Association between circulating GTP cyclohydrolase 1 concentrations and acute ischemic stroke: an exploratory case-control study in a Chinese population.
Yuan S, Yang C, et al. • Frontiers in neurology • 2026
Plasma GCH1 concentrations were significantly lower in AIS patients than in controls and showed high apparent discrimination between groups, but findings do not establish temporality, causality, or clinical diagnostic utility.
Key Findings
Results
Plasma GCH1 concentrations were significantly lower in patients with acute ischemic stroke compared to health-examination controls.
AIS patients had mean plasma GCH1 of 6.51 ± 3.59 ng/mL versus 14.32 ± 3.29 ng/mL in controls (p < 0.001).
The study recruited 71 AIS patients and 92 controls at the Affiliated Hospital of Youjiang Medical University for Nationalities between January 2024 and May 2025.
Plasma GCH1 levels were measured using an enzyme-linked immunosorbent assay (ELISA).
Clinical and biochemical data including lipid profiles, C-reactive protein, homocysteine, and NIHSS scores were also collected.
Results
Lower plasma GCH1 levels were independently associated with acute ischemic stroke in binary logistic regression analysis.
The odds ratio for lower plasma GCH1 and AIS was OR = 0.496 (95% CI: 0.385–0.644, p < 0.001).
This association remained independent after accounting for other clinical and biochemical variables.
Multiple linear regression analysis also demonstrated that AIS was independently associated with lower plasma GCH1 levels (B = -7.687, 95% CI: -9.011 to -6.362, p < 0.001).
Results
Plasma GCH1 showed strong discriminatory performance between AIS patients and controls based on receiver operating characteristic curve analysis.
The area under the curve (AUC) for plasma GCH1 was 0.924 (95% CI: 0.871–0.978).
The authors note that the sample-derived threshold was derived in the same case-control sample, limiting conclusions about clinical diagnostic utility.
The authors state these findings do not establish temporality, causality, or clinical diagnostic utility.
Results
Plasma GCH1 concentrations were not associated with stroke severity as measured by NIHSS scores in AIS patients.
Spearman's rho = -0.034, p = 0.778 for the correlation between plasma GCH1 and NIHSS scores.
NIHSS scores were collected only for patients with AIS.
This lack of association suggests GCH1 levels did not track with acute clinical severity in this sample.
Discussion
The study design has important limitations that preclude causal or diagnostic conclusions.
GCH1 was measured after stroke onset, so temporality cannot be established.
The discriminatory threshold was derived from the same case-control sample without external validation.
The control group consisted of routine health-examination participants rather than clinically relevant disease controls.
The authors call for 'prospective multicenter studies including clinically relevant disease controls and independent external validation.'
What This Means
This research suggests that a protein called GTP cyclohydrolase 1 (GCH1), which plays a role in regulating blood vessel function and reducing harmful oxidative stress, is found at much lower levels in the blood of people who have had an acute ischemic stroke (a stroke caused by a blocked blood vessel) compared to people who have not had a stroke. The study measured blood plasma GCH1 levels in 71 stroke patients and 92 healthy controls in China and found a large, statistically significant difference between the two groups. A statistical test (ROC analysis) suggested that GCH1 levels could potentially distinguish stroke patients from non-stroke individuals with high accuracy within this dataset.
However, the researchers are careful to note that these findings come with important limitations. Because blood was drawn after the stroke had already occurred, it is impossible to know from this study whether low GCH1 levels contributed to the stroke, or whether the stroke itself caused GCH1 levels to drop. Additionally, GCH1 levels were not related to how severe the stroke was (as measured by a standard clinical score), and the ability of GCH1 to distinguish stroke patients was only tested in the same group of people used to calculate the threshold — meaning it has not been independently confirmed. The control group was also composed of healthy individuals rather than people with other diseases, which could inflate how well GCH1 appears to discriminate.
This research suggests GCH1 is a potentially interesting biological marker worth investigating further in the context of ischemic stroke, but much more work is needed before any conclusions can be drawn about its usefulness in diagnosis or its role in causing stroke. The authors recommend larger, prospective studies across multiple hospitals that include patients with other diseases as controls and validate the findings in independent groups of patients.
Yuan S, Yang C, Yong P, Ng Z, Ren B, Li M, et al.. (2026). Association between circulating GTP cyclohydrolase 1 concentrations and acute ischemic stroke: an exploratory case-control study in a Chinese population.. Frontiers in neurology. https://doi.org/10.3389/fneur.2026.1842462