Results
Of the 539, we excluded 25 patients without data of thyroid indices, 10
patients diagnosed with hyperthyroidism or hypothyroidism and 24
patients lost follow-up. Eventually, we included 480 ischemic stroke
patients. During 90 days follow-up, 244(50.8%) patients have poor
outcome. The baseline characteristics (demographic, clinical, and
laboratory data) according to the functional outcome assessed by the mRS
score were presented in Table 1. Compared to the patients with good
outcome, those with poor outcome were older, lower hemoglobin, albumin,
eGFR and higher White Blood Cell, NIHSS score. The proportions of female
(p=0.001) , atrial fibrillation(p<0.001), coronary heart disease/heart
failure(P=0.001) and recanalized therapy(P=0.005)were also
significantly higher in the poor outcome group compared to the good
outcome group. In addition, patients with poor outcome had lower level
of TSH, FT3,but higher FT4 levels.
To explore the independent risk factors for 3-month poor outcome, we
selected variables P < 0.1 in univariate analysis to perform
multivariable logistic regression analysis. It revealed that lower FT3
level was an independent risk factor of poor outcome at 3 months (OR=
0.561; 95%CI 0.375-0.841, P=0.005). In addition, older age (OR = 1.023,
95% CI 1.001-1.047, P=0.044), higher NIHSS score (OR=1.286, 95%CI
1.213-1.363, P<0.001) and no recanalized therapy (OR = 3.527, 95% CI
1.808-6.880, P<0.001) were also independent risk factors of poor
outcome. However, TSH and FT4 levels were not statistical after
adjusting for other variables (See Table 2).
Patients were divided into quartile groups according to FT3 levels. The
distribution of mRS scores at 3 months differed according to FT3
quartile (Q1, Q2, Q3, Q4) (Fig1) since higher mRS scores were observed
with lowering FT3 levels. Further analyses were performed by
constructing two models to explore the relationship between FT3 and poor
outcome. In model 1 adjusted for gender, AF, CHD/HF, Hemoglobin, WBC,
ALB, eGFR, TSH, TG, TC, FT4 and TOAST Classification, lower FT3 levels
were associated with a worse functional outcome at 3 months (OR=4.63;
95% CI 2.33-9.02, p < 0.001 for tertile1 vs. tertile4;
OR=2.42; 95% CI 1.35-4.35, p =0.003 for tertile2 vs. tertile4). In
model 2, after further adjusting variables of age, NIHSS score and
recanalized therapy on the basis of model 1, compared with those in the
1st quartile, FT3 levels in the 4th quartile were still significantly
associated with poor outcome (OR=2.56; 95% CI 1.15-5.69, p =0.021) (See
Table 3). Additionally, the ROC curve analysis (Fig2) revealed that
serum level of FT3<3.69pmol/L in AIS patients was a powerful
predictor of poor outcome (sensitivity 62.70%; specificity 72.03%; AUC
0.713).