Inverse Association Between Triglyceride-Glucose Index and Ischemic Stroke in Hospitalized Patients with Chronic Obstructive Pulmonary Disease and Atrial Fibrillation: A Retrospective Analysis.

Ischemic stroke occurred in 4.5% of hospitalized patients with COPD and atrial fibrillation during the index hospitalization.

• IS occurred in 32 patients out of 710 total hospitalized patients with COPD and AF
• The study period spanned 2014–2024
• Median hospitalization duration was 9 days (IQR: 6–13)
• The outcome was new-onset IS occurring during the index hospitalization

Higher TyG index was associated with lower ischemic stroke risk in univariate analysis among hospitalized COPD and AF patients.

• Univariate analysis yielded OR=0.49 (95% CI: 0.26–0.94)
• This finding was described as unexpected and in contrast to findings in the general population
• The TyG index was calculated as ln[fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2] measured at admission

After full multivariate adjustment, each unit increase in TyG index was associated with significantly lower ischemic stroke risk.

• Adjusted OR = 0.24 (95% CI: 0.10–0.57, P=0.001)
• Covariates adjusted for included age, sex, smoking, blood pressure, diabetes, lipids, and prior stroke
• The wide confidence interval and limited events (n=32) indicate the large effect estimate should be interpreted cautiously as it may reflect statistical instability

Generalized additive models confirmed a linear inverse relationship between TyG index and ischemic stroke after adjusting for stroke history.

• GAM result: OR=0.50 (95% CI: 0.30–0.90, P=0.032)
• The relationship was confirmed to be linear rather than nonlinear
• The model was adjusted specifically for stroke history in this GAM analysis

The TyG index demonstrated modest predictive performance for ischemic stroke in this population.

• AUC = 0.614 (95% CI: 0.513–0.715) based on ROC analysis
• Predictive performance was evaluated via ROC analysis
• The AUC indicates limited but above-chance discriminative ability

The inverse association between TyG index and ischemic stroke in COPD-AF patients may reflect reverse causality related to disease severity rather than a true protective metabolic effect.

• Low TyG may mark disease severity including malnutrition, poor metabolic reserve, and chronic inflammation
• Lack of comprehensive disease severity and nutritional assessments limits causal inference
• The authors characterize this as a 'potential metabolic paradox' in this population
• Population-based studies are considered essential to address selection bias