Objective: The objective of this study was to determine the relationships of serum estrogen levels after hormone replacement therapy (HRT) every other day and every day with body mass index (BMI) in postmenopausal and bilaterally ovariectomized women.
Methods: Eighty-six postmenopausal and 51 bilaterally ovariectomized women who had been suffering from vasomotor symptoms such as hot flush or atrophy of the vagina were randomly treated with HRT every other day or every day. Seventy-four patients received oral administration of 0.625 mg conjugated equine estrogen (CEE) and 2.5 mg medroxyprogesterone acetate (MPA) every other day, and 63 patients received oral administration of 0.625 mg CEE and 2.5 mg MPA every day as conventional HRT.
Results: Eighty-four postmenopausal and 50 bilaterally ovariectomized women completed this study. Serum estradiol levels after HRT every day in postmenopausal and bilaterally ovariectomized women were significantly (P <0.05 and <0.01, respectively) correlated with BMI, while those after HRT every other day were not correlated with BMI. The differences between estradiol levels after 12 months of treatment and initial estradiol levels were also significantly (P <0.01) correlated with BMI in both postmenopausal and bilaterally ovariectomized women who received HRT every day but not in women who received HRT every other day. Serum estrone level after HRT every day and the difference between estrone level after 12 months of treatment and initial estrone level were significantly (P <0.05 and <0.01, respectively) correlated with BMI only in bilaterally ovariectomized women.
Conclusion: Serum estradiol levels after HRT every day increase more in overweight women than in non-overweight postmenopausal and bilaterally ovariectomized women. The results of the present study regarding the relationship between serum estradiol levels after HRT and BMI should be useful for selecting dosages of drugs to be used in HRT.