Isoflavone aglycone supplementation affects bone turnover in relation to estrogen receptor polymorphism

Abstract

Soybean isoflavones have structural similarity to estrogen and have been paid much attention for prevention of postmenopausal symptoms. While isoflavones exist naturally occurring glycosidic forms, they need to be hydrolyzed to aglycones by intestinal flora. In the present study, bone turnover parameters were examined among workers at a local hospital whose isoflavone aglycone supplementation was different. Eighty‐one subjects were recruited with informed consent and all of them were premenopausal women. They took placebo or isoflavone aglycone supplement for 3 month and the changes of bone turnover parameters were investigated. No statistical differences in nutrients intake were observed among the group. There were also no significant differences in bone turnover parameters such as carboxylated osteocalcin (Gla), undercarboxylated osteocalcin (uc‐OC), deoxypridinoline (DPD), and bone mineral parameter (OSI) measured by ultrasound method. Since univariate analysis was insufficient to clarify the association between bone turnover parameters and isoflavone aglycone supplementation, multiple regression analysis was performed. This analysis showed that OSI was correlated with isoflavone aglycone supplementation, Gla and estrogen receptor polymorphism. Since this study was performed only 3 month, long‐term administration of isoflavone aglycone should be further performed. This study was supported in part by a Research Project Grant (No. 17‐501) from Kawasaki Medical School.