Serum Levels And Significance Of Total Ghrelin And Acylated Ghrelin In Mild Cognitive Impairment Patients

Objective:To explore the serum levels of total gbrelin and acylated ghrelin in mild cognitive impairment(MCI)patients and analysis the relationship between these hormone and cognitive performance,so as to provide the theoretical basis of mechanism of brain protection,and to explore the possibility of early diagnostic markers in cognitive dysfunction.Methods:1.22 patients and 30 healthy controls were enrolled from The YangGu Stu dy of Shandong Provincial Hospital and analysised their neuropsychological test s,including Mini-Mental State Examination(MMSE),AD8,Fuld object-memory evaluation(FOM)^ Rapid vocabulary revalution(RVR),Auditory Verbal Learning Test-Huashan version(AVLT-H),Clock Drawing Task(CDT).Block Design Test(BD).Blood samples were collected from patients and controls to assay total g hrelin,acylated ghrelin and insulin by using commercial ELISA kits.2.Categorical variables were presented as frequency(percentage,%),and continuous variables were presented as mean ± standard deviation or median(Q1-Q3)based on the condition of normal distribution.Chi-square test or fisher exact test was performed for categorical variables,and wilcoxonrank sum test was performed for continuous variables between two groups.General linear model was used toinvestigate the factors that influence serum level of acylated ghrelin and total ghrelin,and the correlation between the scores of neuropsychological tests and serum level of ghrelin,and values of p<0.05 were considered statistically significant.All statistical analyses were performed using SPSS and SAS for Windows.Results:1.Acylated ghrelin levels were higher in cognitive impairment patients than controls in both male and female study subjects(p<0.001).Levels of insulin and total ghrelin were not statistically different between cognitive impairment patients and controls(p>0.05).2.The level of acylated ghrelin was correlated positively with the level of total ghrelin(p<0.001),age(p<0.05),hypertension(p<0.05),hyperlipidemia(p<0.05).Meanwhile,other factors,including sex,education level,smoking,alcohol drinking,coronary heart disease,diabetes had no statistically significant effect on the amount of acylated ghrelin.All factors in our study had no statistically significant effect on the amount of total ghrelin.3.AVLT short-term delayed recall(AVLT-SR)scores were negatively associated with acylated ghrelin levels(P<0.05).Moreover,in all models of FOM and AVLT long-term delayed recall(AVLT-LR),the tests scores were negatively correlated with acylated ghrelin levels(P<0.05).No correlation was determined between the total ghrelin levels with any tested neuropsychological measure except for digit span backward(DSB)in model 1 and 2(P<0.05).These results indicate that increased levels of acylated ghrelin may be associated with poorer test performance in the aspects of short-and long-term memory as well aslanguage skills;while the levels of total ghrelin may be inversely correlated with attention andshort-term memory.Conclusion:1.Ghrelin activated significantly in MCI Patients,proving that ghrelin may be involved the systemic progress of Alzheimer's diseases.This study provided the theoretical support of the mechanism of ghrelin in mild cognitive impairment,and explored the possibility of early diagnostic markers in cognitive dysfunction.2.The increasing level of acylated ghrelin was likely to be related to memory deficits,including long-term memory and short-term memory.However,additional research is required to confirm the theoretical mechanism.