The Mediating Role of WBC in the Relationship Between Triglyceride-Glucose Index and Chronic Pain: Evidence From...

The relationship between triglyceride-glucose (TyG) index and chronic pain remains poorly understood. This study sought to evaluate how the TyG index relates to both the occurrence of chronic pain and all-cause mortality in affected individuals, while also assessing whether white blood cell (WBC) count played an intermediary role in these associations.

We analyzed data from 10,452 adults (aged ≥ 20 years) in the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2004. Weighted multivariable logistic regression assessed the TyG index-chronic pain association, with mediation analysis evaluating the role of WBC count. Cox regression analyzed the predictive role of the TyG index for survival in chronic pain patients, and potential mediation analysis examined the influence of WBC.

Among 3764 analyzed participants, the TyG index demonstrated significant associations with chronic pain in both continuous (OR = 1.25, 95% CI = 1.04-1.49, p = 0.020) and categorical models (Q5 vs. Q1: OR = 1.58, 95% CI = 1.09-2.31, p = 0.020) after full adjustment. WBC potentially mediated 9.0% (95% CI = 2.6%-12.4%) of this association. In the mortality analysis, the elevated TyG index predicted increased all-cause mortality risk (T3 vs. T1: HR = 2.05, 95% CI: 1.46-2.89, p < 0.001) in chronic pain patients, and WBC potentially mediated 12.0% (95% CI: 1.0%-23.1%) of this association.

The TyG index was independently associated with both chronic pain and increased mortality in chronic pain patients. Systemic inflammation partially mediated these links, suggesting that inflammation was a potential pathway connecting insulin resistance, chronic pain, and survival outcomes.