Effect of radiation dose on the height of atomic bomb survivors: a longitudinal study.

We conducted a longitudinal analysis of height after age 20 for atomic bomb survivors in the Adult Health Study (AHS) cohort. The measurements we used were made from July 1958 to June 1998 (AHS examination cycles 1-20). We analyzed only the subjects with known atomic bomb radiation doses, excluding those who were not in the city at the time of bombing (ATB) and those exposed in utero. We also excluded from the analysis measurements made after the occurrence of vertebral fracture. The total number of subjects was 11,862, and the total number of measurements was 109,770; the mean number of measurements per subject was 9.25. Assuming that stature after age 20 is approximately constant, a simple mixed-effects model was fitted to stature after age 20, and linear dose effects for young ATB subjects were modeled for both sexes. The estimated mean heights for subjects born in 1945 in Hiroshima were 166.0 cm for men and 155.4 cm for women. The sex difference in height was 10.6 cm, with men significantly taller than women (P < 0.001). The difference between the cities was not significant (P = 0.162). The birth cohort effects per decade were -1.7 cm for men (P < 0.001) and -2.1 cm for women (P < 0.001). A reduction of stature due to radiation exposure was observed for individuals of both sexes who were below 19 years of age ATB (95% confidence interval, 17-21 years), and the dose effect was larger for women than for men (P = 0.028). The estimated effects per gray for those who were age 0 ATB were -1.2 cm for men and -2.0 cm for women and for those who were age 10 ATB were-0.57 cm for men and -0.96 cm for women.