[The impact of different bariatric metabolic surgery on bone marrow fat in patients with metabolic syndrome].

<b>Objective:</b> To explore the impact of sleeve gastrectomy and Roux-en-Y gastric bypass on bone marrow adipose tissue (BMAT) in patients with metabolic syndrome. <b>Methods:</b> A total of 82 patients with metabolic syndrome who underwent bariatric metabolic surgery at the Department of Bariatric and Metabolic Surgery in Beijing Friendship Hospital from January 2022 to October 2023 were conducted retrospectively. Patients who received SG and RYGB were divided into the SG group and RYGB group, respectively. Bone marrow fat fraction (BMFF) of T₉-L₁ was measured using the MRI iterative decomposition of water and fat with echo asymmetry and least squares estimation quantification (IDEAL-IQ) sequence. The changes of body weight, body mass index (BMI), lipid metabolism index and BMFF before and after operation were compared between the two groups. Pearson correlation analysis was used to evaluate the correlation between BMFF changes and body weight, BMI and lipid metabolism index. <b>Results:</b> The age of the 82 patients was (34.8±8.6) years, with 19 males (23.2%). There were 51 patients in the SG group (62.2%) and 31 in the RYGB group (37.8%). The weight, BMI, total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and BMFF were all decreased one year after surgery in metabolic syndrome patients, while the high-density lipoprotein cholesterol (HDL-C) increased compared with preoperative levels (all <i>P</i><0.05). The decreases of TC, TG and LDL-C in SG group were lower than those in RYGB group (all <i>P</i><0.05). There was no statistical difference in the decreases of weight, BMI, HDL-C and BMFF after surgery between two groups (all <i>P></i>0.05). BMFF changes before and after surgery were positive correlated with changes in body weight (<i>r</i>=0.765, 0.753, 0.801) and BMI (<i>r</i>=0.697, 0.646, 0.797) in the whole patients, SG and RYGB groups (all <i>P</i><0.05). <b>Conclusions:</b> BMFF in patients with metabolic syndrome decreases after bariatric and metabolic surgery. BMFF changes are similar after different surgical methods, and positively correlated with body weight and BMI changes.