Endocrine Abstracts

Background: Several studies have shown that medical radiation exposure in childhood might cause alteration in body composition, although all such studies were of a small scale and individual radiation doses were not estimated.

Objective: The aim of this cross-sectional study was to evaluate whether or not atomic-bomb (A-bomb) radiation exposure is associated with alteration of body composition using dual energy X-ray absorptiometry (DXA).

Methods: A total of 1729 participants in the Adult Health Study, comprising A-bomb survivors and their controls, were eligible for the study. Regional fat mass and lean mass were estimated by whole body DXA. Appendicular lean mass (ALM)/height²(ALMH²) and trunk (central) fat and limb (peripheral) fat ratio (trunk-to-limb fat-mass ratio) were calculated. We analyzed association between radiation dose and body composition using multivariate linear regression model.

Results: A-bomb radiation dose was associated with decreased levels of ALMH², after adjustment for smoking status and other conventional risk factors. Significant negative association between radiation dose and ALMH² was observed among A-bomb survivors exposed at young ages. Furthermore, there was significant positive association between radiation dose and trunk-to-limb fat ratio in young female survivors.

Conclusions: The observed effects on body composition may be useful information for elucidation of mechanisms behind late effects of radiation exposure on health outcomes including cardiovascular disease.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.