scholarly journals Genetic variants beyond amyloid and tau associated with cognitive decline

Neurology ◽  
2020 ◽  
Vol 95 (17) ◽  
pp. e2366-e2377 ◽  
Author(s):  
Hang-Rai Kim ◽  
Taeyeop Lee ◽  
Jung Kyoon Choi ◽  
Yong Jeong

ObjectiveTo identify single nucleotide polymorphisms (SNPs) associated with cognitive decline independent of β-amyloid (Aβ) and tau pathology in Alzheimer disease (AD).MethodsDiscovery and replication datasets consisting of 414 individuals (94 cognitively normal control [CN], 185 with mild cognitive impairment [MCI], and 135 with AD) and 72 individuals (22 CN, 39 with MCI, and 11 with AD), respectively, were obtained from the Alzheimer's Disease Neuroimaging Initiative database. Genome-wide association analysis was conducted to identify SNPs associated with individual cognitive function (measured with the Mini-Mental State Examination and Alzheimer's Disease Assessment Scale–Cognitive Subscale ) while controlling for the level of Aβ and tau (measured as CSF phosphorylated-tau/Aβ1-42). Gene ontology analysis was performed on SNP-associated genes.ResultsWe identified 1 significant (rs55906536, β = −1.91, standard error 0.34, p = 4.07 × 10−8) and 4 suggestive variants on chromosome 6 that were associated with poorer cognitive function. Congruent results were found in the replication data. A structural equation model showed that the identified SNP deteriorated cognitive function partially through cortical thinning of the brain in a region-specific manner. Furthermore, a bioinformatics analysis showed that the identified SNPs were associated with genes related to glutathione metabolism.ConclusionsIn this study, we identified SNPs related to cognitive decline in a manner that could not be explained by Aβ and tau levels. Our findings provide insight into the complexity of AD pathogenesis and support the growing literature on the role of glutathione in AD.

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1839
Author(s):  
Chieh-Hsin Lin ◽  
Hsien-Yuan Lane

Glutathione (GSH) is a major endogenous antioxidant. Several studies have shown GSH redox imbalance and altered GSH levels in Alzheimer’s disease (AD) patients. Early detection is crucial for the outcome of AD. However, whether GSH can serve as a biomarker during the very early-phase of AD, such as mild cognitive impairment (MCI), remains unknown. The current prospective study aimed to examine the longitudinal change in plasma GSH concentration and its influence on cognitive decline in MCI. Overall, 49 patients with MCI and 16 healthy individuals were recruited. Plasma GSH levels and cognitive function, measured by the Mini-Mental Status Examination (MMSE) and Alzheimer’s disease assessment scale-cognitive subscale (ADAS-cog), were monitored every 6 months. We employed multiple regressions to examine the role of GSH level in cognitive decline in the 2 years period. The MCI patients showed significant decline in plasma GSH levels and cognitive function from baseline to endpoint (month 24). In comparison, the healthy individuals’ GSH concentration and cognitive function did not change significantly. Further, both GSH level at baseline and GSH level change from baseline to endpoint significantly influenced cognitive decline among the MCI patients. To our knowledge, this is the first study to demonstrate that both plasma GSH levels and cognitive function declined 2 years later among the MCI patients in a prospective manner. If replicated by future studies, blood GSH concentration may be regarded as a biomarker for monitoring cognitive change in MCI.


2020 ◽  
Vol 35 ◽  
pp. 153331752093858
Author(s):  
ChengCheng Zhou ◽  
Qingguang Wu ◽  
Zongwei Wang ◽  
Qi Wang ◽  
Youya Liang ◽  
...  

Previous studies have indicated that estrogen may delay disease progression and minimize the cognitive decline in patients with Alzheimer's disease (AD). However, the evidence for an estrogen deficiency in women with dementia and cognitive dysfunction is inconsistent. In the present review, a fixed effect meta-analysis revealed that the hormone replacement therapy (HRT) group exhibited significant improvements in Alzheimer Disease Assessment Scale-Cognitive subscale scores relative to those observed in the placebo group, suggesting that HRT is feasible for treating cognitive decline in patients with AD. However, no significant differences in Mini-Mental State Examination and Clinical Dementia Rating scale scores were observed between the 2 groups. The results of our systematic review indicate that HRT can improve cognitive function in female patients with AD. Due to limitations in sample size and the available literature, further multicenter trials with larger sample sizes are required to support these findings.


CNS Spectrums ◽  
2000 ◽  
Vol 5 (6) ◽  
pp. 21-22 ◽  
Author(s):  
Martin Farlow ◽  
John Messina ◽  
Ravi Anand ◽  
Richard Hartman ◽  
Jeffrey Veach

AbstractObjectives: Possible disease-modifying effects of rivastigmine have been suggested by analyses using a variation of the randomized start design; however, the results were somewhat confounded by differing attrition rates. We report on an alternative method investigating whether increasing doses reduce the rates of cognitive decline in patients who continue treatment.Methods: The effect of dose on the rate of cognitive decline seen on the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) was explored for patients in a long-term (130-week) extension of a 26-week placebo-controlled trial using two methods: a weighted leas squares regression analysis using each individual's slope, and a weighted analysis of variance (ANOVA) comparing the slopes of patients categorized by dose (≤6 mg/d or >6 mg/d).Results: The results from 408 patients included in the weighted least squares analysis estimated the rate of decline to attenuate by approximately 1 point/y for every 3 mg/d increase (P<.0001). The average annual rate of decline for patients whose mean dose was >6 mg/d was 4.5 points (95% Cl, 5.1–3.9), while for patients with a mean dose of≥6 mg/d a decline of 8.2 points (95% Cl, 9.1–7.3) was seen.Conclusion: These data further support earlier results suggesting that rivastigmine reduces the rate of progression of cognitive deterioration in Alzheimer's disease.


2012 ◽  
Vol 153 (12) ◽  
pp. 461-466 ◽  
Author(s):  
Magdolna Pákáski ◽  
Gergely Drótos ◽  
Zoltán Janka ◽  
János Kálmán

The cognitive subscale of the Alzheimer’s Disease Assessment Scale is the most widely used test in the diagnostic and research work of Alzheimer’s disease. Aims: The aim of this study was to validate and investigate reliability of the Hungarian version of the Alzheimer’s Disease Assessment Scale in patients with Alzheimer’s disease and healthy control subjects. Methods: syxty-six patients with mild and moderate Alzheimer’s disease and 47 non-demented control subjects were recruited for the study. The cognitive status was established by the Hungarian version of the Alzheimer’s Disease Assessment Scale and Mini Mental State Examination. Discriminative validity, the relation between age and education and Alzheimer’s Disease Assessment Scale, and the sensitivity and specificity of the test were determined. Results: Both the Mini Mental State Examination and the Alzheimer’s Disease Assessment Scale had significant potential in differentiating between patients with mild and moderate stages of Alzheimer’s disease and control subjects. A very strong negative correlation was established between the scores of the Mini Mental State Examination and the Alzheimer’s Disease Assessment Scale in the Alzheimer’s disease group. The Alzheimer’s Disease Assessment Scale showed slightly negative relationship between education and cognitive performance, whereas a positive correlation between age and Alzheimer’s Disease Assessment Scale scores was detected only in the control group. According to the analysis of the ROC curve, the values of sensitivity and specificity of the Alzheimer’s Disease Assessment Scale were high. Conclusions: The Hungarian version of the Alzheimer’s Disease Assessment Scale was found to be highly reliable and valid and, therefore, the application of this scale can be recommended for the establishment of the clinical stage and follow-up of patients with Alzheimer’s disease. However, the current Hungarian version of the Alzheimer’s Disease Assessment Scale is not sufficient; the list of words and linguistic elements should be selected according to the Hungarian standard in the future. Orv. Hetil., 2012, 153, 461–466.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Soo Hyun Cho ◽  
Sookyoung Woo ◽  
Changsoo Kim ◽  
Hee Jin Kim ◽  
Hyemin Jang ◽  
...  

AbstractTo characterize the course of Alzheimer’s disease (AD) over a longer time interval, we aimed to construct a disease course model for the entire span of the disease using two separate cohorts ranging from preclinical AD to AD dementia. We modelled the progression course of 436 patients with AD continuum and investigated the effects of apolipoprotein E ε4 (APOE ε4) and sex on disease progression. To develop a model of progression from preclinical AD to AD dementia, we estimated Alzheimer’s Disease Assessment Scale-Cognitive Subscale 13 (ADAS-cog 13) scores. When calculated as the median of ADAS-cog 13 scores for each cohort, the estimated time from preclinical AD to MCI due to AD was 7.8 years and preclinical AD to AD dementia was 15.2 years. ADAS-cog 13 scores deteriorated most rapidly in women APOE ε4 carriers and most slowly in men APOE ε4 non-carriers (p < 0.001). Our results suggest that disease progression modelling from preclinical AD to AD dementia may help clinicians to estimate where patients are in the disease course and provide information on variation in the disease course by sex and APOE ε4 status.


Author(s):  
Zahra Ayati ◽  
Guoyan Yang ◽  
Mohammad Hossein Ayati ◽  
Seyed Ahmad Emami ◽  
Dennis Chang

Abstract Background Saffron (stigma of Crocus sativus L.) from Iridaceae family is a well-known traditional herbal medicine that has been used for hundreds of years to treat several diseases such as depressive mood, cancer and cardiovascular disorders. Recently, anti-dementia property of saffron has been indicated. However, the effects of saffron for the management of dementia remain controversial. The aim of the present study is to explore the effectiveness and safety of saffron in treating mild cognitive impairment and dementia. Methods An electronic database search of some major English and Chinese databases was conducted until 31st May 2019 to identify relevant randomised clinical trials (RCT). The primary outcome was cognitive function and the secondary outcomes included daily living function, global clinical assessment, quality of life (QoL), psychiatric assessment and safety. Rev-Man 5.3 software was applied to perform the meta-analyses. Results A total of four RCTs were included in this review. The analysis revealed that saffron significantly improves cognitive function measured by the Alzheimer’s Disease Assessment Scale-cognitive subscale (ADAS-cog) and Clinical Dementia Rating Scale-Sums of Boxes (CDR-SB), compared to placebo groups. In addition, there was no significant difference between saffron and conventional medicine, as measured by cognitive scales such as ADAS-cog and CDR-SB. Saffron improved daily living function, but the changes were not statistically significant. No serious adverse events were reported in the included studies. Conclusions Saffron may have the potential to improve cognitive function and activities of daily living in patients with Alzheimer’s disease and mild cognitive impairment (MCI). However, due to limited high-quality studies there is insufficient evidence to make any recommendations for clinical use. Further clinical trials on larger sample sizes are warranted to shed more light on its efficacy and safety.


2016 ◽  
Vol 22 (5) ◽  
pp. 577-582 ◽  
Author(s):  
Israel Contador ◽  
Bernardino Fernández-Calvo ◽  
Francisco Ramos ◽  
Javier Olazarán

AbstractObjectives: This research retrospectively analyzed the effect of education on cognitive interventions carried out in patients with mild Alzheimer’s disease (AD). Methods: The total sample consisted of 75 patients with mild AD receiving treatment with cholinesterase inhibitors. The participants were divided into two groups: cognitive intervention (IG; n=45) and waiting list (WLG; n=30). Patients in the IG received either the Big Brain Academy (n=15) or the Integrated Psychostimulation Program (n=30) during 12 weeks. The influence of education on intervention effect was analyzed comparing mean change scores of the two study groups in the cognitive subscale of the Alzheimer’s Disease Assessment Scale (ADAS-cog), stratified by educational level. The potential effect of age, sex, cognitive status, and type of intervention was examined using post hoc stratification analyses. Results: Higher education was associated with faster cognitive decline in the WLG (effect size=0.51; p<.01). However, cognitive evolution was not influenced by education in the IG (effect size=0.12; p=.42). Conclusions: Our results suggest that cognitive intervention might delay accelerated cognitive decline in higher educated individuals with mild AD. (JINS, 2016, 23, 1–6)


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