Relationships between diabetes and medical and dental care costs: findings from a worksite cohort study in Japan.

The purpose of this study was to evaluate the relationships between diabetes and medical and dental care costs from a 5-yr prospective observation of Japanese workers. The data were derived from health and dental examinations and health insurance claims of 4,086 workers aged 40-54 yr. At baseline, the subjects were assigned to four categories: known diabetes; undiagnosed diabetes; impaired fasting glucose (IFG); and non-diabetic. The differences in health care costs among the non-diabetics, IFG and undiagnosed diabetes groups were not seen at baseline, but the costs incurred by the subjects with undiagnosed diabetes substantially increased thereafter. Over 5 yr of the study period, compared with the non-diabetic group, subjects with known diabetes incurred 3.9- and 2.9-fold higher annual inpatient and outpatient costs, respectively, while subjects in the undiagnosed diabetes group incurred 3.0- and 1.6-fold higher costs, respectively. There were no significant associations between annual dental care costs and diabetic status. The excess costs of medical care among subjects with diabetes were attributable to diabetes itself, heart disease and cerebrovascular disease, but not cancer. Among middle-aged workers, diabetics incurred significantly greater medical care costs than non-diabetics, whereas IFG was not associated with higher costs.

[Continuing investigation of effect of toner and its by-product on human health and occupational health management of toner].

OBJECTIVE: As there are reports that ultrafine particles are generated by thermal printer toner, and that mucosal irritation symptoms were observed in users. When printers were operated, we have been examining the effects of not only toner but its by-products on human health. METHODS: We conducted a review of epidemiological and animal data on toner and its by-products such as ultrafine particles and volatile organic compounds (VOC). This was the second survey and it confirmed the results of the first survey. RESULTS: We reviewed the data, and summarized the results as follows. 1) Four cross-sectional studies reported no definite harmful effects of toner. 2) Ultrafine particles were generated in greater numbers at higher fuser heating and higher toner coverages. Ultrafine particles were also observed at lower rates in idle mode. 3) High-sensitive c-reactive protein in serum and heart rate variability (HRV) were useful biomarkers of not only exposure to ultrafine particles but disorder of cardiovascular disease, 8-hydroxydeoxyguanosine in urine is a biomarker of acute lung injury by welder fume, and VEGF and CA15-3 are highly sensitive and specific biomarkers of pulmonary fibrosis. 4) Physico-chemical properties of ultrafine particles were examined, and specific parameters related to pulmonary responses were not observed. CONCLUSIONS: Taken together, we found that there are some biomarkers which are related to not only exposure and but disorders induced by ultrafine particles, and that the generation of ultrafine particles with the operation of printers was associated with other factors than the fixing process. Until now there has been insufficient data for estimation of the hazards of toner and its by-products. However, continuing examinations are useful for complementing and correcting the information and data on toners and for revising the measures of occupational health. We will continue these examinations of toner and its by-products in the future.

Cross-sectional study on respiratory effect of toner exposure.

In this baseline study, part of a cohort study to clarify the effect of toner exposure on the respiratory system, we surveyed 803 male toner workers and 802 referents with regard to their subjective respiratory symptoms and chest X-ray results. We also examined individual exposure history, current working conditions, and personal exposure levels to toner. There was a significantly higher prevalence of "coughing and sputum" related complaints among toner-exposed workers in the 30 and 40-year age groups. The group with toner-exposure history showed a higher odds ratio, by logistic regression, in relation to all questions regarding coughing. Mild fibrotic changes were observed in the chest X-rays of four workers who had engaged in toner-exposure work for at least a decade or more, and all four had reported allergic disease. Although we observed a tendency of higher prevalence of "coughing and sputum" in toner-exposed workers, the possibility of information bias cannot be eliminated. It should also be noted that this tendency did not exceed that of the general public. Further analysis is required in this ongoing 10-year cohort study to clarify the effect of toner exposure on the respiratory system.

Years of life lost due to cancer in a cohort study in Japan.

BACKGROUND: We estimated the burden of cancer using mortality and years of life lost according to life tables in a cohort study in Japan. METHODS: A cohort of 13,270 subjects established in the late 1980s in Japan was followed annually for the vital status of all subjects until 2003. For subjects who died, the underlying cause of death was ascertained from the death certificate. Crude mortality rate from cancer per 100,000 person-years was calculated, and years of life lost (YLL) as well as the average years of life lost (AYLL) were computed using the 1995 life tables in Japan. RESULTS: During the follow-up period, we recorded a total 839 cancer deaths (517 men and 322 women), representing 35.5% of deaths from all causes. Overall crude cancer mortality was 654.9 per 100 000 person-years in men and 312.6 in women. Total YLL due to cancer was 7035.3 years in men and 5627.0 years in women. Overall AYLL due to all cancers was 13.6 years less than life expectancy in men and 17.5 years in women. CONCLUSION: These results showed that cancer was the leading cause of death in this cohort; with stomach, liver and lung cancer the three most frequent cancers in both sexes. YLL and AYLL reflect the cost of dying from cancer in terms of years of life expectancy lost. The different mortality statistics used here may be useful in public health considerations of cancer burden.

[New investigation of the effect of toner and its by-products on human health and occupational health management of toner].

We need a new investigation of the effect of not only toner but also of its by-products on human health, because of the generation of fine particles and the release of volatile organic compounds (VOC) in the process of photocopy. Therefore, we gathered epidemiological and animal data on toner and its by-products, and examined the occupational health management of toner. We examined the effect of carbonblack as the main component of toner, and titanium dioxide and amorphous silica as surface-adhesive nanomaterials, and VOC on human health, and reviewed them. We summarize the results as follows. 1) High sensitive c-reactive protein in serum, 8-hydroxydeoxyguanosine in urine, and heart rate variability (HRV) are useful for biological monitoring of exposure to toner and its by-products. 2) Particle number concentrations have been often measured by scanning mobility particle sizer (SMPS) compared with other apparatus, although this is not measurement gold standard. Taken together, we have examined whole occupational health management of toner and its by-products.

Fish intake and the risk of fatal prostate cancer: findings from a cohort study in Japan.

OBJECTIVE: We investigated the relationship between the intake of fish and the risk of death from prostate cancer. DESIGN: Data were derived from a prospective cohort study in Japan. Fish consumption obtained from a baseline questionnaire was classified into the two categories of 'low intake' and 'high intake'. The Cox proportional hazards model was used to estimate hazard ratios (HR) and 95 % confidence intervals. SUBJECTS: Data for 5589 men aged 30-79 years were analysed. RESULTS: A total of twenty-one prostate cancer deaths were observed during 75 072 person-years of follow-up. Mean age at baseline study of these twenty-one subjects was 67.7 years, ranging from 47 and 79 years old. Results showed a consistent inverse association of this cancer between the high v. low intake groups. The multivariate model adjusted for potential confounding factors and some other food items showed a HR of 0.12 (95 % CI 0.05, 0.32) for the high intake group of fish consumption. CONCLUSIONS: These results support the hypothesis that a high intake of fish may decrease the risk of prostate cancer death. Given the paucity of studies examining the association between prostate cancer and fish consumption, particularly in Asian populations, these findings require confirmation in additional cohort studies.

Perception in relation to a potential influenza pandemic among healthcare workers in Japan: implications for preparedness.

Due to the potential for an influenza pandemic, preparedness for infection control in healthcare settings is essential from the standpoint of occupational health for healthcare workers. We conducted questionnaire surveys among Japanese hospitals to assess preparedness at the individual and institutional levels and their inter-relationship. Questionnaires were administered at 7 tertiary hospitals in Japan during the spring of 2006. We analyzed 7,378 individual responses of the 10,746 questionnaires administered and all seven institutional responses by hospital infection control committees. Healthcare workers assigned low importance to personal protective equipment and showed mixed attitudes (anxious but accepting) to the potential risk. Institutional gaps existed in preparedness across hospitals and most hospitals lacked the specificity to cope with a pandemic. A higher level of institutional preparedness, as determined by expertise as well as general and specific countermeasures, was an important predictor of individual recognition of preventive measures, perception of institutional measures, and attitude toward coping with risk. A higher level of institutional preparedness stood out to be an important predictor of individual preparedness. Considering the risk of a future influenza pandemic, hospitals should improve preparedness at all levels.

The effect of periodontal disease on medical and dental costs in a middle-aged Japanese population: a longitudinal worksite study.

BACKGROUND: Although periodontal disease is one of the most common chronic diseases, it is not clear whether periodontal disease is associated with increased health care costs. The authors examined the effect of periodontal disease on medical and dental costs and use for 3.5 years prospectively. METHODS: The data were derived from health and dental examinations and health insurance claims of 4,285 Japanese civil officers aged 40 to 59 years. The subjects were divided into three categories: no pathological pocket, moderate periodontitis, and severe periodontitis. Age, gender, smoking, body mass index, and hypertension were adjusted in a multivariate analysis after excluding subjects with any history of liver disease, heart disease, or diabetes mellitus. RESULTS: The cumulative cost for subjects with severe periodontitis was approximately 21% higher than for subjects with no pathological pocket, and the hospital admission rates of subjects with severe periodontitis were highest (male: odds ratio [OR]=.34; 95% confidence interval [CI]: 1.00 to 1.80; female: OR=1.29; 95% CI: 0.75 to 2.20). In males, the annual hospital costs of subjects with severe periodontitis were 75% higher than for subjects with no pathological pocket. There was no clear trend identified for outpatient care. The annual dental visit rates and costs for subjects with severe periodontitis were highest in both genders. Periodontal disease might increase the medical care costs for diabetes mellitus, digestive disease, and liver disease. CONCLUSION: Periodontal disease may have played an important role in the cumulative health care cost increases in middle-aged adults over a period of only a few years.

Mortality attributable to cigarette smoking in a cohort study in Japan.

We conducted this study to estimate the association and population attributable risk (PAR) of smoking with all-cause and cause-specific mortality based on a general prospective cohort study in Japan. A total of 8,129 subjects (3,996 males and 4,133 females) aged 40 or over were analyzed. The follow-up period was from 1986 to 2003. Smoking habit was classified into three categories of never smoker, former smoker, and current smoker. The Cox proportional hazard model was used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI). We also estimated the PAR of smoking, and calculated the 95% CI of PAR based on the bootstrap procedure. A total of 112,151 person-years were counted for 8,129 subjects over an average of 13.7 years of follow-up. The results showed that smoking increased the risk of dying from all cancers, cardiovascular, and respiratory diseases in both sexes. For all causes of death, smokers had a HR of 1.30 (95% CI: 1.09, 1.54), PAR of 13.1% (95% CI: 7.6, 22.3) in males, and HR of 1.81 (95% CI: 1.43, 2.29), and PAR of 6.1% (95% CI: 3.1, 9.3) in females compared to never smokers. These results confirm an increased risk of mortality from all causes, as well as from all cancers, cardiovascular disease, and respiratory disease in relation to smoking habit. Smoking is responsible for a considerable proportion of deaths due to all causes as well as cause-specific deaths. Population-based antismoking programs should be implemented to reduce such avoidable deaths.

A prospective study of green tea consumption and oral cancer incidence in Japan.

PURPOSE: To examine the relation of green tea consumption with oral carcinogenesis, we prospectively analyzed data from a nationwide large-scale cohort study in Japan. METHODS: A total of 20,550 men and 29,671 women aged 40-79 years, without any history of oral and pharyngeal cancer at baseline survey, were included in the present study. During a mean follow-up period of 10.3 years, 37 oral cancer cases were identified. The Cox proportional hazard model was used to estimate the hazard ratio (HR) and 95% confidence interval (95% CI) for oral cancer according to green tea consumption by sex, while adjusting for age, smoking, alcohol drinking, and other dietary factors. RESULTS: For women, the HRs of oral cancer for green tea consumption of 1-2, 3-4, and 5 or more cups per day were 0.51 (95% CI: 0.10-2.68), 0.60 (95% CI: 0.17-2.10), and 0.31 (95% CI: 0.09-1.07), respectively, compared with those who drank less than one cup per day (p for trend, 0.08). For men, no such trends were observed. CONCLUSIONS: Our findings did not suggest a prominent inverse association of green tea consumption with oral cancer, although there was a tendency for a reduced risk in women.

[Relationship between lifestyle and subjective symptoms in a food products company].

Although the relationship between lifestyle and subjective symptoms has been reported in the general population, relatively few studies have looked at the link between these two in workplace. To investigate the relationship between lifestyle and subjective symptoms, a cross-sectional study was carried out using data from 4,540 workers aged 20-69 years old in a food products company. The subjective symptoms with a prevalence of more than 10% in either males or females were selected as dependent variables: fatigue, dropsical swelling of hands or feet, stiff neck or shoulders, backpain, deterioration of eye sight, dizziness, diarrhea and constipation. We used a multiple logistic regression model to calculate the odds ratio(OR) and 95% confidence interval(CI) for each subjective symptom according to lifestyle: regular physical activity, proper sleeping, nine hours or less of work, having breakfast, having a nutritionally balanced diet, no smoking and moderate drinking of alcohol. We adjusted for age and type of occupation by gender. The findings confirmed the relationship between smoking and alcohol drinking and subjective symptoms in both genders. In addition, proper sleeping was likely to prevent musculoskeletal symptoms in females.

Mortality and risk factors for stroke and its subtypes in a cohort study in Japan.

OBJECTIVE: To estimate stroke mortality and evaluate risk factors for total stroke deaths and its two principal subtypes in a cohort study in Japan. METHODS: A total of 9651 subjects aged 40 or over and free of stroke were analyzed in a cohort study conducted in Fukuoka Prefecture, Japan. The follow-up period was from 1986 to 2003. Mortality rate per 100,000 person-years of stroke was estimated. The Cox proportional hazards model was used to estimate the hazard ratios and 95% confidence interval. RESULTS: A total of 226 stroke deaths were recorded during 132,972 years of follow-up. Among these, 47 were intracerebral hemorrhage and 109 were cerebral infarction. Stroke mortality rates were 209.4 per 100,000 person-years in males, and 140.5 in females. The results showed that advanced age, male gender, low body mass index (BMI), history of diabetes, hypertension, and transfusion were associated with an increased risk of mortality from total stroke. CONCLUSION: We confirmed that advanced age, male gender, low BMI, history of diabetes, history of hypertension and history of transfusion were associated with an increased risk of total stroke mortality. In addition, the magnitude of these associations differed between the two principal stroke subtypes.

Association of psychological well-being with oral conditions in Japanese workers.

Although the effect of disorders on psychological well-being is well-known, there are few studies focusing on oral conditions at the worksite. The present study examined the association between psychological well-being and oral conditions of Japanese workers. A cross-sectional study was performed using data from 1381 Japanese civil service officers aged 20-59 yr old. Psychological well-being was measured with the 12-item version of the General Health Questionnaire (GHQ-12) in a comprehensive health questionnaire, while measures for oral condition included self-rated oral health, oral symptoms and clinical indicators: dental caries, periodontal status and number of missing teeth. The mean GHQ scores according to the levels of each oral condition were estimated by analysis of variance, separately for males and females. Higher scores corresponded to poorer psychological well-being. Age, gender, smoking and type of occupation were adjusted in a multivariate analysis. Psychological well-being was not associated significantly with dental caries, periodontal status or number of missing teeth. The adjusted means of the GHQ scores for ;conscious of appearance of mouth' were significantly different among the categories for both genders (male: p<0.001, female: p=0.018). For five of six oral symptoms, the adjusted means of GHQ scores were lowest for those respondents who rated their oral symptoms as ;never or hardly ever.' Our results did not show that psychological well-being was associated with oral conditions measured by clinical indicators. However, an association was found between some oral symptoms and psychological well-being. Absence of oral symptoms seems to be related to better psychological well-being.

The Japanese version of the Oral Health Impact Profile (OHIP)--validation among young and middle-aged adults.

OBJECTIVE: To validate the Japanese version of the Oral Health Impact Profile (OHIP-J) for use among young and middle-aged adults. Evaluating the criterion validity was particularly important in this study. METHOD: The original Oral Health Impact Profile (OHIP) was translated into Japanese. Data from 6,079 subjects aged 20-59 were collected by means of a self-administered questionnaire and the oral condition records of a sample of workers. The survey involved items for the OHIP-J and self-rated oral health, denture wearing, number of missing teeth, work type, occupational rank, gender, and age. We adopted a self-rated oral health and number of missing teeth as validity criteria for this analysis. RESULTS: Using multiple linear regression analysis, the adjusted total OHIP-J scores for respondents who rated their oral health as poor were higher than those who did not (46.6 vs. 27.6; p<0.001). The variable of missing teeth was significantly associated with the OHIP-J total and subscale scores independent of gender, age and denture wearing (p<0.001). CONCLUSIONS: These findings suggest that the OHIP-J is suitable for assessing the oral health-related quality of life of young and middle-aged adults in Japan.

Prospective study of vegetable consumption and liver cancer in Japan.

We examined the relationship between vegetable consumption and the risk of death from liver cancer in a cohort study in Japan. This analysis is based on data from 6,049 subjects aged 40 to 79 years enrolled in a cohort study conducted in Fukuoka Prefecture, Japan. The follow-up period was from 1986 to 1999. All liver cancer deaths were recorded. The vegetable consumption was classified into 3 groups: "once per week or less," "2-4 times per week" and "daily intake." The Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence interval (95% CI). A total of 51 male and 22 female liver cancer deaths were recorded during 62,343 person-years of follow-up. The "once per week or less" group was considered the referent group. In males, the multivariate HRs of liver cancer deaths were 0.61 (95% CI: 0.33-1.14) and 0.25 (95% CI: 0.11-0.59) in the "2-4 times per week" and "daily intake" groups, respectively. In females, the multivariate HRs were 0.44 (95% CI: 0.13-1.51) and 0.51 (95% CI: 0.16-1.69), respectively. The multivariate HRs were also reported by history of hepatitis and cirrhosis. In those without a history of these conditions, the multivariate HRs were 0.54 (95% CI: 0.27-1.09) and 0.36 (95% CI: 0.16-0.83). In those with a history of these conditions, the multivariate HRs were 0.58 (95% CI: 0.22-1.56) and 0.37 (95% CI: 0.13-1.06), respectively. Our study reveals an inverse association between vegetable consumption and the risk of death from liver cancer. These results provide further evidence of the protective effect of vegetables against liver cancer.

Visual display terminal work and sick building syndrome--the role of psychosocial distress in the relationship.

The present study investigated the association between visual display terminal (VDT) work and sick building syndrome (SBS) and the role of psychosocial factors in the relationship. Subjects were 2,161 Japanese office workers who responded to a cross-sectional anonymous self-administered questionnaire survey. Questions included were derived from the Miljömedicin 040, a validated questionnaire on SBS symptoms. After exclusion of data with missing information, data for 1,881 subjects were used for analysis. Multivariate logistic regression was used to estimate the odds ratio for SBS with adjustment for potential confounding factors, including psychosocial work stress. In multivariate analysis, the odds ratio for SBS was significantly elevated for men engaged in VDT work for 4 or more hours a day (OR=2.5, 95%CI: 1.0, 5.9) compared with less than 1 hour a day, showing a significant trend association (P for trend=0.04). In women, although the odds ratio for SBS with VDT use of 4 or more hours a day was somewhat elevated with adjustment for non-psychosocial factors (OR=1.5, 95%CI: 0.5, 4.3), the increase was greatly attenuated after adjustment for psychosocial work distress (OR=1.1). In conclusion, our study suggests that extended hours of VDT use might be related to increased SBS symptoms. Moreover, psychosocial distress related to VDT work might mediate the relationship between VDT use and SBS symptoms in women.

Cigarette smoking and mortality due to stomach cancer: findings from the JACC Study.

BACKGROUND: Several epidemiologic studies reported the positive association between cigarette smoking and stomach cancer. The prevalence of smoking in men remains high in Japan compared to other developed countries. It is therefore of great importance to determine the impact of cigarette smoking on stomach cancer among the Japanese population. The Japan Collaborative Cohort Study (JACC Study) provided an opportunity to examine the association between smoking and the risk of mortality due to stomach cancer. METHOD: A baseline survey was conducted throughout Japan from 1988 through 1990 among 110,792 inhabitants of 45 areas. Data retrieved for 98,062 participants (43,482 male and 54,580 female) who provided sufficient information about their smoking habits, without any history of caner at the baseline. Of total 970,251 person-years, 757deaths due to stomach caner were identified. RESULTS: Current smokers were at a higher risk of death due to stomach cancer than non-smokers (Hazard ratio=1.36; 95% confidence interval [CI]: 1.07, 1.73). The risk of stomach cancer for men who smoked 15 or more cigarettes per day was approximately 1.4-fold greater than that of non-smokers, and those who smoked 35 or more cigarettes per day had an approximately 1.7-fold higher risk of stomach cancer, although the dose-response trend among men was unclear (p for trend=0.063). No associations between smoking and stomach cancer were detected among women. CONCLUSION: The present results, together with previous findings, strongly support a hypothesis that cigarette smoking increases the risk of stomach cancer in Japanese men.

A nationwide cohort study of educational background and major causes of death among the elderly population in Japan.

BACKGROUND: This prospective cohort study examined the association between educational level and major causes of death in Japan. METHOD: A baseline survey was conducted between 1988 and 1990 among 110,792 inhabitants of 45 areas aged 40-79 years. Follow-up surveys were conducted annually and causes of death were identified from death certificates. The analysis was restricted to 16,715 men and 23,284 women. RESULTS: During the follow-up period (377,139 person-years), 6628 deaths were recorded. Individuals with low levels of education had an increased overall risk of death [relative risk (RR)=1.16, 95% confidence interval (CI): 1.08, 1.25, in men; RR=1.26, 95% CI: 1.14, 1.39, in women], cancers (RR=1.17, 95% CI: 1.04, 1.32, in men; RR=1.10, 95% CI: 0.93, 1.30, in women), and death from external causes (RR=1.81, 95% CI: 1.29. 2.54, in men; RR=1.78, 95% CI: 1.18, 2.70, in women). Ischemic heart disease risk was marginally reduced in men with low levels of education (RR=0.77, 95% CI: 0.58, 1.01). CONCLUSIONS: These results show that health inequalities exist in Japan, even though wealth inequalities are relatively low. Social and political initiatives will be needed to correct these inequities between different socioeconomic statuses.

[Relationships between participation of national-health-insurance members in a health education program and exercise habits, medical expenses and other related parameters].

PURPOSE: This study was conducted with the aim of multi-faceted evaluation of a health education program, "Genki-jaya", run at Fukushima City Health and Welfare Center. METHODS: "Genki-jaya" is a health education program including individual health instructions combined with group education on exercises as well as diet. A total of 55 participants completed the program through December 1999 to March 2001. Twenty-six were under the medical care covered by national-health-insurance when the program started, and 19 of these, whose medical expenses for one month prior to the program were zero, were studied. The program was evaluated using the following: 1. Results of questionnaire surveys to examine self-care ability and perceived health conducted at the end of the program and three months after it finished. 2. Physical measurement items (blood pressure, weight, body fat rate, and BMI) and physical fitness items (maximum-oxygen-uptake, muscle-strength of legs, etc.) at the start of, and three months after the program. 3. Change in the total medical expenses between one year prior to and after the program, and its relationship with physical measurements and satisfaction with the program. Comparison of the mean three-month medical expenses before, during, and after the program. Comparison of medical expenses three months before, at the beginning and end of, and three months after the program. 4. Follow-up of continuous activities among graduates of the program. RESULTS: 1. Regarding self-care ability, dietary habits, and exercise habits, these continued to improve after the program and all participants were satisfied. Regarding perceived health, subjective symptoms improved. 2. Physical measurements improved through the program. Both mean diastolic pressure and body fat rate at the end of the program were significantly lower than at the beginning. Moreover, mean systolic and diastolic pressures significantly decreased from the end of the program through three months thereafter. 3. The medical expenses before and after the program did not change significantly, and differences did not correlate with physical measurements and satisfaction with the program. 4. Three self-supporting associations among the graduates had been organized to continue instructed exercises were active at the end of March 2001. CONCLUSION: Although Genki-jaya had no significant impact on medical expenses, improvement in self-care ability, perceived health, physical measurements and formation self-supporting associations was observed. Multi-faceted evaluation of the program will now be continued to examine larger numbers of newly enrolled trainees for a longer period of time.

[Health-related lifestyle and mental health among inhabitants of a city in Japan].

AIM: Few studies have linked mental health to lifestyle factors in the Japanese general population. The present investigation was conducted to examine whether mental health is associated with a health-related lifestyle and how the strength of the association, if any, differs across sex and age groups, using health survey data for inhabitants of Japan. METHODS: The data used were obtained from a questionnaire survey on lifestyle and health. In 1998, the questionnaires were mailed to 2,288 subjects selected from among the inhabitants of a city in Japan, of whom 1,642 subjects (71.8%) responded. The present study included 1,343 subjects who completed all the items that were used in the analysis. The General Health Questionnaire (GHQ) -12 was used as an indicator of mental health, with 4 points or higher (high score) indicating poor mental health. Information on eight different lifestyle parameters was also obtained. Logistic regression was used to calculate the odds ratio (OR) of having poor mental health for each lifestyle. RESULTS: Subjects in poor mental health had a lower mean score for a healthy lifestyle than those in good mental health. The difference in the mean score increased with age among men, while it decreased with age among women. The OR for having poor mental health among non-exercisers was higher in the older age group among men, while it was higher in the younger age group among women. A strong association between sleep hours and mental health was observed in the older age group among men, while it was seen in the younger age groups among women. Dietary factors in general showed a clearer association with mental health among women than among men, except for the consumption of salty foods, the association of which with mental health was more evident among men. CONCLUSIONS: Mental health was found to be significantly associated with health-related lifestyles in the Japanese population. The strength of the association for each lifestyle varied considerably across sex and age groups.