Relationship between β-amyloid protein 1-42, thyroid hormone levels and the risk of cognitive impairment after ischemic stroke

Table 1 Baseline clinical characteristics in non-post stroke cognitive impairment and post stroke cognitive impairment patients, n (%)

Variable	PSCI, n = 72	Non-PSCI, n = 116		P value
Age in yr	73 (66-80)	65 (60-74)		< 0.001
Gender, male/female	38/34	79/37		0.027
BMI as kg/m2	24.5 ± 2.6	23.8 ± 2.7		0.081
Education levels				0.011
Illiterate	26 (36.1)	24 (20.7)
Primary school	32 (44.4)	48 (41.4)
Postsecondary school	14 (19.4)	44 (37.9)
Smoking	13 (18.1)	26 (22.4)		0.449
Drinking	8 (11.1)	17 (14.7)		0.448
SBP as mmHg	152 ± 24	147 ± 26		0.189
DBP as mmHg	85 ± 12	83 ± 10		0.219
TC as mmol/L	4.54 ± 0.78	4.58 ± 0.72		0.720
TG as mmol/L	1.48 ± 0.57	1.31 ± 0.41		0.019
HDL as mmol/L	1.19 ± 0.17	1.12 ± 0.22		0.204
LDL as mmol/L	2.85 ± 0.71	2.34 ± 0.76		< 0.001
Aβ1-42 as pg/mL	363.0 ± 37.8	402.2 ± 35.3		< 0.001
hs-CRP as mg/L	4.8 ± 4.6	6.2 ± 7.1		0.138
Hcy as µmol/L	15.8 ± 8.2	15.0 ± 8.6		0.529
T3 as nmol/L	1.23 ± 0.59	1.47 ± 0.77		0.025
T4 as nmol/L	117.2 ± 26.4	110.5 ± 21.4		0.058
FT3 as pmol/L	4.68 ± 0.85	4.42 ± 0.93		0.056
FT4 as pmol/L	13.03 ± 2.26	16.47 ± 3.84		<0.001
TSH as mU/L	1.22 ± 0.64	1.41 ± 0.75		0.076
History of disease
Hypertension	25 (34.7)	37 (31.9)		0.674
Hyperlipidemia	3 (4.2)	9 (7.8)		0.284
Diabetes	16 (22.2)	28 (24.1)		0.750
Stroke/TIA	19 (26.4)	17 (14.7)		0.041
Myocardial infarction	2 (2.8)	3 (2.6)		0.930
Atrial fibrillation	9 (12.5)	5 (4.3)		0.037
NIHSS score on admission	7.2 ± 3.7	5.1 ± 2.9		< 0.001
Cerebral infarction volume in cm3	11.14 ± 2.25	10.86 ± 1.98		0.372
Lesion location
Posterior circulation	16 (22.2)	33 (28.4)		0.313
TOAST				0.890
Large-artery atherosclerosis	39 (54.2)	58 (50)
Cardioembolism	6 (8.3)	8 (6.9)
Small-artery occlusion Lacunar	21 (29.2)	37 (31.9)
Other determined etiology	5 (6.9)	9 (7.8)
Undetermined etiology	1 (1.4)	4 (3.4)
Medications during hospitalization
Hypoglycemic	13 (18.1)	23 (19.8)		0.759
Antihypertensive	35 (48.6)	53 (45.7)		0.681
Lipid-lowering drugs	54 (75.0)	81 (69.8)		0.411
Antiplatelet	65 (90.3)	104 (89.7)		0.888

Data are presented as mean ± SD or median (interquartile range). PSCI: Post stroke cognitive impairment; BMI: Body mass index; SBP: Systolic blood pressure; DBP: Diastolic blood pressure; TC: Total cholesterol; TG: Triglyceride; HDL: High-density lipoprotein; LDL: Low-density lipoprotein; Aβ1-42: β-amyloid protein1-42; hs-CRP: Hypersensitive C-reactive protein; Hcy: Homocysteine; T₃: Triiodothyronine; T₄: Thyroxin; FT₃: Free triiodothyronine; FT₄: Free thyroxin; TSH: Thyrotropin; TIA: Transient ischemic attack; NIHSS: National Institutes of Health Stroke Scale.

Table 2 Difference of biochemical indexes in two groups at different time points

Variable group	1st week	3rd month	6th month	1st year
Aβ1-42 in pg/mL
PSCI, n = 72	363.0 ± 37.8	356.1 ± 37.5	360.7 ± 32.2	372.5 ± 38.6
Non-PSCI, n = 116	402.2 ± 35.3	404.8 ± 32.6	411.4 ± 36.5	428.1 ± 40.9
T3 in nmol/L
PSCI, n = 72	1.23 ± 0.59	1.17 ± 0.62	1.38 ± 0.55	1.45 ± 0.67
Non-PSCI, n = 116	1.47 ± 0.77	1.49 ± 0.85	1.46 ± 0.72	1.52 ± 0.64
FT4 in pmol/L
PSCI, n = 72	13.03 ± 2.26	13.15 ± 2.14	13.79 ± 1.57	14.28 ± 2.19
Non-PSCI, n = 116)	16.47 ± 3.84	16.23 ± 3.21	16.58 ± 4.04	17.67 ± 3.18

Data are presented as mean ± standard deviation. Aβ1-42: F_{Between groups} = 4.782, P_{Between groups} = 0.011; T3: F_{Between groups} = 6.069, P_{Between groups} < 0.001; FT₄: F_{Between groups} = 1.724, P_{Between groups} = 0.195. PSCI: Post stroke cognitive impairment; Aβ1-42: β-amyloid protein1-42; T₃: Triiodothyronine; FT₄: Free thyroxin.

Table 3 Analysis of the correlation between indicators and disease progression

	Montreal Cognitive Assessment			r	P value
	Aggravation, n = 77	Stable condition, n = 65	Improvement, n = 44
Aβ1-42 in pg/mL	358.6 ± 38.7	364.7 ± 33.9	392.5 ± 36.4	0.348	< 0.001
T3 in nmol/L	1.19 ± 0.75	1.42 ± 0.66	1.48 ± 0.61	0.273	< 0.001
FT4 in pmol/L	14.03 ± 2.86	15.15 ± 3.04	16.58 ± 2.42	0.214	0.005

Data are presented as mean ± standard deviation. Aβ1-42: β-amyloid protein1-42; T₃: Triiodothyronine; FT₄: Free thyroxin.

Table 4 Effects of indicators on patients with post stroke cognitive impairment

	Aβ1-42	T3	FT4
Unadjusted
RR	0.658	0.741	0.582
95% CI	0.427-0.933	0.385-0.929	0.306-0.884
P value	0.022	0.036	0.017
Model I
RR	0.932	0.895	0.918
95% CI	0.852-0.936	0.876-0.982	0.923-0.994
P value	0.033	0.028	0.019
Model II
RR	0.684	0.673	0.825
95%CI	0.501-0.846	0.337-0.812	0.762-1.109
P value	0.009	0.017	0.092
Model III
RR	0.282	0.430	0.748
95%CI	0.258-0.833	0.332-0.918	0.747-1.116
P value	0.012	0.038	0.116

Model I: Adjusted for age and gender; Model II: Adjusted for age, gender, body mass index, education levels, smoking, drinking and history of disease; Model III: Adjusted for National Institutes of Health Stroke Scale, low-density lipoprotein, triglyceride in addition to the confounders that were adjusted for in Model II. Aβ1-42: β-amyloid protein1-42; T₃: Triiodothyronine; FT₄: Free thyroxin; RR: Relative risk; CI: Confidence interval.

Table 5 Association between β-amyloid protein 1-42, triiodothyronine levels and post stroke cognitive impairment stratified by age, gender and education levels

Variable	Aβ1-42			T3
	RR1	95%CI	P value	RR1	95%CI	P value
Age in yr
< 70	0.982	0.437-2.188	0.173	0.371	0.208-0.663	0.001
≥ 70	0.416	0.290-0.612	< 0.001	0.319	0.139-0.731	0.007
Gender
Male	0.794	0.328-1.901	0.075	0.618	0.249-1.527	0.298
Female	0.537	0.352-0.846	0.028	0.472	0.270-0.794	0.005
Education levels
Illiterate	0.682	0.511-0.853	0.034	0.151	0.056-0.403	< 0.001
Primary school	0.945	0.875-0.998	0.047	0.786	0.414-1.495	0.464
Postsecondary school	0.853	0.640-1.066	0.089	0.937	0.625-1.403	0.256

¹These statistical results were adjusted for age, gender, body mass index, education levels, smoking, drinking, history of disease, National Institutes of Health Stroke Scale, low-density lipoprotein and triglyceride. Aβ1-42: β-amyloid protein1-42; T₃: Triiodothyronine; RR: Relative risk; CI: Confidence interval.