Association between fibrinogen levels and orthostatic hypotension in stroke patients: a cross-sectional analysis

Orthostatic hypotension (OH) frequently complicates postural training in non-ambulatory stroke patients. Recent studies have suggested an association between inflammation and OH. However, this association remains poorly understood in the stroke population. This study aimed to investigate the relationship between fibrinogen (Fib) levels, an inflammatory marker, and OH in non-ambulatory stroke patients. This observational research project examined a non-ambulatory population of stroke patients. We collected demographic and clinical data, along with morning serum samples for Fib testing, during the first week of admission. For postural training, each patient was securely fastened to an electric standing bed. The tilt angle was progressively increased to 0°, 30°, 60°, and 80°, holding each angle for 5 min. Blood pressure and heart rate were recorded every minute using an ambulatory monitor, and OH was diagnosed based on blood pressure changes within the first 3 min after each tilt. Multiple regression analysis assessed the independent correlation between Fib levels and OH. A total of 215 non-ambulatory patients who experienced a stroke (158 males [73.5%]; mean age 60.37 years) were included in the study. Through a combination of LASSO regression and multivariable logistic regression analysis, several independent risk factors for post-stroke OH were identified, including age, history of diabetes, Fib, urea, and baseline systolic blood pressure. The incorporation of Fib into the clinical prediction model yielded a modest improvement in discriminative performance (AUC: 0.787–0.805), though this difference did not reach statistical significance. Subgroup analyses confirmed that the association between Fib and OH was consistent across most subgroups, with a suggestive trend toward a stronger association observed in patients with hypertension ( P for interaction = 0.087). Elevated fibrinogen levels were independently associated with OH in non-ambulatory post-stroke patients. The addition of fibrinogen to the clinical model modestly improved model discrimination, suggesting that fibrinogen may serve as a potential biomarker associated with post-stroke OH. Trial registration : The study was registered with the Chinese Clinical Trial Registry (Registration number: ChiCTR2500096329; Date of registration: January 22, 2025).