Anaemia And Cerebrospinal Fluid Biomarkers Of Alzheimer’s Pathology In Cognitively Normal Elders

Background: Previous studies have shown that anemia is associated with cognitive decline and Alzheimer’s disease(AD),but the relationship between anemia and cerebrospinal fluid(CSF)AD biomarkers remains to be studied.Objective: The aim of this study was to investigate the relationship between anemia and CSF AD biomarkers.Methods: Participants were from the Chinese Alzheimer’s Disease Biomarker and Lifestyle(CABLE)study.Anaemia was defined as haemoglobin concentrations <13g/dl for men and <12 g/dl for women according to World Health Organization(WHO)criteria.The severity of anaemia was classified as mild(11-12.9 g/dl for men and11-11.9 g/dl for women),moderate(8-10.9 g/dl),or severe(< 8 g/dl).Wilcoxon test and chi-square test were used to test continuous variables(age,years of education,cognitive achievement,etc.)and categorical variables(gender,APOE ε4 allele)between groups.The associations of anaemia and its severity with CSF AD biomarkers includingβ-amyloid 1-42(Aβ42),total tau(t-tau)and phosphorylated tau(p-tau)were analysed by multiple linear regression models adjusted for age,sex,educational levels,APOE ε4alleles and China-Modified Mini-Mental State Examination(CM-MMSE).Results: A total of 646 cognitively normal older adults,consisting of 117 anaemia patients and 529 non-anaemia individuals,were included in this study.Anaemia patients had lower levels of CSF Aβ42 than individuals without anaemia(p=0.029).Besides,participants with more severe anaemia had lower CSF Aβ42 levels(p=0.039).No significant association of anaemia with CSF t-tau and p-tau levels was found.Conclusions: Our study provides further evidence of an association between anemia and CSF Alzheimer’s disease biomarkers in cognitively normal older adults.These results suggest that anemia may have an adverse effect on the core pathology of Alzheimer’s disease.Treatment of anemia will help prevent Alzheimer’s disease.Further studies are needed to determine the longitudinal association between anemia and changes in Alzheimer’s disease biomarkers.