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P4‐113: Incidence of dementia among atomic bomb survivors: Radiation effects research foundation Adult Health Study
Author(s) -
Yamada Michiko,
Kasagi Fumiyoshi,
Mimori Yasuyo,
Miyachi Takafumi,
Ohshita Tomohiko,
Sasaki Hideo
Publication year - 2008
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2008.05.2179
Subject(s) - dementia , medicine , incidence (geometry) , poisson regression , cohort study , cohort , body mass index , gerontology , demography , population , disease , environmental health , physics , optics , sociology
article i nfo Radiotherapy has been reported to cause neuropsychological dysfunction. Here we examined whether exposure toatomicbombradiationaffectedtheincidence ofdementiaamong2286atomicbomb survivorsand controls — all members of the Adult Health Study cohort. Study subjects were non-demented and aged ≥60 years at baseline examination and had been exposed in 1945 at ≥13 years of age to a relatively low dose (≤4 Gy), compared with total dose from radiotherapy. Dementia diagnoses were made during biennial health examinations with a two-phase procedure. DSM IV criteria were used for diagnosing dementia, NINCDS- ADRDA for Alzheimer disease, and NINDS-AIREN for vascular disease. To estimate the effect of radiation on the dementia incidence rate, we applied Poisson regression analysis. Incidence per 1000 person-years was 16.3 in the b5 mGy group,17.0 in the 5-499 mGy group, and 15.2 in the ≥500 mGy group. Alzheimer disease was the predominant type of dementia in each dose category. After adjustment for potential risk factors, radiation exposuredidnotaffecttheincidencerateofeitheralldementiaoranyofitssubtypes.Nocaseofdementiahada history of therapeutic cranial irradiation. Although we found no relationship between radiation exposure and the development of dementia among atomic bomb survivors exposed at ≥13 years old in this longitudinal study, effects on increased risk of early death among atomic bomb survivors will be considered.