Journal of Epidemiology
Online ISSN : 1349-9092
Print ISSN : 0917-5040
ISSN-L : 0917-5040
27 巻 , 1 号
Young Investigator Award Winner’s Special Article
Original Articles
  • Yukiko Ishikawa, Joji Ishikawa, Shizukiyo Ishikawa, Kazuomi Kario, Eij ...
    2017 年 27 巻 1 号 p. 8-13
    発行日: 2017/01/05
    公開日: 2017/02/07
    ジャーナル フリー

    Background: Subjects with prehypertension (pre-HT; 120/80 to 139/89 mm Hg) have an increased risk of cardiovascular disease (CVD); however, whether the risk of pre-HT can be seen at the pre-HT status or only after progression to a hypertensive (HT; ≥140/90 mm Hg) state during the follow-up period is unknown.

    Methods: The Jichi Medical Cohort study enrolled 12,490 subjects recruited from a Japanese general population. Of those, 2227 subjects whose BP data at baseline and at the middle of follow-up and tracking of CVD events were available (median follow-up period: 11.8 years). We evaluated the risk of HT in those with normal BP or pre-HT at baseline whose BP progressed to HT at the middle of follow-up compared with those whose BP remained at normal or pre-HT levels.

    Results: Among the 707 normotensive patients at baseline, 34.1% and 6.6% of subjects progressed to pre-HT and HT, respectively, by the middle of follow-up. Among 702 subjects with pre-HT at baseline, 26.1% progressed to HT. During the follow-up period, there were 11 CVD events in normotensive patients and 16 CVD events in pre-HT patients at baseline. The subjects who progressed from pre-HT to HT had 2.95 times higher risk of CVD than those who remained at normal BP or pre-HT in a multivariable-adjusted Cox hazard model.

    Conclusion: This relatively long-term prospective cohort study indicated that the CVD risk with pre-HT might increase after progression to HT; however, the number of CVD events was small. Therefore, the results need to be confirmed in a larger cohort.

  • Wen Zhang, Tetsuya Ohira, Masafumi Abe, Kenji Kamiya, Shunichi Yamashi ...
    2017 年 27 巻 1 号 p. 14-23
    発行日: 2017/01/05
    公開日: 2017/02/07
    ジャーナル フリー

    Background: Few studies have investigated the relationship between living arrangements and dietary intake among evacuees after disasters.

    Objectives: To examine the relationship between living arrangements and dietary intake using the data of a large-scale cohort survey of evacuees after the Great East Japan Earthquake in 2011.

    Methods: 73,433 residents in evacuation zones responded to the Fukushima Health Management Survey questionnaire. Subjects were excluded if they did not report their living conditions or were missing more than three pieces of information about dietary intake. The data of 52,314 subjects (23,149 men and 29,165 women ≥15 years old) were used for the analyses. Evacuees' living arrangements were characterized into three categories: evacuation shelters or temporary housing, rental houses or apartments, or a relative's home or their own home. Dietary intake was characterized in terms of grains, fruits and vegetables, meat, soybean products, dairy products, and fish. Daily consumption of the third quartile (Q3) or higher for each food group was defined as ‘high consumption’. Prevalence ratios (PRs) and 95% confidence intervals (CIs) were estimated using modified Poisson regression analyses.

    Results: Modified Poisson regression analyses showed that, compared with respondents living in a relative's home or their own home, the PRs and 95% CIs for the people living in rental apartments of high consumption of fruits and vegetables (non-juice), meat, soybean products, and dairy products were 0.69 (95% CI, 0.61–0.77), 0.82 (95% CI, 0.73–0.91), 0.89 (95% CI, 0.83–0.94), and 0.83 (95% CI, 0.74–0.93) respectively. The corresponding PRs and 95% CIs for people living in evacuation shelters or temporary housing were 0.83 (95% CI, 0.78–0.88), 0.90 (95% CI, 0.86–0.95), 0.94 (95% CI, 0.91–0.97), and 0.91 (95% CI, 0.86–0.96) for high consumption of fruits and vegetables (non-juice), meat, soybean products, and dairy products, respectively.

    Conclusion: The present study suggests that, after the earthquake, living in non-home conditions was associated with poor dietary intake of fruits and vegetables (non-juice), meat, soybean products, and dairy products, suggesting the need for early improvements in the provision of balanced meals among evacuees living in non-home conditions.

  • Ling-Chien Hung, Sheng-Feng Sung, Cheng-Yang Hsieh, Ya-Han Hu, Huey-Ju ...
    2017 年 27 巻 1 号 p. 24-29
    発行日: 2017/01/05
    公開日: 2017/02/07
    ジャーナル フリー

    Background: Stroke severity is an important outcome predictor for intracerebral hemorrhage (ICH) but is typically unavailable in administrative claims data. We validated a claims-based stroke severity index (SSI) in patients with ICH in Taiwan.

    Methods: Consecutive ICH patients from hospital-based stroke registries were linked with a nationwide claims database. Stroke severity, assessed using the National Institutes of Health Stroke Scale (NIHSS), and functional outcomes, assessed using the modified Rankin Scale (mRS), were obtained from the registries. The SSI was calculated based on billing codes in each patient's claims. We assessed two types of criterion-related validity (concurrent validity and predictive validity) by correlating the SSI with the NIHSS and the mRS. Logistic regression models with or without stroke severity as a continuous covariate were fitted to predict mortality at 3, 6, and 12 months.

    Results: The concurrent validity of the SSI was established by its significant correlation with the admission NIHSS (r = 0.731; 95% confidence interval [CI], 0.705–0.755), and the predictive validity was verified by its significant correlations with the 3-month (r = 0.696; 95% CI, 0.665–0.724), 6-month (r = 0.685; 95% CI, 0.653–0.715) and 1-year (r = 0.664; 95% CI, 0.622–0.702) mRS. Mortality models with NIHSS had the highest area under the receiver operating characteristic curve, followed by models with SSI and models without any marker of stroke severity.

    Conclusions: The SSI appears to be a valid proxy for the NIHSS and an effective adjustment for stroke severity in studies of ICH outcome with administrative claims data.

  • Minatsu Kobayashi, Seung Chik Jwa, Kohei Ogawa, Naho Morisaki, Takeo F ...
    2017 年 27 巻 1 号 p. 30-35
    発行日: 2017/01/05
    公開日: 2017/02/07
    ジャーナル フリー

    Background: The relative validity of food frequency questionnaires for estimating long-chain polyunsaturated fatty acid (LC-PUFA) intake among pregnant Japanese women is currently unclear. The aim of this study was to verify the external validity of a food frequency questionnaire, originally developed for non-pregnant adults, to assess the dietary intake of LC-PUFA using dietary records and serum phospholipid levels among Japanese women in early and late pregnancy.

    Methods: A validation study involving 188 participants in early pregnancy and 169 participants in late pregnancy was conducted. Intake LC-PUFA was estimated using a food frequency questionnaire and evaluated using a 3-day dietary record and serum phospholipid concentrations in both early and late pregnancy.

    Results: The food frequency questionnaire provided estimates of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intake with higher precision than dietary records in both early and late pregnancy. Significant correlations were observed for LC-PUFA intake estimated using dietary records in both early and late pregnancy, particularly for EPA and DHA (correlation coefficients ranged from 0.34 to 0.40, p < 0.0001). Similarly, high correlations for EPA and DHA in serum phospholipid composition were also observed in both early and late pregnancy (correlation coefficients ranged 0.27 to 0.34, p < 0.0001).

    Conclusions: Our findings suggest that the food frequency questionnaire, which was originally designed for non-pregnant adults and was evaluated in this study against dietary records and biological markers, has good validity for assessing LC-PUFA intake, especially EPA and DHA intake, among Japanese women in early and late pregnancy.

  • Long-Gang Zhao, Hong-Lan Li, Jiang-Wei Sun, Yang Yang, Xiao Ma, Xiao-O ...
    2017 年 27 巻 1 号 p. 36-41
    発行日: 2017/01/05
    公開日: 2017/02/07
    ジャーナル フリー

    Background: Green tea is one of the most widely consumed beverages in Asia. While a possible protective role of green tea against various chronic diseases has been suggested in experimental studies, evidence from human studies remains controversial.

    Methods: We conducted this study using data from Shanghai Men's Health Study (SMHS) and Shanghai Women's Health Study (SWHS), two population-based prospective cohorts of middle-aged and elderly Chinese adults in urban Shanghai, China. Hazard ratios (HR) and 95% confidence intervals (CI) for risk of all-cause and cause-specific mortality associated with green tea intake were estimated using Cox proportional hazards regression models.

    Results: During a median follow-up of 8.3 and 14.2 years for men and women, respectively, 6517 (2741 men and 3776 women) deaths were documented. We found that green tea consumption was inversely associated with risk of all-cause mortality (HR 0.95; 95% CI, 0.90–1.01), particularly among never-smokers (HR 0.89; 95% CI, 0.82–0.96). The inverse association with cardiovascular disease (CVD) mortality (HR 0.86; 95% CI, 0.77–0.97) was slightly stronger than that with all-cause mortality. No significant association was observed between green tea intake and cancer mortality (HR 1.01; 95% CI, 0.93–1.10).

    Conclusions: Green tea consumption may be inversely associated with risk of all-cause and CVD mortality in middle-aged and elderly Chinese adults, especially among never smokers.

  • Cong Huang, Haruki Momma, Yufei Cui, Masahiko Chujo, Atsushi Otomo, Sh ...
    2017 年 27 巻 1 号 p. 42-47
    発行日: 2017/01/05
    公開日: 2017/02/07
    ジャーナル フリー

    Background: Unhealthy eating has been found to be associated with the prevalence of depressive symptoms. However, prospective evidence of the combined effects of unhealthy eating and depressive symptoms has not been reported. This study aimed to elucidate the prospective relationship between habitual unhealthy eating habits and depressive symptoms.

    Methods: A 2-year prospective cohort study of 376 Japanese adults aged 24–83 years without depressive symptoms at baseline was conducted. Information about participants' eating behaviors was obtained via a self-administered questionnaire, in which skipping breakfast, eating dinner shortly before bedtime, and snacking after dinner were recorded. Depressive symptoms were assessed using the Japanese version of the Zung Self-rating Depression Scale.

    Results: The 2-year incidence of depressive symptoms was found to be 23.7% (89/376). Covariate-adjusted multivariate Poisson regression analyses showed that habitual snacking after dinner was significantly associated with the incidence of depressive symptoms (relative risk [RR] 1.77; 95% confidence interval [CI], 1.00–3.14, p = 0.049), whereas no relationship was found between skipping breakfast or eating dinner shortly before bedtime and depressive symptoms. On the other hand, there was an interaction effect of snacking after dinner and dinner before bedtime on depressive symptoms (p for the interaction = 0.044). Participants with more than two unhealthy eating behaviors had a higher incidence of depressive symptoms compared to those with fewer than two unhealthy eating behaviors (RR 1.71; 95% CI, 1.06–2.77, p = 0.028).

    Conclusions: This prospective study is the first to reveal the combined relationship between unhealthy eating and the incidence of depressive symptoms.