Circulating sclerostin and estradiol levels are associated with inadequate response to bisphosphonates in postmenopausal women with osteoporosis

•Postmenopausal osteoporosis patients suffer fractures in spite of being on bisphosphonate therapy and with good adherence.•It is unknown whether estradiol and sclerostin circulating levels are associated with inadequate response to bisphosphonate therapy in this population.•Several reports showed that estrogen affect sclerostin production. We observed a nonlinear, inverted U-shaped relation between estradiol and sclerostin levels.•Our findings suggest that increased expression of sclerostin, accompanied by estrogen deficiency, can influence the response to bisphosphonate therapy.