Insulin resistance (IR) is an important factor in the development of chronic pain. The triglyceride–glucose (TyG) index is a convenient measure of insulin resistance. However, as a common subtype of chronic pain, the relationship between postherpetic neuralgia (PHN) and the TyG index remains unclear. Through a retrospective analysis of the relationship between the TyG index and the incidence of PHN, we aim to determine whether the TyG index possesses predictive capability for PHN occurrence, thereby enabling the development of strategies to reduce the incidence of PHN. This retrospective study analyzed the medical records of patients diagnosed with acute herpes zoster (with a disease course of ≤ 1 month) in the Pain Department of Jiaxing University Affiliated Hospital from November 2024 to May 2025. Eligible patients were those who had available data on triglycerides and glucose, and no history of diabetes. Relevant clinical data were extracted from existing records and subjected to retrospective analysis. The numerical rating scale (NRS) score was utilized as the primary outcome measure to assess whether patients developed PHN. Those who still had pain (NRS ≥ 4) were classified as the PHN group, while those without pain symptoms (NRS < 4) were classified as the non-PHN group. The association between the TyG index and PHN was evaluated using multi-model logistic regression. In addition, the nonlinear relationship between these indicators and the results was studied using a restricted cubic spline plot. Subsequently, subgroup analyses were conducted on the sensitive population. The predictive value of the TyG index for PHN was evaluated using the receiver operating characteristic curve. The retrospective study comprised 157 patients with acute herpes zoster, of whom 55 were male and 102 female, with a mean age of 64.87 ± 11.67 years. The TyG index in patients with acute herpes zoster exhibited a nonlinear relationship with PHN, with an odds ratio (OR) and 95% confidence interval (CI) of 4.32 (1.56–11.97). A linear correlation was found between the triglyceride-glucose–body mass index (TyG-BMI) and PHN, with OR and 95% CI of 1.07 (1.02–1.11). The TyG index and the TyG-BMI showed similar performance on the receiver operating characteristic (ROC) curve for evaluating PHN and have certain predictive value. Higher TyG index and TyG-BMI are associated with an increased risk of PHN. ClinicalTrials.gov identifier, ChiCTR2500113190 (retrospectively registered). Registration Date: November 26, 2025.
Lu et al. (Fri,) studied this question.