Browsing by Author "Gifford, Katherine A."
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Item Associations of Sex, Race, and Apolipoprotein E Alleles With Multiple Domains of Cognition Among Older Adults(American Medical Association, 2023) Walters, Skylar; Contreras, Alex G.; Eissman, Jaclyn M.; Mukherjee, Shubhabrata; Lee, Michael L.; Choi, Seo-Eun; Scollard, Phoebe; Trittschuh, Emily H.; Mez, Jesse B.; Bush, William S.; Kunkle, Brian W.; Naj, Adam C.; Peterson, Amalia; Gifford, Katherine A.; Cuccaro, Michael L.; Cruchaga, Carlos; Pericak-Vance, Margaret A.; Farrer, Lindsay A.; Wang, Li-San; Haines, Jonathan L.; Jefferson, Angela L.; Kukull, Walter A.; Keene, C. Dirk; Saykin, Andrew J.; Thompson, Paul M.; Martin, Eden R.; Bennett, David A.; Barnes, Lisa L.; Schneider, Julie A.; Crane, Paul K.; Hohman, Timothy J.; Dumitrescu, Logan; Alzheimer’s Disease Neuroimaging Initiative; Alzheimer’s Disease Genetics Consortium; Alzheimer’s Disease Sequencing Project; Radiology and Imaging Sciences, School of MedicineImportance: Sex differences are established in associations between apolipoprotein E (APOE) ε4 and cognitive impairment in Alzheimer disease (AD). However, it is unclear whether sex-specific cognitive consequences of APOE are consistent across races and extend to the APOE ε2 allele. Objective: To investigate whether sex and race modify APOE ε4 and ε2 associations with cognition. Design, setting, and participants: This genetic association study included longitudinal cognitive data from 4 AD and cognitive aging cohorts. Participants were older than 60 years and self-identified as non-Hispanic White or non-Hispanic Black (hereafter, White and Black). Data were previously collected across multiple US locations from 1994 to 2018. Secondary analyses began December 2021 and ended September 2022. Main outcomes and measures: Harmonized composite scores for memory, executive function, and language were generated using psychometric approaches. Linear regression assessed interactions between APOE ε4 or APOE ε2 and sex on baseline cognitive scores, while linear mixed-effect models assessed interactions on cognitive trajectories. The intersectional effect of race was modeled using an APOE × sex × race interaction term, assessing whether APOE × sex interactions differed by race. Models were adjusted for age at baseline and corrected for multiple comparisons. Results: Of 32 427 participants who met inclusion criteria, there were 19 007 females (59%), 4453 Black individuals (14%), and 27 974 White individuals (86%); the mean (SD) age at baseline was 74 years (7.9). At baseline, 6048 individuals (19%) had AD, 4398 (14%) were APOE ε2 carriers, and 12 538 (38%) were APOE ε4 carriers. Participants missing APOE status were excluded (n = 9266). For APOE ε4, a robust sex interaction was observed on baseline memory (β = -0.071, SE = 0.014; P = 9.6 × 10-7), whereby the APOE ε4 negative effect was stronger in females compared with males and did not significantly differ among races. Contrastingly, despite the large sample size, no APOE ε2 × sex interactions on cognition were observed among all participants. When testing for intersectional effects of sex, APOE ε2, and race, an interaction was revealed on baseline executive function among individuals who were cognitively unimpaired (β = -0.165, SE = 0.066; P = .01), whereby the APOE ε2 protective effect was female-specific among White individuals but male-specific among Black individuals. Conclusions and relevance: In this study, while race did not modify sex differences in APOE ε4, the APOE ε2 protective effect could vary by race and sex. Although female sex enhanced ε4-associated risk, there was no comparable sex difference in ε2, suggesting biological pathways underlying ε4-associated risk are distinct from ε2 and likely intersect with age-related changes in sex biology.Item Evaluating the association between APOE genotypes and cognitive resilience in SuperAgers(Wiley, 2025-01-03) Durant, Alaina; Mukherjee, Shubhabrata; Lee, Michael L.; Choi, Seo-Eun; Scollard, Phoebe; Trittschuh, Emily H.; Mez, Jesse; Bush, William S.; Kunkle, Brian W.; Naj, Adam C.; Gifford, Katherine A.; Cuccaro, Michael L.; Cruchaga, Carlos; Hassenstab, Jason J.; Pericak-Vance, Margaret A.; Farrer, Lindsay A.; Wang, Li-San; Haines, Jonathan L.; Jefferson, Angela L.; Kukull, Walter A.; Keene, C. Dirk; Saykin, Andrew J.; Thompson, Paul M.; Martin, Eden R.; Bennett, David A.; Barnes, Lisa L.; Schneider, Julie A.; Albert, Marilyn S.; Johnson, Sterling C.; Engelman, Corinne D.; Mayeux, Richard; Vardarajan, Badri N.; Crane, Paul K.; Dumitrescu, Logan C.; Hohman, Timothy J.; Gaynor, Leslie S.; The Alzheimer’s Disease Neuroimaging Initiative (ADNI); Alzheimer’s Disease Genetics Consortium (ADGC); The Alzheimer’s Disease Sequencing Project (ADSP); Medical and Molecular Genetics, School of MedicineBackground: “SuperAgers” are older adults (ages 80+) whose cognitive performance resembles that of adults in their 50s to mid‐60s. Factors underlying their exemplary aging are underexplored in large, racially diverse cohorts. Using eight cohorts, we investigated the frequency of APOE genotypes in SuperAgers compared to middle‐aged and older adults. Method: Harmonized, longitudinal memory, executive function, and language scores in Non‐Hispanic White (NHW) and Non‐Hispanic Black (NHB) participants were obtained from the ADSP Phenotype Harmonization Consortium. Scores were age‐ and sex‐adjusted. SuperAgers (NHW = 1,625; NHB = 106) included individuals 80+ years of age with a memory score equal to or exceeding individuals aged 50‐64 and language and executive function domain scores within normal limits who remain cognitively normal across visits. SuperAgers were compared to Alzheimer’s disease (AD) cases (NHW = 8,400; NHB = 925) and cognitively normal controls (NHW = 7,355; NHB = 1,305), as well as age‐defined subgroups (Young = ages 50‐64, Older = ages 65‐79, Oldest‐Old = age 80+). We performed binary logistic regression analyses comparing APOE‐ε2 and APOE‐ε4 alleles (0 = none, 1 = 1+ alleles present) among SuperAgers and their counterparts, covarying for sex and education. We corrected for multiple comparisons using the Benjamini‐Hochberg procedure. Results: Across racial groups, SuperAgers had significantly higher proportions with APOE‐ε2 alleles and lower proportions with APOE‐ε4 alleles compared to cases (Table 1, Figure 1). Similar differences were observed between SuperAgers and Young and Old Controls, although differences were restricted to APOE‐ε4 in NHB comparisons. NHW SuperAgers had lower proportions with APOE‐ε4 alleles compared to Oldest‐Old Controls; APOE‐ε2 proportions did not differ. Conclusion: Within our large, harmonized cohort, larger proportions of SuperAgers had APOE‐ε2 alleles and smaller proportions had APOE‐ε4 alleles than AD cases across both NHW and NHB participants. Crucially, higher proportions of NHW SuperAgers had APOE‐ε2 alleles than younger controls (ages<80) and lower proportions had APOE‐ε4 alleles than all controls including age‐matched controls (ages 80+). This work provides the strongest evidence to date that APOE is associated with SuperAging. APOE‐ε2 did not differentiate NHB SuperAgers from controls nor APOE‐ε4 from other oldest‐old adults in present analyses. Future work will extend to whole genome analysis to identify novel genomic drivers of SuperAging.Item Evaluating the association of APOE genotype and cognitive resilience in SuperAgers(medRxiv, 2025-01-07) Durant, Alaina; Mukherjee, Shubhabrata; Lee, Michael L.; Choi, Seo-Eun; Scollard, Phoebe; Klinedinst, Brandon S.; Trittschuh, Emily H.; Mez, Jesse; Farrer, Lindsay A.; Gifford, Katherine A.; Cruchaga, Carlos; Hassenstab, Jason; Naj, Adam C.; Wang, Li-San; Johnson, Sterling C.; Engelman, Corinne D.; Kukull, Walter A.; Keene, C. Dirk; Saykin, Andrew J.; Cuccaro, Michael L.; Kunkle, Brian W.; Pericak-Vance, Margaret A.; Martin, Eden R.; Bennett, David A.; Barnes, Lisa L.; Schneider, Julie A.; Bush, William S.; Haines, Jonathan L.; Mayeux, Richard; Vardarajan, Badri N.; Albert, Marilyn S.; Thompson, Paul M.; Jefferson, Angela L.; Alzheimer’s Disease Neuroimaging Initiative (ADNI); Alzheimer’s Disease Genetics Consortium (ADGC); The Alzheimer’s Disease Sequencing Project (ADSP); Crane, Paul K.; Dumitrescu, Logan; Archer, Derek B.; Hohman, Timothy J.; Gaynor, Leslie S.; Radiology and Imaging Sciences, School of MedicineImportance: "SuperAgers" are oldest-old adults (ages 80+) whose memory performance resembles that of adults in their 50s to mid-60s. Factors underlying their exemplary memory are underexplored in large, racially diverse cohorts. Objective: To determine the frequency of APOE genotypes in non-Hispanic Black and non-Hispanic White SuperAgers compared to middle-aged (ages 50-64), old (ages 65-79), and oldest-old (ages 80+) controls and Alzheimer's disease (AD) dementia cases. Design: This multicohort study selected data from eight longitudinal cohort studies of normal aging and AD. Setting: Variable recruitment criteria and follow-up intervals, including both population-based and clinical-based samples. Participants: Inclusion in our analyses required APOE genotype, that participants be age 50+, and are identified as either non-Hispanic Black or non-Hispanic White. In total, 18,080 participants were included in the present study with a total of 78,549 datapoints. Main outcomes and measures: Harmonized, longitudinal memory, executive function, and language scores were obtained from the Alzheimer's Disease Sequencing Project Phenotype Harmonization Consortium (ADSP-PHC). SuperAgers, controls, and AD dementia cases were identified by cognitive scores using a residual approach and clinical diagnoses across multiple timepoints when available. SuperAgers were compared to AD dementia cases and cognitively normal controls using age-defined bins (middle-aged, old, oldest-old). Results: Across racialized groups, SuperAgers had significantly higher proportions of APOE-ε2 alleles and lower proportions of APOE-ε4 alleles compared to cases. Similar differences were observed between SuperAgers and middle-aged and old controls. Non-Hispanic White SuperAgers had significantly lower proportions of APOE-ε4 alleles and significantly higher proportions of APOE-ε2 alleles compared to all cases and controls, including oldest-old controls. In contrast, non-Hispanic Black SuperAgers had significantly lower proportions of APOE-ε4 alleles compared to cases and younger controls, and significantly higher proportions of APOE-ε2 alleles compared only to cases. Conclusions and relevance: In the largest study to date, we demonstrated strong evidence that the frequency of APOE-ε4 and -ε2 alleles differ between non-Hispanic White SuperAgers and AD dementia cases and cognitively normal controls. Differences in the role of APOE in SuperAging by race underlines distinctions in mechanisms conferring resilience across race groups given likely differences in genetic ancestry.Item Leveraging longitudinal diffusion MRI data to quantify differences in white matter microstructural decline in normal and abnormal aging(bioRxiv, 2023-05-18) Archer, Derek B.; Schilling, Kurt; Shashikumar, Niranjana; Jasodanand, Varuna; Moore, Elizabeth E.; Pechman, Kimberly R.; Bilgel, Murat; Beason-Held, Lori L.; An, Yang; Shafer, Andrea; Ferrucci, Luigi; Risacher, Shannon L.; Gifford, Katherine A.; Landman, Bennett A.; Jefferson, Angela L.; Saykin, Andrew J.; Resnick, Susan M.; Hohman, Timothy J.; Alzheimer’s Disease Neuroimaging Initiative; Radiology and Imaging Sciences, School of MedicineIntroduction: It is unclear how rates of white matter microstructural decline differ between normal aging and abnormal aging. Methods: Diffusion MRI data from several well-established longitudinal cohorts of aging [Alzheimer's Neuroimaging Initiative (ADNI), Baltimore Longitudinal Study of Aging (BLSA), Vanderbilt Memory & Aging Project (VMAP)] was free-water corrected and harmonized. This dataset included 1,723 participants (age at baseline: 72.8±8.87 years, 49.5% male) and 4,605 imaging sessions (follow-up time: 2.97±2.09 years, follow-up range: 1-13 years, mean number of visits: 4.42±1.98). Differences in white matter microstructural decline in normal and abnormal agers was assessed. Results: While we found global decline in white matter in normal/abnormal aging, we found that several white matter tracts (e.g., cingulum bundle) were vulnerable to abnormal aging. Conclusions: There is a prevalent role of white matter microstructural decline in aging, and future large-scale studies in this area may further refine our understanding of the underlying neurodegenerative processes. Highlights: Longitudinal data was free-water corrected and harmonizedGlobal effects of white matter decline were seen in normal and abnormal agingThe free-water metric was most vulnerable to abnormal agingCingulum free-water was the most vulnerable to abnormal aging.Item Linking Self-Perceived Cognitive Functioning Questionnaires Using Item Response Theory: The Subjective Cognitive Decline Initiative(American Psychological Association, 2023) Rabin, Laura A.; Sikkes, Sietske A. M.; Tommet, Douglas; Jones, Richard N.; Crane, Paul K.; Elbulok-Charcape, Milushka M.; Dubbelman, Mark A.; Koscik, Rebecca; Amariglio, Rebecca E.; Buckley, Rachel F.; Boada, Mercè; Chételat, Gaël; Dubois, Bruno; Ellis, Kathryn A.; Gifford, Katherine A.; Jefferson, Angela L.; Jessen, Frank; Johnson, Sterling; Katz, Mindy J.; Lipton, Richard B.; Luck, Tobias; Margioti, Eleni; Maruff, Paul; Molinuevo, Jose Luis; Perrotin, Audrey; Petersen, Ronald C.; Rami, Lorena; Reisberg, Barry; Rentz, Dorene M.; Riedel-Heller, Steffi G.; Risacher, Shannon L.; Rodriguez-Gomez, Octavio; Sachdev, Perminder S.; Saykin, Andrew J.; Scarmeas, Nikolaos; Smart, Colette; Snitz, Beth E.; Sperling, Reisa A.; Taler, Vanessa; van der Flier, Wiesje M.; van Harten, Argonde C.; Wagner, Michael; Wolfsgruber, Steffen; Alzheimer’s Disease Neuroimaging Initiative; Canadian Longitudinal Study on Aging; Health and Aging Brain Study; Health Disparities (HABS-HD) Study Team; Radiology and Imaging Sciences, School of MedicineObjective: Self-perceived cognitive functioning, considered highly relevant in the context of aging and dementia, is assessed in numerous ways-hindering the comparison of findings across studies and settings. Therefore, the present study aimed to link item-level self-report questionnaire data from international aging studies. Method: We harmonized secondary data from 24 studies and 40 different questionnaires with item response theory (IRT) techniques using a graded response model with a Bayesian estimator. We compared item information curves to identify items with high measurement precision at different levels of the self-perceived cognitive functioning latent trait. Data from 53,030 neuropsychologically intact older adults were included, from 13 English language and 11 non-English (or mixed) language studies. Results: We successfully linked all questionnaires and demonstrated that a single-factor structure was reasonable for the latent trait. Items that made the greatest contribution to measurement precision (i.e., "top items") assessed general and specific memory problems and aspects of executive functioning, attention, language, calculation, and visuospatial skills. These top items originated from distinct questionnaires and varied in format, range, time frames, response options, and whether they captured ability and/or change. Conclusions: This was the first study to calibrate self-perceived cognitive functioning data of geographically diverse older adults. The resulting item scores are on the same metric, facilitating joint or pooled analyses across international studies. Results may lead to the development of new self-perceived cognitive functioning questionnaires guided by psychometric properties, content, and other important features of items in our item bank.Item Longitudinal change in memory performance as a strong endophenotype for Alzheimer's disease(Wiley, 2024) Archer, Derek B.; Eissman, Jaclyn M.; Mukherjee, Shubhabrata; Lee, Michael L.; Choi, Seo-Eun; Scollard, Phoebe; Trittschuh, Emily H.; Mez, Jesse B.; Bush, William S.; Kunkle, Brian W.; Naj, Adam C.; Gifford, Katherine A.; Alzheimer's Disease Neuroimaging Initiative (ADNI); Alzheimer's Disease Genetics Consortium (ADGC); Alzheimer's Disease Sequencing Project (ADSP); Cuccaro, Michael L.; Pericak-Vance, Margaret A.; Farrer, Lindsay A.; Wang, Li-San; Schellenberg, Gerard D.; Mayeux, Richard P.; Haines, Jonathan L.; Jefferson, Angela L.; Kukull, Walter A.; Keene, C. Dirk; Saykin, Andrew J.; Thompson, Paul M.; Martin, Eden R.; Bennett, David A.; Barnes, Lisa L.; Schneider, Julie A.; Crane, Paul K.; Dumitrescu, Logan; Hohman, Timothy J.; Radiology and Imaging Sciences, School of MedicineIntroduction: Although large-scale genome-wide association studies (GWAS) have been conducted on AD, few have been conducted on continuous measures of memory performance and memory decline. Methods: We conducted a cross-ancestry GWAS on memory performance (in 27,633 participants) and memory decline (in 22,365 participants; 129,201 observations) by leveraging harmonized cognitive data from four aging cohorts. Results: We found high heritability for two ancestry backgrounds. Further, we found a novel ancestry locus for memory decline on chromosome 4 (rs6848524) and three loci in the non-Hispanic Black ancestry group for memory performance on chromosomes 2 (rs111471504), 7 (rs4142249), and 15 (rs74381744). In our gene-level analysis, we found novel genes for memory decline on chromosomes 1 (SLC25A44), 11 (BSX), and 15 (DPP8). Memory performance and memory decline shared genetic architecture with AD-related traits, neuropsychiatric traits, and autoimmune traits. Discussion: We discovered several novel loci, genes, and genetic correlations associated with late-life memory performance and decline. Highlights: Late-life memory has high heritability that is similar across ancestries. We discovered four novel variants associated with late-life memory. We identified four novel genes associated with late-life memory. Late-life memory shares genetic architecture with psychiatric/autoimmune traits.Item Sex and APOE ε4 allele differences in longitudinal white matter microstructure in multiple cohorts of aging and Alzheimer's disease(Wiley, 2025) Peterson, Amalia; Sathe, Aditi; Zaras, Dimitrios; Yang, Yisu; Durant, Alaina; Deters, Kacie D.; Shashikumar, Niranjana; Pechman, Kimberly R.; Kim, Michael E.; Gao, Chenyu; Khairi, Nazirah Mohd; Li, Zhiyuan; Yao, Tianyuan; Huo, Yuankai; Dumitrescu, Logan; Gifford, Katherine A.; Wilson, Jo Ellen; Cambronero, Francis E.; Risacher, Shannon L.; Beason-Held, Lori L.; An, Yang; Arfanakis, Konstantinos; Erus, Guray; Davatzikos, Christos; Tosun, Duygu; Toga, Arthur W.; Thompson, Paul M.; Mormino, Elizabeth C.; Habes, Mohamad; Wang, Di; Zhang, Panpan; Schilling, Kurt; Alzheimer's Disease Neuroimaging Initiative (ADNI); BIOCARD Study Team; Alzheimer's Disease Sequencing Project (ADSP); Albert, Marilyn; Kukull, Walter; Biber, Sarah A.; Landman, Bennett A.; Johnson, Sterling C.; Schneider, Julie; Barnes, Lisa L.; Bennett, David A.; Jefferson, Angela L.; Resnick, Susan M.; Saykin, Andrew J.; Hohman, Timothy J.; Archer, Derek B.; Radiology and Imaging Sciences, School of MedicineIntroduction: The effects of sex and apolipoprotein E (APOE)-Alzheimer's disease (AD) risk factors-on white matter microstructure are not well characterized. Methods: Diffusion magnetic resonance imaging data from nine well-established longitudinal cohorts of aging were free water (FW)-corrected and harmonized. This dataset included 4741 participants (age = 73.06 ± 9.75) with 9671 imaging sessions over time. FW and FW-corrected fractional anisotropy (FAFWcorr) were used to assess differences in white matter microstructure by sex and APOE ε4 carrier status. Results: Sex differences in FAFWcorr in projection tracts and APOE ε4 differences in FW limbic and occipital transcallosal tracts were most pronounced. Discussion: There are prominent differences in white matter microstructure by sex and APOE ε4 carrier status. This work adds to our understanding of disparities in AD. Additional work to understand the etiology of these differences is warranted. Highlights: Sex and apolipoprotein E (APOE) ε4 carrier status relate to white matter microstructural integrity. Females generally have lower free water-corrected fractional anisotropy compared to males. APOE ε4 carriers tended to have higher free water than non-carriers.Item Sex differences in the genetic architecture of cognitive resilience to Alzheimer's disease(Oxford University Press, 2022) Eissman, Jaclyn M.; Dumitrescu, Logan; Mahoney, Emily R.; Smith, Alexandra N.; Mukherjee, Shubhabrata; Lee, Michael L.; Scollard, Phoebe; Choi, Seo Eun; Bush, William S.; Engelman, Corinne D.; Lu, Qiongshi; Fardo, David W.; Trittschuh, Emily H.; Mez, Jesse; Kaczorowski, Catherine C.; Hernandez Saucedo, Hector; Widaman, Keith F.; Buckley, Rachel F.; Properzi, Michael J.; Mormino, Elizabeth C.; Yang, Hyun Sik; Harrison, Theresa M.; Hedden, Trey; Nho, Kwangsik; Andrews, Shea J.; Tommet, Douglas; Hadad, Niran; Sanders, R. Elizabeth; Ruderfer, Douglas M.; Gifford, Katherine A.; Zhong, Xiaoyuan; Raghavan, Neha S.; Vardarajan, Badri N.; Alzheimer’s Disease Neuroimaging Initiative (ADNI); Alzheimer’s Disease Genetics Consortium (ADGC); A4 Study Team; Pericak-Vance, Margaret A.; Farrer, Lindsay A.; Wang, Li San; Cruchaga, Carlos; Schellenberg, Gerard D.; Cox, Nancy J.; Haines, Jonathan L.; Keene, C. Dirk; Saykin, Andrew J.; Larson, Eric B.; Sperling, Reisa A.; Mayeux, Richard; Cuccaro, Michael L.; Bennett, David A.; Schneider, Julie A.; Crane, Paul K.; Jefferson, Angela L.; Hohman, Timothy J.; Radiology and Imaging Sciences, School of MedicineApproximately 30% of elderly adults are cognitively unimpaired at time of death despite the presence of Alzheimer's disease neuropathology at autopsy. Studying individuals who are resilient to the cognitive consequences of Alzheimer's disease neuropathology may uncover novel therapeutic targets to treat Alzheimer's disease. It is well established that there are sex differences in response to Alzheimer's disease pathology, and growing evidence suggests that genetic factors may contribute to these differences. Taken together, we sought to elucidate sex-specific genetic drivers of resilience. We extended our recent large scale genomic analysis of resilience in which we harmonized cognitive data across four cohorts of cognitive ageing, in vivo amyloid PET across two cohorts, and autopsy measures of amyloid neuritic plaque burden across two cohorts. These data were leveraged to build robust, continuous resilience phenotypes. With these phenotypes, we performed sex-stratified [n (males) = 2093, n (females) = 2931] and sex-interaction [n (both sexes) = 5024] genome-wide association studies (GWAS), gene and pathway-based tests, and genetic correlation analyses to clarify the variants, genes and molecular pathways that relate to resilience in a sex-specific manner. Estimated among cognitively normal individuals of both sexes, resilience was 20-25% heritable, and when estimated in either sex among cognitively normal individuals, resilience was 15-44% heritable. In our GWAS, we identified a female-specific locus on chromosome 10 [rs827389, β (females) = 0.08, P (females) = 5.76 × 10-09, β (males) = -0.01, P(males) = 0.70, β (interaction) = 0.09, P (interaction) = 1.01 × 10-04] in which the minor allele was associated with higher resilience scores among females. This locus is located within chromatin loops that interact with promoters of genes involved in RNA processing, including GATA3. Finally, our genetic correlation analyses revealed shared genetic architecture between resilience phenotypes and other complex traits, including a female-specific association with frontotemporal dementia and male-specific associations with heart rate variability traits. We also observed opposing associations between sexes for multiple sclerosis, such that more resilient females had a lower genetic susceptibility to multiple sclerosis, and more resilient males had a higher genetic susceptibility to multiple sclerosis. Overall, we identified sex differences in the genetic architecture of resilience, identified a female-specific resilience locus and highlighted numerous sex-specific molecular pathways that may underly resilience to Alzheimer's disease pathology. This study illustrates the need to conduct sex-aware genomic analyses to identify novel targets that are unidentified in sex-agnostic models. Our findings support the theory that the most successful treatment for an individual with Alzheimer's disease may be personalized based on their biological sex and genetic context.Item Sex, racial, and APOE-ε4 allele differences in longitudinal white matter microstructure in multiple cohorts of aging and Alzheimer’s disease(bioRxiv, 2024-06-12) Peterson, Amalia; Sathe, Aditi; Zaras, Dimitrios; Yang, Yisu; Durant, Alaina; Deters, Kacie D.; Shashikumar, Niranjana; Pechman, Kimberly R.; Kim, Michael E.; Gao, Chenyu; Khairi, Nazirah Mohd; Li, Zhiyuan; Yao, Tianyuan; Huo, Yuankai; Dumitrescu, Logan; Gifford, Katherine A.; Wilson, Jo Ellen; Cambronero, Francis; Risacher, Shannon L.; Beason-Held, Lori L.; An, Yang; Arfanakis, Konstantinos; Erus, Guray; Davatzikos, Christos; Tosun, Duygu; Toga, Arthur W.; Thompson, Paul M.; Mormino, Elizabeth C.; Zhang, Panpan; Schilling, Kurt; Alzheimer’s Disease Neuroimaging Initiative (ADNI); BIOCARD Study Team; Alzheimer’s Disease Sequencing Project (ADSP); Albert, Marilyn; Kukull, Walter; Biber, Sarah A.; Landman, Bennett A.; Johnson, Sterling C.; Schneider, Julie; Barnes, Lisa L.; Bennett, David A.; Jefferson, Angela L.; Resnick, Susan M.; Saykin, Andrew J.; Hohman, Timothy J.; Archer, Derek B.; Radiology and Imaging Sciences, School of MedicineIntroduction: The effects of sex, race, and Apolipoprotein E (APOE) - Alzheimer's disease (AD) risk factors - on white matter integrity are not well characterized. Methods: Diffusion MRI data from nine well-established longitudinal cohorts of aging were free-water (FW)-corrected and harmonized. This dataset included 4,702 participants (age=73.06 ± 9.75) with 9,671 imaging sessions over time. FW and FW-corrected fractional anisotropy (FAFWcorr) were used to assess differences in white matter microstructure by sex, race, and APOE-ε4 carrier status. Results: Sex differences in FAFWcorr in association and projection tracts, racial differences in FAFWcorr in projection tracts, and APOE-ε4 differences in FW limbic and occipital transcallosal tracts were most pronounced. Discussion: There are prominent differences in white matter microstructure by sex, race, and APOE-ε4 carrier status. This work adds to our understanding of disparities in AD. Additional work to understand the etiology of these differences is warranted.Item Sex, racial/ethnic, and APOE‐ε4 allele differences in longitudinal white matter microstructure in multiple cohorts of aging(Wiley, 2025-01-09) Peterson, Amalia Jo; Sathe, Aditi; Yang, Yisu; Durant, Alaina; Shashikumar, Niranjana; Pechman, Kimberly R.; Dumitrescu, Logan C.; Gifford, Katherine A.; Risacher, Shannon L.; Beason-Held, Lori L.; An, Yang; Schilling, Kurt; Landman, Bennett A.; Schneider, Julie A.; Barnes, Lisa L.; Bennett, David A.; Jefferson, Angela L.; Resnick, Susan M.; Saykin, Andrew J.; Hohman, Timothy J.; Archer, Derek B.; Alzheimer’s Disease Neuroimaging Initiative (ADNI); Radiology and Imaging Sciences, School of MedicineBackground: There is growing recognition that white matter microstructural integrity is affected in Alzheimer’s disease. The goal of this study was to characterize sex, racial/ethnic, and apolipoprotein (APOE)‐ε4 allele differences in white matter integrity. Methods: This study included participants from ADNI, BLSA, ROS/MAP/MARS, and VMAP, all longitudinal cohorts of aging. This combined dataset included 6,837 imaging sessions from 2,619 participants age 50+ with diffusion MRI (dMRI) and demographic and clinical data (60% female, 31.4% APOE‐ε4 carriers, 78.9% White). dMRI was preprocessed using the PreQual pipeline. Free‐water (FW) correction was used to generate FW and FW‐corrected intracellular metrics including fractional anisotropy (FAFWcorr), mean diffusivity (MDFWcorr), axial diffusivity (AxDFWcorr), and radial diffusivity (RDFWcorr). Conventional and FW‐corrected metrics were harmonized using the Longitudinal ComBat package. Linear mixed‐effects models related sex, race/ethnicity, and APOE‐ε4 allele status to longitudinal diffusion metrics in 48 white matter tracts, adjusting for age at baseline, sex, education, race/ethnicity, APOE‐ε4 carrier status, cognitive status at baseline, and converter status. All models were corrected for multiple comparisons using the FDR approach. Result: Sex differences in white matter were most notable in projection tracts (Figure 1A) and were primarily in FW‐corrected metrics. Females had lower FAFWcorr and higher RDFWcorr, indicative of worse microstructure, but lower AxDFWcorr. This sex difference was most pronounced for FAFWcorr in the ventral premotor projection tract (p=1.53x10‐62). There were global differences in white matter integrity by race/ethnicity (Figure 1B). Non‐Hispanic White participants tended to have higher conventional FA, FAFWcorr and AxDFWcorr and lower RDFWcorr. There was no association between APOE‐ε4 status and white matter integrity and no significant sex x race/ethnicity, sex x APOE‐ε4, or race/ethnicity x APOE‐ε4 interactions for conventional or FW‐corrected metrics when corrected for multiple comparisons. Conclusion: There were striking sex and racial/ethnic (but not APOE‐ε4) differences in white matter tract integrity in a large cohort of aging adults. Female participants tended to have measures reflective of worse white matter integrity, and non‐Hispanic White participants tended to have measures reflective of greater integrity. Additional research exploring the etiology of these differences will be important to better understand disparities in Alzheimer’s disease.