Trends in Age and Anthropometric Data at Start of Growth Hormone Treatment for Girls with Turner Syndrome in Japan

The purpose of this study is to evaluate the trends in age and anthropometric data for girls with Turner syndrome (TS) at start of growth hormone (GH) treatment in Japan. The data for analysis were obtained from a retrospective cohort, the Foundation for Growth Science, Japan. We analyzed trends in starting age of GH treatment for girls with TS in Japan after dividing subjects (n = 1,478) into three registration periods: 1991-1994, 1995-1999 and 2000- 2004. We also assessed the ratio of the subpopulation of subjects under five years of age. As results, the mean age (standard deviation (SD)) at start of GH treatment was significantly different among the three groups (10.95 (3.63), 10.15 (3.39) and 8.78 (3.61), p<0.0001). The proportion of the subjects under five years of age increased significantly over time (5.11%, 7.11% and 16.85%, p<0.0001). Mean (SD) height SD scores were also significantly different (-3.41 (0.87), -3.26 (0.81) and -3.17 (0.79), p<0.0001). However, the proportions of the karyotype of 45,X were not significantly different among the three groups (p = 0.25). We concluded that age and shortness at initiation of GH treatment had been improving over time. However, these favorable trends have not fully met the conditions recommended by international clinical guidelines for TS.