Prognostic significance of the glucose-to-lymphocyte ratio in acute pulmonary embolism

Background: Acute pulmonary embolism has a heterogeneous clinical course, and simple laboratory markers reflecting metabolic and inflammatory stress may provide additional prognostic information. We investigated the association between the glucose-to-lymphocyte ratio (GLR) and in-hospital mortality in acute pulmonary embolism. Methods: This retrospective observational study included 631 consecutive patients diagnosed between January 2023 and June 2025. GLR was calculated as admission blood glucose divided by absolute lymphocyte count. Receiver operating characteristic (ROC) analysis assessed the discriminatory ability of GLR for in-hospital mortality and identified a ROC-derived exploratory threshold for subsequent analyses. Clinical characteristics and in-hospital outcomes were compared between GLR groups, and logistic regression analyses identified factors associated with mortality. Results: The median age was 69 years, 52.6% were female, and in-hospital mortality occurred in 41 patients (6.5%). GLR showed modest discrimination for mortality (area under the curve 0.626, 95% confidence interval [CI] 0.548-0.705; p=0.007), with a ROC-derived exploratory threshold of 80.06. Mortality was higher in patients with GLR ≥80.06 than in those with GLR <80.06 (9.5% vs. 3.3%; p=0.001). Elevated GLR was also associated with right ventricular dysfunction, vasopressor requirement, intensive care unit admission, hemodynamic deterioration, active infection, and longer hospital stay. GLR ≥80.06 remained associated with mortality in the primary multivariable model (adjusted odds ratio [OR] 2.43, 95% CI 1.15-5.15; p=0.020), but this association was attenuated after additional adjustment for active infection (adjusted OR 1.85, 95% CI 0.86-3.97; p=0.118). Conclusion: Higher admission GLR was associated with in-hospital mortality in the primary multivariable analysis. Although its discriminatory performance was modest, GLR may provide complementary prognostic information; however, the attenuation of the association after adjustment for active infection warrants cautious interpretation.