal screening abnormalities.

Effects of voluntary/involuntary retirement on their own and spouses' depressive symptoms.

OBJECTIVES: The aim of our study was to elucidate the effect of voluntary/involuntary retirement on individuals' and spouses' depressive symptoms using the Korean Longitudinal Study of Aging (KLoSA). METHODS: This study used a sample derived from the first- to fourth-wave cohort datasets of KLoSA, which was conducted in 2006, 2008, 2010, and 2012. After applying inclusion and exclusion criteria, we analyzed a total of 6706 subjects. Information about employment status, the short-form Center for Epidemiological Studies-Depression scale, and covariates (age, property, household income, perceived health status and medical disability) were obtained. Cox proportional hazards models were used to evaluate the effects of voluntary/involuntary retirement on individuals' and spouses' depressive symptoms. RESULTS: The voluntary/involuntary retirement groups showed significantly more depressive symptoms than the working group in wave 1-4, and the same results were revealed in the spouse's retirement and job loss measures. The hazard ratios of depressive symptoms of the voluntary/involuntary retirement groups were 1.26-1.31 during the 6year follow-up period. The wives' risk of depressive symptoms was also significantly increased if their husbands voluntarily retired (HR=1.35, 95% CI=1.10-1.65). CONCLUSION: During the 6year follow-up study, Voluntary/involuntary retirement increased the risk of depressive symptoms in a Korean elderly population. Furthermore, husbands' voluntary retirement increased wives' risk of depressive symptoms.

Reproductive disorders among cosmetologists and hairdressers: a meta-analysis.

PURPOSE: Occupational risks for reproductive disorders among hairdressers and cosmetologists have been examined in numerous epidemiological studies, although the results of those studies have been inconsistent. Therefore, we conducted a meta-analysis of published studies to evaluate the risks of reproductive disorders among cosmetologists and hairdressers. METHODS: We searched the MEDLINE, EMBASE, and Cochrane Library databases, as well as the reference lists of relevant publications, to identify studies for our analysis. After careful consideration, 19 eligible studies were included in the meta-analysis. We also performed systematic evaluations of publication bias, heterogeneity, and publication quality. RESULTS: Study-specific odds ratios (ORs) were weighted using the inverse of their variance to calculate fixed- and random-effect pooled estimates. The meta-analysis revealed a significantly increased risk of infertility (OR 1.15, 95 % CI 1.03-1.28), fetal death (OR 1.14, 95 % CI 1.04-1.24), and preterm delivery (OR 1.04, 95 % CI 1.00-1.07) among hairdressers and cosmetologists. CONCLUSION: These findings indicate that hairdressers and cosmetologists have a higher risk of reproductive disorders, compared to the general population.

Long working hours may increase risk of coronary heart disease.

OBJECTIVE: To evaluate the association between long working hours and risk of coronary heart disease (CHD) estimated by Framingham risk score (FRS) in Korean adults. METHODS: This study evaluated adult participants in Korean National Health and Nutrition Examination Survey IV (2007-2009). After inclusion and exclusion criteria were applied, the final sample size for this study model was 8,350. Subjects were asked about working hours and health status. Participants also completed physical examinations and biochemical measurement necessary for estimation of FRS. Multiple logistic regression was conducted to investigate the association between working hours and 10-year risk for CHD estimated by FRS. RESULTS: Compared to those who work 31-40 hr, significantly higher 10-year risk was estimated among subjects working longer hours. As working hours increased, odds ratio (OR) for upper 10 percent of estimated 10-year risk for CHD was increased up to 1.94. CONCLUSIONS: Long working hours are significantly related to risk of coronary heart disease.

Association between work from home and health-related productivity loss among Korean employees.

Background: After the coronavirus disease 2019 pandemic, the widespread adoption of working from home, or teleworking, has prompted extensive research regarding its effects on work productivity and the physical and mental health of employees. In this context, our study aimed to investigate the association between working from home and health-related productivity loss (HRPL). Methods: An online survey was conducted with a sample of 1,078 workers. HRPL was estimated by the Work Productivity and Activity Impairment Questionnaire: General Health version. Workers that have been working from home in the last 6 months were categorized into the "work from home" group. Generalized linear models were used to compare the mean difference of HRPL between "work from home" and "commuters" group. Stratified analyses were conducted based on various factors including gender, age, income level, occupation, education level, previous diagnosis of chronic disease, presence of preschool children, living in studio apartment, living alone, commuting time, working hours and regular exercise. Results: The overall HRPL was higher in the "work from home" group than in the "commuters" group with a mean difference of 4.05 (95% confidence interval [CI]: 0.09-8.01). In the stratified analyses, significant differences were observed in workers with chronic diseases (mean difference: 8.23, 95% CI: 0.38-16.09), who do not live alone (mean difference: 4.84, 95% CI: 0.35-9.33), and workers that do not exercise regularly (mean difference: 4.96, 95% CI: 0.12-9.80). Conclusions: Working from home is associated with an increased HRPL in the Korean working population, especially among those with chronic diseases, those who do not live alone, and those who do not exercise regularly.

Systematic review and meta-analysis of the association between long working hours and hypertension risk.

BACKGROUND: Hypertension, a major public health problem worldwide, has been linked to lifestyle factors and work conditions, with conflicting evidence on the association between long work hours and risk of hypertension. METHODS: We conducted a systematic review and meta-analysis of observational studies to investigate the relationship between working hours and hypertension or blood pressure, assessed the risk of bias and performed subgroup analyses. The protocol was registered with the International Prospective Register of Systematic Reviews. RESULTS: The pooled OR for the association between long working hours and risk of hypertension was 1.09 (95% CI: 0.88 to 1.35) in the 15 studies that used hypertension as the outcome. In the three studies that used blood pressure as the outcome, diastolic blood pressure was higher among those with long working hours compared with those with non-long working hours (1.24 mm Hg, 95% CI: 0.19 to 2.29). In subgroup analysis, the pooled OR for the association between long working hours and risk of hypertension was 1.28 (95% CI: 1.14 to 1.44) and 1.00 (95% CI: 0.64 to 1.56) in women and men, respectively. CONCLUSIONS: Although this study could not clearly confirm the relationship between long working hours and hypertension, the subgroup analysis suggests that long working hours may be associated with hypertension, particularly among women. More reliable research is needed to establish causality. PROSPERO REGISTRATION NUMBER: CRD42023406961.

The Relationship Between Postural Torticollis Abnormalities and Plagiocephaly on the Early Motor Development Milestones of Lying and Rolling Activities in Infants: A Retrospective Study.

The study examined how neck muscle imbalance and plagiocephaly affect the lying and rolling activities in 118 infants aged 4 to 6 months with postural torticollis. Outcome measures included age, sex, cervical movement, and plagiocephaly severity. Neck muscle function was assessed with the Muscle Function Scale (MFS), and infant motor abilities in lying and rolling were evaluated through the corresponding dimensions of the Gross Motor Function Measure (GMFM). Multiple regression analysis showed that a better MFS score of the affected neck was significantly associated with improved lying and rolling activities in the GMFM (p < .01), and importantly, the interaction between the plagiocephaly and the MFS scores of the affected neck muscle in these activities was found to be significant (p < .05). These results highlight the need for early intervention in infants with torticollis to address muscle imbalance and plagiocephaly, crucial for early motor development (KCT0008367).

Association between social jetlag and self-rated health: Evidence from Korean representative working population.

BACKGROUND: Social jetlag is a circadian misalignment that arises from a discrepancy between activity/sleep schedules on school/work days and free days. This study explored the correlation between social jetlag and self-rated health (SRH) in a representative sample of Korea. METHODS: This study included 8259 working population in the Korea National Health and Nutrition Examination Survey, 2016-2018. Social jetlag was calculated as the difference between the midpoint of sleep time on work day and work-free day. Five-point Likert scale of SRH was used to assess subjective health perception on general health conditions. Multiple logistic regression analysis was performed to calculate the odds ratios (ORs) and 95 % confidence interval (CI) for poor SRH in the 1-2 h or longer than 2 h social jetlag groups compared to that in the reference group (less than 1 h), after adjusting for age, sex, marital status, occupation, household income, and weekly working hours. RESULTS: The proportions of those with <1 h, 1-2 h, >2 h of social jetlag were 63.80 %, 25.67 %, and 10.53 %, respectively. The risk of poor SRH increased as social jetlag increased. Greater social jetlag was significantly associated with an increased likelihood of reporting poor SRH. The adjusted ORs for the groups with social jetlag between 1 and <2 h, and >2 h were 1.100 (95 % CI = 0.935-1.295), and 1.503 (95 % CI = 1.097-1.727), respectively. Moreover, the OR trend was statistically significant (p for trend = 0.008). CONCLUSION: This study found that social jetlag and poor SRH were significantly related in the Korean working population.

Effects of cold and hot temperatures on the renal function of people with chronic disease.

OBJECTIVE: This study investigated the effects of hot and cold temperature on the renal function of people with chronic diseases, such as diabetes, hypertension, and chronic kidney disease, using large-scale clinical data. METHODS: We used retrospective cohort data from the Clinical Data Warehouse of the Seoul St. Mary's Hospital, which was containing clinical, diagnostic, laboratory, and other information of all patients who have visited the hospital since 1997. We obtained climate data from the Automated Synoptic Observing System of the Korea Meteorological Administration. The heat index was used as a measuring tool to evaluate heat exposure by indexing the actual heat that individuals feel according to temperature and humidity. The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. To investigate changes in renal function trends with heat index, this study used generalized additive mixed models. RESULTS: Renal function decreased linearly with the increasing heat index after approximately 25°C, which was considered the flexion point of temperature. A linear decrease in the eGFR was observed with the effects of 0 to 5 lag days. While there was a correlation observed between the decrease in eGFR and temperatures below -10°C, the results do not indicate statistical significance. CONCLUSIONS: The results of our study provide scientific evidence that high temperatures affect the renal function of people with chronic diseases. These results can help prevent heat-related morbidity by identifying those who are more likely to develop renal disease and experience worsening renal function.

Investigation of Working Conditions and Health Status in Platform Workers in the Republic of Korea.

Background: The present study aimed to analyze several aspects of the working conditions and health status of platform workers in the Republic of Korea, such as ergonomic and emotional hazards. We also compared the health status of the platform workers with that of the general population. Methods: A total of 1,000 platform workers participated in this survey from August 7 to August 17, 2022. The participants included 400 designated drivers, 400 food-delivery drivers, and 200 housekeeping managers. A face-to-face survey with a structured questionnaire was conducted by researchers who had received specific instructions. The focus of the survey extended to the work environment, encompassing factors such as workplace violence, as well as physical, chemical, and ergonomic hazards. Health-related data for the previous year were also collected, covering a range of issues such as hearing problems, skin problems, musculoskeletal symptoms, headaches, injuries, mental health issues, and digestive problems. Subsequently, we compared the health symptom data of the responders with those of the general population in the Republic of Korea. Results: Platform workers, including designated drivers, food-delivery drivers, and housekeeping managers, existed in the blind spot of social insurance, facing frequent exposure to physical and chemical hazards, ergonomic risk factors, and direct or indirect violence. The prevalence of health problems, including musculoskeletal symptoms, general fatigue, and depressive symptoms, in each occupational group was statistically higher than that in the general population after standardization for age and gender. Conclusion: The results revealed unfavorable working environment and inferior occupational health of platform workers compared with those of the general population.

Effects of environmental cadmium exposure on liver function in adults.

BACKGROUND: There is inconsistency regarding the effects of cadmium exposure on liver function between the positive results found in animal studies and the negative results highlighted in epidemiological studies. We investigated whether environmental cadmium exposure is associated with an elevation in serum liver enzyme activity in Korean adults. METHODS: This cross-sectional study evaluated adult participants without liver disease from the Korean National Health and Nutrition Examination Survey for 2008-2009. Multiple linear regression was conducted to investigate the association between blood cadmium concentration and the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) adjusting for age, sex, body mass index and the amount of alcohol consumption. Subjects were stratified into quartiles by their cumulative cadmium exposure rank. We estimated the multivariate-adjusted ORs for liver enzyme elevation using logistic regression models with the first quartile as the reference group. RESULTS: Total number of the subjects in the analysis was 3914. The blood cadmium concentrations were significantly associated with liver enzyme levels (AST, ß=2.677, p value <0.0001; ALT, ß=3.696, p value <0.0001; ALP, ß=11.730, p value <0.0001). As the cadmium levels approached higher quartiles, the ORs for an elevated AST, ALT and ALP was increased significantly. CONCLUSIONS: Environmental cadmium exposures are associated with an elevation in serum liver enzyme levels in Korean adults.

Who is the most precarious among the nonstandard workers? A comparative study of unmet medical needs among standard workers and subtypes of nonstandard workers.

OBJECTIVE: Nonstandard workers might have a relatively higher risk of unmet medical needs than standard workers. This study subdivided nonstandard workers to investigate the effects of nonstandard employment on unmet medical needs. METHODS: We used the Korea Health Panel 2011-2018 data. The independent variable, employment contract, was defined using the nonstandard form described by the ILO: Temporary workers, Part-time workers, and Temporary agent workers. The analytical method used in this study was a panel logit model that accounted for repeated measured participants. By controlling for time-invariant individual-fixed effects, we investigate the relationship between subdivided nonstandard work and the risk of unmet medical needs with reference to standard work. RESULTS: The results of the analysis clearly showed that compared with standard workers, temporary agency workers had a significantly higher risk of unmet medical needs (Odds ratio = 1.182, 95% CI = 1.016-1.374). The main cause of this phenomenon was economic reasons in this group. CONCLUSIONS: This study found that temporary agency workers in the general Korean population have a significantly higher risk of unmet healthcare needs. The result of this study implies that financial hardship might be a fundamental health hazard among workers with nonstandard employment.

Association between social jetlag and chronic kidney disease among the Korean working population.

Social jetlag refers to the discrepancy between social time and the body's internal rhythm, which can lead to unfavorable health outcomes. However, no study has directly explored the relation between social jetlag and chronic kidney disease (CKD). This study aims to investigate the relationship between social jetlag and CKD in a representative population of South Korea. This study included 8259 currently economically active Korean population in the Korea National Health and Nutrition Examination Survey. Social jetlag was calculated as the difference between the midpoint of sleep time on weekdays and free days. The estimated glomerular filtration rate (eGFR) was calculated the by using the serum creatinine value according to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Participants with an eGFR less than 60 ml/min/1.73 m2 were defined as CKD cases. The estimated glomerular filtration rate decreased as social jetlag increased. Multiple logistic regression analysis showed that the adjusted odds ratio (95% confidence interval) of CKD for 1-2 h of social jetlag was 0.926 (0.660-1.299), while the odds ratio for more than 2 h was 2.042 (1.328-3.139) when less than 1 h was used as reference. This study found that social jetlag and risk of CKD were significantly related in the Korean working population.