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 with previously normal BMD.

INTERVENTIONS: Oral conjugated estrogens and progesterone acetate were administered 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 was determined during young adulthood. The change in BMD over the previous 6 years also was evaluated. Serum concentrations of the carboxy-terminal propeptide of type 1 collagen and of the carboxy-terminal cross-linked telopeptide of type 1 collagen were measured.

RESULT(S): The BMD of the lumbar spine was reduced significantly in our patients. There was no change in the BMD of the femoral neck or lumbar spine over a period of 6.1 years. Concentrations of the carboxy-terminal propeptide of type 1 collagen were decreased, whereas concentrations of the carboxy-terminal 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 bone resorption.