Bone loss often occurs after bariatric surgery (also called metabolic surgery: currently including gastric bypass surgery RYGB, and gastric sleeve resection SG). Christian Muschitz and colleagues at the Medical University of Vienna, Austria, found that a sustained increase in Sclerostin and bone turnover markers after bariatric surgery was associated with reduced bone mineral density (BMD).Sclerostin, an inhibitor of bone morphogenetic protein (BMP), downregulates BMP activity by competitively binding to BMP receptors Sclerostin, as an inhibitor of bone morphogenetic protein (BMP), can inhibit osteogenesis by competitively binding to BMP receptors, downregulating BMP activity, and coordinating bone metabolic processes through interaction with nuclear binding factors. However, the changes in sclerostin, which is an important regulator of bone formation after Roux-en-Y gastric bypass (RYGB) or laparoscopic gastric sleeve resection (SG), and its role are not well understood. This is a prospective, observational, single-center, two-group study of premenopausal women who have been severely obese for more than 24 months. A total of 52 premenopausal women after Roux-en-Y gastric bypass (40±8 years, BMI 43.4) and 38 premenopausal women after laparoscopic gastric sleeve resection (41±7 years, BMI 45.7) were included in the study, and serum sclerostin, Dickkopf-1 ( DKK-1), CTX, P1NP levels and bone mineral density BMD. the study also evaluated the correlation of postoperative sclerostin and DKK-1 serum levels with markers of bone transformation (P1NP, CTX), parathyroid hormone (iPTH) and area bone mineral density (aBMD, including whole body skeleton, lumbar spine and total hip). Results found that two years after surgery, subjects had an average 45% reduction in BMI, 60% and 25% reduction in body fat and lean body mass, respectively, and a significant 18% reduction in whole-body BMD. Postoperative elevations in sclerostin, CTX and (to a lesser extent) P1NP caused an increase in bone metabolism, leading to a loss of BMD at all skeletal sites. This study suggests an urgent need for attention to the potential endocrine problems of weight loss surgery. Phase II and III studies are currently underway regarding the use of sclerostin inhibitors in postmenopausal women.