Midlife Residential Greenness and Late-Life Cognitive Decline among Nurses' Health Study Participants

BACKGROUND

Midlife residential exposure to greenspace may slow cognitive decline by increasing opportunities for physical activity and social connection, restoring attention, or reducing stress or adverse environmental exposures. However, prospective studies on the association between greenness and cognitive decline are sparse.

OBJECTIVE

We investigated the prospective association between greenness at midlife and cognitive decline later in life. We explored effect measure modification by apolipoprotein E (APOE)-ɛ4 carrier status, neighborhood socioeconomic status (NSES), and rural/urban regions.

METHODS

The Nurses' Health Study (N = 121,700 ) started in 1976 with married female nurses, 30-55 years of age, located across 11 US states. We examined 16,962 nurses who were enrolled in a substudy starting in 1995-2001 (mean age = 74 y ) through 2008. We assessed average summer residential greenness in a 270 -m buffer using Landsat Normalized Difference Vegetation Index data from 1986-1994. Starting in 1995-2001, participants underwent up to four repeated measures of five cognitive tests. A global composite score was calculated as the average of all z -scores for each task to evaluate overall cognition. We used linear mixed models to evaluate the association of average greenness exposure at midlife with cognitive decline in later life, adjusted for age, education, NSES, and depression.

RESULTS

In adjusted models, higher midlife greenness exposure [per interquartile range (IQR): 0.18] was associated with a 0.004-unit (95% CI: 0.001, 0.006) slower annual rate of cognitive decline. For comparison, we found that 1 year of age is related to a - 0.006 mean annual difference for global cognition in the full sample; thus, higher midlife greenness appeared equivalent to slowing cognitive decline by ∼ 8 months. In analysis exploring gene-environment interactions, we found that among APOE-ɛ4 carriers, an IQR increase in greenness was associated with a rate of decline that was slower by 0.01 units of global composite score (95% CI: 0.0004, 0.02). This association was attenuated among APOE-ɛ4 noncarriers. We did not observe associations between greenness and baseline or annual rate of cognitive decline of verbal memory.

DISCUSSION

Higher midlife greenness exposure is associated with slower cognitive decline later in life. Future research is necessary to confirm these findings. https://doi.org/10.1289/EHP13588.

The Impact of Apolipoprotein E (APOE) Epigenetics on Aging and Sporadic Alzheimer's Disease

Sporadic Alzheimer's disease (AD) derives from an interplay among environmental factors and genetic variants, while epigenetic modifications have been expected to affect the onset and progression of its complex etiopathology. Carriers of one copy of the apolipoprotein E gene (APOE) ε4 allele have a 4-fold increased AD risk, while APOE ε4/ε4-carriers have a 12-fold increased risk of developing AD in comparison with the APOE ε3-carriers. The main longevity factor is the homozygous APOE ε3/ε3 genotype. In the present narrative review article, we summarized and described the role of APOE epigenetics in aging and AD pathophysiology. It is not fully understood how APOE variants may increase or decrease AD risk, but this gene may affect tau- and amyloid-mediated neurodegeneration directly or indirectly, also by affecting lipid metabolism and inflammation. For sporadic AD, epigenetic regulatory mechanisms may control and influence APOE expression in response to external insults. Diet, a major environmental factor, has been significantly associated with physical exercise, cognitive function, and the methylation level of several cytosine-phosphate-guanine (CpG) dinucleotide sites of APOE.

APOE-Genotype and Insulin Modulate Estimated Effect of Dietary Macronutrients on Cognitive Performance: Panel Analyses in Nondiabetic Older Adults at Risk of Dementia

BACKGROUND

The apolipoprotein E gene (APOE ε-2/3/4, combined as 6 different genotypes: ε-22/23/24/33/34/44) and insulin status modulate dementia risk and play a role in the metabolism of macronutrients.

OBJECTIVES

We aimed to examine APOE-genotype and fasting insulin as effect modifiers of the slopes between dietary macronutrients and cognitive performance among older adults at risk of dementia.

METHODS

Panel analyses-with diet and cognition measured at baseline and follow-up at years 1 and 2-were performed in a sub-sample from the FINGER (Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability) trial (n = 676, 60-77 y, 46% females, all nondiabetics). The associations between macronutrients (3-d food records, z-scores) and global cognition (modified Neuropsychological Test Battery, z-score) were analyzed in mixed regression models adjusted for confounders selected a priori. After a gradient was implied by the point estimates in categorical APOE analyses, we investigated a continuous APOE variable [APOE-gradient, coded -1 (for ε-23), -0.5 (ε-24), 0 (ε-33), 1 (ε-34), 2 (ε-44)] as an effect-modifier.

RESULTS

At increasing levels of the APOE-gradient, a relatively more favorable slope between diet and cognition was observed for a lower carbohydrate/fat ratio [β = -0.040, 95% confidence interval (CI): -0.074, -0.006; P = 0.020 for interaction diet × APOE-gradient), and higher protein (β = 0.075, 95% CI: 0.042, 0.109; P = 9.4 × 10-6). Insulin concentration (log-linear) modulated the association between the carbohydrate/fat ratio and cognition by a quadratic interaction (β = -0.016, P = 0.039). Coherent findings for exploratory predictors (fiber, fat subtypes, composite score, metabolic biomarkers) were compatible with published hypotheses of differential dietary adaptation by APOE, with cognition among ε-33 being relatively independent of dietary parameters-implying "metabolic flexibility." Antagonistic slopes to cognition for ε-23 (positive) compared with ε-34 and ε-44 (negative) were found for a Higher-carbohydrates-fiber-Lower-fat-protein composite score, even as within-subjects effects.

CONCLUSIONS

APOE-based precision nutrition appears conceptually promising, but replications in wider samples are warranted, as well as support from trials. Both relative hyper- and hypoinsulinemia might modulate the effect of diet on cognition.

Apolipoprotein E deficiency attenuated osteogenesis via down-regulating osterix

Apolipoprotein E (ApoE), a ligand for low-density lipoprotein receptors, is strongly induced during osteogenesis and has a physiologic role in regulating osteoblast function, but the mechanisms of its action are still unclear. The study aims to elucidate the influence and molecular mechanisms of ApoE on bone formation. An ovariectomy-induced osteoporotic model were conducted in ApoE knockout (ApoE-/-) mice to study the effect of ApoE on the bone system. Bone quality were assessed through bone mineral density and histomorphometric analysis. To investigate the underlying role and mechanisms of ApoE during osteogenesis, primary osteoblasts from the calvariums of newborn ApoE-/- or wild-type (WT) mice were cultured in the osteoblastic differentiation medium in vitro for further research. Our animal experiment data showed that ApoE-/- mice exhibited bone loss, exacerbated by estrogen deprivation after ovariectomy. ApoE deficiency attenuated osteoblast activity and inhibited osteoblast osteogenesis, accompanied by decreased osterix expression. ApoE deficiency did not affect primary osteoblast viability and collagen-1 expression. Moreover, osteoprotegerin expression in ApoE-/- osteoblasts was reduced compared to WT controls. Our study demonstrated that ApoE gene deficiency contributed to bone loss and attenuated osteogenesis by down-regulating osterix expression.

Association of the APOE Gene Polymorphism with Depression in White Adults in the WHO "MONICA-Psychosocial" Program

The APOE gene polymorphism is associated with the risk of the development of several neurological disorders. The aim of the study was to investigate the association of the APOE gene polymorphism with depression in the white adult population aged 25-64 years in Novosibirsk (Western Siberia). The third screening of the WHO program "MONICA-psychosocial" was conducted in 1994-1995. In total, 403 men (the average age was 34 ± 0.4 years, the response was 71%) and 531 women (the average age was 35 ± 0.4 years, the response was 72%) of the open population of residents aged 25-64 years of the Oktyabrsky district of Novosibirsk were examined. The "MONICA-MOPSY" psychosocial questionnaire was used to assess depression. A high level of depression was found in 12.8% of the population: in 8.9% of men and in 15.8% of women. The frequencies of APOE gene polymorphism genotypes ε2/3, ε2/4, ε3/3, ε3/4, and ε4/4 were 14.9%, 3.1%, 61.6%, 17.5%, and 2.9%, respectively. Carrying the ε3/4 genotype of the APOE gene increased the odds of developing major depression by 2.167 times (95% CI 1.100-4.266) compared to carrying the ε3/3 genotype of the APOE gene in people without depression (χ2 = 5.120 df = 1 p = 0.024). Carriers of the ε4 allele were 2.089 times (95% CI 1.160-3.761) more likely to have a high level of depression than those without this allele and no depression (χ2 = 6.148 df = 1 p = 0.013), and 2.049 times (95% CI 1.117-3.758) more likely to have a moderate level of depression than those without this allele (χ2 = 5.470 df = 1 p < 0.019). The ε4 allele of the APOE gene is associated with a high level of depression.

Hair mercury is associated with dyslipidemia and cardiovascular risk: An anthropometric, biochemical and genetic cross-sectional study of Amazonian vulnerable populations

This cross-sectional study evaluated the association between human exposure to mercury and cardiovascular risk using lipid profile (including apolipoproteins) and genetic analysis of Amazonian riverine population. Anthropometric data (gender, age, height, weight, blood pressure, and neck and waist circumferences) of the participants were recorded. Total mercury and methylmercury (MeHg) content were quantified in hair by ICP-MS and GC-pyro-AFS system. Polymorphisms rs662799, rs693, rs429358 and rs7412 (of genes of apolipoproteins A-V, B, and E at positions 112 and 158, respectively) were genotyped by real-time PCR. The population presented a dyslipidemia profile significantly correlated with high mercury levels. The apolipoprotein B/apolipoprotein A-I (ApoB/ApoA-I) index was also positively correlated with mercury, supporting a possible causal relationship. Allelic distributions were similar to those described in other populations, suggesting that genetic susceptibility may not have a significant role in the lipid alterations found in this work. This study demonstrated for the first time: i) the relationship between mercury exposure and cardiovascular risk-related apolipoproteins in humans, ii) the ApoB levels and the ApoB/ApoA-I index as the risk factors more strongly associated to the mercury-related dyslipidemia in humans, and iii) the prevalence of high/moderate risk of acute myocardial infarction in the vulnerable and chronically exposed-populations of the Amazon, in addition to the genotypic profile of the three most frequent polymorphisms in apolipoproteins of relevance for cardiovascular risk. This early detection of lipid alterations is essential to prevent the development of cardiovascular diseases (CVD), especially in chronically exposed populations such as those found in the Amazon. Therefore, in addition to provide data for the Minamata Convention implementation, our work is in line with the efforts joined by all members of the World Health Organization committed to reducing premature deaths originating from non-communicable diseases by 25% in 2025, including CVD.

How Important Are Genes to Achieve Longevity?

Several studies on the genetics of longevity have been reviewed in this paper. The results show that, despite efforts and new technologies, only two genes, APOE and FOXO3A, involved in the protection of cardiovascular diseases, have been shown to be associated with longevity in nearly all studies. This happens because the genetic determinants of longevity are dynamic and depend on the environmental history of a given population. In fact, population-specific genes are thought to play a greater role in the attainment of longevity than those shared between different populations. Hence, it is not surprising that GWAS replicated associations of common variants with longevity have been few, if any, as these studies pool together different populations. An alternative way might be the study of long-life families. This type of approach is proving to be an ideal resource for uncovering protective alleles and associated biological signatures for healthy aging phenotypes and exceptional longevity.

Associations of APOE Gene Variants rs429358 and rs7412 with Parameters of the Blood Lipid Profile and the Risk of Myocardial Infarction and Death in a White Population of Western Siberia

The present study aimed to analyze possible associations of rs7412 and rs429358 of the APOE gene with lipid profile parameters, the risk of myocardial infarction, and death in the mostly white population of Western Siberia (Russia). The study population was selected from a sample surveyed within the framework of the Health, Alcohol and Psychosocial Factors In Eastern Europe (HAPIEE) study (9360 subjects, age 53.8 ± 7.0 years, males/females 50/50). PCR was conducted with fluorescence detection according to the TaqMan principle on a real-time PCR machine. The frequency of a minor allele (C) of rs429358 was 0.13, and the frequency of a minor allele (T) of rs7412 was 0.09. In our study, the woman with the rare ɛ1/ɛ4 genotype had substantial aberrations in blood lipid levels. In Kaplan–Meier curves, statistically significant differences were revealed in the prognosis of survival within the subgroup of females who had a myocardial infarction (p = 0.0006): the prognosis was worse for carriers of the ɛ2/ɛ2 genotype and for ɛ4/ɛ4 carriers. Survival analysis regarding deaths from all causes showed (p = 0.0238) that female carriers of the ɛ2/ɛ4 genotype had a worse prognosis than did carriers of other genotypes. Thus, in the population of Western Siberia (Russia), we confirmed statistically significant associations between rs7412 & rs429358 genotypes and lipid profile parameters.

Are apolipoprotein E fragments a promising new therapeutic target for Alzheimer’s disease?

Human apolipoprotein E (ApoE) is a 299-amino acid secreted glycoprotein that binds cholesterol and phospholipids. ApoE exists as three common isoforms (ApoE2, ApoE3, and ApoE4) and heterozygous carriers of the ε4 allele of the gene encoding ApoE (APOE) have a fourfold greater risk of developing Alzheimer’s disease (AD). The enzymes thrombin, cathepsin D, α-chymotrypsin-like serine protease, and high-temperature requirement serine protease A1 are responsible for ApoE proteolytic processing resulting in bioactive C-terminal-truncated fragments that vary depending on ApoE isoforms, brain region, aging, and neural injury. The objectives of the present narrative review were to describe ApoE processing, discussing current hypotheses about the potential role of various ApoE fragments in AD pathophysiology, and reviewing the current development status of different anti-ApoE drugs. The exact mechanism by which APOE gene variants increase/decrease AD risk and the role of ApoE fragments in the deposition are not fully understood, but APOE is known to directly affect tau-mediated neurodegeneration. ApoE fragments co-localize with neurofibrillary tangles and amyloid β (Aβ) plaques, and may cause neurodegeneration. Among anti-ApoE approaches, a fascinating strategy may be to therapeutically overexpress ApoE2 in APOE ε4/ε4 carriers through vector administration or liposomal delivery systems. Another approach involves reducing ApoE4 expression by intracerebroventricular antisense oligonucleotides that significantly decreased Aβ pathology in transgenic mice. Differences in the proteolytic processing of distinct ApoE isoforms and the use of ApoE fragments as mimetic peptides in AD treatment are also under investigation. Treatment with peptides that mimic the structural and biological properties of native ApoE may reduce Aβ deposition, tau hyperphosphorylation, and glial activation in mouse models of Aβ pathology. Alternative strategies involve the use of ApoE4 structure correctors, passive immunization to target a certain form of ApoE, conversion of the ApoE4 aminoacid sequence into that of ApoE3 or ApoE2, and inhibition of the ApoE-Aβ interaction.

Factors Influencing Alzheimer's Disease Risk: Whether and How They are Related to the APOE Genotype

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease featuring progressive cognitive impairment. Although the etiology of late-onset AD remains unclear, the close association of AD with apolipoprotein E (APOE), a gene that mainly regulates lipid metabolism, has been firmly established and may shed light on the exploration of AD pathogenesis and therapy. However, various confounding factors interfere with the APOE-related AD risk, raising questions about our comprehension of the clinical findings concerning APOE. In this review, we summarize the most debated factors interacting with the APOE genotype and AD pathogenesis, depict the extent to which these factors relate to APOE-dependent AD risk, and discuss the possible underlying mechanisms.

Whole Genome Sequence Analysis of the Plasma Proteome in Black Adults Provides Novel Insights Into Cardiovascular Disease

BACKGROUND

Plasma proteins are critical mediators of cardiovascular processes and are the targets of many drugs. Previous efforts to characterize the genetic architecture of the plasma proteome have been limited by a focus on individuals of European descent and leveraged genotyping arrays and imputation. Here we describe whole genome sequence analysis of the plasma proteome in individuals with greater African ancestry, increasing our power to identify novel genetic determinants.

METHODS

Proteomic profiling of 1301 proteins was performed in 1852 Black adults from the Jackson Heart Study using aptamer-based proteomics (SomaScan). Whole genome sequencing association analysis was ascertained for all variants with minor allele count ≥5. Results were validated using an alternative, antibody-based, proteomic platform (Olink) as well as replicated in the Multi-Ethnic Study of Atherosclerosis and the HERITAGE Family Study (Health, Risk Factors, Exercise Training and Genetics).

RESULTS

We identify 569 genetic associations between 479 proteins and 438 unique genetic regions at a Bonferroni-adjusted significance level of 3.8×10-11. These associations include 114 novel locus-protein relationships and an additional 217 novel sentinel variant-protein relationships. Novel cardiovascular findings include new protein associations at the APOE gene locus including ZAP70 (sentinel single nucleotide polymorphism [SNP] rs7412-T, β=0.61±0.05, P=3.27×10-30) and MMP-3 (β=-0.60±0.05, P=1.67×10-32), as well as a completely novel pleiotropic locus at the HPX gene, associated with 9 proteins. Further, the associations suggest new mechanisms of genetically mediated cardiovascular disease linked to African ancestry; we identify a novel association between variants linked to APOL1-associated chronic kidney and heart disease and the protein CKAP2 (rs73885319-G, β=0.34±0.04, P=1.34×10-17) as well as an association between ATTR amyloidosis and RBP4 levels in community-dwelling individuals without heart failure.

CONCLUSIONS

Taken together, these results provide evidence for the functional importance of variants in non-European populations, and suggest new biological mechanisms for ancestry-specific determinants of lipids, coagulation, and myocardial function.

Leisure Activities, APOE ε4, and Cognitive Decline: A Longitudinal Cohort Study

Background: Both leisure activities and the ε4 allele of the apolipoprotein E (APOE ε4) have been shown to affect cognitive health. We aimed to determine whether engagement in leisure activities protects against APOE ε4-related cognitive decline.

Methods: We used the cohort data from the Chinese Longitudinal Healthy Longevity Survey. A total of 3,017 participants (mean age of 77.0 years, SD = 9.0; 49.3% female) from 23 provinces of China were recruited in 2008 and were reinterviewed in 2014. We assessed cognitive function using the Mini-Mental State Examination (MMSE). We calculated cognitive decline using subtraction of the MMSE score of each participant in 2008 and 2014. We genotyped a number of APOE ε4 alleles for each participant at baseline and determined the Index of Leisure Activities (ILAs) by summing up the frequency of nine types of typical activities in productive, social, and physical domains. We used ordinal logistic regression models to estimate the effects of leisure activities, APOE ε4, and their interaction on cognitive decline, statistically adjusted for a range of potential confounders.

Results: There were significant associations between APOE ε4 and faster cognitive decline, independent of potential confounders, and between leisure activities and mitigated cognitive decline. The odds ratios were 1.25 (95% CI: 1.03, 1.53) and 0.93 (95% CI: 0.89, 0.97), respectively. We found significant interactions of APOE ε4 with leisure activities with a P-value of 0.018. We also observed interactive effects of subtypes of leisure activities: participants who regularly engaged in productive activities were more likely to reduce the risk of APOE ε4-related cognitive decline.

Conclusion: Our findings provide support for the indication that participating in leisure activities reduces the risk of APOE ε4-related cognitive decline.

Vigorous physical activity and cognitive trajectory later in life: prospective association and interaction by apolipoprotein E e4 in the Nurses' Health Study

BACKGROUND

The apolipoprotein E (APOE) e4 allele is a well-established genetic risk factor of brain ageing. Vigorous physical activity may be particularly important in APOE-e4 carriers, but data have been inconsistent, likely due to differences in the timing of the physical activity assessment, definition of cognitive decline and/or sample size.

METHODS

We prospectively evaluated the association between vigorous physical activity and cognition assessed at least 9 years later, according to APOE-e4 carrier status. Biennially from 1986, Nurses' Health Study participants reported their leisure-time physical activities. Starting in 1995-2001 and through 2008, participants (aged 70+ years) underwent up to four repeated cognitive telephone assessments (6 tasks averaged together using z-scores).

RESULTS

Among 7,252 women, latent process mixed models identified three major patterns of cognitive change over 6 years: high-stable, medium-stable, and decline. Taking the high-stable cognitive trajectory as the outcome reference in multinomial logistic regressions, highest tertile of vigorous physical activity (≥5.9 metabolic-equivalent[MET]-hours/week) compared to lowest tertile (≤0.9 MET-hours/week) was significantly associated with subsequent lower likelihood of the medium-stable trajectory in the global score (OR[95%CI]=0.72[0.63,0.82]), verbal memory (OR[95%CI]=0.78[0.68-0.89]) and telephone interview of cognitive status score (OR[95%CI]=0.81[0.70-0.94]). Vigorous physical activity was also associated with lower likelihood of decline in category fluency (OR[95%CI]=0.72[0.56,0.92]). We observed some evidence (p-interaction=0.06 for the global score) that the association was stronger among APOE-e4 carriers than non-carriers (OR[95%CI]=0.60[0.39,0.92] versus 0.82[0.59,1.16]).

CONCLUSION

Midlife vigorous physical activity was associated with better cognitive trajectories in women in their seventies, with suggestions of stronger associations among APOE-e4 carriers.

Apolipoprotein E genotype, lifestyle and coronary artery disease: Gene-environment interaction analyses in the UK Biobank population

BACKGROUND AND AIMS

The APOE ε4 genotype has a higher risk for developing coronary artery disease (CAD), but there is preliminary evidence that antioxidative lifestyle factors interact with APOE genotype on CAD risk. Here, we assessed the effect modification of physical activity, oily fish and polyunsaturated fatty acid (PUFA) intake with APOE genotype on risk of incident CAD.

METHODS

The present study comprised 345,659 white European participants from UK Biobank (mean age: 56.5 years, 45.7% men) without a history of CAD. Information regarding physical activity, oily fish intake and PUFA intake was collected through questionnaires, and information on incident CAD through linkage with hospital admission records. Analyses were performed using Cox proportional hazard models adjusted for age and sex.

RESULTS

Higher physical activity level and oily fish intake were both associated with a lower incidence of CAD. However, these associations were similar across the different APOE genotypes (p-values for interaction > 0.05). Most notable, higher PUFA intake was associated with a lower CAD risk in APOE ε4 genotype carriers (hazard ratio: 0.76, 95% confidence interval: 0.63-0.92), and not in APOE ε3/ε3 genotype carriers (0.90; 0.79, 1.02), but without statistical evidence for effect modification (p-value_interaction = 0.137).

CONCLUSIONS

While higher physical activity and high fish and PUFA intake were associated with a lower risk of incident CAD, no evidence for interaction of these lifestyle factors with APOE genotype was observed in UK Biobank participants. Interventions intended to reduce cardiovascular risk might therefore be similarly effective across the APOE genotype carriers.

Physical Activity as Moderator of the Association Between APOE and Cognitive Decline in Older Adults: Results from Three Longitudinal Cohort Studies

Background

Previous studies have suggested that the association between APOE ɛ ₄ and dementia is moderated by physical activity (PA), but the results remain inconclusive and longitudinal data on cognitive decline are missing. In this study, we examine whether there is a gene–environment interaction between APOE and PA on cognitive decline in older adults using 9-year follow-up data of three cohort studies.

Methods

We followed 7,176 participants from three longitudinal cohort studies: Longitudinal Aging Study Amsterdam (LASA), InCHIANTI, and Rotterdam Study for 9 years. PA was assessed with self-reported questionnaires and was categorized in low, moderate, and high PA. Cognitive function was assessed with the Mini-Mental State Examination (MMSE) and cognitive decline was defined as a decrease of three points or more on the MMSE during 3 years follow-up. We fitted logistic regression models using generalized estimating equations adjusting for age, sex, education, depressive symptoms, and number of chronic disease. Interaction between APOE and PA was tested on multiplicative and additive scale.

Results

Cohorts were similar in most aspects but InCHIANTI participants were on average older and had lower education. APOE ɛ ₄ carriers had higher odds of cognitive decline (odds ratio [OR] = 1.46, 95% confidence interval [CI]: 1.29–1.64) while PA was not significantly associated with cognitive decline overall (moderate PA: OR = 0.87, 0.67–1.13; high PA: OR = 0.71, 0.36–1.40). There was no evidence for an interaction effect between PA and APOE ɛ ₄ in cognitive decline in older adults (APOE × moderate PA: p = .83; APOE × high PA: p = .90).

Conclusions

Previous claims of a gene–environment interaction between APOE ɛ ₄ and PA in cognitive decline are not supported by our results.

Varying Effects of APOE Alleles on Extreme Longevity in European Ethnicities

APOE is a well-studied gene with multiple effects on aging and longevity. The gene has three alleles: e2, e3, and e4, whose frequencies vary by ethnicity. While the e2 is associated with healthy cognitive aging, the e4 allele is associated with Alzheimer's disease and early mortality and therefore its prevalence among people with extreme longevity (EL) is low. Using the PopCluster algorithm, we identified several ethnically different clusters in which the effect of the e2 and e4 alleles on EL changed substantially. For example, PopCluster discovered a large group of 1,309 subjects enriched of Southern Italian genetic ancestry with weaker protective effect of e2 (odds ratio [OR] = 1.27, p = .14) and weaker damaging effect of e4 (OR = 0.82, p = .31) on the phenotype of EL compared to other European ethnicities. Further analysis of this cluster suggests that the odds for EL in carriers of the e4 allele with Southern Italian genetic ancestry differ depending on whether they live in the United States (OR = 0.29, p = .009) or Italy (OR = 1.21, p = .38). PopCluster also found clusters enriched of subjects with Danish ancestry with varying effect of e2 on EL. The country of residence (Denmark or United States) appears to change the odds for EL in the e2 carriers.

ApoE Genotype, Lipid Profile, Exercise, and the Associations With Cardiovascular Morbidity and 18-Year Mortality

Background

Studies of longevity examined apolipoprotein E (ApoE), a gene involved in lipoprotein metabolism, which interacts with susceptibility to age-related diseases, and with mortality. We evaluated the association of ApoE isoforms with cardiovascular disease (CVD) and all-cause mortality.

Methods

A prospective cohort of 949 survivors of the Israel Study of Glucose Intolerance, Obesity, and Hypertension, examined during 1999–2004, mean age 72 years, was followed for mortality until 2017. Participants were interviewed for lifestyle habits and medical history. Anthropometrics and biochemical markers were taken. Logistic regression was used to assess CVD morbidity and Cox proportional hazard model for mortality.

Results

The most common genotype in the cohort was ApoE E3 (76.3%), with the other two almost equally distributed (ApoE E2 11.2% and ApoE E4 12.5%). In men only, ApoE E4 associated with CVD (adjusted odds ratio = 1.46, 95% confidence interval [CI] 0.76, 2.80) and with 18-year mortality (adjusted hazard ratio = 1.47, 95% CI 0.95, 2.26), adjusting for age, ethnicity, physical activity, hypertension, diabetes, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol, triglycerides and lipid-lowering medications. Low levels of HDL cholesterol, adjusted for ApoE and the above-mentioned variables, associated with higher prevalence of CVD (adjusted odds ratio = 1.35, 95% CI 1.00, 1.83) and all-cause mortality (adjusted hazard ratio = 1.42, 95% CI 1.14, 1.78). ApoE E3 and E2 conferred a lower 18-year mortality risk in the physically active individuals, compared to the sedentary (adjusted hazard ratio = 0.57, 95% CI 0.44, 0.74, and adjusted hazard ratio = 0.53, 95% CI 0.78, 1.02, respectively).

Conclusions

In community-dwelling older adults, sociodemographic characteristics and physical activity, blood pressure and HDL-cholesterol levels, may outweigh the impact of ApoE polymorphisms on CVD morbidity and all-cause mortality.

The Alzheimer's Disease Exposome

INTRODUCTION

Environmental factors are poorly understood in the etiology of Alzheimer's disease (AD) and related dementias. The importance of environmental factors in gene environment interactions (GxE) is suggested by wide individual differences in cognitive loss, even for carriers of AD-risk genetic variants.

RESULTS AND DISCUSSION

We propose the "AD exposome" to comprehensively assess the modifiable environmental factors relevant to genetic underpinnings of cognitive aging and AD. Analysis of endogenous and exogenous environmental factors requires multi-generational consideration of these interactions over age and time (GxExT). New computational approaches to the multi-level complexities may identify accessible interventions for individual brain aging. International collaborations on diverse populations are needed to identify the most relevant exposures over the life course for GxE interactions.