Journal of Epidemiology
Online ISSN : 1349-9092
Print ISSN : 0917-5040
ISSN-L : 0917-5040
Volume 27, Issue 3
Displaying 1-9 of 9 articles from this issue
Original Articles
  • Long-Gang Zhao, Xiao-Ou Shu, Hong-Lan Li, Wei Zhang, Jing Gao, Jiang-W ...
    2017 Volume 27 Issue 3 Pages 89-97
    Published: 2017
    Released on J-STAGE: April 03, 2017
    Supplementary material

    Background: Few studies have evaluated dietary antioxidant vitamins intake in relation to risk of mortality in Asia.

    Methods: We examined the associations between total carotene, vitamin C, and vitamin E from diet and risk of mortality from all causes, cancer, and cardiovascular disease in 134,358 participants (59,739 men and 74,619 women) from the Shanghai Men's Health Study and Shanghai Women's Health Study, two prospective cohort studies of middle-aged and elderly Chinese adults in urban Shanghai. Participants were followed up for a median period of 8.3 and 14.2 years for men and women, respectively. Hazard ratios (HRs) and 95% confidence interval (CIs) were estimated using Cox proportional hazards regression models.

    Results: During the 495,332 and 1,029,198 person-years of follow-up for men and women, respectively, there were 10,079 deaths (4170 men and 5909 women). For men, compared with the lowest quintiles, the multivariable-adjusted risk reductions in the highest categories were 17% (HR 0.83; 95% CI, 0.76–0.92) for dietary total carotene and 17% (HR 0.83; 95% CI, 0.75–0.91) for dietary vitamin C. Associations were weaker in women than in men, though they were still statistically significant (highest versus lowest quintiles of dietary total carotene, HR 0.87; 95% CI, 0.80–0.95; dietary vitamin C: HR 0.83; 95% CI, 0.77–0.91). Significant inverse associations were observed between dietary total carotene, vitamin C, and risk of cardiovascular disease mortality but not cancer mortality.

    Conclusion: This study suggests that total carotene and vitamin C intake from diet were inversely associated with deaths from all causes and cardiovascular disease in middle-aged or elderly people in China.

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  • Amy Ming-Fang Yen, Wendy Yi-Ying Wu, Laszlo Tabar, Stephen W. Duffy, R ...
    2017 Volume 27 Issue 3 Pages 98-106
    Published: 2017
    Released on J-STAGE: April 03, 2017
    Supplementary material

    Background: The risk factors responsible for breast cancer have been well documented, but the roles of risk factors as initiators, causing the occurrence of screen-detected breast cancer, or promoters, responsible for the progression of the screen-detected to the clinically-detected breast cancer, have been scarcely evaluated.

    Methods: We used data from women in a cohort in Kopparberg (Dalarna), Sweden between 1977 and 2010. Conventional risk factors, breast density, and tumor-specific biomarkers are superimposed to the temporal course of the natural history of the disease.

    Results: The results show that older age at first full-term pregnancy, dense breast, and a family history of breast cancer increased the risk of entering the preclinical screen-detectable phase of breast cancer by 23%, 41%, and 89%, respectively. Overweight/obesity (body mass index ≥25 kg/m2) was a significant initiator (adjusted relative risk [aRR] 1.15; 95% confidence interval [CI], 0.99–1.33), but was inversely associated with the role of promoter (aRR 0.65; 95% CI, 0.51–0.82). Dense breast (aRR 1.46; 95% CI, 1.12–1.91), triple-negative (aRR 2.07; 95% CI, 1.37–3.15), and Ki-67 positivity (aRR 1.66; 95% CI, 1.19–2.30) were statistically significant promoters. When the molecular biomarkers were considered collectively as one classification, the basal-like subtype was the most influential subtype on promoters (aRR 4.24; 95% CI, 2.56–7.02) compared with the Luminal A subtype.

    Discussion: We ascertained state-dependent covariates of initiators and promoters to classify the risk of the two-step progression of breast cancer. The results of the current study are useful for individuallytailored screening and personalized clinical surveillance of patients with breast cancer that was detected at an early stage.

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  • Hisayoshi Morioka, Osamu Itani, Yoneatsu Osaki, Susumu Higuchi, Maki J ...
    2017 Volume 27 Issue 3 Pages 107-111
    Published: 2017
    Released on J-STAGE: April 03, 2017

    Background: This study aimed to clarify the associations between the frequency and amount of alcohol consumption and problematic Internet use, such as Internet addiction and excessive Internet use.

    Methods: A self-administered questionnaire survey was administered to students enrolled in randomly selected junior and senior high schools throughout Japan, and responses from 100,050 students (51,587 males and 48,463 females) were obtained. Multiple logistic regression analyses were performed in order to examine the associations between alcohol use and problematic Internet, use such as Internet addiction (Young Diagnostic Questionnaire for Internet Addiction ≥5) and excessive Internet use (≥5 h/day).

    Results: The results of multiple logistic regression analyses indicated that the adjusted odds ratios for Internet addiction (YDQ ≥5) and excessive Internet use (≥5 h/day) became higher as the number of days in which alcohol had been consumed during the previous 30 days increased. In addition, the adjusted odds ratio for excessive Internet use (≥5 h/day) indicated a dose-dependent association with the amount of alcohol consumed per session.

    Conclusions: This study revealed that adolescents showing problematic Internet use consumed alcohol more frequently and consumed a greater amount of alcohol than those without problematic Internet use. These findings suggest a close association between drinking and problematic Internet use among Japanese adolescents.

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  • Tomosa Mine, Taichiro Tanaka, Tadashi Nakasone, Toru Itokazu, Zentaro ...
    2017 Volume 27 Issue 3 Pages 112-116
    Published: 2017
    Released on J-STAGE: April 03, 2017
    Supplementary material

    Background: Although several studies have focused on the association between maternal smoking during pregnancy and rapid weight gain (RWG) during infancy, the dose-response relationship has not yet been confirmed, and very few studies have included Asian populations. Using a record-linkage method, we examined the association between maternal smoking during pregnancy and RWG in infants at around 4 months of age to clarify the dose-response relationship.

    Methods: Two databases were used: maternal check-ups during pregnancy and early infancy check-ups (between April 1, 2013 and March 31, 2014 in Okinawa, Japan) were linked via IDs and provided to us after unlinkable anonymizing. For 10,433 subjects (5229 boys and 5204 girls), we calculated the change in infants' weight z-score by subtracting the z-score of their birth weight from their weight at early infancy check-ups. Smoking exposure was categorized into five groups. We used Poisson regression to examine the association of maternal smoking during pregnancy with RWG in early infancy.

    Results: Overall, 1524 (14.6%) were ex-smoker and 511 (4.9%) were current smoker. Compared with the reference category of non-smokers, the adjusted risk ratio of RWG was 1.18 (95% confidence interval [CI], 1.06–1.32) for ex-smokers, 1.18 (95% CI, 0.93–1.50) for those who smoked 1–5 cigarettes per day, 1.57 (95% CI, 1.24–2.00) for those who smoked 6–10 cigarettes per day, and 2.13 (95% CI, 1.51–3.01) for those who smoked ≥11 cigarettes per day. There was a clear dose-response relationship.

    Conclusion: Our study suggests that maternal smoking during pregnancy is associated in a dosedependent manner with increased risk of RWG in early infancy.

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  • Yosuke Ono, Sachiko Ono, Hideo Yasunaga, Hiroki Matsui, Kiyohide Fushi ...
    2017 Volume 27 Issue 3 Pages 117-122
    Published: 2017
    Released on J-STAGE: April 03, 2017

    Background: Myxedema coma is a life-threatening and emergency presentation of hypothyroidism. However, the clinical features and outcomes of this condition have been poorly defined because of its rarity.

    Methods: We conducted a retrospective observational study of patients diagnosed with myxedema coma from July 2010 through March 2013 using a national inpatient database in Japan. We investigated characteristics, comorbidities, treatments, and in-hospital mortality of patients with myxedema coma.

    Results: We identified 149 patients diagnosed with myxedema coma out of approximately 19 million inpatients in the database. The mean (standard deviation) age was 77 (12) years, and two-thirds of the patients were female. The overall proportion of in-hospital mortality among cases was 29.5%. The number of patients was highest in the winter season. Patients treated with steroids, catecholamines, or mechanical ventilation showed higher in-hospital mortality than those without. Variations in type and dosage of thyroid hormone replacement were not associated with in-hospital mortality. The most common comorbidity was cardiovascular diseases (40.3%). The estimated incidence of myxedema coma was 1.08 per million people per year in Japan. Multivariable logistic regression analysis revealed that higher age and use of catecholamines (with or without steroids) were significantly associated with higher in-hospital mortality.

    Conclusions: The present study identified the clinical characteristics and outcomes of patients with myxedema coma using a large-scale database. Myxedema coma mortality was independently associated with age and severe conditions requiring treatment with catecholamines.

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  • Yoichiro Hirakawa, Toshiharu Ninomiya, Yutaka Kiyohara, Yoshitaka Mura ...
    2017 Volume 27 Issue 3 Pages 123-129
    Published: 2017
    Released on J-STAGE: April 03, 2017

    Background: Diabetes mellitus is a strong risk factor for cardiovascular disease. However, the age-specific association of diabetes with cardiovascular risk, especially in the elderly, remains unclear in non-Western populations.

    Methods: A pooled analysis was conducted using 8 cohort studies (mean follow-up period, 10.3 years) in Japan, combining the data from 38,854 individual participants without history of cardiovascular disease. In all, 1867 of the participants had diabetes, defined based on the 1998 World Health Organization criteria. The association between diabetes and the risk of death from cardiovascular disease, coronary heart disease (CHD), and stroke was estimated using a stratified Cox model, accounting for variability of baseline hazard functions among cohorts.

    Results: During the follow-up, 1376 subjects died of cardiovascular disease (including 268 of coronary heart disease and 621 of stroke). Diabetes was associated with an increased risk of cardiovascular death after multivariable adjustment (hazard ratio [HR] 1.62; 95% confidence interval [CI], 1.35–1.94). Similarly, diabetes was a risk factor for CHD (HR 2.13; 95% CI, 1.47–3.09) and stroke (HR 1.40; 95% CI, 1.05–1.85). In the age-stratified analysis of the risk of cardiovascular death, the relative effects of diabetes were consistent across age groups (p for heterogeneity . 0.18), whereas the excess absolute risks of diabetes were greater in participants in their 70s and 80s than in younger subjects.

    Conclusions: The management of diabetes is important to reduce the risk of death from cardiovascular disease, not only in midlife but also in late life, in the Japanese population.

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Short Communication
  • Soo Cheng Lee, Noran Naqiah Hairi, Foong Ming Moy
    2017 Volume 27 Issue 3 Pages 130-134
    Published: 2017
    Released on J-STAGE: April 03, 2017

    Background: Non-obese individuals could have metabolic disorders that are typically associated with elevated body mass index (BMI), placing them at elevated risk for chronic diseases. This study aimed to describe the prevalence and distribution of metabolically obese, non-obese (MONO) individuals in Malaysia.

    Methods: We conducted a cross-sectional study involving teachers recruited via multi-stage sampling from the state of Melaka, Malaysia. MONO was defined as individuals with BMI 18.5–29.9 kg/m2 and metabolic syndrome. Metabolic syndrome was diagnosed based on the Harmonization criteria. Participants completed self-reported questionnaires that assessed alcohol intake, sleep duration, smoking, physical activity, and fruit and vegetable consumption.

    Results: A total of 1168 teachers were included in the analysis. The prevalence of MONO was 17.7% (95% confidence interval [CI], 15.3–20.4). Prevalence of metabolic syndrome among the normal weight and overweight participants was 8.3% (95% CI, 5.8–11.8) and 29.9% (95% CI, 26.3–33.7), respectively. MONO prevalence was higher among males, Indians, and older participants and inversely associated with sleep duration. Metabolic syndrome was also more prevalent among those with central obesity, regardless of whether they were normal or overweight. The odds of metabolic syndrome increased exponentially from 1.9 (for those with BMI 23.0–24.9 kg/m2) to 11.5 (for those with BMI 27.5–29.9 kg/m2) compared to those with BMI 18.5–22.9 kg/m2 after adjustment for confounders.

    Conclusions: The prevalence of MONO was high, and participants with BMI ≥23.0 kg/m2 had significantly higher odds of metabolic syndrome. Healthcare professionals and physicians should start to screen nonobese individuals for metabolic risk factors to facilitate early targeted intervention.

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Study Profile
  • Hiroko Matsubara, Mami Ishikuro, Masahiro Kikuya, Shoichi Chida, Mitsu ...
    2017 Volume 27 Issue 3 Pages 135-142
    Published: 2017
    Released on J-STAGE: April 03, 2017
    Supplementary material

    Background: To investigate the impact of the Great East Japan Earthquake on preschool children's physical growth in the disaster-affected areas, the three medical universities in Iwate, Miyagi, and Fukushima Prefectures conducted a health examination survey on early childhood physical growth.

    Methods: The survey was conducted over a 3-year period to acquire data on children who were born in different years. Our targets were as follows: 1) children who were born between March 1, 2007 and August 31, 2007 and experienced the disaster at 43–48 months of age, 2) children who were born between March 1, 2009 and August 31, 2009 and experienced the disaster at 19–24 months of age, and 3) children who were born between June 1, 2010 and April 30, 2011 and were under 10 months of age or not born yet when the disaster occurred.We collected their health examination data from local governments in Iwate, Miyagi, and Fukushima Prefectures. We also collected data from Aomori, Akita, and Yamagata Prefectures to use as a control group. The survey items included birth information, anthropometric measurements, and methods of nutrition during infancy.

    Results: Eighty municipalities from Iwate, Miyagi, and Fukushima Prefectures and 21 from the control prefectures participated in the survey. As a result, we established three retrospective cohorts consisting of 13,886, 15,474, and 32,202 preschool children.

    Conclusions: The large datasets acquired for the present survey will provide valuable epidemiological evidence that should shed light on preschool children's physical growth in relation to the disaster.

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