The Elderly People With MCI In The Community Of Tianjin: Case-control Study Of Risk Factors And Intervention Study Of Folic Acid

Objective1. To explore the risk factors and protective factors of elderly people with mild cognitive impairment(MCI) by case-control study.2. To explore the intervention effect of oral folic acid on cognitive function improvement and provide scientific basis for the further study of early intervention of elderly people with MCI in community. Methods1. Elderly people over 60 years old from Tanggu District, Tianjin city, who met the diagnostic criteria and provided complete and relevant information were recruited into the investigation to do the health status questionnaire and measure the cognitive function. After the baseline survey, 120 patients with MCI were selected as MCI group and 120 elderly people who made a physical examination in the corresponding period with normal cognition were randomly selected as control group. The characteristics of cognitive impairment were evaluated, and blood samples were stored for analysis of MCI related indicators, such as serum folate and VB12, plasma Hcy and methionine cycle intermediates(SAM and SAH), serum inflammatory factors(IL-6 and TNF-?), amyloid beta protein and m RNA expression of MCI related genes. Paired t test, chi square test, non parametric test and Logistic regression analysis were used for statistical analysis of the relationship between MCI with the above factors.2. Patients with MCI were divided at random into folic acid intervention group and control group, matched 1:1, 60 cases in each group. The intervention group took oral folic acid(400?g/d) + health education, and the control group only took health education. The patients were followed up for 6 months. MMSE, WAIS, ADL, blood biochemical indicators, methionine cycle intermediates, serum inflammatory factors, amyloid beta protein and m RNA expression of MCI related genes were evaluated at the baseline(0 months) and after intervention(6 months). Repeated measures analysis of variance was used to evaluate the effect of folic acid intervention, study the association between folic acid, DNA methylation and MCI, and explore the mechanism of folic acid in the prevention and treatment of MCI. Results1. Case-control study found that total score of MMSE, time orientation, place orientation, immediate memory, attention, recall, repeat, command and structure of patients with MCI were significantly lower than the control group(P<0.05); Knowledge, arithmetic, picture completion, block design, picture arrangement, episodic memory, noun immediate memory(listening and verbal memory) scores of WAIS-RC of patients with MCI were significantly lower than the control group(P<0.05). Multiariable Logistic regression analysis results showed that marriage(95% CI: 0.011- 0.811), serum folate(95% CI: 0.808- 0.967), plasma SAM(95% CI: 0.467- 0.814) and SAM / SAH(95% CI: 0.621- 0.988) were protective factors, unhealthy lifestyle: smoking(95% CI: 1.219- 10.600) and drinking(95% CI: 1.405-10.254), family history(95% CI: 1.120- 3.964), comorbidities: hypertension(95% CI: 1.284- 4.136) and diabetes(95% CI:1.592- 6.808), plasma Hcy(95% CI: 1.078-1.298), SAH(95% CI:1.037- 1.096), serum IL-6(95% CI: 1.045- 1.232), A?42(95% CI: 1.008- 1.036), A?42/A?40(95% CI: 1.123- 1.195), high expression of PS1-m RNA(95% CI: 1.015- 1.059), DNMT1-m RNA(95% CI: 1.012- 1.047), DNMT3a-m RNA(95% CI: 1.007- 1.024) and IL-6-m RNA(95% CI: 1.017- 1.228) were risk factors for MCI(P<0.05).2. Folic acid intervention study showed that after 6 months, serum folic acid, plasma SAM and SAM/SAH ratio were significantly increased; plasma Hcy and SAH were significantly decreased; serum IL-6, TNF-? and A?42/A?40 ratio were significantly decreased; m RNA gene expression of PS1 and APP were significantly decreased. Total score of MMSE, knowledge, arithmetic, picture completion, block design, picture arrangement, episodic memory, listening and verbal memory scores of WAIS-RC were significantly decreased(P<0.05). There was no significant difference in ADL score(P>0.05). Conclusion1. Unhealthy lifestyle, low level of folic acid, high level of Hcy, inflammatory factors and gene expression were risk factors for MCI outcome and cognitive function.2. Blood biochemical indicators, inflammatory factors, gene expression and cognitive function in patients with MCI were improved through folic acid supplementation.