Abstract: Objective To investigate the effects of laparoscopic sleeve gastrectomy(LSG) on long-term weight loss maintenance and glycemic stability in patients with type 2 diabetes mellitus (T2DM) and obesity, and to explore the relationship between weight loss and glycemic stability. 
Methods A total of 80 T2DM patients diagnosed with obesity in Jiangning Hospital of Nanjing City, Jiangsu Province, were selected as the research subjects, and underwent LSG. Body weight, body mass index (BMI), and waist circumference of the patients were compared before surgery and at various follow-up points within two years after the surgery. The glycemic profile ［glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), 2-hour postprandial blood glucose (2 hPBG)］, HOMA model parameters ［homeostatic model assessment of β-cell function (HOMA-β), homeostatic model assessment of insulin resistance (HOMA-IR)］, insulin secretion index (△I10/△G10), and thyroid function indicators ［thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4)］ before and after surgery were compared before and after surgery. Correlation analysis was performed based on the results between various indicators. 
Results At various follow-up points within two years after intervention, body weight, waist circumference, BMI and blood glucose indexes were significantly lower than those before surgery, the postoperative HOMA-β and insulin secretion index were significantly higher than those before operation, the HOMA-IR was lower than that before surgery, and the TSH value of postoperative patients decreased significantly, while FT3 and FT4 showed a continuous upward trend, suggesting significant differences (all P＜0.05). Correlation analysis showed that BMI was positively correlated with blood glucose index and thyroid hormone level, and negatively correlated with insulin secretion index (P＜0.05). 
Conclusion For patients with obesity and T2DM, blood glucose, insulin, and thyroid indicators all affect their weight and waist circumference. The application of LSG helps to maintain weight loss effects and improve glycemic stability, providing a more reliable treatment option for patients. 

Key words: diabetes mellitus, type 2, obesity, glycemic stability