Koichiro Hayashi: Faculty of Human Development, Kokugakuin University, Yokohama, Kanagawa, Japan. ORCID
Hidetaka Yamaguchi: Department of Sport Social Management, Kibi International University, Takahashi, Okayama, Japan.
Hiroshi Amaoka: Department of Sport Social Management, Kibi International University, Takahashi, Okayama, Japan.
Terumasa Takahara: Department of Sport Social Management, Kibi International University, Takahashi, Okayama, Japan.
Shiori Kunisa: Department of Sport Social Management, Kibi International University, Takahashi, Okayama, Japan.
Nanae Tamai: Faculty of Human Development, Kokugakuin University, Yokohama, Kanagawa, Japan.
Nagisa Maejima: Faculty of Human Development, Kokugakuin University, Yokohama, Kanagawa, Japan.
Nana Watanabe: Faculty of Human Development, Kokugakuin University, Yokohama, Kanagawa, Japan.
Yui Kobayashi: Faculty of Human Development, Kokugakuin University, Yokohama, Kanagawa, Japan.
Hirofumi Tanaka: Cardiovascular Aging Research Laboratory, Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas.
Central arterial compliance decreases drastically after menopause. Regular intake of soy isoflavone and aerobic exercise increase arterial compliance. The equol is a metabolite of isoflavone daidzein by gut microbiome. We determined whether the equol-producing status affects aerobic exercise-induced improvement in carotid arterial compliance. Forty-three postmenopausal women were assigned to two intervention groups: ) exercise and isoflavone (Ex+Iso, = 27 females) or ) isoflavone interventions (Iso; = 16 females). Participants of the Ex+Iso intervention group completed an 8-wk aerobic exercise training, and all participants were administered with oral isoflavone supplements during the interventions. The equol-producing status (equol producers or nonproducers) was determined from urine equol concentrations after a soy challenge. In the Ex+Iso intervention group, carotid arterial compliance increased in the equol producers (0.084 ± 0.030→0.117 ± 0.035 mm/mmHg), but not in the nonproducers (0.089 ± 0.028→0.097 ± 0.026 mm/mmHg) after the intervention (interaction effect; < 0.05). The magnitude of increases in carotid arterial compliance was significantly greater in the equol producers than in the non-equol producers ( < 0.05). In the isoflavone intervention group, there were no changes in any parameters after the intervention irrespective of the equol status. These results suggest that equol-producing status is obligatory to aerobic exercise training-induced improvements in central arterial compliance in postmenopausal women. Isoflavone intake and aerobic exercise increase central artery compliance. Equol, a metabolite of isoflavone daidzein by gut microbiome, has beneficial effects on vascular function. We demonstrated for the first time that the interaction of aerobic exercise and equol production status plays an essential role in improvements in central artery compliance in postmenopausal women. More specifically, the equol-producing status was obligatory to exercise training-induced improvements in central arterial compliance in postmenopausal women.
