scholarly journals Genetic Risk of Alzheimer's Disease and Sleep Duration in Non‐Demented Elders

2020 ◽  
Vol 89 (1) ◽  
pp. 177-181 ◽  
Author(s):  
Yue Leng ◽  
Sarah F. Ackley ◽  
Maria M. Glymour ◽  
Kristine Yaffe ◽  
Willa D. Brenowitz
SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A439-A439
Author(s):  
Y Leng ◽  
K Yaffe ◽  
S Ackley ◽  
M Glymour ◽  
W Brenowitz

Abstract Introduction Sleep disturbances including short sleep duration are common in older adults, especially in those with Alzheimer’s disease (AD). However, it is unclear to what extent sleep duration is a manifestation of AD disease process. We examined whether genetic variants related to AD influence sleep duration in middle-aged and older adults and estimated the causal effects of AD on sleep duration using a mendelian randomization (MR) analysis. Methods We examined 406,687 UK Biobank participants with Caucasian genetic ancestry who self-reported sleep duration at baseline (2006-2010). Sleep duration was assessed by asking: “About how many hours sleep do you get in every 24 hours? (please include naps).” A genetic risk score for AD (AD-GRS) was calculated as a weighted sum of 23 previously identified AD-related single nucleotide polymorphisms in individuals of European ancestry. We evaluated whether AD-GRS predicted sleep duration using linear regression, adjusting for age, sex and principle components for genetic ancestry. We also stratified the analysis by age at baseline (≤55y or >55y) and conducted a MR analysis to estimate the effect of AD (ICD-9/10 codes for AD/dementia diagnosis) on sleep duration. Results The participants (aged 56.91±8.00y) had an average sleep duration of 7.2 (Standard deviation [SD]=1.1) hours and AD-GRS of 0.11 (SD=0.40) (range: -1.15~1.85). Higher AD-GRS score predicted shorter sleep duration (b= -0.013, 95%CI:-0.022,-0.005), mainly among those aged over 55y (b= -0.023, 95%CI:-0.034,-0.012) and not in those 55y or younger (b= 0.006, 95%CI:-0.012,0.013); p for interaction by age=0.02. MR analysis using AD-GRS as an instrumental variable suggested that AD was associated with 1.76 hrs (b=-1.76, -2.62~ -0.90) shorter sleep duration in those aged >55y. Conclusion Using a novel analytical approach, we found that higher genetic risk for AD predicted shorter sleep duration among older adults. This suggests shared genetic pathways; the biologic processes that lead to AD may also affect sleep duration. Support Dr. Leng received support from the National Institute on Aging (NIA) 1K99AG056598, and from GBHI, Alzheimer’s Association, and Alzheimer’s Society (GBHI ALZ UK-19-591141).


2020 ◽  
Vol 16 (S10) ◽  
Author(s):  
Yue Leng ◽  
Sarah F Ackley ◽  
M Maria Glymour ◽  
Kristine Yaffe ◽  
Willa D Brenowitz

2021 ◽  
pp. 1-11
Author(s):  
Mirjam Frank ◽  
Jonas Hensel ◽  
Lisa Baak ◽  
Sara Schramm ◽  
Nico Dragano ◽  
...  

Background: The apolipoprotein E (APOE) ɛ4 allele is reported to be a strong genetic risk factor for mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Additional genetic loci have been detected that influence the risk for late-onset AD. As socioeconomic position (SEP) is also strongly related to cognitive decline, SEP has been suggested to be a possible modifier of the genetic effect on MCI. Objective: To investigate whether APOE ɛ4 and a genetic sum score of AD-associated risk alleles (GRSAD) interact with SEP indicators to affect MCI in a population-based cohort. Methods: Using data of 3,834 participants of the Heinz Nixdorf Recall Study, APOE ɛ4 and GRSAD by SEP interactions were assessed using logistic regression models, as well as SEP-stratified genetic association analysis. Interaction on additive scale was calculated using the relative excess risk due to interaction (RERI). All analysis were additionally stratified by sex. Results: Indication for interaction on the additive scale was found between APOE ɛ4 and low education on MCI (RERI: 0.52 [95% -confidence interval (CI): 0.01; 1.03]). The strongest genetic effects of the APOE ɛ4 genotype on MCI were observed in groups of low education (Odds ratio (OR): 1.46 [95% -CI: 0.79; 2.63] for≤10 years of education versus OR: 1.00 [95% -CI: 0.43; 2.14] for≥18 years of education). Sex stratified results showed stronger effects in women. No indication for interaction between the GRSAD and SEP indicators on MCI was observed. Conclusion: Results indicate that low education may have an impact on APOE ɛ4 expression on MCI, especially among women.


2015 ◽  
Vol 112 (38) ◽  
pp. 11965-11970 ◽  
Author(s):  
Li Zhu ◽  
Minghao Zhong ◽  
Gregory A. Elder ◽  
Mary Sano ◽  
David M. Holtzman ◽  
...  

The apolipoprotein E4 (ApoE4) allele is the strongest genetic risk factor for developing sporadic Alzheimer’s disease (AD). However, the mechanisms underlying the pathogenic nature of ApoE4 are not well understood. In this study, we have found that ApoE proteins are critical determinants of brain phospholipid homeostasis and that the ApoE4 isoform is dysfunctional in this process. We have found that the levels of phosphoinositol biphosphate (PIP2) are reduced in postmortem human brain tissues of ApoE4 carriers, in the brains of ApoE4 knock-in (KI) mice, and in primary neurons expressing ApoE4 alleles compared with those levels in ApoE3 counterparts. These changes are secondary to increased expression of a PIP2-degrading enzyme, the phosphoinositol phosphatase synaptojanin 1 (synj1), in ApoE4 carriers. Genetic reduction of synj1 in ApoE4 KI mouse models restores PIP2 levels and, more important, rescues AD-related cognitive deficits in these mice. Further studies indicate that ApoE4 behaves similar to ApoE null conditions, which fails to degrade synj1 mRNA efficiently, unlike ApoE3 does. These data suggest a loss of function of ApoE4 genotype. Together, our data uncover a previously unidentified mechanism that links ApoE4-induced phospholipid changes to the pathogenic nature of ApoE4 in AD.


Brain ◽  
2006 ◽  
Vol 129 (11) ◽  
pp. 2984-2991 ◽  
Author(s):  
N. Brouwers ◽  
K. Sleegers ◽  
S. Engelborghs ◽  
V. Bogaerts ◽  
S. Serneels ◽  
...  

2011 ◽  
Vol 7 ◽  
pp. S102-S103 ◽  
Author(s):  
Eric Reiman ◽  
Carlos Velez-Pardo ◽  
Marelene Jimenez del Rio ◽  
Margarita Giraldo ◽  
Natalia Acosta-Baena ◽  
...  

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