Postmenopausal femur bone loss: effects of a low dose hormone replacement therapy

OBJECTIVES: Previous studies indicate that low-dose hormone replacement therapy (LD-HRT) can relieve vasomotor symptoms and prevent spine bone loss. METHODS: In the present study, we evaluated the effects of a low dose of conjugated equine estrogens (CEE; 0.3 mg) associated with different progestins in continuous combined scheme [2.5 mg of medroxyprogesterone acetate (n=25), 5 mg dydrogesterone (n=27), 2.5 mg nomegestrol (n=11)] as single group, on femur bone mineral density (BMD) and bone metabolism in young postmenopausal women (<or=56 years). All women were supplemented with 1 g of calcium per day, and compared with women treated with 1 g of calcium per day alone (control group, n=15). There were no significant differences in age, body mass index (BMI), hormone values, bone metabolism markers and femur BMD in the treatment and control groups before the study. RESULTS: In calcium-treated women serum plasma osteocalcin (BGP) and hydroxyproline/creatinine urinary excretion (OHP/Cr) remained stable during all the observation period. In this group, femoral neck, Ward's triangle and trochanter BMD showed a progressive and significant (P<0.05) decrease. In the LD-HRT group, a significant (P<0.05) decrease in serum BGP and OHP/Cr was observed. In these women, the values of these markers of bone turnover at 36 months were significantly (P<0.01) different from those of calcium-treated women. During the LD-HRT administration, all BMD measures did not show any significant modifications. In these women, treated with LD-HRT the BMD values were significantly (P<0.05) different from those measured in calcium-treated women in all the femur sites of measurements. In the control group, BMI significantly (P<0.05) increased from baseline value with a weight gain of 3%, while in the LD-HRT group, BMI did not change after 36 months of treatment and the 1.3% gain in body weight was not significant. LD-HRT was effective in reducing menopausal clinical symptoms and provided a favorable bleeding profile, and minimal side effects. CONCLUSION: LD-HRT was effective in reducing menopausal clinical symptoms and minimal and transient side effects were reported. In addition, the 0.30 mg/day of CEE, in addition to a proper calcium supplementation, irrespective of the progestin used, can provide effective protection against activation of bone turnover and femur osteopenia.