Association between circulating GTP cyclohydrolase 1 concentrations and acute ischemic stroke: an exploratory...

Ischemic stroke (IS) is a leading global cause of disability and mortality, characterized by cerebral hypoxia and tissue necrosis. GTP cyclohydrolase 1 (GCH1) regulates endothelial function and oxidative stress; however, whether circulating GCH1 concentrations are altered in acute ischemic stroke (AIS) remains unclear. This exploratory case-control study aimed to investigate plasma GCH1 levels and their associations with clinical characteristics in patients with AIS.

Seventy-one patients with AIS and 92 controls undergoing routine health examinations were recruited at the Affiliated Hospital of Youjiang Medical University for Nationalities (January 2024-May 2025). Clinical and biochemical data including lipid profiles, C-reactive protein, homocysteine, and National Institutes of Health Stroke Scale (NIHSS) scores (only for patients with AIS) were collected. Plasma GCH1 levels were measured using an enzyme-linked immunosorbent assay. Statistical analyses were performed to evaluate differences between groups and to examine the associations between plasma GCH1 levels and clinical characteristics. Receiver operating characteristic curve analysis was conducted to assess the discriminatory performance of circulating GCH1.

Plasma GCH1 concentrations were significantly lower in AIS patients (6.51 ± 3.59 ng/mL vs. 14.32 ± 3.29 ng/mL, p < 0.001). Binary logistic regression analysis showed that lower plasma GCH1 levels were independently associated with AIS (OR = 0.496, 95% CI: 0.385-0.644, p < 0.001), while multiple linear regression analysis demonstrated that AIS was independently associated with lower plasma GCH1 levels (B = -7.687, 95% CI: -9.011 to -6.362, p < 0.001). Plasma GCH1 showed strong discrimination between the two groups (AUC = 0.924, 95% CI: 0.871-0.978) but was not associated with NIHSS scores (Spearman's rho = -0.034, p = 0.778).

Plasma GCH1 concentrations were lower in patients with AIS than in health-examination controls and showed high apparent discrimination in this dataset. Because GCH1 was measured after stroke onset and the sample-derived threshold was derived in the same case-control sample, these findings do not establish temporality, causality, or clinical diagnostic utility. Prospective multicenter studies including clinically relevant disease controls and independent external validation are required.