Study On The Changes Of Blood Lipids And Thyroid Hormones Levels In Alzheimer's Disease

Objective: Alzheimer's disease is an age-related degenerative disease of the central nervous system,whose cause remains unclear.Studies have shown that the levels of lipids and thyroid hormones play roles in the pathogenesis of AD.This study explored the changes of plasma lipid and serum thyroid hormone in the development process of AD by monitoring the levels of these blood indicators above in elderly patients with AD at different age groups,in order to provide a theoretical basis for early diagnosis,disease course monitoring and drug efficacy observation of AD.Methods: From September 2016 to June 2018,ninety-five patients were selected as the AD group,who met the diagnostic criteria of "dementia caused by AD" in the NIA-AA standard revised by the national institute of aging and the Alzheimer's disease society(NIA-AA)in 2011.Among them,65 were aged 65 to 79 years old and 30 were aged over80 years old.Another 98 elderly people with normal cognitive function were selected as the control group,including 70 patients aged 65 to 79 years old and 28 patients aged more than 80 years old.All subjects signed the informed consent form,completed head CT or MRI examination,and their general conditions were assessed by self-made questionnaires,simple mental state examination(MMSE),depression scale for the elderly(GDS),Hachinski ischemia scale and daily living ability scale(ADL).Fasting blood samples were collected from the subjects and sent to Laboratory Department of our hospital.The levels of serum triglyceride were measured using ARCHITECTcil6200 fully automatic biochemical instrument.OLYMPUS AU5400 was used to detect the plasma levels of total cholesterol,high-density lipoprotein cholesterol,low density lipoprotein,apolipoprotein A1 and apolipoprotein B.The serum levels of thyroid-stimulating hormone and free thyroid hormone were gauged chemiluminescence immunoassay particles.Result:1.Results of the comparative study of blood lipid levels between AD group and control group:1.1 The levels of triglyceride,total cholesterol,low density lipoprotein andapolipoprotein B in AD group were significantly increased compared to the control group(P<0.01).1.2 In the elderly aged from 65 to 79,the levels of triglyceride,total cholesterol,low density lipoprotein and apolipoprotein B in AD group were ascended in comparison with the control group(P<0.01).1.3 In the elderly aged over 80 years old: the levels of total cholesterol,low density lipoprotein and apolipoprotein B in AD group were rised than those in the control group(P<0.05).2.Results of the comparative study of thyroid hormone and thyrotropin levels between AD group and control group:2.1 The serum FT3 levels in AD group were significantly decreased compared to the control group(P<0.01).2.2 In the elderly aged 65-79: the levels of serum FT3 in AD group were descended in comparison with the control group(P<0.01);2.3 In the elderly aged over 80 years: the levels of serum FT3 were reduced in AD group than those in the control group(P<0.05).Conclusion: The increase levels of triglyceride,cholesterol,low density lipoprotein,apolipoprotein B and the decrease levels of thyroid hormone are related to the occurrence of AD.Abnormal blood lipid levels and hypothyroidism are important risk factors for AD.