Background and objectives: Chinese type 2 diabetes mellitus (T2DM) patients are characterized by a low body mass index (BMI), and significant insulin resistance (IR). The triglyceride glucose (TyG) index has not been studied as a means of assessing IR in Chinese T2DM patients with a BMI < 35 kg/m². Materials and Methods: An open-label cross-sectional study recruited 102 Chinese T2DM patients with a BMI < 35 kg/m². The hyper-insulinemic euglycemic clamp, homeostatic model assessment of IR (HOMA-IR), and TyG index were used to determine the level of IR. Based on Pearson’s correlations, glucose disposal rate (GDR), TyG index, and HOMA-IR were analyzed. HOMA-IR and TyG index for IR were evaluated using multiple linear regression and multivariate logistic regression analyses. On the basis of the receiver operating characteristic (ROC) curve, the sensitivity, specificity, and optimal cut-off value of HOMA-IR and the TyG index were determined. Results: The mean values of GDR, HOMA-IR, and TyG index were 4.25 ± 1.81, 8.05 ± 7.98, and 8.12 ± 0.86 mg/kg/min, respectively. Pearson’s correlation coefficient was −0.418 between GDR and TyG index and −0.324 between GDR and HOMA-IR. ROC curve analysis showed that, among both sexes, the TyG index was a better discriminator of IR than HOMA-IR. The area under the ROC curve (AUC) of the TyG index (0.785, 0.691–0.879) was higher than that of HOMA-IR (0.73, 0.588–0.873) in all genders. The optimal cut-off values of the TyG index and HOMA-IR were 7.99 and 3.39, respectively. Conclusions: The TyG index showed more effectiveness in identifying IR in Chinese T2DM patients with a BMI < 35 kg/m² compared to HOMA-IR.

Background: Roux-en-Y gastric bypass (RYGB) results in extraordinary weight loss and glycemic control outcomes for patients with obesity; however, the effect of gastric pouch size is still unclear, and the reported results are contradictory. Additionally, long-term data on type 2 diabetes (T2D) patients with low body mass index (BMI) are sparse. This study was to assess the effect of 6-year outcomes in Chinese patients with T2D and a BMI < 35 kg/m2 who underwent RYGB with gastric pouches of different sizes.Methods: A retrospective cohort study was performed. There were 42 patients in the large gastric pouch group (L) and 53 patients in the small gastric pouch group (S). Baseline demographic history, pre- and postoperative BMI, waist circumference, and glucose- and lipid metabolism-related indicators were compared.Results: Assessments were completed in 100%, 100%, 93.6%, and 89.4% of patients at baseline, 1 year, 3 years, and 6 years, respectively. At 6 years, the changes in BMI and fasting plasma glucose were greater in the S group (-4.25 ± 0.51 kg/m2 and -4.58 ± 0.73 mmol/l) than in the L group (-2.06 ± 0.48 kg/m2 and -2.64 ± 0.61 mmol/l). The independent predictors of complete remission of T2D were preoperative BMI and the size of the gastric pouch. A large gastric pouch was associated with a higher risk for marginal ulcers.Conclusions: A small gastric pouch results in better weight loss and glycemic control. High preoperative BMI and a small gastric pouch are associated with better T2D remission rates. A large gastric pouch leads to a higher incidence of marginal ulcers.

Background: Obesity is a widely recognized global public health issue, and bariatric surgery has emerged as an effective intervention for alleviating obesity associated health complications. However, the impact of bariatric surgery on male reproductive function remains inconclusive in the literature. The current understanding of the impact of laparoscopic sleeve gastrectomy (LSG) on male reproductive function remains ambiguous, despite its status as the most commonly performed bariatric surgery. This prospective cohort study aimed to investigate the impact of LSG on erectile function and semen quality. Patients and methods: A total of 34 obese patients were enrolled in this study and underwent LSG. Prior to the operation and at 3, 6, and 12 months postoperation, all participants were required to complete the International Index of Erectile Function-5 (IIEF-5) questionnaire and undergo a nocturnal erectile function test and semen quality analysis. Results: Within 12 months postoperation, BMI, blood lipids, and insulin resistance showed significant improvement. The IIEF-5 score increased significantly (18.88±5.97 vs. 23.78±3.19, P<0.05), and the frequency and duration of erections significantly improved compared to baseline. Sperm concentration, total motility, survival rate, and sperm morphology parameters exhibited a significant decline at 3 months but demonstrated a significant improvement at 6 and 12 months postoperation. At 12 months, sperm concentration was shown to be correlated with changes in zinc (r=0.25, P=0.033) as well as changes in testosterone (r=0.43, P=0.013). Conclusions: LSG has beneficial effects on erectile function, despite a transient decline in semen quality at 3 months postoperatively, followed by a significant improvement at 12 months.