Ambulatory and home blood pressure (BP) can be measured over an extended period, thus generating information about BP variability. We have monitored a Japanese general population (Ohasama) for 20 years with respect to morbidity and mortality based on ambulatory and home BP, and have demonstrated the unique prognostic significance of variability in these values. A disturbed nocturnal decline in BP is associated with cerebral infarction and heart diseases, whereas a large morning pressor surge and a large nocturnal decline in BP, which are analogous to a large diurnal increase in BP, are both associated with cerebral hemorrhage. A high BP at various times of the day is associated with different subtypes of cerebrovascular and cardiovascular disease risk. Home BP in the morning and in the evening provide equally useful information for stroke risk, whereas morning hypertension, which is that specifically observed only in the morning, might be a good predictor of stroke, particularly among individuals using anti-hypertensive medication. The BP and heart rate variabilities estimated as standard deviation measured every 30 minutes by ambulatory monitoring are independent predictors. That is, a higher short-term BP variability with a lower short-term heart rate variability leads to a worse cardiovascular prognosis. These variations in BP also bias the diagnosis and treatment of hypertension, which can be managed effectively by considering the phasic, as well as the tonic, component of BP. J Epidemiol 2007; 17: 109-113.
BACKGROUND: Both male gender and low socioeconomic status have been related to depression and suicide, but their possible relationship to mental health literacy remains uncertain. The objectives of this study were to assess the level of mental health literacy in rural communities in Japan and to examine related factors. METHODS: A population-based cross-sectional study using a questionnaire was conducted. Response rate was 88.2% from 8163 residents aged 30-69 years. The relationships between mental health literacy (including cognition of depression, attitude toward depression, and acceptance of suicide) and demographics, socioeconomic status, and the severity of depression were assessed by logistic regression analysis. RESULTS: Of the respondents, 25.2% showed an inadequate cognition of depression, 12.5% showed an inadequate attitude toward depression, and 13.1% showed an acceptance of suicide. Of the complete respondents (65.5%), an inadequate cognition of depression was associated with being male (adjusted odds ratio=1.93, 95% confidence interval: 1.68-2.22), advanced age (2.18, 1.58-3.00), and a lower level of education (1.95, 1.34-2.86); an inadequate attitude toward depression was associated with being male (2.18, 1.82-2.61), a lower education (2.34, 1.38-3.97), and the severity of depression (2.26, 1.54-3.32); and an acceptance of suicide was associated with being male (1.33, 1.13-1.58) and the severity of depression (5.77, 4.20-7.93). CONCLUSIONS: Poor mental health literacy related strongly to male gender and a low level of education. According to our results, poor mental health literacy may possibly be a factor contributing to male vulnerability to suicide. J Epidemiol 2007; 17: 114-119.
BACKGROUND: C-reactive protein (CRP) is an acute phase reactant, and has been reported as a predictor of cardiovascular diseases. Measurements of high sensitive CRP in thawed samples are possible and the values are thought to remain stable even after frozen storage. However, the long-term stability of CRP values has not been documented. We measured the values of CRP before and after long-term storage, and examined the difference in determined values. METHODS: High sensitive CRP was measured before and after long-term storage of samples from 99 men and women among the JMS Cohort Study subjects. We selected subjects who underwent measurement of high sensitive CRP at the baseline by stratified sampling methods using baseline CRP values. CRP was measured in serum samples at the baseline and in thawed plasma samples after an average storage period of 13.8 years. RESULTS: Geometric means of CRP were 0.25 mg/L and 0.59 mg/L before and after storage, respectively. The CRP values were significantly higher after long-term frozen storage than at the baseline (p<0.0001). The both values of logarithm CRP were significantly correlated using Pearson's correlation (r = 0.920, 95% confidence interval: 0.883-0.945). CONCLUSION: CRP values increased after long-term frozen storage. The CRP values showed a high correlation between before and after long-term storage. J Epidemiol 2007; 17: 120-124.
Background: A causal association between cigarette smoking and periodontal disease has been established. The present study examined the association between smoking and tooth loss using national databases in Japan. Methods: Records of the Survey of Dental Diseases and the National Nutrition Survey in 1999 were linked electronically using common identification. Records of 3,999 subjects aged older than 40 years were analyzed using logistic regression models, controlling for confounding factors, such as age, frequency of tooth brushing, body mass index, alcohol consumption, and intakes of vitamin C and E. Results: Prevalence of tooth loss in terms of having less than 19 existing teeth was 37.3% overall. Smoking rates differed in males (45.6%) and females (7.8%). The prevalence of tooth loss in nonsmokers, former, and current smokers was 28.5%, 38.6%, and 36.9% in males, and 38.6%, 34.3% and 38.9% in females, respectively. Adjusted means of existing teeth controlling for confounders by smoking status were 21.5, 19.7 and 18.2 in males and 19.0, 19.2 and 16.4 in females, respectively. The association of tooth loss was non-significant in former smokers but significant in current smokers: adjusted odds ratios (95% confidence intervals) relative to nonsmokers in males and females were 1.29 (0.92-1.80) and 0.86 (0.46, 1.60) for former smokers and 2.22 (1.61-3.06) and 2.14 (1.45-3.15) for current smokers, respectively. A dose-response relationship between lifetime exposure and tooth loss was seen (P for trend <0.0001). Conclusion: The findings of this cross-sectional study of a nationwide population of Japanese indicated an association between smoking and tooth loss. J Epidemiol 2007; 17: 125-132.
BACKGROUND: Trend of the mortality rate of Creutzfeldt-Jakob disease (CJD) in Japan is still unclear. This study aimed to estimate annual crude mortality rates due to CJD and examine the CJD mortality trend in Japan during the period of 1979-2004. METHODS: National death certificate data on CJD were used (CJD coded as 046.1 for ICD-9 and A81.0 for ICD-10). Trends in age-standardized mortality rates for CJD were examined by using time series analyses including the joinpoint regression analysis. RESULTS: A total of 1,966 deaths (862 males and 1,104 females) were identified with CJD coded as the underlying-cause-of-death. The annual number of deaths and crude mortality rates peaked in 2004 at 163 (66 for males and 97 for females) deaths and 1.28 (1.06 for males and 1.48 for females) deaths per million population per year, respectively. The age-specific mortality rates rapidly increased with age between 50 and 74 years, especially among females, and sharply declined at 80+ years. Throughout the observed period, there were no significant change points, and the annual percentage changes (95% confidence intervals) were +3.09 (2.18 - 4.02) % for males and +3.90 (2.98-4.83) % and females. The total number of CJD deaths under 50 years of age was 131, and there was found no increase in the annual number of deaths for the past few years in this age group. CONCLUSION: CJD mortality in trend data based on death certificates has significantly increased in Japan during the period of 1979-2004. J Epidemiol 2007; 17: 133-139.