Journal of Epidemiology
Online ISSN : 1349-9092
Print ISSN : 0917-5040
ISSN-L : 0917-5040
Volume 25 , Issue 6
Showing 1-10 articles out of 10 articles from the selected issue
Original Article
  • Krisztina Gero, Ehab S. Eshak, Enbo Ma, Hideto Takahashi, Hiroyuki Nod ...
    2015 Volume 25 Issue 6 Pages 399-406
    Published: June 05, 2015
    Released: June 05, 2015
    [Advance publication] Released: May 16, 2015
    Background: The objective of this study was to examine long-term trends in rates of ischaemic heart disease (IHD) mortality, a leading cause of mortality in Hungary. The study examined the effects of age, period, and cohort on IHD mortality rates and compared mortality rates between the capital (Budapest) and non-capital counties.
    Methods: Data on IHD deaths and population censuses were obtained from the Hungarian Central Statistical Office. Age-period-cohort analysis utilized nine age-group classes for ages 40 to 84 years, eight time periods from 1970 to 2009, and 16 birth cohorts from 1886 to 1969.
    Results: Age-adjusted IHD mortality rates for men and for women generally increased from 1970 to 1993 and from 1980 to 1999, respectively, decreasing thereafter for both sexes. IHD mortality rates for men and for women from Budapest were lower from 1991 and from 1970, respectively, than corresponding rates in non-capital counties, with the difference increasing after 1999. Age had a more significant influence on mortality rates for women than for men. The period effect increased from 1972 to 1982 and decreased thereafter for men, while the period effect decreased consistently for women from 1972 to 2007. The decline in period effect for both sexes was larger for individuals from the capital than for those from non-capital counties. The cohort effect for both sexes declined from birth years 1890 to 1965, with a steeper decline for individuals from the capital than for those from non-capital counties.
    Conclusions: The findings indicate a need for programs in Hungary for IHD prevention, especially for non-capital counties.
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  • Takumi Hirata, Aya Higashiyama, Yoshimi Kubota, Kunihiro Nishimura, Da ...
    2015 Volume 25 Issue 6 Pages 407-414
    Published: June 05, 2015
    Released: June 05, 2015
    [Advance publication] Released: May 23, 2015
    Background: Several studies have reported that insulin resistance was a major risk factor for the onset of type 2 diabetes mellitus in individuals without diabetes or obesity. We aimed to clarify the association between insulin resistance and glycemic control in Japanese subjects without diabetes or obesity.
    Methods: We conducted a community-based cross-sectional study including 1083 healthy subjects (323 men and 760 women) in an urban area. We performed multivariate regression analyses to estimate the association between the homeostasis model assessment of insulin resistance (HOMA-IR) values and markers of glycemic control, including glycated haemoglobin (HbA1c), 1,5-anhydroglucitol (1,5-AG), and fasting plasma glucose (FPG) levels, after adjustment for potential confounders.
    Results: Compared with the lowest tertile of HOMA-IR values, the highest tertile was significantly associated with HbA1c and FPG levels after adjustment for potential confounders, both in men (HbA1c: β = 1.83, P = 0.001; FPG: β = 0.49, P < 0.001) and women (HbA1c: β = 0.82, P = 0.008; FPG: β = 0.39, P < 0.001). The highest tertile of HOMA-IR values was inversely associated with 1,5-AG levels compared with the lowest tertile (β = −18.42, P = 0.009) only in men.
    Conclusions: HOMA-IR values were associated with markers of glycemic control in Japanese subjects without diabetes or obesity. Insulin resistance may influence glycemic control even in a lean, non-diabetic Asian population.
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  • Kai Lu, Jia Chen, Shouling Wu, Ji Chen, Dayi Hu
    2015 Volume 25 Issue 6 Pages 415-422
    Published: June 05, 2015
    Released: June 05, 2015
    [Advance publication] Released: April 25, 2015
    Background: Previous studies demonstrated conflicting results about the association of sleep duration and hypertension. Given the potential relationship between sleep quality and hypertension, this study aimed to investigate the interaction of self-reported sleep duration and sleep quality on hypertension prevalence in adult Chinese males.
    Methods: We undertook a cross-sectional analysis of 4144 male subjects. Sleep duration were measured by self-reported average sleep time during the past month. Sleep quality was evaluated using the standard Pittsburgh Sleep Quality Index. Hypertension was defined as blood pressure level ≥140/90 mm Hg or current antihypertensive treatment. The association between hypertension prevalence, sleep duration, and sleep quality was analyzed using logistic regression after adjusting for basic cardiovascular characteristics.
    Results: Sleep duration shorter than 8 hours was found to be associated with increased hypertension, with odds ratios and 95% confidence intervals (CIs) of 1.25 (95% CI, 1.03–1.52) for 7 hours, 1.41 (95% CI, 1.14–1.73) for 6 hours, and 2.38 (95% CI, 1.81–3.11) for <6 hours. Using very good sleep quality as the reference, good, poor, and very poor sleep quality were associated with hypertension, with odds ratios of 1.20 (95% CI, 1.01–1.42), 1.67 (95% CI, 1.32–2.11), and 2.32 (95% CI, 1.67–3.21), respectively. More importantly, further investigation of the association of different combinations of sleep duration and quality in relation to hypertension indicated an additive interaction.
    Conclusions: There is an additive interaction of poor sleep quality and short sleep duration on hypertension prevalence. More comprehensive measurement of sleep should be performed in future studies.
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  • Kota Kataoka, Daisuke Ekuni, Shinsuke Mizutani, Takaaki Tomofuji, Tets ...
    2015 Volume 25 Issue 6 Pages 423-430
    Published: June 05, 2015
    Released: June 05, 2015
    [Advance publication] Released: April 11, 2015
    Objectives: Bruxism can result in temporomandibular disorders, oral pain, and tooth wear. However, it is unclear whether bruxism affects malocclusion. The aim of this study was to examine the association between self-reported bruxism and malocclusion in university students.
    Methods: Students (n = 1503; 896 men and 607 women) aged 18 and 19 years were examined. Malocclusion was defined using a modified version of the Index of Orthodontic Treatment Need. The presence of buccal mucosa ridging, tooth wear, dental impression on the tongue, palatal/mandibular torus, and the number of teeth present were recorded, as well as body mass index (BMI). Additional information regarding gender, awareness of bruxism, orthodontic treatment, and oral habits was collected via questionnaire.
    Results: The proportion of students with malocclusion was 32% (n = 481). The awareness of clenching in males with malocclusion was significantly higher than in those with normal occlusion (chi square test, P < 0.01). According to logistic regression analysis, the probability of malocclusion was significantly associated with awareness of clenching (odds ratio [OR] 2.19; 95% confidence interval [CI], 1.22–3.93) and underweight (BMI <18.5 kg/m2) (OR 1.89; 95% CI, 1.31–2.71) in males but not in females. In subgroup analyses, the probability of crowding was also significantly associated with awareness of clenching and underweight (P < 0.01) in males.
    Conclusions: Awareness of clenching and underweight were related to malocclusion (crowding) in university male students.
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  • Shigekazu Ukawa, Akiko Tamakoshi, Hiroshi Yatsuya, Kazumasa Yamagishi, ...
    2015 Volume 25 Issue 6 Pages 431-436
    Published: June 05, 2015
    Released: June 05, 2015
    [Advance publication] Released: May 02, 2015
    Background: Sedentary behavior is associated with cardiovascular disease, diabetes mellitus, and cancer morbidity, and watching television (TV) is an important sedentary behavior. The aim of this study is to clarify the association between TV viewing time and chronic obstructive pulmonary disease (COPD)-related mortality in Japanese adults.
    Methods: Using the Cox proportional hazard model, we assessed COPD-related mortality by TV viewing time in a national cohort of 33 414 men and 43 274 women without cancer, stroke, myocardial infarction, or tuberculosis at baseline (1988–1990).
    Results: The median follow-up was 19.4 years; 244 men and 34 women died of COPD. Men watching ≥4 hours/day of TV were more likely to die of COPD than those watching <2 hours/day (hazard ratio 1.63; 95% confidence interval, 1.04–2.55), independent of major confounders. No association was found in women.
    Conclusions: Avoiding a sedentary lifestyle, particularly prolonged TV viewing, may help in preventing death from COPD among men.
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  • Shinji Takahashi, Wakaba Fukushima, Takuaki Yamamoto, Yukihide Iwamoto ...
    2015 Volume 25 Issue 6 Pages 437-444
    Published: June 05, 2015
    Released: June 05, 2015
    [Advance publication] Released: April 25, 2015
    Background: Nontraumatic osteonecrosis of the femoral head (ONFH) is a rare disorder caused by ischemic necrosis of unknown etiology. A few studies have demonstrated trends in the number of patients with ONFH. However, there are no data on temporal trends in characteristics such as age, gender, and causative factors. To investigate this, we examined data from a multicenter hospital-based sentinel monitoring system in Japan.
    Methods: A total of 3041 newly-diagnosed ONFH patients from 34 participating hospitals who were reported to the system from 1997–2011 were analyzed. We examined age at diagnosis, potential causative factors, and underlying diseases for which patients received systemic steroid administration. Their temporal trends were assessed according to date of diagnosis in 5-year intervals (1997–2001, 2002–2006, and 2007–2011).
    Results: The gender ratio and distribution of potential causative factors did not change. Regarding underlying diseases requiring steroid administration, the proportion of patients with systemic lupus erythematosus decreased in males (10% to 6.4%) and in females (37% to 29%). Proportion of patients with renal transplantation fell consistently across the study period in both males (3.8% to 1.2%) and females (3.2% to 0.8%). In contrast, the proportion of patients receiving steroids for pulmonary disease (except asthma) significantly increased in both males (0.5% to 5.5%) and females (0.5% to 3.6%).
    Conclusions: This large descriptive study is the first to investigate temporal trends in the characteristics of ONFH, which provide useful information for future studies.
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  • Yu Sun, Chien-Jung Lu, Rong-Chi Chen, Wen-Hsuan Hou, Chung-Yi Li
    2015 Volume 25 Issue 6 Pages 445-451
    Published: June 05, 2015
    Released: June 05, 2015
    [Advance publication] Released: May 02, 2015
    Background: Glucose intolerance in patients with amyotrophic lateral sclerosis (ALS) has been inconsistently reported. Evidence for the association of ALS and diabetes mellitus is limited. We aimed to assess the overall and age- and sex-specific risks of ALS among patients with diabetes in Taiwan.
    Methods: The study cohort included 615 492 diabetic patients and 614 835 age- and sex-matched subjects as a comparison cohort, followed from 2000 to 2008. We estimated the incidence densities of ALS and calculated the relative hazard ratios (HRs) of ALS (ICD-9-CM 335.20) in relation to diabetes using a Cox proportional hazard regression model, with adjustment for potential confounders, including sex, age, geographic area, urbanization status, Charlson Comorbidity Index, frequency of medical visit, and histories of hypertension, hyperlipidemia, and chronic obstructive pulmonary disease.
    Results: Over a 9-year period, 255 diabetic and 201 non-diabetic subjects developed ALS, corresponding to incidence densities of 7.42 and 5.06 per 100 000 person-years, respectively. After adjustment for potential confounders, patients with diabetes experienced a significantly elevated HR of 1.35 (95% confidence interval [CI], 1.10–1.67). A higher covariate adjusted HR was noted in men (HR 1.48; 95% CI, 1.13–1.94) than in women (HR 1.17; 95% CI, 0.84–1.64), while men aged ≤65 years showed the most increased HR of 1.67 (95% CI, 1.18–2.36).
    Conclusions: This study demonstrated a moderate but significant association of diabetes with ALS onset, and such association is not confounded by socio-demographic characteristics or certain ALS-related co-morbidities. Further studies are warranted to examine whether the findings observed in our study can be replicated.
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Statistical Data
  • Takehiro Michikawa, Hiroshi Nitta, Shoji F. Nakayama, Masaji Ono, Junz ...
    2015 Volume 25 Issue 6 Pages 452-458
    Published: June 05, 2015
    Released: June 05, 2015
    [Advance publication] Released: April 25, 2015
    Background: The Japan Environment and Children’s Study (JECS) is an ongoing nationwide birth cohort study launched in January 2011. In this progress report, we present data collected in the first year to summarize selected maternal and infant characteristics.
    Methods: In the 15 Regional Centers located throughout Japan, the expectant mothers were recruited in early pregnancy at obstetric facilities and/or at local government offices issuing pregnancy journals. Self-administered questionnaires were distributed to the women during their first trimester and then again during the second or third trimester to obtain information on demographic factors, physical and mental health, lifestyle, occupation, environmental exposure, dwelling conditions, and socioeconomic status. Information was obtained from medical records in the first trimester and after delivery on medical history, including gravidity and related complications, parity, maternal anthropometry, and infant physical examinations.
    Results: We collected data on a total of 9819 expectant mothers (mean age = 31.0 years) who gave birth during 2011. There were 9635 live births. The selected infant characteristics (singleton births, gestational age at birth, sex, birth weight) in the JECS population were similar to those in national survey data on the Japanese general population.
    Conclusions: Our final birth data will eventually be used to evaluate the national representativeness of the JECS population. We hope the JECS will provide valuable information on the impact of the environment in which our children live on their health and development.
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Letter to the Editor