Decreased bone mass despite long-term estrogen replacement therapy in young women with Turner's syndrome and previously normal bone density

Objective: To determine whether young women with Turner's syndrome who had normal bone mineral density (BMD) before the induction of puberty maintain normal BMD in young adulthood. Design: Controlled clinical study. Setting: A private hospital clinical research setting. Patients: Young women with Turner's syndrome in Tanner stage V of puberty w ith previously normal BMD. Interventions: Oral conjugated estrogens and progesterone acetate were admi nistered continuously for a mean (+/-SD) of 4.1 +/- 1.0 years. Bone mineral densities and blood samples were evaluated. Main Outcome Measure(s): The BMD of the lumbar spine and the femoral neck w as determined during young adulthood. The change in BMD over the previous 6 years also was evaluated. Serum concentrations of the carboxy-terminal pro peptide of type 1 collagen and of the carboxy-terminal cross-linked telopep tide of type 1 collagen were measured. Result(s): The BMD of the lumbar spine was reduced significantly in our pat ients. There was no change in the BMD of the femoral neck or lumbar spine o ver a period of 6.1 years. Concentrations of the carboxyterminal propeptide of type 1 collagen were decreased, whereas concentrations of the carboxy-t erminal cross-linked telopeptide of type 1 collagen were increased. Conclusion(s): Young women with Turner's syndrome do not attain normal peak bone mass even when estrogen replacement therapy is begun in adolescence. Their low BMD seems to be due to decreased bone formation and increased bon e resorption. (Fertil Steril(R) 1999;72:896-9. (C)1999 by American Society for Reproductive Medicine.).