The purpose of this study is to evaluate the effects of neoadjuvant therapy on glucose and lipid metabolism, bone mineral density (BMD) and muscle, and to explore the relationship between metabolic disorders and changes in body composition, so as to provide better health management strategies for breast cancer survivors.The clinical data of 43 patients with breast cancer who received neoadjuvant therapy in Xuanwu Hospital from January 2020 to June 2021 were analyzed retrospectively. The biochemical results, including albumin, blood glucose, triglyceride and cholesterol, were collected before neoadjuvant therapy and before surgery. The pectoral muscle area, pectoral muscle density and cancellous bone mineral density of the 12th thoracic vertebra were also measured by chest CT.After neoadjuvant therapy, fasting blood glucose, triglyceride and cholesterol were significantly increased, albumin was decreased. At the same time, pectoral muscle area, pectoral muscle density and T12 BMD were decreased. After treatment, BMD was positively correlated with pectoral muscle area, R2 = 0.319, P = 0.037, and BMD was also positively correlated with pectoral muscle density, R2 = 0.329, P = 0.031. Multivariate analysis showed that BMD and pectoral muscle density were correlated with menstrual status, and pectoral muscle area was correlated with body mass index before treatment, none of which was related to glucose and lipid metabolism.Neoadjuvant therapy can cause glucose and lipid metabolism disorder, BMD decrease and muscle reduction. BMD was positively correlated with muscle area and density after treatment, suggesting that patients had an increased chance of developing osteosarcopenia.© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.