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Background: Pharmacogenetic effects of statins on clinical changes in Alzheimer’s disease (AD) could be mediated by epistatic interactions among relevant genetic variants involved in cholesterol metabolism. Objective: To investigate associations of HMGCR (rs3846662), NR1H2 (rs2695121), or CETP (rs5882&rs708272) with cognitive and functional changes in AD, with stratification according to APOE ɛ4 carrier status and lipid-lowering treatment with lipophilic statins. Methods: Consecutive outpatients with late-onset AD were screened with cognitive tests, while caregivers scored functionality and global ratings, with prospective neurotranslational associations documented for one year. Results: Considering n = 190:142 had hypercholesterolemia, 139 used lipophilic statins; minor allele frequencies were 0.379 (rs2695121-T:46.3% heterozygotes), 0.368 (rs5882-G:49.5% heterozygotes), and 0.371 (rs708272-A:53.2% heterozygotes), all in Hardy-Weinberg equilibrium. For APOE ɛ4 carriers: rs5882-GG protected from cognitive decline; rs5882-AA caused faster cognitive decline; carriers of rs2695121-CC or rs5882-AA were more susceptible to harmful cognitive effects of lipophilic statins; carriers of rs5882-GG or rs708272-AG had functional benefits when using lipophilic statins. APOE ɛ4 non-carriers resisted any cognitive or functional effects of lipophilic statins, while invariability of rs3846662 (all AA) prevented the assessment of HMGCR effects. When assessing CETP haplotypes only: rs5882-GG protected from cognitive and functional decline, regardless of lipophilic statin therapy; lipophilic statins usually caused cognitive and functional harm to carriers of rs5882-A and/or rs708272-A; lipophilic statins benefitted cognition and functionality of carriers of rs5882-G and/or rs708272-G. Conclusion: Reportedly protective variants of CETP and NR1H2 also slowed cognitive and functional decline particularly for APOE ɛ4 carriers, and regardless of cholesterol variations, while therapy with lipophilic statins might affect carriers of specific genetic variants.

Background: Behavioral features may reflect proteinopathies predicting pathophysiology in neurodegenerative diseases. Objective: We aimed to investigate associations of cerebrospinal fluid biomarkers of amyloidogenesis and neurodegeneration with neuropsychiatric features in dementia with Lewy bodies (DLB) compared with late-onset Alzheimer’s disease (AD) and cognitively healthy people. Methods: Consecutive outpatients with DLB were paired with outpatients with AD according to sex, dementia stage, and cognitive scores, and with cognitively healthy controls according to sex and age to investigate associations of cerebrospinal fluid amyloid-β (Aβ)42, Aβ40, Aβ38, total tau, phospho-tau Thr181, α-synuclein, ubiquitin, and neurofilament light with neuropsychiatric features according to APOE ɛ4 carrier status. Results: Overall, 27 patients with DLB (78.48±9.0 years old, eleven APOE ɛ4 carriers) were paired with 27 patients with AD (81.00±5.8 years old, twelve APOE ɛ4 carriers) and 27 controls (78.48±8.7 years old, four APOE ɛ4 carriers); two thirds were women. Behavioral burden was more intense in DLB. Biomarker ratios reflecting amyloidogenesis and neurodegeneration in DLB were more similar to those in AD when patients carried APOE ɛ4 alleles. After corrections for false discovery rates, the following associations remained significant: in DLB, dysphoria was associated with tauopathy and indirect measures of amyloidogenesis, while in AD, agitation, and night-time behavior disturbances were associated with tauopathy, and delusions were associated with tauopathy and indirect measures of amyloidogenesis. Conclusion: Biomarker ratios were superior to Aβ and tau biomarkers predicting neuropsychiatric symptoms when associations with isolated biomarkers were not significant. At the end, APOE ɛ4 carrier status influenced amyloidogenesis and tau pathology in DLB and in AD, and axonal degeneration only in DLB.

Controversy over benefits of angiotensin-converting enzyme inhibitors (ACEIs) for treatment of dementia due to Alzheimer's disease (AD) led to this alternative investigational approach by the employment of pharmacogenetic methods, correlating the cognitive change of patients with late-onset AD with the presence of common ACE gene promoter polymorphisms, and stratifying the sample in groups of patients who responded or not to the brain-penetrating ACEIs Captopril or Perindopril. A trend was found for treatment with brain-penetrating ACEIs to slow cognitive decline in AD patients with the haplotype rs1800764 (CC): rs4291 (TT) (p = 0.024), and also non-significantly for independent carriers of rs1800764 or rs4291.