Short-term effects of new synthetic conjugated estrogens on biochemical markers of bone turnover.

Author(s): Garnero P, Stevens RE, Ayres SA, Phelps KV

Affiliation(s): INSERM Research Unit 403, Hjpital E. Herriot, Lyon, France.

Publication date & source: 2002-03, J Clin Pharmacol., 42(3):290-6.

Publication type: Clinical Trial; Randomized Controlled Trial

Fifty early postmenopausal women completed a double-blind, placebo-controlled study evaluating the short-term effect of a new synthetic conjugated estrogens formulation (Cenestin) on bone turnover. Subjects were randomized to either 0.625 mg/day synthetic conjugated estrogens (n = 35) or placebo (n = 15) for 3 months. Biochemical markers were evaluated at baseline (three measurements at Days -2, -1, and 0) and Days 30, 60, and 90. Bone resorption assessed by urinary NTX (-31.4%) and serum CTX (-34.2%) was significantly (p < 0.01) decreased in the estrogen-treated group compared to the placebo group within 1 month of treatment. The mean percent decreases for urinary NTX from baseline during estrogen treatment were -58.0% (p < 0.01 vs. placebo) and -34.1% (ns) after 2 and 3 months, respectively. For serum CTX, the percent changes from baseline were -17.6% (p < 0.01) and -16.9% (p < 0.01) at 2 and 3 months, respectively. As expected, the decrease of both bone formation markers (bone ALP and PINP) was delayed compared to that of bone resorption and significant (p < 0.05-0.01) only after 2 months of treatment in the estrogen-treated group compared to the placebo group. Synthetic conjugated estrogens significantly decreased bone resorption and bone formation comparable to that previously reported for estrogen treatments proven efficacious in preventing postmenopausal bone loss.