Low triiodothyronine is associated with high risk of malnutrition and poor functional status in subacute stroke patients

Background and aims: Stroke patients may exhibit low thyroid hormone (TH) levels and disease-related malnutrition, both potentially affecting clinical status; their relationships remain unexplored. This study aimed to evaluate TH concentrations in subacute stroke patients and investigate the relationships between TH levels, nutritional risk, and functional status. Methods and results: Early subacute stroke patients admitted to a rehabilitation unit were assessed using various nutritional screening tools (Geriatric Nutritional Risk Index-GNRI, Prognostic Nutritional Index-PNI, and Controlling Nutritional Status-CONUT score) and with the Global Leadership Initiative on Malnutrition (GLIM) criteria. Thyroid-Stimulating Hormone (TSH), free Tetraiodothyronine-Thyroxine (fT4) and free Triiodothyronine (fT3) levels were determined. Functional and cognitive status was evaluated using different scales. Associations between altered THs and nutritional status were examined through univariate/multivariate analyses and ROC analyses. Among 264 patients (age 72.0 ± 10.5 yrs), significant correlations emerged between fT3 and nutritional risk and functional tests (mostly p < 0.001). The prevalence of high nutritional risk determined by GNRI, PNI and CONUT increased from higher to lower fT3 tertiles. Lower fT3 levels were observed in patients at high nutritional risk and with GLIM-based malnutrition. fT3 exhibited reasonable predictive power for high nutritional risk (particularly PNI: AUC 0.769, 95%CI 0.702-0.836, p < 0.001). Multivariate logistic regression identified nutritional risk (p < 0.001) and time from stroke onset as predictors of low fT3 values. Conclusion: Altered fT3 levels in early subacute stroke patients correlate with high nutritional risk and poor functional status. Low fT3 values upon admission for stroke rehabilitation may serve as a further parameter to be considered in patients at high nutritional risk.