Developing a broad perspective of future work and career in medical students through field trips to a disaster area: a qualitative study.

OBJECTIVE: Field trips to disaster-affected areas (FTDAs) without a specific purpose, such as medical cooperation, are widely used in medical education. However, what medical students gain from FTDAs remains unclear. The present study aimed to clarify what medical students gain from FTDAs. Five medical students who had visited the Fukushima nuclear power plant in Japan participated in a semi-structured group interview to ask what they gained from such a visit. The narratives were analysed using open coding. RESULTS: The following four themes emerged: "Spirit of scientific inquiry", "Foundation for lifelong education and personal growth", "Broadened understanding of the medical profession", and "Importance of practicing medicine in the community setting". The ambiguity of medical students' specific roles in the field trip compared to the fieldwork may have encouraged them to make sense of the experience from their perspective. As a result, students may have gained a broader perspective of their future work and career through the FTDA. If medical educators can gain consensus from the residents of a disaster site, different disaster-affected areas can be potential sites for medical education using FTDAs.

Association between home meal preparers and salt intake in haemodialysis patients: a cross-sectional study.

OBJECTIVES: This study aimed to examine the association between home meal preparer and salt intake among haemodialysis patients, including daily dietary status. We hypothesised that salt intake is higher among individuals who rely on meal preparation from others than those who prepare meals by themselves. DESIGN: Cross-sectional study. SETTING: Two medical facilities in Fukushima Prefecture, Japan. PARTICIPANTS: 237 haemodialysis outpatients who visited one of the medical facilities between February 2020 and August 2021 and were diagnosed with anuria, defined as urination of <100 mL/day, were the potential participants of the present study. Finally, 181 participants (131 male and 50 female) were included in the analysis. OUTCOME MEASURE: Salt intake amount was calculated from the results of predialysis and postdialysis blood draws, using Watson's formula based on predialysis weight, predialysis serum sodium level, postdialysis weight and serum sodium level at the end of dialysis. RESULTS: Salt intake was significantly higher in participants who relied on meal preparation from others ('relying on others') than those who prepared meals by themselves ('self-prepared') (B=1.359; 95% CI: 0.495 to 2.222). No statistical difference was found between individuals who ate out or ate takeout ('outsourcing') and those who prepared their own meals ('self-prepared'). These results were robust after adjustment for confounding factors. CONCLUSIONS: The present study revealed an association between self-preparation of meals at home and reduced salt intake among dialysis patients. Our findings suggest that whoever is the home meal preparer is possibly a social determinant of salt intake. To improve the prognosis of haemodialysis patients, actively reaching out to the family and assessing their social environment, such as identifying the home meal preparer and, if the patient relies on others for meal preparation, conducting nutritional/dietary guidance for that person, are effective in enhancing salt reduction.

Inappropriate timing of salt intake increases the risk of heat-related illness: An observational study.

The importance of salt intake in preventing heat-related illness (HRI) is well established, however, the specific method of ingestion has not been sufficiently studied. This study, therefore, aimed to investigate the optimal timing of salt intake to prevent HRI during hot outdoor work. We recruited 28 healthy male firefighters working at a fire department in Japan. They were provided a questionnaire to complete before and after receiving training in the summer season. We assessed their salt intake as before, during, and after training or none. In addition, they completed a brief self-administered diet history questionnaire to evaluate their daily salt and alcohol intake. HRI was determined through subjective and objective symptoms listed in the questionnaire, and environmental data were obtained from a national database. Subsequently, factors related to HRI were determined using a logistic regression model. The mean age of the participants was 31.0 ± 7.7 years. The study was performed within 250 working days, and we detected 28 HRI symptoms (11.2%). The median alcohol intake was 25.6 g/day when calculated according to the actual work system. Logistic mixed effect model analysis revealed that salt intake before training (OR: 5.893, 95% CI: 1.407-24.675), and salt intake before and during training (OR: 22.889, 95% CI: 4.276-122.516) were positively associated with HRI symptoms. The results indicate that inappropriate timing of salt intake increases the risks of HRI. Thus, a timely intake of salt in adequate amounts may be important in preventing these risks.

Associations of endurance, muscle strength, and balanced exercise with subjective sleep quality in sedentary workers: A cross-sectional study.

BACKGROUND: The optimal exercise combination for improving sleep quality among sedentary workers is unclear. OBJECTIVE: To reveal what combination of exercises contributes to good sleep quality. METHODS: In this cross-sectional study, we enrolled 5,201 sedentary workers who underwent health examinations in 2019. Data on sleep quality, basic attributes, energy expenditure, and lifestyle aspects such as exercise and physical activity, supper time close to bedtime, and alcohol intake were obtained. The subjects reported their exercise habits by selecting up to three forms of exercise from a list of 182 options, which were classified into three types: endurance (e.g., jogging), muscle strength (e.g., bench pressing), and balanced types which combined both endurance and muscle strength characteristics. (e.g., walking). These forms were then categorized into eight combination patterns: endurance only; muscle strength only; balanced only; endurance and muscle strength; endurance and balanced; muscle strength and balanced; all types; and absence of any exercise habits. Binary logistic regression analysis was used to examine the associations between the exercise combination patterns and sleep quality. RESULTS: Good sleep quality was significantly associated with "endurance" (OR = 1.419; 95% CI 1.110-1.814), "balanced only" (OR = 1.474; 95% CI 1.248-1.741), and "endurance and balance" (OR = 1.782; 95% CI 1.085-2.926) exercise patterns. No significant associations were found between the combinations that included muscle strength exercises and sleep quality. CONCLUSION: The endurance or balanced-type exercises, or a combination of both, may help to improve the sleep quality of sedentary workers as part of occupational health management.

Perceived Future Outcomes of Unsuccessful Treatment and Their Association with Treatment Persistence Among Type-2 Diabetes Patients: A Cross-Sectional Content Analysis.

INTRODUCTION: Despite the known strong association between patients' knowledge of outcomes of type 2 diabetes mellitus (T2DM) and treatment persistence, this knowledge in this patient population requires further clarification. The aim of our study was to reveal the perception of unsuccessful treatment outcomes among patients with T2DM and its association with treatment persistence by analysing answers to open-ended questions. METHODS: In this cross-sectional study, 106 patients with T2DM who lived in Fukushima Prefecture, Japan, had a medical record in the Fukushima National Health Insurance Organisation database and had no cognitive problems were enrolled by purposive sampling. Treatment status was defined as "non-persistent" when a participant's treatment medical record was absent for a continuous period of ≥ 6 months; otherwise, it was referred to as "persistent". We asked about the possible future problems of untreated T2DM, inductively classified the open answers into 15 codes and then statistically examined the association between these codes and treatment persistence using logistic regression analysis adjusted for age and sex. RESULTS: Persistent treatment was prevalent among participants who mentioned the code "treatment", which encompasses the terms that indicated invasiveness, such as dialysis, insulin injection, and shots (odds ratio 4.339; 95% confidence interval 1.104-17.055). CONCLUSION: Persistent treatment was prevalent among patients with T2DM who mentioned the code "treatment", suggesting that these patients may anticipate a threat due to the invasiveness of diabetes and thus participate in persistent treatment to avoid this threat. Healthcare professionals should provide appropriate information and supportive conditions to achieve both a reduced feeling of threat and persistent treatment engagement.

Prognostic impact of LILRB4 expression on tumor-infiltrating cells in resected non-small cell lung cancer.

BACKGROUND: Leukocyte immunoglobulin-like receptor subfamily B member 4 (LILRB4/ILT3) is an up-and-coming molecule that promotes immune evasion. We have previously reported that LILRB4 facilitates myeloid-derived suppressor cells (MDSCs)-mediated tumor metastasis in mice. This study aimed to investigate the impact of the LILRB4 expression levels on tumor-infiltrating cells on the prognosis of non-small cell lung cancer (NSCLC) patients. METHODS: We immunohistochemically evaluated the LILRB4 expression levels of completely resected 239 NSCLC specimens. Whether the blocking of LILRB4 on human PBMC-derived CD33+ MDSCs inhibited the migration ability of lung cancer cells was also examined using transwell migration assay. RESULTS: The LILRB4 high group, in which patients with a high LILRB4 expression level on tumor-infiltrating cells, showed a shorter overall survival (OS) (p = 0.013) and relapse-free survival (RFS) (p = 0.0017) compared to the LILRB4 low group. Multivariate analyses revealed that a high LILRB4 expression was an independent factor for postoperative recurrence, poor OS and RFS. Even in the cohort background aligned by propensity score matching, OS (p = 0.023) and RFS (p = 0.0046) in the LILRB4 high group were shorter than in the LILRB4 low group. Some of the LILRB4 positive cells were positive for MDSC markers, CD33 and CD14. Transwell migration assay demonstrated that blocking LILRB4 significantly inhibited the migration of human lung cancer cells cocultured with CD33+ MDSCs. CONCLUSION: Together, signals through LILRB4 on tumor-infiltrating cells, including MDSCs, play an essential role in promoting tumor evasion and cancer progression, impacting the recurrence and poor prognosis of patients with resected NSCLC.

Fibronectin on target cells attenuates natural cytotoxicity of NK cells via myeloid immune checkpoint ILT3/LILRB4/gp49B.

Natural killer (NK) cells play pivotal roles in innate immunity as well as in anti-tumor responses via natural killing, while their activity is tightly regulated by cell-surface inhibitory receptors. Immunoglobulin-like transcript 3/leukocyte immunoglobulin-like receptor B4 (ILT3/LILRB4, also known as gp49B in mice) is an inhibitory receptor expressed on activated NK cells as well as myeloid-lineage cells. The common physiologic ligand of human LILRB4 and gp49B was identified very recently as fibronectin, particularly the N-terminal 30 kDa domain (FN30). We hypothesized that LILRB4 could bind fibronectin on target cells in trans together with integrins, classical fibronectin receptors, in cis and deliver an inhibitory signal in NK cells, leading to attenuated natural killing. Flow cytometric and confocal microscopic analyses of NK cell-surface gp49B and integrins suggested that these novel and classical fibronectin receptors, respectively, co-engage fibronectin immobilized on a culture plate. Biochemical analyses indicated that tyrosine phosphorylation of spleen tyrosine kinase was augmented in gp49B-deficient NK cells upon binding to the immobilized fibronectin. While surface fibronectin-poor YAC-1 cells were evenly sensitive as to natural killing of both gp49B-positive and -negative NK cells, the killing of fibronectin-rich Lewis lung carcinoma cells, but not the FN30-knockout cells, was augmented among gp49B-deficient NK cells. These results suggest that the natural cytotoxicity of NK cells is negatively regulated through LILRB4/gp49B sensing fibronectin on target cells, which sheds light on the unexpected role of LILRB4 and fibronectin as a potential attenuator of NK cell cytotoxicity in the tumor microenvironment.

Reliability and validity of the Japanese version of the weight bias internalization scale.

OBJECTIVE: The weight bias internalization scale (WBIS) is widely used in several languages. However, there is no Japanese version of the WBIS. The purpose of this study is to develop a Japanese version of the WBIS and to verify its reliability and validity. We translated the original version of the WBIS and had approval from the scale developer. Adults who perceived themselves to be obese completed online baseline survey (N = 285) and two-week follow-up survey (N = 100). We used the Japanese WBIS and scales for obesity-related quality of life, self-esteem, self-efficacy, and depression. We calculated Cronbach's alpha and intra-class correlation coefficient (ICC) to assess reliability of the WBIS and conducted confirmatory factor analysis (CFA) and correlation analysis to assess its validity. RESULTS: Cronbach's alpha was 0.91 at baseline and 0.92 at follow-up, and the ICC was 0.87. CFA showed that a one-factor model demonstrated an acceptable fit (χ2 (44) = 158.6, CFI = 0.93, RMSEA = 0.096, SRMR = 0.051), similar to the original version. As we had hypothesized, overall, the Japanese version of the WBIS was significantly correlated with obesity-related quality of life, self-esteem, self-efficacy, and depression. These results confirmed its adequate reliability and validity.

Concerns related to returning home to a "difficult-to-return zone" after a long-term evacuation due to Fukushima Nuclear Power Plant Accident: A qualitative study.

This study aimed to identify concerns related to returning to the Nagadoro district of Iitate Village, Fukushima Prefecture, Japan, in 2023 among its residents as it is designated as a difficult-to-return zone after the Fukushima Daiichi nuclear power plant accident. The following four concerns were extracted from the interviews and qualitative analysis: "Difficulties in restarting/continuing farming," which represent the difficulties in making a living from agriculture due to the absence of family members and neighbors, and the insufficient radiation decontamination; "Discriminatory treatment of products and residents from villagers," which suggests the presence of discriminations that residents of Nagadoro district are eccentrics and its agricultural products should not be treated together with those of other districts in the Village due to the recognition that the district is severely polluted by radiation; "Shift of the responsibility of returning home from the country to residents by scapegoating," which is characterized by the shift of responsibility from the government to the residents, including harsh social criticism of the residents of Nagadoro district for not returning even though the evacuation order has been lifted, when it should have been the government's responsibility to recover the district to a habitable state; "Loss of options for continued evacuation," which is the loss or weakening of the position of residents of the Nagadoro district who continue to evacuate, and of administrative compensation, resulting from the legal change that they are no longer "evacuees" after the evacuation order is lifted. The findings of this study will provide a foundation for the support of residents of the Nagadoro district after lifting the evacuation order scheduled for the spring of 2023. The findings may be transferable to the residents of other difficult-to-return zones expected to be lifted after the Nagadoro district and to also a radiation disaster-affected place in the future.

Myeloid immune checkpoint ILT3/LILRB4/gp49B can co-tether fibronectin with integrin on macrophages.

LILRB4 (B4, also known as ILT3/CD85k) is an immune checkpoint of myeloid lineage cells, albeit its mode of function remains obscure. Our recent identification of a common ligand for both human B4 and its murine ortholog gp49B as the fibronectin (FN) N-terminal 30 kDa domain poses the question of how B4/gp49B regulate cellular activity upon recognition of FN in the plasma and/or the extracellular matrix. Since FN in the extracellular matrix is tethered by FN-binding integrins, we hypothesized that B4/gp49B would tether FN in cooperation with integrins on the cell surface, thus they should be in close vicinity to integrins spatially. This scenario suggests a mode of function of B4/gp49B by which the FN-induced signal is regulated. The FN pull-down complex was found to contain gp49B and integrin ß 1 in bone marrow-derived macrophages. The confocal fluorescent signals of the three molecules on the intrinsically FN-tethering macrophages were correlated to each other. When FN-poor macrophages adhered to culture plates, the gp49-integrin ß 1 signal correlation increased at the focal adhesion, supporting the notion that gp49B and integrin ß 1 become spatially closer to each other there. Adherence of RAW264.7 and THP-1 cells to immobilized FN induced phosphorylation of spleen tyrosine kinase, whose level was augmented under B4/gp49B deficiency. Thus, we concluded that B4/gp49B can co-tether FN in cooperation with integrin in the cis configuration on the same cell, forming a B4/gp49B-FN-integrin triplet as a regulatory unit of a focal adhesion-dependent pro-inflammatory signal in macrophages.

Co-localization of Fibronectin Receptors LILRB4/gp49B and Integrin on Dendritic Cell Surface.

A myeloid immune checkpoint, leukocyte immunoglobulin-like receptor (LILR) B4 (B4, also known as ILT3/CD85k in humans and gp49B in mice) is expressed on dendritic cells (DCs). However, a mode of regulation of DCs by B4/gp49B is not identified yet in relation to the ligand(s) as well as to the counteracting, activation-type receptor. Our recent identification of the physiological/pathological ligand for B4/gp49B as the fibronectin (FN) N-terminal 30-kDa domain poses the question of the relationship between B4/gp49B and a classical FN receptor/cellular activator, integrin, on DCs. Here we showed that FN is not constitutively tethered on the surface of bone marrow-derived cultured DCs (BMDCs) or splenic DCs, even though the FN receptor integrin and gp49B are co-expressed on these cells. Confocal laser scanning microscopic analysis, however, revealed weak correlation of fluorescent signals between gp49B and integrin ß1, suggesting their partial co-localization on the BMDC surface even in the absence of FN. We found that the plating of BMDCs onto immobilized FN induced tyrosine phosphorylation of focal adhesion kinase (FAK) and spleen tyrosine kinase (Syk). In the absence of gp49B, while the FAK phosphorylation level was virtually unchanged, that of phosphorylation of Syk was markedly augmented. These results suggested that the immobilized FN induced a crosstalk between gp49B and integrin in terms of the intracellular signaling of BMDCs, in which gp49B suppressed the integrin-mediated pro-inflammatory cascade. Our observations may provide a clue for elucidating the mechanism of the therapeutic efficacy of B4/gp49B blocking in autoimmune disease and cancer.

LILRB4 promotes tumor metastasis by regulating MDSCs and inhibiting miR-1 family miRNAs.

Myeloid-derived suppressor cells (MDSCs) are a population of immune suppressive cells that are involved in tumor-associated immunosuppression, and dominate tumor progression and metastasis. In this study, we report that the leukocyte immunoglobulin-like receptor subfamily B member 4 (LILRB4, murine ortholog gp49B) orchestrates the polarization of MDSCs to exhibit pro-tumor phenotypes. We found that gp49B deficiency inhibited tumor metastases of cancer cells, and reduced tumor-infiltration of monocytic MDSCs (M-MDSCs) in tumor-bearing mice. Gp49B-/- MDSCs inhibited pro-tumor immune responses, such as activation of Treg cells, promotion of cancer cell migration, and stimulation of tumor angiogenesis. Treatment of wild-type tumor-bearing mice with gp49B-/- M-MDSCs reduced cancer metastasis. Furthermore, gp49B knockout affected plasma exosome composition in terms of increased miR-1 family microRNAs (miRNAs) expression, which correlates with the upregulation of gp49B-/- MDSC-derived anti-tumor miRNAs. Collectively, our findings reveal that LILRB4/gp49B promotes MDSC-mediated tumor metastasis by regulating the M2-polarization of MDSCs and suppressing the secretion of miR-1 family miRNAs, which facilitate tumor migration and invasion. Abbreviations CTLA-4: cytotoxic T-lymphocyte-associated protein-4; FBS: fetal bovine serum; G-MDSCs: granulocytic-MDSCs; GP49B: glycoprotein 49B; HE: hematoxylin-eosin; ICI: immune checkpoint inhibitor; ITIM: immunoreceptor tyrosine-based inhibition motif; LILRB4: leukocyte immunoglobulin-like receptor B4; M-CSF: macrophage colony stimulating factor; MDSC: myeloid-derived suppressor cell; M-MDSC: monocytic MDSC; MMP-9: metallopeptidase-9; mAb: monoclonal antibody; PBS: phosphate-buffered saline; PCR: polymerase chain reaction; PD-1: programmed death-1; PD-L1: programmed death ligand-1; PMN-MDSC: polymorphonuclear-MDSC; qRT-PCR: quantitative reverse transcription PCR; TAM: tumor associated macrophage; TME: tumor microenvironment; TMM: trimmed mean of M value; VEGFA: vascular endothelial growth factor A.

The Systematic Workplace-Improvement Needs Generation (SWING): Verifying a Worker-Centred Tool for Identifying Necessary Workplace Improvements in a Nursing Home in Japan.

This study developed and tested a new measurement instrument, the Systematic Workplace-Improvement Needs Generation (SWING), to identify workplace-improvement needs. The participants were 53 workers in a Japanese nursing home for the elderly. The respondents used the SWING questionnaire to self-generate five 'cues' they considered important to improve the workplace. The workers determined each cue's sufficiency level and weight balance (importance), and then we summarised the 265 cues into 21 categories for workplace improvements. The respondents identified the following items as the most important and the least sufficiently provided areas for workplace improvement: 'interaction with customers', 'physical and psychological harassment', 'rewarding and challenging work', and 'sharing goals and objectives'. Although the workplace-improvement recommendations differed greatly from person to person, SWING prioritised the items by weight (importance) and sufficiency (current status), allowing organisations to address the needed improvements systematically. The SWING tool effectively elicited and prioritised respondents' recommendations for improving the workplace. Because its items are self-generated by the respondents, SWING can be used for any occupation or workplace. Visualisation with bubble plots to clarify the improvement needs is incorporated into SWING.

Visualizing the decline of public interest in the Great East Japan Earthquake and Fukushima Daiichi nuclear power plant accident by analyzing letters to the editor in Japanese newspapers.

This study aimed to delineate the decline in public interest toward the March 2011 Great East Japan Earthquake (GEJE) and the Fukushima Daiichi nuclear power plant (FNPP) accident in Japan over a ten-year period. In this longitudinal descriptive study, we searched for publications within a ten-year period in Letters to the Editor that mentioned the GEJE, the FNPP accident, or the January 1995 Great Hanshin-Awaji Earthquake (GHAE) that occurred in Japan, using the official databases of the three largest Japanese newspapers. The GEJE- and GHAE-related publications (4,809 and 2,092, respectively) are depicted as scatter plots. The results show a gradual decrease in the publications mentioning GEJE or GHAE. The impact of GEJE and FNPP on Japanese society was enormous, but the public interest waned over time. Communication strategies that maintain a high public interest in previous disasters may be necessary.

Predictors of Treatment Response and Long-Term Outcomes in Young Children with Steroid-Dependent Nephrotic Syndrome Treated with High-Dose Mizoribine as First-Line Steroid-Sparing Agent.

Mizoribine may be a safe and effective treatment for children with steroid-dependent nephrotic syndrome (SDNS). However, predictors of treatment response and long-term outcomes after mizoribine discontinuation remain unknown. We retrospectively reviewed the clinical course of 22 children aged ≤ 10 years (median age, 5.3 years) with SDNS who received high-dose mizoribine as the initial steroid-sparing agent (SSA). Mizoribine was administered at a single daily dose of 10 mg/kg (maximum, 300 mg/day) after breakfast. The dose was adjusted to maintain 2-h post-dose mizoribine levels of > 3 µg/mL and was tapered off after 12 months of steroid-free remission. Patients who regressed to SDNS were switched from mizoribine to other SSAs. The primary endpoint was probability of survival without regression to SDNS after mizoribine initiation. Ten patients were able to discontinue SDNS (response group), whereas twelve were switched from mizoribine to other SSAs (non-response group) during a median observation period of 6.0 years after mizoribine. The steroid-dependent dose prior to mizoribine was significantly lower in the response group than in the non-response group (p < 0.05). The Kaplan-Meier analysis revealed that the probability of regression-free survival was significant higher in patients with steroid-dependent dose of < 0.25 mg/kg/day than in those with steroid-dependent dose of ≥ 0.25 mg/kg/day (p < 0.05). During a median follow-up of 5.5 years after mizoribine discontinuation, all but one patient did not develop SDNS. High-dose mizoribine may be an attractive treatment option as initial SSA in young children with low steroid-dependent dose for improved long-term outcomes.

Association between subjective economic status and refusal of life-prolonging treatment: a cross-sectional study using content analysis with stratified random sampling.

INTRODUCTION: Older adults tend to refuse life-prolonging treatment for various reasons, and it is important to respect their choice of treatment at the end-of-life stage. The present study examines the associations of subjective economic status and gender with reasons for refusal of life-prolonging treatment in older adults in general population. METHODS: In this cross-sectional study, using stratified random sampling, 1,595 older adults living in Koriyama City, Japan, as of 2016, completed self-administered questionnaires on subjective economic status and preference for life-prolonging treatment, with free-description regarding reasons for refusal. We analyzed the associations between the combination of subjective economic status and gender with frequently mentioned terms and their clusters regarding such reasons, using χ2 test, content analysis, text mining and hierarchical cluster analysis. RESULTS: The combinations of subjective economic status and gender were significantly associated with clustered reasons for refusal of life-prolonging treatment (p < 0.01). The reasons frequently mentioned were: 'avoidance of unnecessary medical care' and 'dignity' in well-off females; and 'financial burden on family' in poor males. CONCLUSIONS: Our findings suggest that older adults who at first glance appear to be freely refusing life-prolonging treatment, may have their decision making restricted through economic constraints.

Effect of occupation on sleep duration among daytime Japanese workers: A cross-sectional study.

ABSTRACT: Occupation is one of the factors contributing to the loss of sleep. Although many studies have investigated sleep loss due to irregular and nighttime shifts, the causes of sleep loss in daytime workers remain unknown. The aims of the present study were to determine whether occupation is a dependent factor for sleep duration and whether working status and lifestyle are related to sleep duration.We examined the health check results of 17,519 (9028 men and 8491 women) workers who had at least 1 health check between the fiscal years 2013 and 2019. We asked about the workers' occupation, bedtime, dinner time, overtime work, and commuting time, using a self-administered questionnaire at their health check. The occupations were classified into 4 categories: high white-collar, low white-collar, pink-collar, and blue-collar. We conducted a linear regression model and analysis of covariance to investigate the effect of occupation on sleep duration.As a result of linear regression analysis, bedtime, overtime work and occupation were significantly associated with decreased sleep duration in males, and bedtime, age, and occupation were significantly associated with decreased sleep duration in females. Analysis of covariance revealed that both male and female blue-collar tended to sleep for significantly shorter durations than those in the other occupations.The results of the current study indicate that sleep duration is affected by occupation. When determining the cause of loss of sleep, medical personnel should consider their patient's lifestyles and how they have been affected by their occupation.