Lifestyle and the development of dyslipidemia: a 4-year follow-up study of middle-aged Japanese Male Office Workers

To examine the lifestyle factors related to the development of dyslipidemia [low-density lipoprotein (LDL) cholesterol ≥ 150 mg/dL, high-density lipoprotein (HDL) cholesterol < 40 mg/dL, or triglyceride ≥ 250 mg/dL], 979 dyslipidemia-free Japanese male office workers aged 35 to 54 years were followed up for four years. The numbers of new incidence cases during the follow-up period were 216 for high LDL cholesterol level, 109 for low HDL cholesterol level, and 78 for high triglyceride level. From the Cox proportional hazards model, adjusted hazard ratios (HRs) for the incidence of high LDL cholesterol level were 0.62 [95% confidence interval (CI): 0.47-0.82] for consuming alcohol every day, 1.39 (95% CI: 1.10-1.77) for 5-kg/m² increase in body mass index (BMI), 1.45 (95% CI: 1.10-1.91) for snacking between meals every day, and 1.64 (95% CI: 1.18-2.30) for not eating vegetables every day. As for the incidence of low HDL cholesterol level, adjusted HRs for current cigarette smoking, consuming alcohol every day, and 5-kg/m² increase in BMI were 1.74 (95% CI: 1.17-2.59), 0.61 (95% CI: 0.41-0.89), and 1.79 (95% CI: 1.29-2.46), respectively. Adjusted HRs for the incidence of high triglyceride level were 1.73 (95% CI: 1.07-2.77) for current cigarette smoking, 1.74 (95% CI: 1.10-2.77) for 5-kg/m² increase in BMI, and 0.50 (95% CI: 0.27-0.90) for working 10 h per day or more. These results suggest that an increase in BMI, current cigarette smoking, and snacking between meals every day is closely associated with an increased risk of atherogenic lipid profiles. On the other hand, alcohol consumption and eating vegetables every day may have an anti-atherogenic effect on serum lipid profiles.     

Association between lifestyle and white blood cell count: a study of Japanese male office workers

METHODS: We assessed the association of lifestyle factors with white blood cell (WBC) count in 3681 Japanese male office workers aged 35-59 years. RESULTS: The WBC count differed significantly across lifestyle factors (overall obesity, alcohol consumption, cigarette smoking, eating breakfast, nutritional balance, physical exercise and hours of work). From multiple linear regression analyses, overall obesity, alcohol intake, cigarette smoking, nutritional balance and hours of work remained as statistically significant factors associated with WBC count. The WBC count increment showed a positive dose-response relationship with poor lifestyle factors regarding overall obesity, cigarette smoking and nutritional balance. On the other hand, the WBC count increment showed a negative dose-response relationship with alcohol intake and hours of work. CONCLUSION: These data indicate that lifestyle factors may exert an important effect on WBC count.     

White blood cell count and clustered features of metabolic syndrome in Japanese male office workers

We assessed the association of white blood cell (WBC) count with different components of metabolic syndrome (MS)-obesity, hypertension, hypercholesterolemia, low high-density lipoprotein cholesterol levels, hypertriglyceridemia, high fasting plasma glucose levels and hyperuricemia-in 5275 Japanese male office workers aged 23-59 years. After controlling for age, smoking and alcohol intake, the relative risks for the presence of 1, 2, 3, 4 and > or =5 features of MS compared with the lowest quintile of WBC count increased in a dose-dependent manner as WBC count increased (P for trend < 0.001 for all) and the increased relative risks for clustered features of MS were more pronounced as the number of features of MS increased. The WBC count increments in subjects with 1, 2, 3, 4 and > or =5 features of MS were 0.28, 0.45, 0.68, 0.76 and 1.40 x10(9) cells/l, respectively, compared with the subjects without features of MS (P for trend < 0.001). These findings indicate a strong association between WBC count and clustered features of MS in middle-aged Japanese men.     

Lifestyle and work predictors of fatigue in Japanese manufacturing workers

BACKGROUND: Fatigue is one of the most common symptoms encountered in medical practice. However, little is known about the causal relationship between change in lifestyle and fatigue. AIM: To help prevent fatigue-related disorders, we investigated the association between changes in lifestyle and fatigue among employees. METHODS: We studied data sets from the High-risk and Population Strategy for Occupational Health Promotion study for employees at 10 workplaces in Japan. The baseline survey was done in 1999 and the follow-up survey in 2003 via a questionnaire which examined lifestyle and fatigue variables using the vitality domain scale of the SF-36 Health Survey. The lifestyle factors focused on were diet, smoking and alcohol habits and working conditions. Four-year changes in lifestyle that predicted the vitality domain score in the follow-up survey were examined by analysis of covariance RESULTS: Of the 6284 participants in the baseline survey, 4507 replied to the follow-up survey, of whom 3498, with a mean age of 37 (SD 18) years, returned valid responses. A low vitality score at follow-up was predicted by a change in lifestyle factors such as an increase in overtime work, change to non-sedentary work and increased frequency of eating between meals (P < 0.01, P < 0.01 and P = 0.02, respectively). CONCLUSION: Fatigue in salaried workers as measured by the vitality domain of the SF-36 is predicted by an increase in overtime work, change to non-sedentary work and an increase in the frequency of eating between meals.     

Effects of coffee consumption against the development of liver dysfunction: a 4-year follow-up study of middle-aged Japanese male office workers

The association of coffee consumption with the development of increased serum aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) activities over 4 years was studied in 1221 liver dysfunction-free (serum AST and ALT < or = 39 IU/l and no medical care for or no past history of liver disease) Japanese male office workers aged 35 to 56 years. From the analysis using the Kaplan-Meier method, the estimated incidence of serum AST and/or ALT > or = 40 IU/l, > or = 50 IU/l, and > or = 60 IU/l decreased with an increase in coffee consumption. From the Cox proportional hazards model, coffee drinking was independently inversely associated with the development of serum AST and/or ALT > or = 40 IU/l (p = 0.019 by test for tendency), > or = 50 IU/l (p = 0.002), and > or = 60 IU/l (p = 0.007), controlling for age, body mass index, alcohol intake, and cigarette smoking. These results suggest that coffee may be protectively against the liver dysfunction in middle-aged Japanese men.     

Serum uric acid and risk for development of hypertension and impaired fasting glucose or Type II diabetes in Japanese male office workers

We examined the association of serum uric acid (SUA) with development of hypertension (blood pressure 140/90 mmHg and/or medication for hypertension) and impaired fasting glucose (IFG) (a fasting plasma glucose level 6.1–6.9 mmol/l) or Type II (non-insulin-dependent) diabetes (a fasting plasma glucose level 7.0 mmol/l and/or medication for diabetes) over a 6-year follow-up among 2310 Japanese male office workers aged 35–59 years who did not have hypertension, IFG, Type II diabetes, or past history of cardiovascular disease at study entry. After controlling for potential predictors of hypertension and diabetes, the relative risk for hypertension compared with quintile 1 of SUA level was 1.27 [95% confidence interval (CI): 1.00–1.62] for quintile 2, 1.34 (95% CI: 1.08–1.74) for quintile 3, 1.48 (95% CI: 1.18–1.89) for quintile 4, and 1.58 (95% CI: 1.26–1.99) for quintile 5 (p for trend <0.001). The respective multivariate-adjusted relative risks for IFG or Type II diabetes compared with quintile 1 of SUA level were 1.55 (95% CI: 0.95–2.63), 1.62 (95% CI: 0.98–2.67), 1.61 (95% CI: 1.01–2.58), and 1.78 (95% CI: 1.11–2.85) (p for trend = 0.030). The association between SUA level and risk for hypertension and IFG or Type II diabetes was stronger among men with a body mass index (BMI) <24.2 kg/m² than among men with a BMI 24.2 kg/m², although the absolute risk was greater in more obese men. These results indicate that SUA level is closely associated with an increased risk for hypertension and IFG or Type II diabetes.     

The relationship between waist-to-hip ratio and occupational status and life-style factors among middle-aged male and female Japanese workers.

As a marker of body fat distribution and therefore level of obesity, the waist-to-hip ratio (W:H) is a good indicator of coronary heart disease risk status. The present study investigated the association between occupational status and life-style factors, and W:H of middle-aged Japanese male (n = 2,550) and female (n = 1,283) workers in a metal-products factory. A higher W:H was observed in the management level males as compared with the other male workers and we suggest this was promoted by the sedentary aspect of their work, as well as their higher levels of alcohol consumption and lower levels of leisure-time physical activity. In contrast, a higher W:H was recorded in female labourers, whose work was typically less sedentary as compared with female managers. Life-style factors included in the study were not related to this observation. We conclude that other unmeasured psychosocial factors may be important in promoting higher W:H in female labourers.     

Effects of overtime work on blood pressure and body mass index in Japanese male workers

BACKGROUND: Effects of overtime work on health is a controversial issue. AIMS: To determine the effects of overtime work on blood pressure and body mass index (BMI) for male workers in Japan. METHODS: Participants were 323 male participants of three companies. Data were collected by occupational physicians at periodic physical examinations and additional examinations. The time courses for the development of definite hypertension and an increase in BMI were recorded. The Kaplan-Meier method was used to estimate the cumulative incidence rates of developing definite hypertension and increasing BMI, and the Cox proportional hazard model was used to determine the adjusted relative hazard of overtime work. RESULTS: The age-adjusted incidence rates of developing definite hypertension and increasing BMI were significantly lower among the participants whose mean overtime was > or =50 h than among those whose mean overtime was <50 h/month (log-rank P < 0.05). The Cox proportional hazard model indicated that those who worked a mean overtime of > or =50 h/month had lower risks of developing definite hypertension (hazard ratio, 0.36; 95% CI, 0.15-0.88; P < 0.05) and increasing their BMI (hazard ratio, 0.44; 95% CI, 0.31-0.63; P < 0.01) after adjusting for age. CONCLUSIONS: The results of this study indicate that workers whose mean overtime was > or =50 h have lower risks of developing definite hypertension and increasing their BMI.     

A follow-up study on the association of working conditions and lifestyles with the development of (perceived) mental symptoms in workers of a telecommunication enterprise

AIM: This study investigated the association of working conditions and lifestyle with mental health in Japanese workers. METHODS: A follow-up study was carried out in the Kanto district of Japan of workers in a telecommunications enterprise who received their first annual health check-up between 1992 and 1996 and were between 20 and 54 years old. Workers who reported mental symptoms, had a past history of disease, or current illness at their first check-up were excluded from the analysis. In total, the study included 23 837 workers. The association between working conditions and lifestyle and the development of mental symptoms was investigated by pooled logistic regression analyses. RESULTS: Working long hours and part-time work, as opposed to normal daytime hours of work, were factors associated with the development of mental symptoms in males, as were smoking, short sleeping hours, little physical exercise, rarely taking three meals a day, frequently eating within 1 h before sleep, much preference for salty meals and little preference for vegetables. Consumption of alcohol was negatively associated with the development of mental symptoms in males. Overall, the results suggested that the lower the Healthy Work and Lifestyle Score, the higher the risk of developing mental symptoms. CONCLUSIONS: Working conditions and lifestyle, especially food preferences, have an apparent influence on the mental health of Japanese workers. Moreover, the Healthy Work and Lifestyle Score indicates that working conditions and lifestyle appear to have a cumulative influence upon the mental health of Japanese workers.     

Physical activity, fitness and body composition of Finnish police officers: a 15-year follow-up study

This study evaluated Changes in the physical activity, fitnessand body composition of 103 police officers during a 15-yearfollow-up. The absolute aerobic capacity was similar in 1981and 1996, muscular performance had declined, and body weighthad increased approximately 0.5 kg/year. More than half thesubjects (53%) had increased their leisure-time physical activityin 1996. The correlation was significant between physical activityin 1981 and physical fitness in 1996, but weak between physicalactivity in 1996 and fitness in 1996. It was also significantbetween waist circumference and waist/hip ratio in 1996 andphysical activity during the previous 5 and 15 years. No significantcorrelations were found between physical activity and work abilityor perceived physical or mental job stress. The physical fitnessof middle-aged police officers seems to be predicted stronglyby physical activity in early adulthood. Therefore health andfitness promotion measures should start at that time. This,together with regular systematic training, should help to sustainwork ability of middle-aged police officers.     

Low prevalence of clinical latex allergy in UK health care workers: a cross-sectional study.

The prevalence of natural rubber latex allergy amongst health care workers has been reported to vary between 1 and 40%. This is because different diagnostic criteria have been used on heterogeneous groups of subjects. We have undertaken a cross-sectional study of all 5600 employees in two National Health Service trusts served by one department of occupational health and one department of clinical immunology. The period prevalence (1999-2000) for Type I clinical latex allergy in the clinical health care workers was found to be 17/3500 (0.5%). Difficulties in diagnosis and factors which may have contributed to this low prevalence rate are discussed. No cases were forced to leave health care work as a consequence of their allergy.     

Organizational practices, work demands and the well-being of employees: a follow-up study in the metal industry and retail trade

BACKGROUND: Rapid technological change and increased international competition have changed working life and work organizations. These changes may not be considered when researching employee work ability and well-being. AIM: This study investigates the impact of organizational practices, work demands and individual factors on work ability, organizational commitment and mental well-being of employees in the metal industry and retail trade. METHOD: A follow-up study was conducted to examine these connections among 1389 employees (mean age 42 years at baseline) in 91 organizations. The first survey was conducted in 1998 and was repeated in 2000. RESULTS: Changes in organizational practices and the demands of work were strongly associated with changes in employee well-being. Work ability, organizational commitment and the mental well-being of employees were increased most if the opportunities for development and influence and the promotion of employee well-being were increased and if the supervisory support and organization of work were improved. Well-being also improved with less uncertainty at work and with decreasing mental and physical work demands. In addition physical exercise and affluence also had favourable effects. CONCLUSIONS: The results confirm that several features of organizational practices are strongly associated with employees' well-being. Organizational development is an important method of improving employees' work ability, commitment and well-being.     

Influence of mitochondrial DNA 5178 C/A polymorphism on serum cholesterol changes: a short-term follow-up in middle-aged Japanese men

Objective

The mitochondrial DNA 5178 cytosine/adenine (Mt5178 C/A) polymorphism is reportedly associated with longevity in the Japanese population, and the Mt5178A genotype may exert anti-atherogenic effects. The aim of this study was to determine whether there were longitudinal differences in serum lipid levels between carriers of the Mt5178C genotype and those of the Mt5178A genotype and to assess the impact of these genotypes on serum cholesterol levels.

Methods

The serum levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), and low-density lipoprotein cholesterol (LDLC) were measured and the Mt5178 C/A genotypes determined in 110 Japanese men aged 41–66 (mean 52.3) years who had received medical checkups twice in the period 1999–2005. The longitudinal changes of TC, HDLC, and LDLC were calculated according to genotype.

Results

The serum levels of TC at baseline and follow-up were significantly different, whereas those of HDLC and LDLC were not. The changes in HDLC differed significantly between the two Mt5178 C/A genotype groups, with the changes in HDLC level being significantly greater in the Mt5178A genotype group than in the Mt5178C group (p = 0.015).

Conclusions

The Mt5178 C/A genotype may modify longitudinal changes in serum TC and HDLC levels in middle-aged Japanese men.     

Retrospective longitudinal study on the relationship between 8-year weight change and current eating speed

Most of the studies that have examined the relationship between the speed of eating and obesity have been cross-sectional. We investigated 529 male workers who received health check-ups provided by the employer in 2000 and 2008. We obtained information on the subjects’ alcohol consumption, smoking status, self-reported speed of eating, and exercise in 2008, and height and weight in both 2000 and 2008. We compared weight change from 2000 to 2008 between 2 groups classified according to the speed of eating: a group of fast eaters, and a combined group of medium and slow eaters. The fast-eating group had a higher average weight gain (1.9 kg) than the medium and slow eating group (0.7 kg). Although statistically significant only for the 20-29-year age group, weight gain was greater in the fast-eating group for all age groups and was statistically significant when the age groups were combined. The relationship between eating fast and weight change was statistically significant even after adjusting for age and body mass index in 2000, drinking, smoking, and exercise. Our results suggested that the speed of eating is related to the rate of weight gain.     

The effect of acute broncho-pulmonary infections on the FEV1 change in 13-year follow-up. The Cracow study

The aim of this study was to assess the effect of acute bronchitis and pneumonia on the FEVI decline rate in a random sample of Cracow inhabitants followed over a 13-year period. A total of 718 males and 1029 females completed the spirometric testing and interview in 13-year follow-up period. Acute chest diseases diagnosed and treated by doctors and reported by respondents in surveys were the source of data on broncho-pulmonary infections. The rate of FEVI change, expressed in ml per year was estimated for each person in 13-year follow-up period.Persons who reported recurrent bronchitis and pneumonia had significantly lower initial FEVI levels than those without infections. The effect was controlled for confounders like age, height, smoking and chronic chest symptoms. The initial low ventilatory function by itself was not a predisposing factor for chest infections, unless they were associated with chronic respiratory symptoms.Lung function in men decreased steeply after pneumonia infection, but the effect appeared to be reversible. This effect was not limited to people with pre-existing chronic respiratory disease. The data indicated that in some subjects who reported new symptoms of dyspnea on effort, the acceleration of FEVI decline due to pneumonia was greater than in people without the symptoms. This may result from the fact that in lower respiratory infection, bacterial or viral agents can produce serious dysfunction of small airways.Corresponding author.     

Maternal occupation and adverse pregnancy outcomes: a Finnish population-based study

BACKGROUND: There is accumulating evidence that the type of work and environmental exposures in the working environment may have adverse effects on foetal development. AIM: To compare the risk of low birth weight (LBW), small-for-gestational age (SGA) and pre-term delivery (PD) in broad categories of maternal occupation including farming and forestry; factory, mining and construction; office, non-manual and service work and housewives. METHODS: The study population consisted of 2568 singleton newborns of women who participated in The Finnish Prenatal Environment and Health Study after the delivery (response rate 94%). Information on maternal occupation and work during pregnancy was collected after the delivery. The health outcomes were LBW (<2500 g), SGA and PD (<37 weeks). RESULTS: In newborns of women working in factories, mining and construction, the risk of LBW (adjusted odds ratio [OR] 3.66, 95% confidence interval [CI] 1.15-11.62), SGA (adjusted OR 1.53, 95% CI 0.73-3.21), but not the risk of PD (adjusted OR 0.64, 95% CI 0.19-2.22), was higher compared with newborns of housewives. In newborns of farmers and forestry workers, the risks of PD (adjusted OR 2.38, 95% CI 1.01-5.65), LBW (adjusted OR 2.86, 95% CI 0.78-11.58) and SGA (adjusted OR 1.51, 95% CI 0.62-3.65) were all elevated. In office, non-manual and service workers, the corresponding estimates were lower (LBW: 1.62, 0.67-3.95; SGA: 1.45, 0.92-2.28; PD: 1.18, 0.69-2.01). CONCLUSIONS: There were substantial differences in the risk of adverse pregnancy outcomes between the main branches of industry.     

A longitudinal study of the influence of shift work on serum uric acid levels in workers at a telecommunications company

BACKGROUND: Hyperuricemia is a lifestyle-related disease. Although there have been many previous reports about the association of serum uric acid (UA) levels with lifestyle, including eating habits and alcohol intake, there has been no report of a longitudinal study of the relationship between serum UA levels and shift work. AIMS: To clarify the influence of shift work on serum UA levels in Japanese workers. METHODS: This was a 4-year cohort study of 15 871 workers at a telecommunications company. Pooled logistic regression analyses by sex were performed, with job schedule type, age, body mass index (BMI), lifestyle and the results of blood chemistries as covariates. RESULTS: In males, shift work, part-time work, BMI, consumption of alcohol (less than twice per week, two to five times per week or more than five times per week) and little preference for vegetables were positively associated with the development of increased serum UA (>or=8 mg/dl in males, >or=6 mg/dl in females). In females, age, BMI and a history of smoking were positively associated with the development of increased serum UA. CONCLUSION: This study revealed that shift work is independently related to increased serum UA in males.     

Job stress and dissatisfaction in association with non-fatal injuries on the job in a cross-sectional sample of petrochemical workers

This cross-sectional study analysed the frequency and severity of work stressors and job satisfaction at workplaces in relation to work-related non-fatal injuries amongst a sample of petrochemical workers in Taiwan. The study participants consisted of 568 cases injured on the job between 1991 and 1997, and 954 injury-free controls matched to cases on frequencies of age, sex and work site. After adjusting for potential confounders, we found that cases were more likely than controls to report stressors with a higher frequency [odds ratio (OR) = 1.4, 95% confidence interval (CI) = 0.9-2.0] and a more severe reaction (OR = 1.3, 95% CI = 0.9-1.8). The dose-response analyses further indicated that the OR of injury was monotonically associated with stress reaction only (P for test for trend of ORs = 0.02). Job satisfaction, though, was unrelated to non-fatal injury. Although the cross-sectional nature of our study precludes a causal inference between stress reaction to stressors and risk of developing non-fatal injuries, our results tend to suggest that the severity of stress reaction is more associated with occupational non-fatal injury than is the frequency of stress or job dissatisfaction.