Trimegestone in a low-dose, continuous-combined hormone therapy regimen prevents bone loss in osteopenic postmenopausal women.

Objective: To determine the efficacy of estrogen + progestogen therapy with 1 mg 17beta-estradiol and 0.125 mg trimegestone in the prevention of postmenopausal osteoporosis.

Design: For this study, 360 healthy, postmenopausal women with osteopenia [lumbar spine bone mineral density (BMD) between -1.0 and -2.5 SD of the premenopausal mean value] were enrolled in a 2-year prospective, randomized study, and 70% completed. Treatments were 1 mg 17beta-estradiol + 0.125 mg trimegestone (n = 179) or placebo (n = 181), given as daily oral therapy. All received a daily supplement of 500 mg calcium and 400 IU vitamin D. BMD measurements at the lumbar spine, total hip, and femoral neck as well as blood and urinary biochemical markers of bone turnover (serum osteocalcin), serum bone-specific alkaline phosphatase, serum CrossLaps, and urinary CrossLaps took place regularly.

Results: BMD increases relative to placebo were 6.3%, 3.9%, and 3.8% at the lumbar spine, total hip, and femoral neck, respectively (all P < 0.001). The biochemical markers of bone turnover were suppressed accordingly. Serum CrossLaps and urinary CrossLaps decreased rapidly, by 52% and 54%, respectively, whereas serum osteocalcin and serum bone-specific alkaline phosphatase revealed a more retarded decrease of 40% and 33%, respectively. Of the women receiving hormone therapy, 75% had amenorrhea from the first cycle, and 5% withdrew prematurely due to metrorrhagia or mastalgia.

Conclusion: This new estrogen + progestogen therapy is efficient in increasing BMD in an osteopenic postmenopausal population. Furthermore, it is well tolerated, with few adverse events and an early bleeding control, which is likely to improve compliance to the treatment over the long term.