A prospective,randomized, placebo-controlled study of the dose effect of oral estradiol on bone mineral density in postmenopausal Chinese women

OBJECTIVES: One of the long-term consequences of estrogen deficiency in postmenopausal women is an increased risk of osteoporosis. Fractures of the hip and lumbar spine are associated with considerable morbidity and mortality. Estrogen replacement therapy reduces the risk of osteoporosis, but there is no clear agreement on the most appropriate doses to be used. The aim of this study was to compare changes in bone mineral density (BMD) measurements using conventional and lower dose estradiol. METHODS: A prospective, randomized, placebo-controlled 12-month study of the effect of 1 and 2 mg estradiol on BMD in 152 hysterectomized postmenopausal Chinese women with no contraindication to the use of estrogen replacement therapy. RESULTS: Over 12 months, spinal BMD in placebo treated patients decreased by a mean of 2% from baseline (-0.02+/-0.03 g/cm(2)) while it increased by 2% in the 1 mg (0.02+/-0.03 g/cm(2)) and 3% in the 2 mg group (0.03+/-0.03 g/cm(2)). Mean changes in BMD over 12 months in the hip were -0.02+/-0.02 g/cm(2) (-2%), 0.01+/-0.02 g/cm(2) (+1%) and 0.01+/-0.03 g/cm(2) (+1%) in the placebo, 1 and 2 mg estradiol groups, respectively (P<0.05). Relative to placebo, increases in BMD in both 1 and 2 mg groups were statistically significant for both spine and hip (P<0.05). However, there was no significant difference in the increase in BMD between the 1 and 2 mg doses for either lumbar spine or hip (P=0.82, 0.53, respectively). CONCLUSION: The results of our study show that a 1 mg dose of oral estradiol is effective in preventing bone loss in postmenopausal Chinese women.