Homocysteine, cysteine and methionine are associated with 90-day prognosis in intracerebral hemorrhage patients.

ICH patients had significantly higher plasma homocysteine, cysteine, and methionine levels compared to healthy controls.

• A total of 212 ICH patients and 215 age- and sex-matched healthy controls were enrolled in this retrospective study.
• Plasma Hcy, Cys, and Met levels were compared between ICH patients and healthy controls.
• The differences in all three biomarkers between groups were statistically significant.

Patients with unfavorable 90-day prognosis had higher homocysteine and cysteine levels but lower methionine levels compared to those with favorable prognosis.

• ICH patients were categorized into favorable and unfavorable prognostic groups based on their 90-day prognosis.
• Unfavorable prognosis patients presented higher Hcy and Cys levels.
• Unfavorable prognosis patients presented lower Met levels.
• This divergent pattern distinguished the prognostic groups across all three sulfur amino acid metabolites.

High plasma homocysteine was an independent risk factor for unfavorable 90-day prognosis in ICH patients.

• Multivariate logistic regression analysis identified Hcy as an independent predictor.
• OR = 1.235 (95% CI 1.137–1.342) for high Hcy.
• This association remained significant after adjustment for other variables.

High plasma cysteine was an independent risk factor for unfavorable 90-day prognosis in ICH patients.

• Multivariate logistic regression analysis identified Cys as an independent predictor.
• OR = 1.017 (95% CI 1.008–1.025) for high Cys.
• This association remained significant after adjustment for other variables.

Methionine exhibited a dual nonlinear (concentration-dependent) relationship with 90-day prognosis, with a protective effect observed at levels below 32.88 µmol/L.

• Restricted Cubic Spline (RCS) analysis was used to explore the nonlinear relationship between Met and prognosis.
• Met played a protective role at levels <32.88 µmol/L with OR = 0.924 (95% CI 0.860–0.992).
• The dual nonlinear effect means Met's association with prognosis changes direction or magnitude at the threshold of 32.88 µmol/L.
• Lower odds of adverse outcomes were observed for Met <32.88 µmol/L.

The combined detection of all three biomarkers (Hcy, Cys, and Met) yielded the highest predictive accuracy for 90-day ICH prognosis, superior to single and pairwise combinations.

• ROC curve analysis was used to assess predictive efficacy of individual and combined biomarkers.
• The combined three-biomarker model achieved AUC = 0.819.
• This was superior to all single biomarker and pairwise biomarker combinations.
• The predictive model was internally validated and compared with classic ICH prognostic scoring systems.
• The authors note the model requires external prospective verification before clinical translation.