Abstract
BackgroundPeripheral blood Apolipoprotein E (ApoE) levels have been proposed as biomarkers of Alzheimer’s disease (AD), but previous studies on levels of ApoE in blood remain inconsistent. This meta-analysis was designed to re-examine the potential role of peripheral ApoE in AD diagnosis and its potential value as a candidate biomarker.MethodsWe conducted a systematic literature search of MEDLINE, EMBASE, the Cochrane library, and BIOSIS previews for case-control studies measuring ApoE levels in serum or plasma from AD subjects and healthy controls. The pooled weighted mean difference (WMD) and 95% confidence interval (CI) were used to estimate the association between ApoE levels and AD risk.ResultsEight studies with a total of 2250 controls and 1498 AD cases were identified and analyzed. The pooled WMD from a random-effect model of AD participants compared with the healthy controls was −5.59 mg/l (95% CI: [−8.12, −3.06]). The overall pattern in WMD was not varied by characteristics of study, including age, country, assay method, publication year, and sample type.ConclusionsOur meta-analysis supports a lowered level of blood ApoE in AD patients, and indicates its potential value as an important risk factor for AD. Further investigation employing standardized assay for ApoE measurement are still warranted to uncover the precise role of ApoE in the pathophysiology of AD.
Highlights
Alzheimer’s disease (AD) is the most common type of dementia characterized by a profound loss of memory, progressive decline in cognition, and changes in personality [1]
Literature search and characteristics of included studies After the application of search strategy, we found that a total of 18 relevant articles appeared to fulfill the inclusion criteria [14231]
After reviewing the full texts, 10 additional studies were excluded, leaving 8 trials [24231], published between 1998 and 2012, that met our selection criteria and had accessible plasma or serum Apolipoprotein E (ApoE) concentration information to study the association between ApoE levels and AD (Figure 1)
Summary
Alzheimer’s disease (AD) is the most common type of dementia characterized by a profound loss of memory, progressive decline in cognition, and changes in personality [1]. Some cerebrospinal fluid (CSF) biomarkers and amyloid imaging have been established to detect AD pre-clinically [5,6], these are not suitable for large scale screening programs in consideration of the invasiveness and a host of comorbidities Taking into account these facts, finding proteins from peripheral blood samples that could identify AD may be useful for pre-symptomatic. Peripheral blood Apolipoprotein E (ApoE) levels have been proposed as biomarkers of Alzheimer’s disease (AD), but previous studies on levels of ApoE in blood remain inconsistent. This meta-analysis was designed to re-examine the potential role of peripheral ApoE in AD diagnosis and its potential value as a candidate biomarker
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
