COMPARISON OF THE EFFECTS OF ESTROGEN ALONE AND ESTROGEN PLUS ANDROGEN ON BIOCHEMICAL MARKERS OF BONE-FORMATION AND RESORPTION IN POSTMENOPAUSAL WOMEN

The present study was undertaken to determine whether the addition of an androgen to estrogen therapy in postmenopausal women would alter th e skeletal response as determined by measurements of markers of bone f ormation and resorption. Postmenopausal women were treated for 9 weeks with either a combination of 1.25 mg esterified estrogen and 2.5 mg m ethyltestosterone (E + A) or 1.25 mg conjugated equine estrogen (GEE). Both groups showed a similar decrease in urinary excretion of the bon e resorption markers, deoxy-pyridinoline, pyridinoline, and hydroxypro line. Patients treated with CEE showed decreases in the serum markers of bone formation, bone-specific alkaline phosphatase, osteocalcin, an d C-terminal procollagen peptide. In contrast, subjects treated with E + A showed increases in these markers of bone formation. CEE increase d, and E + A decreased serum levels of sex hormone-binding globulin as well as triglycerides and high density lipoprotein levels. Only CEE s ignificantly reduced low density lipoproteins. Both regimens were effe ctive in reducing postmenopausal somatic symptoms, but only E + A had a significant effect on psychological symptoms. We conclude that short term administration of androgen with estrogen may reverse the inhibit ory effects of estrogen on bone formation. Long term studies are neede d to determine the relative benefits and risks of the combination of e strogen and androgen and whether this results in greater increases in bone mass and strength.