Glucose-to-lymphocyte ratio in treatment-naive pulmonary arterial hypertension: association with PAH presence and baseline severity markers

Aims: Pulmonary arterial hypertension (PAH) remains associated with substantial morbidity and mortality despite therapeutic advances. The glucose-to-lymphocyte ratio (GLR), a composite marker reflecting metabolic and inflammatory status, has not been well studied in PAH. This study aimed to investigate the association of GLR with PAH presence and baseline severity markers in treatment-naive patients. Methods: This retrospective study included 72 treatment-naive PAH patients and 58 healthy controls. Risk was categorized using REVEAL Lite 2 risk score. GLR's discriminatory performance was compared with neutrophil-to-lymphocyte ratio (NLR) and high-sensitivity C-reactive protein (hs-CRP) using receiver operating characteristic (ROC) analysis and pairwise DeLong test. Correlation and logistic regression assessed associations with severity markers. Results: GLR levels were significantly higher in PAH patients, especially in high-risk cases. GLR showed strong discriminatory performance for PAH presence (area under the curve [AUC] 0.962, 95% CI 0.929-0.988), with optimal cut-off 38.43 (94.4% sensitivity, 86.2% specificity). In adjusted logistic regression, GLR remained independently associated with PAH (odds ratio [OR] 1.73, 95% CI 1.40-2.14; p<0.001). GLR correlated negatively with 6-minute walk distance and positively with N-terminal pro-B-type natriuretic peptide, right atrial area, and systolic pulmonary artery pressure (all p<0.001). Conclusion: GLR was significantly associated with treatment-naïve PAH presence and baseline severity markers. GLR may serve as a simple adjunctive biomarker for baseline PAH evaluation, though prospective validation is required.