The Application Value Of Lipoprotein Associated Phospholipase A2 And Hippocampal Volume Determination In The Diagnosis Of Cognitive Dysfunction In Patients

Objective:The first part discussed the plasma level changes of lipoprotein associated phospholipase A2(LP-PLA2) in mild cognitive impairment(MCI) and Alzheimer’s disease(AD) patients, and its correlation with the severity of cognitive decline and MMSE score; the second part analyzed the different hippocampal volume amony MCI patients, AD patients and normal people through Magnetic resonance imaging, and further to study its correlation with MMSE and LP-PLA2 levels. In all, this experiment aimed to explore the application value of LP-PLA2 and hippocampal volume in the diagnosis of MCI and AD patients.Methods:There were 43 cases of MCI patients and 50 cases of AD patients collected from the outpatient and department of neurology of the First Affiliated Hospital of Soochow University from December 2014 to February 2016, which were in line with relevant diagnostic criteria. Meanwhile, 40 cases of healthy volunteers were recruited without subjective cognitive decline, and exclusion of mental disease, chronic disease and other systemic effects of cognitive dysfunction diseases as control group. All the subjects were tested by neuropsychological scales after being informed consent, these scales included the Mini Mental State Scale(MMSE), activity of daily living scale(ADL), the clinical dementia rating scale(CDR) and Hachinski ischemic index scores.Then the fasting blood of subjects were gathered to detect the content of LP-PLA2 in plasma. After ruling out the relevant taboo, all subjects were underwent 3.0T MRI scan, then we used the images to reconstructe the three-dimensional structure. According to the method of bounding hippocampus from Watson, we manually drew the shape of hippocampal in reconstruction images, then we can get the hippocampal volume through professional software and normalized hippocampal volume. Using SPSS 18.0 statistical software to process the data, and compare neuropsychological scale scores, LP-PLA2 levels, and standardized of left and right sides of hippocampal volume as well as the total volume of hippocampus in three groups of subjects, then further to analysis the correlation between them.Results:1. The result of MMSE and ADL scores in these groupsCompared MMSE, ADL scores amony NC group, MCI group and AD group, MMSE score: NC group >MCI group >AD group, each two groups were significantly difference(P<0.05); ADL score: NC group and MCI group were lower than that of AD group(P<0.05); there was no statistical difference between NC group and MCI group.From comparison amony the mild, moderate and severe AD patients with MMSE and ADL scores, we can get that, the MMSE scores: mild AD group > moderate AD group> severe AD group, there were statistically significant differences; ADL scores: mild AD group < moderate AD group < severe AD group, the differences were statistically significant.Correlation analysis: MMSE score was negatively correlated with the severity of AD(r=-0.888, P<0.05); ADL score was positively correlated with the severity of AD(r=0.613, P<0.05).2. Comparison of LP-PLA2 levels amony these groupsLP-PLA2 levels of MCI group and AD group were higher than that of the control group, there were statistically significant differences, P<0.05; LP-PLA2 levels of AD group was statistically significant than in MCI group, P<0.05.AD were compared in patients with different degree of dementia from the levels of LP-PLA2, results show that, severe AD group’s LP-PLA2 level was higher than the mild AD group’s, a statistically significant difference between each other, while there was no difference between moderate AD group and mild AD, severe AD group.Correlation analysis: correlation of LP-PLA2 levels and the severity of AD was positive(r=0.464, P<0.05).Differences in the level of LP-PLA2 were compared with male and female in NC group, MCI group and AD group, showed that, no difference was existed between male and female in NC group and MCI group(P>0.05); while the level of female was significantly higher than that of male in AD group(P<0.05).3. The correlation analysis showed that there was a negative correlation between the LP-PLA2 level and MMSE scores(r=-0.566, P<0.01).4. Comparison of hippocampal volume(HV) in three groupsTo compare the different standardized volume between left and right hippocampus in three groups, there was no difference in NC group and the MCI group; the right side of hippocampal volume was larger than the left in AD group, the difference is statistically significant. Standardization of left and right side and total HV were contrasted among the three groups, results showed: the left and right sides HV of the MCI group and the AD group were less than NC group as well as the total HV, the difference is statistically significant(P < 0.05); the left and right sides and the total HV of AD group were significantly less than the MCI group(P < 0.05).Correlation analysis: the relation between the standardization HV in two sides and total HV and MMSE score showed a positive correlation(r = 0.519, P < 0.05; r = 0.471. 05; r = 0.611, P < 0.05).There was a negative correlation between the two sides and the total HV and LP-PLA2 levels(r=-0.328, P<0.05, r=-0.179, P<0.05, r=-0.350, P<0.05,).5. Multiple linear regression analysis was used to study the regression analysis of LP-PLA2 level, left and right sides and total hippocampal volume and MMSE score of the subjects. Results showed that, the regression coefficients of LP-PLA2 level and total hippocampal volume were-0.463, 0.418 and P<0.05, respectively, there was statistical significance. No statistical significance was existed in left and right hippocampal volume, P>0.05.Conclusion:1. The change of LP-PLA2 level is related to the incidence of MCI and AD, and it provides a new way for clinical diagnosis and prevention of MCI and AD. Elevated levels of LP-PLA2 may be one of the risk factors for female AD.2. The degree of atrophy of hippocampal volume combined with MMSE score and LP-PLA2 level could be used as an important means to assess the degree of cognitive decline.3. LP-PLA2 level and total hippocampal volume can be used as one of the diagnostic methods of cognitive dysfunction, and the LP-PLA2 index is more sensitive.