Effects of genistein on the endometrium: ultrasonographic evaluation

The aim of our study was to evaluate the effects of isoflavones on climacteric-related symptoms and on the endometrium in postmenopausal women, in a prospective, open, randomized, clinical trial performed at the Menopause Clinic of our Department. Seventy postmenopausal women were randomly assigned to two treatment groups receiving 12 cycles of treatment with genistein (group A) or calcium (group B). In all patients ultrasonographic endometrial thickness and Kupperman Index (KI) were evaluated at baseline and after 6 and 12 cycles of treatment. At baseline no significant difference was detected in endometrial thickness and in KI between groups A and B. After 6 and 12 cycles of treatment, no significant difference was observed in endometrial thickness between or within groups. Endometrial thickness was lower than 5 mm in all cases before and during treatment except in two cases in group B and in one case in group A after 12 months. At 6 and 12 months, the KI was significantly (p < 0.05) lower in group A in comparison with baseline values and group B. We conclude that genistein administration reduces climacteric symptoms in postmenopausal women and does not increase endometrial thickness.