The lower the level of T3 and FT3, the more severe the cognitive impairment in stroke patients? Shijiazhuang People’s Hospital published important correlation analysis

This article has been officially authorized by "Chinese Stroke Journal", please do not reprint without authorization.

This article is organized by: Text/Tang Jiu (Chinese Journal of Stroke) A large number of documents show that 20% to 80% of patients with a stroke will have varying degrees of cognitive impairment, which seriously affects the quality of life of the patients.

And early exploration of the influencing factors of cognitive function after stroke has important clinical significance in restoring patients' cognitive function and improving the prognosis.

At present, some scholars have found that, in addition to impairing neurological function and undermining patients' cognition, stroke can also cause hypothalamic-pituitary-thyroid axis disorders, causing abnormal levels of thyroid hormones and affecting cognitive function.

To clarify the correlation between the levels of triiodothyronine (T3) and free triiodothyronine (FT3) in thyroid hormones and the cognitive function of stroke patients, Li Hong, Ma Jiang, Shi Wanying and other scholars from Shijiazhuang People’s Hospital Published important correlation studies in our journal to explore potential clinical predictive indicators that may affect cognitive function, and provide references for cognitive function rehabilitation.

 Inclusion: The author prospectively included 210 patients in the recovery phase of stroke who were admitted to the Department of Rehabilitation Medicine of Shijiazhuang People's Hospital from December 2018 to January 2020 based on the following review criteria.

Inclusion criteria: ①age>50 years; ②years of education ≥8 years; ③conform to the diagnostic criteria revised in the 4th National Cerebrovascular Disease Conference, confirmed by CT or MRI ④Stroke onset is 2 weeks to 6 months, and vital signs are stable ⑤The first onset was a unilateral hemispheric lesion, including cerebral infarction and cerebral hemorrhage.

Exclusion criteria: ①Subarachnoid hemorrhage and TIA ②Combined with severe heart, lung, liver, kidney and other organ dysfunction ③Severe mental, psychological, visual, auditory comprehension and aphasia ④Previous thyroid disease ⑤Coma, unconsciousness, Cognitive impairment before dementia and stroke ⑥ complicated with severe infection ⑦ long-term use of glucocorticoid or amiodarone drugs.

 Research methods Collect baseline data: record the patient's baseline data, including demographic information (age, gender, education level), past history (hypertension, diabetes, hyperlipidemia, smoking, drinking), hospital admission NIHSS score, stroke type , The side of the lesion and the course of stroke.

 Classification method: According to whether the patients have cognitive impairment, they are divided into the cognitive impairment group and the non-cognitive impairment group.

The patient’s cognitive function is assessed using MMSE.
MMSE includes seven aspects: time orientation, place orientation, immediate memory, attention and calculation, delayed memory, language, and visual spatial structure.
There are 30 questions in total, each with 1 point, totaling 30.
The higher the score, the better the cognitive function; MMSE is assessed as cognitive impairment with illiteracy ≤ 17 points, elementary school culture ≤ 20 points, middle school culture ≤ 22 points, and university or higher culture ≤ 23 points.

 Hematology test: standard serum samples are made by collecting cubital venous blood in the early morning on the second day of admission and in a quiet state, using automatic immunoassay analyzer and thyroid hormone detection reagents to detect T3, T4, FT3, FT4) and thyroid stimulating hormone (TSH) level.

 Statistical methods: Multiple linear regression was used to analyze the relationship between the levels of thyroid hormones and MMSE scores in patients with stroke recovery.

The difference was statistically significant when P<0.
05.

 Comparison of baseline data of study results: 210 patients with an average age of 59.
97±7.
12 years old were finally included.
Among them, 146 were in the cognitive impairment group and 64 were in the non-cognitive impairment group.
The incidence of cognitive impairment during stroke recovery was 69.
52.
%.

The age and NIHSS scores of the cognitive impairment group were higher than those of the non-cognitive impairment group, and the T3 and FT3 levels were lower than those of the non-cognitive impairment group.
The difference was statistically significant.

 There was no statistically significant difference between the two groups of patients in gender, education level, past history, stroke type, side of the lesion, and stroke course.

Multiple linear regression analysis: Serum T3 and FT3 levels in patients with stroke recovery stage were positively correlated with MMSE score (β=0.
389, P<0.
001; β=0.
237, P=0.
014). Result analysis and mechanism discussion The results of this study show: ①The age and NIHSS score of patients with cognitive impairment during stroke recovery were higher than those of the non-cognitive impairment group, and the levels of T3 and FT3 were lower than those of the non-cognitive impairment group ② The patient's serum T3 and FT3 levels are positively correlated with the MMSE score, suggesting that within the normal range, the lower the T3 and FT3 levels, the more severe the cognitive impairment.

 Based on the comprehensive analysis of experimental results and previous literature, the author found that stroke, as a clinical stress event, on the one hand causes the hypothalamic-pituitary-thyroid axis dysfunction, which directly leads to the reduction of T3 and FT3 levels; on the other hand, a large number of literatures have found that T3 is The biological effect of the nervous system is higher than that of T4, and stroke can destroy the blood-brain barrier, reduce the level of organic anion transport polypeptides in epithelial cells, cause a decrease in T3 in the brain, and cause diffuse neurological dysfunction, which can cause cognitive impairment.

 In addition, areas such as the cerebral cortex and hippocampus are also the main areas where thyroid hormones play a biological role in the brain.
Damage to these areas may inhibit the biological effects of thyroid hormones and further aggravate cognitive impairment.

 Based on experimental results, the author believes that the incidence of cognitive impairment in stroke recovery patients is higher, and it is related to the decrease of thyroid hormones T3 and FT3.

Therefore, thyroid hormone levels should be routinely tested during the recovery period of stroke, and cognitive function should be actively paid attention to, and comprehensive cognitive rehabilitation treatment measures should be given to patients as soon as possible.

The original source of the article: Li Hong, Ma Jiang, Shi Wanying, et al.
Study on the correlation between thyroid hormone levels and cognitive function during stroke recovery period[J].
Chinese Journal of Stroke, 2021, 16(05): 482-486.
Literature download Link: http://