Technical Report No. 19-92
A longitudinal study of growth and development among prenatally exposed atomic-bomb survivors
Otake M, Fujikoshi Y, Schull WJ, Izumi SEditor’s note: A publication based on this report was published in Radiat Res 134:94-101, 1993.
Summary
Growth retardation due to atomic-bomb exposure has been evaluated for 455 individuals with nine repeated measurements of stature at age 10-18 yr using growth curve analysis and either two covariates, Dosimetry System 1986 (DS86) uterine absorbed dose and postovulatory age (weeks), or three covariates, DS86 uterine dose, DS86 uterine dose squared, and postovulatory age. Of the several comparisons made by city, sex, DS86 dose, and postovulatory age, the largest significant difference was between males and females. However, on the basis of a linear-quadratic (L-Q) dose-response, no significant difference was found between Hiroshima and Nagasaki males or females except for all trimesters (of pregnancy) combined and for males only exposed in the first trimester. A highly significant growth retardation due to DS86 uterine absorbed dose (in gray) was observed for all trimesters combined and for the first and second trimesters. In the first trimester, all parameter estimates based on a linear (L) or L-Q dose-response relationship were negative in relation to DS86 uterine absorbed dose. The parameter estimates in the second trimester were negative for a constant term and positive for an L or L-Q term, but growth and development (stature) evidently showed a declining trend dependent on DS86 uterine dose. The positive estimate tends slightly to be close to a control level with an increase of dose. A significant difference is determined by a multivariate test statistic to examine whether a set of two or three parameter estimates including a constant term related to an L or L-Q dose-response relationship is significantly different from zero. The longitudinal repeated measurements of stature for individuals age 10-18 yr demonstrated radiation-related growth retardation. The dose effect in the third trimester was not significant with either the L or the L-Q model.
The first outward sign of the beginning of the secondary development of boys (the adolescent growth spurt) appears at age 14 yr on the average. Accordingly, a growth analysis, based on an L dose-response relationship, was made for 704 and 838 children with four repeated measurements of stature from ages 10-13 and 15-18 yr, respectively. An analysis by prematurity and maturity was made by increasing the number of individuals, which in turn increases the statistical power. The retardation effect is clearly evident at age 10-13 and continues unabated through age 15-18. Growth retardation in the group age 10-13 was highly significant for all trimesters combined but suggestive only for the first trimester. However, the group age 15-18 revealed a highly significant growth retardation for both the first and second trimesters. The relationship between birth weights and repeated measurements of stature in adolescence was discussed on the basis of the results obtained by a growth curve analysis.
Growth retardation due to atomic-bomb exposure has been evaluated for 455 individuals with nine repeated measurements of stature at age 10-18 yr using growth curve analysis and either two covariates, Dosimetry System 1986 (DS86) uterine absorbed dose and postovulatory age (weeks), or three covariates, DS86 uterine dose, DS86 uterine dose squared, and postovulatory age. Of the several comparisons made by city, sex, DS86 dose, and postovulatory age, the largest significant difference was between males and females. However, on the basis of a linear-quadratic (L-Q) dose-response, no significant difference was found between Hiroshima and Nagasaki males or females except for all trimesters (of pregnancy) combined and for males only exposed in the first trimester. A highly significant growth retardation due to DS86 uterine absorbed dose (in gray) was observed for all trimesters combined and for the first and second trimesters. In the first trimester, all parameter estimates based on a linear (L) or L-Q dose-response relationship were negative in relation to DS86 uterine absorbed dose. The parameter estimates in the second trimester were negative for a constant term and positive for an L or L-Q term, but growth and development (stature) evidently showed a declining trend dependent on DS86 uterine dose. The positive estimate tends slightly to be close to a control level with an increase of dose. A significant difference is determined by a multivariate test statistic to examine whether a set of two or three parameter estimates including a constant term related to an L or L-Q dose-response relationship is significantly different from zero. The longitudinal repeated measurements of stature for individuals age 10-18 yr demonstrated radiation-related growth retardation. The dose effect in the third trimester was not significant with either the L or the L-Q model.
The first outward sign of the beginning of the secondary development of boys (the adolescent growth spurt) appears at age 14 yr on the average. Accordingly, a growth analysis, based on an L dose-response relationship, was made for 704 and 838 children with four repeated measurements of stature from ages 10-13 and 15-18 yr, respectively. An analysis by prematurity and maturity was made by increasing the number of individuals, which in turn increases the statistical power. The retardation effect is clearly evident at age 10-13 and continues unabated through age 15-18. Growth retardation in the group age 10-13 was highly significant for all trimesters combined but suggestive only for the first trimester. However, the group age 15-18 revealed a highly significant growth retardation for both the first and second trimesters. The relationship between birth weights and repeated measurements of stature in adolescence was discussed on the basis of the results obtained by a growth curve analysis.