Bone protection for early menopausal women in China: standard or half-dose estrogen with progestin? A one-year prospective randomized trail.

The aim of the study is to compare the bone sparing effect of half-dose with standard-dose conjugated equine estrogen (CEE) combined with progestin. A total of 123 participants were administrated with 0.625 mg of CEE and 100 mg of micronized progesterone (MP) in group A, 0.3 mg of CEE and 100 mg of MP in group B, 0.625 mg of CEE and 10 mg of dydrogesterone (DDG) in group C for one year. Percent changes from baseline in BMD at lumbar spine and fracture rate were primary outcomes. Secondary endpoints included changes of BMD at femoral neck, total hip and arm, bone markers (alkaline phosphatase, calcium and phosphorus), serum alanine aminotransferase (ALT) and endometrial thickness. No fractures occurred during the treatment. Standard dose of CEE leads to significant changes in lumbar spine and arm. The 3.78% growth of BMD at femoral neck in group C marked a statistically difference. There was no statistically remarkable bone loss at hip in all three groups. Bone turnover markers and ALT significantly decreased from basic values. Endometrium thickened more with traditional dose of CEE. Both the half and standard dose CEE are effective in BMD preservation among early menopausal women with subtle side effects. Low-dose estrogen is less efficacious than traditional one.