Bone mineral density assessed by phalangeal radiographic absorptiometry before and during long-term growth hormone treatment in girls with Turner's syndrome participating in a randomized dose-response study

To assess bone mineral density (BMD) in girls with Turner's syndrome before and during long-term treatment with GH, longitudinal measurements using ph alangeal radiographic absorptiometry were performed in 68 girls with Turner 's syndrome. These previously untreated girls, age 2-11 y. participating in a randomized, dose-response trial, were randomly assigned to one of three GH dosage groups: group A, 4 IU/m(2)/d (0.045 mg/kg/d); group B. first year 4 IU/m(2)/d, thereafter 6 IU/m(2)/d (approximate to0.0675 mg/kg/d); or gro up C, first year 4 IU/m(2)/d, second year 6 IU/m(2)/d, thereafter 8 IU/m(2) /d (approximate to0.090 mg/kg/d), In the first 4 y of GH treatment, no estr ogens for pubertal induction were prescribed to the girls. Thereafter, girl s started with 17 beta -estradiol (5 mug/kg body weight/d, orally) when the y had reached the age of 12 y. Mm results were adjusted for bone age and se x, and expressed as SD scores using reference values of healthy Dutch girls . At baseline, almost every individual BMD value of bone consisting predomi nantly of cortical bone, as well as that of bone consisting predominantly o f trabecular bone, was within the normal range of healthy girls and the SD scores were not significantly different from zero [mean (SE) 0.38 (0.22) an d -0.04 (0.13)]. During 7 y of GH treatment, BMD SD scores showed a signifi cant increase to values significantly higher than zero [mean (SE) 0.87 (0.1 5) and 0.95 (0.14)]. The increment in BMD SD score of bone consisting predo minantly of cortical bone was significantly higher in group C compared with that of the other two GH dosage groups. The pretreatment bone age was sign ificantly negatively related to the increment in BMD SD score. We found no significant influence of spontaneous puberty or the use of low-dose estroge ns in the last 3 y of the study period on the increment in BMD SD score dur ing 7 y of GH treatment. In conclusion, most untreated young girls with Tur ner's syndrome have a normal volumetric BMD. During 7 y of GH treatment wit h 4, 6, or 8 IU/m(2)/d, the BMD SD score increased significantly.