Effect of Apolipoprotein E ɛ4 Carrier Status on Cognitive Response to Acetylcholinesterase Inhibitors in Patients with Alzheimer’s Disease: A Systematic Review and Meta-Analysis

2018 ◽  
Vol 45 (5-6) ◽  
pp. 335-352 ◽  
Author(s):  
Ying-Chih Cheng ◽  
Yu-Chen Huang ◽  
Hsing-Cheng Liu

Background: The apolipoprotein E ɛ4 (APOE ɛ4) genotype is the major genetic risk factor for Alzheimer’s disease (AD). However, its effect on an individual’s response to treatment is less well understood. Many studies have reported that the presence or absence of APOE ɛ4 may have influence on the therapeutic response for acetylcholinesterase inhibitors (AChEIs), but the results were inconsistent. This study performed a systematic review and meta-analysis to evaluate the association between response of treatment with AChEIs and the APOE ɛ4 carrier status. Methods: Clinical studies with AD patients reporting APOE ɛ4 genotype were included in the analysis. Cognitive outcome was measured by the change in Mini-Mental State Examination (MMSE), cognition subscales of the Alzheimer’s Disease Assessment Scale (ADAS-cog), or Cognitive Abilities Screening Instrument (CASI). A random effects model was employed to calculate the standardized mean difference (SMD) and odds ratio (OR). Results: Of the 284 screened abstracts, 38 studies were identified, 30 of which were included for meta-analysis. Continuous data for assessing the association between APOE ε4 and cognitive outcomes of AChEIs were available from 18 studies. The cognitive outcomes showed no significant difference between APOE ε4 carriers and APOE ε4 non-carriers (SMD = 0.022, 95% CI: –0.089∼0.133, p = 0.702, I2 = 55.3%). Twelve studies with binary data were included, also revealing insignificant difference between the two groups (OR = 1.164, 95% CI: 0.928∼1.459, p = 0.189, I2 = 16.4%). Subgroup analysis indicated that AChEIs were significantly more effective than placebo in both groups. Conclusions: APOE ɛ4 carrier status had no significant influence on the treatment response to AChEIs in patients with AD. AChEIs had a positive therapeutic effect compared with placebo regardless of APOE ε4 carrier status.

2018 ◽  
Vol 31 (11) ◽  
pp. 1627-1633 ◽  
Author(s):  
Shinji Matsunaga ◽  
Hiroshige Fujishiro ◽  
Hajime Takechi

ABSTRACTObjective:The efficacy and tolerability of idalopirdine, a selective 5-hydroxytryptamine6 receptor antagonist, in patients with Alzheimer’s disease (AD) is uncertain. A systematic review and meta-analysis of randomized controlled trials (RCTs) testing idalopirdine for patients with AD was performed.Methods:We included RCTs of idalopirdine for patients with AD and used Alzheimer’s Disease Assessment Scale-cognitive subscale (ADAS-cog) scores as a primary measure.Results:Four RCTs with 2,803 patients with AD were included. There was no significant difference in ADAS-cog between the idalopirdine and placebo groups [mean difference (MD) = −0.41,P= 0.32,I2= 62%]. However, significant heterogeneity remained. Sensitivity analysis revealed that idalopirdine was more effective than placebo for ADAS-cog in the high dose and moderate AD subgroups (high dose subgroup: MD = −2.15,P= 0.005, moderate AD subgroup: MD = −2.15,P= 0.005). Moreover, meta-regression analysis showed that idalopirdine effect size for ADAS-cog was associated with mean dose (coefficient, −0.0289), ADAS-cog at baseline (coefficient, −0.9519), and proportion of male participants (coefficient, 0.2214). For safety outcomes, idalopirdine was associated with a higher incidence of at least one adverse event and increased γ-glutamyltransferase, alanine aminotransferase, aspartate aminotransferase, and vomiting than placebo. There were no significant differences in other secondary outcomes between both treatments.Conclusions:Idalopirdine is not effective for AD patients and is associated with a risk of elevated liver enzymes and vomiting. Although idalopirdine might be more effective at high doses and in moderate AD subgroups, the effect size is small and may be limited.


2018 ◽  
Vol 15 (7) ◽  
pp. 610-617 ◽  
Author(s):  
Huifeng Zhang ◽  
Dan Liu ◽  
Huanhuan Huang ◽  
Yujia Zhao ◽  
Hui Zhou

Background: β-amyloid (Aβ) accumulates abnormally to senile plaque which is the initiator of Alzheimer's disease (AD). As one of the Aβ-degrading enzymes, Insulin-degrading enzyme (IDE) remains controversial for its protein level and activity in Alzheimer's brain. Methods: The electronic databases PubMed, EMBASE, The Cochrane Library, OVID and Sinomed were systemically searched up to Sep. 20th, 2017. And the published case-control or cohort studies were retrieved to perform the meta-analysis. Results: Seven studies for IDE protein level (AD cases = 293; controls = 126), three for mRNA level (AD cases = 138; controls = 81), and three for enzyme activity (AD cases = 123; controls = 75) were pooling together. The IDE protein level was significantly lower in AD cases than in controls (SMD = - 0.47, 95% CI [-0.69, -0.24], p < 0.001), but IDE mRNA and enzyme activity had no significant difference (SMD = 0.02, 95% CI [-0.40, 0.43] and SMD = 0.06, 95% CI [-0.41, 0.53] respectively). Subgroup analyses found that IDE protein level was decreased in both cortex and hippocampus of AD cases (SMD = -0.43, 95% CI [-0.71, -0.16], p = 0.002 and SMD = -0.53, 95% CI [-0.91, -0.15], p = 0.006 respectively). However, IDE mRNA was higher in cortex of AD cases (SMD = 0.71, 95% CI [0.14, 1.29], p = 0.01), not in hippocampus (SMD = -0.26, 95% CI [-0.58, 0.06]). Conclusions: Our results indicate that AD patients may have lower IDE protease level. Further relevant studies are still needed to verify whether IDE is one of the factors affecting Aβ abnormal accumulation and throw new insights for AD detection or therapy.


2021 ◽  
pp. 1-12
Author(s):  
Mingyue Qu ◽  
Hanxu Shi ◽  
Kai Wang ◽  
Xinggang Wang ◽  
Nan Yu ◽  
...  

Background: Multiple lines of evidence indicate protective effects of carotenoids in Alzheimer’s disease (AD). However, previous epidemiological studies reported inconsistent results regarding the associations between carotenoids levels and the risk of AD. Objective: Our study aims to evaluate the associations of six major members of carotenoids with the occurrence of AD by conducting a systematic review and meta-analysis. Methods: Following PRISMA guidelines, a comprehensive literature search of PubMed, Web of Science, Ebsco, and PsycINFO databases was conducted, and the quality of each included studies was evaluated by a validated scoring systems. Standardized mean differences (SMD) with 95%confidence intervals (CI) were determined by using a random effects model. Heterogeneity was evaluated by I2 statistics. Publication bias was detected using funnel plots and Egger’s test. Results: Sixteen studies, with 10,633 participants were included. Pooled analysis showed significantly lower plasma/serum levels of lutein (SMD = –0.86, 95%CI: –1.67 to –0.05, p = 0.04) and zeaxanthin (SMD = –0.59; 95%CI: –1.12 to –0.06, p = 0.03) in patients with AD versus cognitively intact controls, while α-carotene (SMD = 0.21, 95%CI: –0.68 to 0.26, p = 0.39), β-carotene (SMD = 0.04, 95%CI: –0.57 to 0.65, p = 0.9), lycopene (SMD = –0.12, 95%CI: –0.96 to 0.72, p = 0.78), and β-cryptoxanthin (SMD = –0.09, 95%CI: –0.83 to 0.65, p = 0.81) did not achieve significant differences. Conclusion: Of six major members of carotenoids, only lutein and zeaxanthin concentrations in plasma/serum were inversely related to the risk of AD. More high-quality longitudinal studies are needed to verify these findings.


Sign in / Sign up

Export Citation Format

Share Document