Low Endogenous Estradiol Levels Maintain Bone Mass in Younger Postmenopausal Women After One Year Follow Up.

A BAGUR; B. OLIVERI; S. MASTAGLIA; A CRISTOFARI; D YANKELEVICH; F SAYEGH; M ROYER; C MAUTALEN

Minneapolis

Congreso; 25th Anual Meeting ASBMR; 2003

American Society for Bone and Mineral Research

Estradiol levels higher than 10 pg/ml and testosterone were involved in themaintenance of bone mineral density (BMD) in healthy postmenopausal (PMP)women as reported in a previous cross-sectional study.The aim of this study was to evaluate if the low endogenous estradiol levelsprotect BMD along one year of follow up without any preventive treatment forosteoporosis. Preliminary results of 34 PMP women aged 55 to 75 years wereincluded. We excluded 3 patients because they started specific osteoporosistreatment. The BMD of L2-L4, Total Femur (TF) and Total Skeleton (TS) wasmeasured by DXA (Lunar Prodigy). Serum calcium, bone alkaline phosphatase(BAP), crosslaps (CTX), estradiol and testosterone, and urine calcium weremeasured. Estradiol was measured with a sensitive assay that detects up to 5pg/ml. The population was divided in two groups: ¡Ü65 (n:19) and >65 years ofage (n:15). The preliminary biochemical results of the population were (mean ¡ÀDS): Serum calcium 9.4¡À0.4 mg/dl, phosphate 3.9¡À0.4 mg/dl, BAP 69.2¡À23.2UI/L and urine calcium 152¡À83.1 mg/24hs.The groups were also stratified according to baseline estradiol levels: ¡Ü10 and>10 pg/ml and the results were analyzed as a percentage of change of estradioland BMD from the baseline to one year follow up. Younger PMP women (¡Ü65)who had > 10 pg/ml of estradiol at baseline maintained their BMD at all skeletalsites and estradiol levels. On the other hand PMP women >65 with > 10 pg/mlof estradiol at baseline had a diminution of their estradiol levels (-44%, p<0.01)and also of the BMD of the TF (p<0.05), TS (p<0.01) and L2-L4 (p 0.07,ns). Allthe population with ¡Ü10 pg/ml of estradiol decreased their BMD at all skeletalareas although the change did not reach statistical significance.In conclusion, 1- Endogenous estradiol levels more than 10 pg/ml maintainedthe BMD in younger postmenopausal women along one year follow up withoutpreventive treatment for osteoporosis.2-Healthy postmenopausal women > 65 years of age had an important changesin the estradiol levels (-44%) accompanied with a decrease in the BMD.