Objectives: Very few longitudinal studies have investigated the question of whether differences in company size may give rise to health inequalities. The aim of this study was to examine the relationship between company size of the longest-held job and mortality in older Japanese adults.
Methods: This study used longitudinal data from the Japan Gerontological Evaluation Study. Surveys were sent to functionally independent individuals aged 65 or older who were randomly sampled from 13 municipalities in Japan. Respondents were followed for a maximum of 6.6 years. The Cox proportional hazards model was used to calculate mortality hazard ratios (HRs) for men and for women. Analysis was carried out on 35 418 participants (197 514 person-years).
Results: A total of 3935 deaths occurred during the 6-year follow-up period. Among men, in Model 1 that adjusted for age, educational attainment, type of longest-held job, and municipalities, mortality HRs decreased significantly with increasing size of company (P for trend = .002). Compared to companies with 1-9 employees, the mortality HR (0.78, 95% confidence interval: 0.68-0.90) was significantly lower for companies with 10 000 or more employees. However, there were no significant differences among women (P for trend = .41).
Conclusions: In men, mortality in old age may decrease with increasing size of company of the longest-held job. To reduce health inequalities in old age due to differences in size of company, studies should be conducted to determine the underlying mechanisms and moderating factors and those findings should be reflected in labor policies and occupational health systems.
Objectives: Using annual health check-up data, the aim of this study was to identify target populations for lifestyle interventions to effectively prevent diabetes in a real-world setting.
Methods: The Japan Diabetes Outcome Intervention Trial-1, a prospective, cluster-randomized controlled trial, was launched to test if year-long telephone-delivered lifestyle support by health professionals can prevent the development of type 2 diabetes (T2D) in people with impaired fasting glucose (IFG) identified at health check-ups. A total of 2607 participants aged 20-65 years with IFG were randomized to an intervention arm (n = 1240) or a control arm (n = 1367). We performed subgroup analysis to examine the effects of the intervention on the incidence of T2D in participants with body mass index (BMI) ≥25, metabolic syndrome (MetS), and non-alcoholic or alcoholic elevated liver enzymes at the baseline. Cox regression analysis adjusted for sex was used to calculate the hazard ratios (HRs).
Results: In addition to IFG, the presence of BMI ≥25, MetS, and elevated liver enzymes increased the incidence of diabetes by two- or three-fold. During a median follow-up period of 4.9 years, only the non-alcoholic elevated liver enzyme group showed a low incidence rate owing to lifestyle interventions (adjusted HR: 0.42, 95% confidence interval: 0.18-0.98).
Conclusion: The results suggest that people who have IFG and non-alcoholic elevated liver enzymes are a good target population for lifestyle interventions to effectively reduce the incidence of diabetes in a real-world setting.
Objective: Poultry farm workers are exposed to barn air and suffer from various respiratory disorders. Due to frequent prevalence of endotoxin in the farm settings workers can get co-exposed to barn air and endotoxin. The study was aimed to explore the pulmonary damage following long-term multiple exposures to poultry barn air with or without endotoxin.
Methods: We studied the pulmonary expression of Toll-like receptor 4 (TLR4) and Interleukin-1β (IL-1β) by exposing Swiss albino mice to poultry barn air for 6 days (Monday-Saturday) in a week for 5 and 10 weeks. At the end of exposure, animals were challenged with lipopolysaccharide (LPS) or normal saline solution @80 μg/mouse intranasally. Histopathology, bronchoalveolar lavage (BAL) fluid and blood analysis were used to characterize lung damage. mRNA and protein expression of TLR4 and IL-1β were evaluated using quantitative polymerase chain reaction (qPCR) and immunohistochemistry, respectively.
Results: Histopathology along with TLC and DLC of blood and BAL fluid revealed lung damage following multiple exposures and damage was severe in combination with LPS. Exposures altered mRNA and protein expression of TLR-4 and IL-1β and the expression was more marked following 30 days of exposure. Further LPS co-challenge showed a synergistic effect on the expression of TLR4 and IL-1β.
Conclusions: The data suggest that long-term exposures with or without LPS caused lung damage and altered the pulmonary expression of TLR4 and IL-1β.
Miyuki Hasegawa, Shamima Akter, Huanhuan Hu, Ikuko Kashino, Keisuke Kuwahara, Hiroko Okazaki, Naoko Sasaki, Takayuki Ogasawara, Masafumi Eguchi, Takeshi Kochi, Toshiaki Miyamoto, Tohru Nakagawa, Toru Honda, Shuichiro Yamamoto, Taizo Murakami, Makiko Shimizu, Akihiko Uehara, Makoto Yamamoto, Teppei Imai, Akiko Nishihara, Kentaro Tomita, Satsue Nagahama, Ai Hori, Maki Konishi, Isamu Kabe, Tetsuya Mizoue, Naoki Kunugita, Seitaro Dohi, the Japan Epidemiology Collaboration on Occupational Health Study Group
Objective: The present study aimed to estimate cumulative incidence of overweight and obesity and describe 5-year longitudinal changes in body mass index (BMI) in a large occupational cohort in Japan.
Methods: Participants were 55 229 Japanese employees, who were aged 20-59 years and attended at all subsequent annual health check-ups between 2009 and 2014. Mixed model analysis was performed to examine the effects of age and cohort by gender on BMI change, with age as a random variable. Cumulative incidence of overweight (23.0≤ BMI <27.5 kg/m2) and obesity (BMI ≥27.5 kg/m2) was calculated. Logistic regression analysis was used to estimate odds ratios for the incidence of overweight and obesity according to age group.
Results: The incidence of overweight and obesity was approximately double in men (28.3% and 6.7%, respectively) compared to women (14.3% and 3.9%, respectively). The incidence of obesity decreased with age in men, but did not differ according to age in women (P for trend: .02 and .89, respectively). Among overweight participants, the incidence of obesity was higher in women (18.9%) than men (14.5%) and decreased with advancing age (P for trend: <.001 in men and .003 in women). Mean BMI was higher in men than women in all age groups throughout the period. Younger cohorts tended to have a higher BMI change compared with older cohorts.
Conclusions: In this Japanese occupational cohort, transition from overweight to obesity is higher in women than men, and the more recent cohorts had a higher change in mean BMI than the older cohorts.
Objectives: Neck pain ranks 4th highest in terms of disability as measured by years lived with disabilities. This study was conducted to determine whether Tasuki-style posture supporter improves neck pain compared to waiting-list.
Methods: This trial was an individually-randomized, open-label, waiting-list-controlled study. Adults (20 years or older) with non-specific chronic neck pain who reported 10 points or more on modified Neck Disability Index (mNDI: range, 0-50; higher points indicate worse condition) were enrolled. Participants were randomly assigned 1:1 to the intervention group or waiting-list. Prespecified primary outcome was the change in mNDI at 1 week. The principle of intention-to-treat analyses (as randomized) was applied. This trial was prospectively registered with UMIN (UMIN000034825).
Results: In total, 50 participants (mean age, 40.9 [standard deviation (SD) = 9.6]; 32 participants [64%] were female, mean mNDI, 14.3 [SD = 2.9]) were enrolled. Of these participants, 26 (52%) were randomly assigned to the intervention group and 24 (48%) to the waiting-list. Attrition rate was low in both groups (1/50). The mean mNDI change score at 1 week was more favorable for Tasuki than waiting-list (between-group difference, −3.5 points (95% confidence interval (CI), −5.3 to −1.8); P = .0002). More participants (58%) had moderate benefit (at least 30% improvement) with Tasuki than waiting-list (13%) (relative risk 4.6 (95% CI 1.5 to 14); risk difference 0.45 (0.22 to 0.68)).
Conclusion: This trial suggests that wearing Tasuki might moderately improve neck pain. With its low-cost, low-risk, and easy-to-use nature, Tasuki could be an option for those who suffer from neck pain.
Mi Xiang, Huanhuan Hu, Teppei Imai, Akiko Nishihara, Naoko Sasaki, Takayuki Ogasawara, Ai Hori, Tohru Nakagawa, Shuichiro Yamamoto, Toru Honda, Hiroko Okazaki, Akihiko Uehara, Makoto Yamamoto, Toshiaki Miyamoto, Takeshi Kochi, Masafumi Eguchi, Taizo Murakami, Makiko Shimizu, Kentaro Tomita, Satsue Nagahama, Akiko Nanri, Maki Konishi, Shamima Akter, Keisuke Kuwahara, Ikuko Kashino, Miwa Yamaguchi, Isamu Kabe, Tetsuya Mizoue, Naoki Kunugita, Seitaro Dohi, the Japan Epidemiology Collaboration on Occupational Health Study Group
Objectives: We aimed to compare the association of body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) with risk of cardiovascular disease (CVD) among middle-aged working Japanese men.
Methods: A nested case-control study was performed among middle-aged male employees who underwent periodic health checkup. A total of 241 CVD cases were identified and matched individually on age, gender, and worksite with 1205 controls. Data on BMI, WC, WHtR, smoking, hypertension, diabetes, and dyslipidemia collected at 4 years before the event/index date were retrieved. Associations between BMI, WC, WHtR, and CVD risk were assessed by using conditional logistic regression models.
Results: The strength of the association of BMI, WC, and WHtR with CVD risk was similar. The smoking-adjusted odds ratio (95% confidence interval) for CVD was 1.60 (1.38-1.85), 1.53 (1.33-1.78), and 1.56 (1.35-1.81) for a 1 SD unit increase in BMI, WC, and WHtR respectively. After further adjustment for hypertension, diabetes, and dyslipidemia, these associations were attenuated but remained statistically significant.
Conclusions: Measures of general (BMI) and abdominal (WC and WHtR) obesity were similarly associated with CVD in middle-aged Japanese men.
Objectives: The increasing number of working elderly people has enhanced the importance of workplace health promotion activities. We investigated the association between the health status of workers approximately 60 years of age and the risk of all-cause mortality after compulsory retirement in Japan.
Methods: The 2026 participants (1299 males and 727 females) had retired from a metal-products factory at ≥60 years of age. Baseline health examinations were conducted at 60 years of age and included questions about medical history and lifestyle factors; the participants also underwent a physical examination. The participants were followed up annually by mail for an average of 7.4 years. The association between health status at age 60 years and the risk of all-cause mortality was assessed by Cox proportional hazards regression analysis.
Results: During the study, 71 deaths were reported. The age- and sex-adjusted hazard ratio (HR [95% confidence interval]) for all-cause mortality was higher for males (HR, 3.41 [1.73-6.69]) compared with females, participants with a low body mass index (<18.5 kg/m2; HR 3.84 [1.91-7.73]) compared with normal body weight, smokers (HR, 2.63 [1.51-4.58]) compared with nonsmokers, and those with three or more of four metabolic abnormalities (obesity, high blood pressure, dyslipidemia, and glucose intolerance) (HR 2.29 [1.04-5.02]) compared with no metabolic abnormalities. The associations were unaffected by adjustment for these factors.
Conclusion: Maintenance of an appropriate body weight, smoking cessation, and elimination of metabolic syndrome are required for older workers to prevent early death after retirement.
Jarmo Kuronen, Klas Winell, Sami Riekki, Jelena Hartsenko, Kimmo Räsänen
Objectives: Early retirement due to disability is a problem in Finland. That causes pension costs that are heavy for the society. This study was designed to find out whether a quality network can support the reduction in incident disability pensions and promote a shift from full to partial disability pensions.
Methods: The study population (N = 41 472 in 2016) consisted of municipal employees whose occupational health care (OHC) was provided by the members of the Finnish Occupational Health Quality Network (OQN). The comparison population consisted of all municipality employees whose OHC was provided by non-members of the OQN (N = 340 479 in 2016). The outcomes were measured by comparing the trends in incident disability pensions of full and partial permanent pension and full and partial provisional pension, partial/full pension indexes from 2011 to 2016 according to the principles of Benchmarking Controlled Trials. Linear regression models were used to explore the dynamics of different pension forms. Regression coefficients were calculated to show the average change per year.
Results: The incidence of permanent disability pensions decreased faster in the study population (P for trend .03) and the study group showed a stronger shift from full to partial permanent pensions (P for trend <.001).
Conclusion: Quality networking between OHC units including common goal setting, systematic quality improvement, and repeated quality measurements decreased new permanent disability pensions and increased partial permanent pensions. Such changes are important while thriving for increased work participation.
Marc Rocholl, Michaela Ludewig, Swen Malte John, Eva Maria Bitzer, Annika Wilke
Objectives: Since January 2015, squamous cell carcinoma or multiple actinic keratosis of the skin caused by natural ultraviolet irradiation (UVR) is recognized as occupational disease in Germany. Interventions which improve the sun protection behavior of outdoor workers are urgently needed. When developing preventive interventions, the attitudes of target groups need to be taken into consideration. Therefore, outdoor workers’ perceptions and attitudes were investigated.
Methods: Seven guided, problem-centered qualitative interviews with healthy male outdoor workers were conducted. A qualitative content analysis was used to analyze the data.
Results: We found an underestimation of the perceived skin cancer risk in the seven outdoor workers and heterogeneous attitudes toward the usage of sun-protective measures. Participants stated that the feasibility of technical sun-protective measures depends on the size of the working area. While using a headgear seemed common, none of the participants stated using additional neck protection. Wearing long-sleeved shirts and long trousers were considered problematic. The interviews revealed important requirements for sun-protective clothes, especially in terms of different materials. Although the usage of sunscreen was common, our interviewees seemed to apply it wrongly.
Conclusion: Risk perceptions of outdoor workers and their attitudes toward sun protection measures may influence the factual UV protection behavior in the workplace. Structures to facilitate the implementation of technical and organizational sun-protective measures seem to be necessary. Educational interventions and clear instructions which are tailored to the individual needs and attitudes of outdoor workers are required to improve the UV protection behavior and to avoid common mistakes.
Objectives: To develop and validate a global occupational health and safety management system (OHSMS) model for Japanese companies.
Methods: In cooperation with a Japanese company, we established a research team and gathered information on occupational health and safety (OHS) practices in nine countries where the target company operated manufacturing sites. We then developed a model hypothesis via research team meeting. The model hypothesis was introduced to local factories in Indonesia and Thailand as trial sites. We evaluated the roles of the company headquarters, the implementation process, and any improvements in OHS practices at the sites. Based on the results, a global OHSMS model was formalized for global introduction.
Results: The model consisted of both headquarters and site roles. These roles were well-functioning, and OHS at the sites improved. Two issues concerning the functioning of the headquarters were identified: the need to establish a reporting system to the headquarters and the need to support the improvement of specialized human resources. By improving the model hypothesis to address these issues, the model was formalized for global introduction.
Conclusions: The global OHSMS model was based on the use of methods and specialized human resources relevant to each region and their common objectives, as well as evaluation indicators based on the minimum requirements of the company headquarters. To verify the effectiveness of this model, the experiment should be extended to other countries.
Koji Mori, Takahiro Mori, Tomohisa Nagata, Masako Nagata, Mahoko Iwasaki, Hiroki Sakai, Koki Kimura, Natsumi Shinzato
Objective: A systematic review was performed to study factors of occurrence and improvement methods of presenteeism attributed to diabetes.
Methods: We set 2 clinical questions; (a) how comorbidities and complications of diabetes induce presenteeism and (b) what interventions or conditions effectively improve presenteeism. Then, we conducted a comprehensive search with MEDLINE/PubMed and Scopus databases and extracted those that met the clinical questions.
Results: Eighteen papers studied occurrence of presenteeism by comorbidities and complications of diabetes. Most studies were cross-sectional and had a low quality of evidence. However, the associations of hypoglycemia, diabetic neuropathy, and mood disorders with presenteeism were relatively well studied. The papers that discussed effective interventions or conditions for improving presenteeism were very limited.
Conclusions: Our review suggests that presenteeism attributed to diabetes is mainly caused by hypoglycemia, diabetic neuropathy, and mood disorders. There are very limited evidences, but available information suggests that improving glycemic control, adjusting treatment regimen by evaluating the impact on work, providing psychological support, and developing suitable work accommodations may effectively reduce presenteeism.
Expert Division of Occupational Hygiene & Ergonomics, the Japan Society for Occupational Health, "The Committee for Personal Exposure Monitoring", Haruo Hashimoto, Kenichi Yamada, Hajime Hori, Shinji Kumagai, Masaru Murata, Toshio Nagoya, Hirohiko Nakahara, Nobuyuki Mochida
This Document, "Guidelines for personal exposure monitoring of chemicals" ("this Guideline"), has been prepared by "The Committee for Personal Exposure Monitoring" ("the Committee") of the Expert Division of Occupational Hygiene & Ergonomics, Japan Society for Occupational Health. Considering the background of the growing importance of personal exposure monitoring in risk assessment and the need to prepare for the introduction of monitoring using personal samplers from an administrative perspective in recent years, the Committee was organized in November 2012. The Committee has prepared this Guideline as a "practical guideline" for personal exposure monitoring, so as to offer proposals and recommendations to the members of the Japan Society for Occupational Health and to society in general. The scope of this Guideline covers all chemical substances and all related workplaces regarded as targets for general assessment and the management of risk. It thus is not to be considered to comment on legal regulations and methodology. The main text provides the basic methods and concepts of personal exposure monitoring, while 31 "Appendices" are provided later in this Guideline throughout the series; technical descriptions, statistical bases, and actual workplace examples are provided in these appendices, to assist better understanding. The personal exposure monitoring described as per this Guideline is equivalent to an "expert-centered basic method to reasonably proceed with the assessment and management of risk at workplaces." It is considered that practicing and expanding on this method will significantly contribute in reforming the overall framework of occupational hygiene management in Japan.