2022 Fiscal Year Final Research Report
Effects of dioxin exposure on brain regional volumes and connectivity between among regions in highly exposed male residents in Vietnam
| Project/Area Number |
18K19709
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Review Section |
Medium-sized Section 58:Society medicine, nursing, and related fields
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| Research Institution | Kanazawa Medical University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
的場 宗孝 金沢医科大学, 医学部, 教授 (90288308)
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| Project Period (FY) |
2018-06-29 – 2023-03-31
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| Keywords | ダイオキシン / MRI / 脳領域体積 / 脳領域間結合 / 成人男性 / 周産期曝露 / 血中ダイオキシン |
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| Outline of Final Research Achievements |
Our subjects included 32 men who are fathers from Bien Hoa birth cohort in Vietnam. Blood dioxin levels and perinatal dioxin exposure suspected from residency of their mothers in Bien Hoa during pregnancy were used as dioxin exposure markers. T1-weighted images and diffusion tensor images (DTI) by brain MRI scan were subjected to regional volume analysis using the VBM tool and to regional connectivity indicated by fractional anisotropy (FA) using DT tractography.
Significant inverse associations were found between blood TCDD and fusiform gyrus volume, and between TEQ-PCDDs and temporal pole volume. FA values in high blood TCDD group were lower in right and left cingulum hippocampal part and right uncinate fasciculus. In men with suspected perinatal dioxin exposure, the left inferior frontal gyrus pars orbitalis volume was significantly lower, whereas the total gray matter volume was significantly higher. FA value in left uncinate fasciculus was lower in men with perinatal exposure.
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| Free Research Field |
環境保健
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| Academic Significance and Societal Importance of the Research Achievements |
近年、ベトナム戦争で枯葉剤曝露を受けたアメリカ退役軍人にアルツハイマー型認知症に罹患する者が多いことが報告され、ダイオキシン曝露の脳への影響が注目されている。これまでにも、小児の脳神経発達にダイオキシン曝露が負の影響を与えることが、欧米での研究で報告され、我々もベトナムの旧米軍基地周辺の出生コホートにおいて同様な報告を行ってきた。しかし、本研究では、小児には実施することが困難であったMRI検査を実施することにより、ダイオキシン曝露による脳への器質的な変化を明らかにすることができたことは、学術的に意義深く、ダイオキシンの神経毒性を明らかにする上で重要な知見を得ることができたと考えている。
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