The distribution of serum C-reactive protein (CRP) levels and their association with age, sex, and atherosclerotic risk factors were studied in a large Japanese population between 1992 and 1995. The subjects consisted of 2,275 males and 3,832 females aged 30 years and over. CRP was measured by nephelometry. The distribution of CRP was highly skewed toward a lower level than that of previous studies and seemed to be a combination of two separate distribution curves. The increase in CRP with age was statistically significant, and males had higher CRP levels than did females. Males who were current smokers had higher CRP levels than did nonsmokers. Age, systolic blood pressure, diastolic blood pressure, triglycerides, fibrinogen, and body mass index were all positively associated with CRP in both sexes, while total cholesterol and blood glucose were positively related in females only. High density lipoprotein cholesterol was inversely related in both sexes. Multiple logistic regression analysis showed that sex, age, systolic pressure, high density lipoprotein cholesterol, triglycerides, fibrinogen, and body mass index were significant independent variables. In conclusion, the distribution of CRP among the Japanese was quite different from that among Westerners, although CRP levels correlated with other atherosclerotic risk factors, similar to those in Westerners.

BACKGROUND: Although sleep is one of the most important health-related factors, relationship between sleep duration and mortality has not been fully discussed. METHODS: Study subjects were 11,325 participants (4,419 males and 6,906 females) in the Jich Medical School Cohort Study, a population-based prospective study. Baseline data were obtained by questionnaire and health checkups between April 1992 and July 1995 in 12 rural areas in Japan. Main outcome measures were all-cause and cause-specific mortality derived from death certificates up to December 31, 2001. Cox’s proportional hazard models were applied to analyze the association of sleep duration with mortality. RESULTS: A total of 495 deaths (289 males and 206 females) were observed during the average of 8.2-year follow-up period. After adjusting for age, systolic blood pressure, serum total cholesterol, body mass index, smoking habits, alcohol drinking habits, education, and marital status, the hazard ratios (95% confidence intervals) of all-cause mortality for individuals sleeping shorter than 6 hours and 9 hours or longer were 2.4 (1.3-4.2) and 1.1 (0.8-1.6) in males, and 0.7 (0.2-2.3) and 1.5 (1.0-2.4) in females, respectively, relative to those with 7-7.9 hours sleep. CONCLUSION: Our data suggest that males with short sleep and females with long sleep were at an elevated risk of death.

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Objectives-To explore the association between the prevalence of hypertension in a Japanese working population and job strain (a combination of low control over work and high psychological demands), and to estimate this association in diVerent sociodemographic strata. Methods-From a multicentre community based cohort study of Japanese people, sex specific cross sectional analyses were performed on 3187 men and 3400 women under 65 years of age, all of whom were actively engaged in various occupations throughout Japan. The baseline period was 1992-4. The association between job characteristics-measured with a Japanese version of the Karasek demand-control questionnaire-and the prevalence of hypertension defined by blood pressure and from clinical diagnoses were examined. Adjustments were made for possible confounders. The analyses were repeated for stratified categories of occupational class, educational attainment, and age group. Results-In men, the level of job strain (the ratio of psychological job demands to job control) correlated with the prevalence of hypertension. In a multiple logistic regression model, job strain was significantly related to hypertension (odds ratio 1.18; 95% confidence interval 1.05 to 1.32), after adjustment for age, employment (white collar v blue collar), marital status, family history of hypertension, cigarette smoking, alcohol intake, physical activity, and body mass index. The stratified analyses showed significant excess risks in the subordinate groups compared with managers, blue collar workers, less educated workers, and the older age groups. This association was not significant in women. Multiple linear regression analyses, with systolic and diastolic blood pressures as dependent variables, did not show any significant association. Conclusions-The findings provided limited proof that job strain is related to hypertension in Japanese working men. Older men in a lower social class may be more vulnerable to the hypertensive effects of job strain. (Occup Environ Med 2001;58:367-373)

BackgroundAssociations between dietary patterns and cardiovascular disease risk factors remain unclear. The objective of this study was to evaluate the association between dietary patterns derived from factor analysis and the levels of blood pressure and serum lipids in a Japanese population.MethodsWe conducted a cross-sectional analysis among 6886 (in the analysis on blood pressure) and 7641 (in the analysis on serum lipids) Japanese subjects aged 40-69 years. Dietary patterns were identified from a food frequency questionnaire by factor analysis. Associations between dietary patterns and blood pressure and serum lipids were examined after taking potential confounders into account.ResultsThree dietary patterns were identified: vegetable, meat, and Western. In men, the meat pattern was associated with higher total, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol. The Western pattern was associated with higher total and LDL cholesterol. In women, the vegetable pattern was associated with lower systolic and diastolic blood pressure and pulse pressure, and higher HDL cholesterol. The meat pattern was associated with higher total and HDL cholesterol. The Western pattern was associated with higher total, HDL, and LDL cholesterol, and the least intake pattern of Western diet was associated with higher systolic and diastolic blood pressures.ConclusionsDietary patterns of a Japanese population were related to cardiovascular disease risk factors, especially in women.