To investigate the reliability and validity of 4 selected scales from the Japanese version of the Job Content Questionnaire (JCQ. Karasek, 1985)-decision latitude, psychological demand, supervisor support, and coworker support-a survey was conducted on a total of 626 employees of telephone and electric companies in Japan. The survey questionnaire was composed of 22 items. Data from 472 male and 108 female respondents were analyzed. Cronbach's alpha coefficients for the four JCQ scales ranged from .61 to .89 for men and from .65 to .87 for women. Scree plots based on factor analyses of scale items indicated that one major factor explained 30% to 75% of each scale variance in men and women. Factor structures of the 22 items for men and women were consistent with those theoretically expected Distributions of the decision latitude scores among occupations for men and women were similar to those in the U.S. national samples; the scores significantly and positively correlated with occupational class. It is suggested that the JCQ scales are reliable and valid instruments for assessing job stressors in a Japanese working population.

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Muscle sympathetic nerve activity (MSNA) was measured directly along with blood pressure at rest in 69 healthy women (20–79 yr old) and 76 age-matched healthy men (16–80 yr old). All were nonobese and normotensive. In the women and men the MSNA was positively correlated with age (women: y = 0.788 x − 5.418, r = 0.846, P < 0.0001; men: y = 0.452 x + 12.565, r = 0.751, P < 0.0001). The regression intercept of y was significantly lower ( P < 0.0001) in the women than in the men, and the regression slope was significantly steeper ( P < 0.0001) in the women. The MSNA was lower in women than in men among those <30 ( P = 0.0012), 30–39 ( P = 0.0126), and 40–49 yr old ( P = 0.0462) but was similar in women and men among those 50–59 ( P = 0.1911, NS) and ≥60 yr old ( P = 0.1739, NS). The results suggest that MSNA increases with age in women and men and that the activity is markedly lower in young women than in men but is markedly accelerated with age.

BackgroundChronic pain is recognized as a public health problem that affects the general population physically, psychologically, and socially. However, there is little knowledge about the associated factors of chronic pain, such as the influence of weather, family structure, daily exercise, and work status.ObjectivesThis survey had three aims: 1) to estimate the prevalence of chronic pain in Japan, 2) to analyze these associated factors, and 3) to evaluate the social burden due to chronic pain.MethodsWe conducted a cross-sectional postal survey in a sample of 6000 adults aged ≥20 years. The response rate was 43.8%.ResultsThe mean age of the respondents was 57.7 years (range 20–99 years); 39.3% met the criteria for chronic pain (lasting ≥3 months). Approximately a quarter of the respondents reported that their chronic pain was adversely influenced by bad weather and also oncoming bad weather. Risk factors for chronic pain, as determined by a logistic regression model, included being an older female, being unemployed, living alone, and no daily exercise. Individuals with chronic pain showed significantly lower quality of life and significantly higher psychological distress scores than those without chronic pain. The mean annual duration of absence from work of working-age respondents was 9.6 days (range 1–365 days).ConclusionsOur findings revealed that high prevalence and severity of chronic pain, associated factors, and significant impact on quality of life in the adult Japanese population. A detailed understanding of factors associated with chronic pain is essential for establishing a management strategy for primary care.

A cross-sectional study on 6,676 workers consisting of 4,243 males and 2,433 females aged 20-58 yr in a metal product factory was conducted to elucidate the relationship between work characteristics, e.g. job demand/control/support, sedentary job, overtime work and shift work, and waist to hip ratio (WHR) as well as body mass index (BMI) taking alcohol consumption, smoking, exercise and other psychosocial factors such as education and marital status into account. By a stepwise multiple regression analysis, BMI was associated with shift work, marital status and sedentary job for males, and with exercise but inversely associated with education for females. WHR was also associated with shift work, alcohol consumption, marital status and sedentary job but inversely associated with exercise for males, and with sedentary job, marital status and education but inversely associated with smoking for females. These results suggest that work characteristics such as sedentary job and shift work should also be considered when trying to prevent increases in BMI and WHR.

Muscle sympathetic nerve activity (MSA) was recorded microneurographically from the tibial nerve in 40 healthy male subjects aged 18 to 75. Passive and graded head-up tiltings were loaded on the subjects. The effects of aging on the resting activity of muscle sympathetic nerve in supine position at rest (burst number per minute), increase in MSA from the resting level by orthostasis (slope of the regression line between sine of the tilt angle and MSA bursts per minute), and the MSA in upright standing position were analyzed. The resting MSA increased with age, and a significant positive correlation was observed between age and resting activity (Y = -6.83 +/- 0.876X, r = .882, p less than .001). The MSA was enhanced by head-up tilt linearly with the sine of the tilt angle, and a significant negative correlation was observed between age and the MSA increase by orthostasis (Y = 57.6 - 0.582X, r = . 843, p less than .001). Standing MSA increased significantly but less remarkably than resting MSA. It was concluded that aging increases the resting activity, but there is less increase in the standing activity of sympathetic outflow to muscles in humans.

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parts producer. Only full-time employees were invited to participate in the study. At four study sites, all full-time employees were invited. At three other sites, full-time employees who participated in health checkups within a certain period were invited. At one site, full-time employed men who had participated in health checkups were invited. At another site, all supervisors and managers were invited. A questionnaire was distributed by mail with a letter of invitation explaining the objectives and procedure of the study to a total of 29,417 eligible subjects between April 1996 and May 1998. The subjects were asked to complete the questionnaire at the worksite or at home and return it in a thick envelope with their written consent to participate to occupational health division. Information on their IDs was also collected for a future linkage with medical records. A total of 25,104 questionnaires were returned. The average response rate was 85%, ranging from 73% to 100% at most study sites, with an exception (43%) at one site. We excluded 3,026 responses from one study site collected during the health checkups between June 1997 and November 1997 because the questionnaire that was distributed during that period lacked a part of the JCQ scales due to an editorial mistake. In addition, 2,421 respondents were excluded because of at least one missing response for variables relevant to the study. Furthermore, a small number of respondents (n=135) who reported their occupation as farming or in a miscellaneous category were excluded from the following analyses. The data from 19,522 respondents (16,444 men and 3,078 women) were analyzed. Classification of occupationThe ISCO88 classifies and ranks occupations according to the levels of skills required and education needed to perform a particular occupation.11 Legislators and managers were ranked the highest, followed by professionals, technicians, clerks, service and sales workers, craft and related trade workers, and machine operators and assemblers. Laborers were ranked the lowest. Respondents were asked to briefly describe their job titles and their most important roles at work, as well as to select their occupation from a multiple-choice question. Based on the descriptions, a four-digit occupational code was entered from the ISCO88 by trained raters under the supervision of researchers (TH, NK). In this study, the first digit of the ISCO88 occupation code (except for military and agricultural/fishery occupations) was used to determine eight occupation categories: managers, professionals, technicians, clerks, service and sales workers, craft and related trade workers, machine operators and assemblers, and laborers. A thorough review of the respondent's description and coding revealed a problem with this procedure: a number of respondents who rated themselves as having managerial occupations (a section chief or a higher position) in the multiple-choice question regarding occupation did not mention their positions as managers in the description section. Thus, their occu...