The Triglyceride–Glucose (TyG) Index as a Practical Marker for Predicting Outcomes After Varicocelectomy

Objective: Although microsurgical varicocelectomy improves semen parameters in many infertile men with varicocele, postoperative outcomes remain heterogeneous. Identifying reliable preoperative predictors of surgical success is therefore clinically important. The triglyceride–glucose (TyG) index has emerged as a simple and practical surrogate marker of insulin resistance (IR). We aimed to evaluate the predictive value of the TyG index for varicocelectomy success.Methods: Patients who underwent microsurgical subinguinal varicocelectomy between 2019 and 2024 were retrospectively analyzed. The TyG index was calculated using fasting triglyceride and fasting blood glucose levels. Semen analyses were performed preoperatively and six months postoperatively. Surgical success was defined as a >50% increase in postoperative total motile sperm count (TMSC), or >100% in patients with baseline TMSC <5 million. ROC analysis was used to determine the optimal TyG cut-off value, and logistic regression analyses were performed to identify independent predictors of surgical success.Results: Among 149 patients, 96 (64.4%) showed postoperative improvement in semen parameters (Group 1), whereas 53 (35.6%) did not (Group 2). The TyG index was significantly lower in Group 1 compared with Group 2 (8.49 ± 0.47 vs. 8.95 ± 0.58; p<0.001). ROC analysis identified a TyG cut-off value of 8.86 for predicting varicocelectomy success (AUC: 0.732; sensitivity 80.2%, specificity 54.7%). In multivariate analysis, a TyG index ≤8.86 was an independent predictor of postoperative improvement (OR: 5.183; 95% CI: 2.373–11.319; p<0.001).Conclusions: Lower preoperative TyG index values are associated with improved semen parameters after varicocelectomy and may serve as a practical predictor of surgical success.