〔報 文〕大学生における抑うつ症状および非定型うつ特徴とその関連要因の検討

Objectives: The prevalence of depression appears to have increased over the past two decades in Japan. Recently, atypical depression which is a subtype of depression has been increasing among young adult women. Although the relationship between depression and modifiable lifestyle factors has been reported, the factors associated with atypical depression have not been examined in Japan. We examine the factors associated with depression and atypical depression in Japanese University students. Methods: Subjects were 568 University students. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression(CES-D)Scale. Atypical depression features were understood to include the presence of ten major features, including significant weight gain or increase in appetite, hypersomnia, leaden paralysis, and interpersonal rejection sensitivity. To investigate risk factors for depressive symptoms and atypical depression features, logistic regression analysis was conducted. Results: Forty-five percent of subjects(men: 31.9%, women: 49.0%)were identified as having depressive symptoms. There was sexual difference in atypical depression features; women were significantly more likely to experience "craving for sweets", "presence of bulimia" and to be "more depressed at night." The multivariate-adjusted odds ratios(OR)and 95% confidence intervals(95%CI)of having depressive symptoms and atypical depression features for self-rated health among female students were 4.35(95%CI: 2.05-9.25)and 3.22(95%CI: 1.63-6.39), respectively. The odds ratio for stress was highest among modifiable lifestyle factors. Furthermore, the factors associated with atypical depression were "eating snacks and/or nighttime eating"(OR: 1.70, 95%CI: 1.04-2.77), and "smoking"(OR: 3.68, 95%CI: 1.22-11.10)among women. Conclusion: The results of this study suggest that stress is a major risk factor for both depressive symptoms and atypical depression features. According to these results about atypical depression, the factors associated with atypical depression were "eating snacks and/or nighttime eating", and "smoking" in women

Effects of prenatal exposure to dioxin-like compounds on allergies and infections during infancy

Dioxin-like compounds are endocrine disruptors. The effects of prenatal exposure to environmental levels of dioxins on immune function during infancy have not been clarified, although dioxins induce immunosuppression in offspring of animals. Moreover, human studies have not assessed the effects of gender- or congener-specific differences. The purpose of this study was to investigate the association between dioxin levels in maternal blood and the risk of infection and allergies in infancy. We examined 364 mothers and their infants enrolled in a Hokkaido Study on Environment and Children's Health between 2002 and 2005 in Sapporo, Japan. Relevant information was collected from a baseline questionnaire during pregnancy, medical records at delivery, and a follow-up questionnaire when the child was 18 months of age that assessed development of allergies and infections in infancy. Dioxin-like compound levels in maternal blood were measured with high-resolution gas chromatography/high-resolution mass spectrometry. Relatively higher levels of polychlorinated dibenzofuran were associated with a significantly increased risk of otitis media, especially among male infants (odds ratio=2.5, 95% confidence interval=1.1-5.9). Relatively higher levels of 2,3,4,7,8-pentachlorodibenzofuran were also associated with a significantly increased risk of otitis media (odds ratio=5.3, 95% confidence interval=1.5-19). However, we observed a weak association between dioxin-like compound levels and allergic symptoms in infancy. At environmental levels, prenatal exposure to dioxin-like compounds may alter immune function and increase the risk of infections in infancy, especially among males. The compound 2,3,4,7,8-pentachlorodibenzofuran may be responsible for this

Effects of low-level prenatal exposure to dioxins on cognitive development in Japanese children at 42 months

Background: Prenatal exposure to polychlorinated dibenzo-p-dioxins (PCDDs) or polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dioxin-like compounds [DLCs]) through environmental chemicals may affect the neurodevelopment of children. In our previous study, an inverse association was observed between prenatal DLCs and neurodevelopment of infants aged 6 months in both sexes. However, studies are yet to determine how long these adverse effects last. Objective: To examine whether the effects of DLCs on cognitive development remains at 42 months. Methods: In this prospective cohort study conducted in Sapporo, Japan, pregnant mothers' blood was analyzed for the congener level of DLCs. The Kaufman Assessment of Battery for Children (K-ABC) was used to test their children's cognitive development at 42 months. A total of 141 mother-child pairs were included in the final analysis. The multiple linear regression analysis was used to examine the association between the K-ABC scores and DLC levels in the maternal blood. Results: Seven isomers (1,2,3,6,7,8-HxCDD, 2,3,4,7,8-PeCDF, 33'44'55'-HxCB(#169), 2344'5-PenCB(#114), 233'44'5-HexCB(#156), 233'44'5'-HexCB(#157), 23'44'55'-HexCB(#167), total PCDF, and TEQ-PCDD, PCDF, PCDD/DFs levels were positively associated with the achievement score (AS) of K-ABC. However, total non-ortho PCBs were negatively associated with the Mental Processing Composite Score (MPCS) of K-ABC in males. In females, increased TEQ-dl PCB and TEQ-PCDD/F/dl-PCB were also associated with increasing AS score. Conclusions: This study suggests that the negative effects of prenatal DLC exposure on children's cognitive development at 6 months were not observed in children aged 42 months. Regarding the sex-specific effects, AS and DLCs were positively correlated in females, whereas those of MPCS and DLCs were significantly negative in males