Browsing by Author "Gao, Sujuan"
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Item A comparison of techniques for deriving clustering and switching scores from verbal fluency word lists(Frontiers Media, 2022-09-14) Bushnell, Justin; Svaldi, Diana; Ayers, Matthew R.; Gao, Sujuan; Unverzagt, Frederick; Del Gaizo, John; Wadley, Virginia G.; Kennedy, Richard; Goñi, Joaquín; Clark, David Glenn; Neurology, School of MedicineObjective: To compare techniques for computing clustering and switching scores in terms of agreement, correlation, and empirical value as predictors of incident cognitive impairment (ICI). Methods: We transcribed animal and letter F fluency recordings on 640 cases of ICI and matched controls from a national epidemiological study, amending each transcription with word timings. We then calculated clustering and switching scores, as well as scores indexing speed of responses, using techniques described in the literature. We evaluated agreement among the techniques with Cohen's κ and calculated correlations among the scores. After fitting a base model with raw scores, repetitions, and intrusions, we fit a series of Bayesian logistic regression models adding either clustering and switching scores or speed scores, comparing the models in terms of several metrics. We partitioned the ICI cases into acute and progressive cases and repeated the regression analysis for each group. Results: For animal fluency, we found that models with speed scores derived using the slope difference algorithm achieved the best values of the Watanabe-Akaike Information Criterion (WAIC), but with good net reclassification improvement (NRI) only for the progressive group (8.2%). For letter fluency, different models excelled for prediction of acute and progressive cases. For acute cases, NRI was best for speed scores derived from a network model (3.4%), while for progressive cases, the best model used clustering and switching scores derived from the same network model (5.1%). Combining variables from the best animal and letter F models led to marginal improvements in model fit and NRI only for the all-cases and acute-cases analyses. Conclusion: Speed scores improve a base model for predicting progressive cognitive impairment from animal fluency. Letter fluency scores may provide complementary information.Item A locus at 19q13.31 significantly reduces the ApoE ε4 risk for Alzheimer's Disease in African Ancestry(Public Library of Science, 2022-07-05) Rajabli, Farid; Beecham, Gary W.; Hendrie, Hugh C.; Baiyewu, Olusegun; Ogunniyi, Adesola; Gao, Sujuan; Kushch, Nicholas A.; Lipkin-Vasquez, Marina; Hamilton-Nelson, Kara L.; Young, Juan I.; Dykxhoorn, Derek M.; Nuytemans, Karen; Kunkle, Brian W.; Wang, Liyong; Jin, Fulai; Liu, Xiaoxiao; Feliciano-Astacio, Briseida E.; Alzheimer’s Disease Sequencing Project; Alzheimer’s Disease Genetic Consortium; Schellenberg, Gerard D.; Dalgard, Clifton L.; Griswold, Anthony J.; Byrd, Goldie S.; Reitz, Christiane; Cuccaro, Michael L.; Haines, Jonathan L.; Pericak-Vance, Margaret A.; Vance, Jeffery M.; Psychiatry, School of MedicineAfrican descent populations have a lower Alzheimer disease risk from ApoE ε4 compared to other populations. Ancestry analysis showed that the difference in risk between African and European populations lies in the ancestral genomic background surrounding the ApoE locus (local ancestry). Identifying the mechanism(s) of this protection could lead to greater insight into the etiology of Alzheimer disease and more personalized therapeutic intervention. Our objective is to follow up the local ancestry finding and identify the genetic variants that drive this risk difference and result in a lower risk for developing Alzheimer disease in African ancestry populations. We performed association analyses using a logistic regression model with the ApoE ε4 allele as an interaction term and adjusted for genome-wide ancestry, age, and sex. Discovery analysis included imputed SNP data of 1,850 Alzheimer disease and 4,331 cognitively intact African American individuals. We performed replication analyses on 63 whole genome sequenced Alzheimer disease and 648 cognitively intact Ibadan individuals. Additionally, we reproduced results using whole-genome sequencing of 273 Alzheimer disease and 275 cognitively intact admixed Puerto Rican individuals. A further comparison was done with SNP imputation from an additional 8,463 Alzheimer disease and 11,365 cognitively intact non-Hispanic White individuals. We identified a significant interaction between the ApoE ε4 allele and the SNP rs10423769_A allele, (β = -0.54,SE = 0.12,p-value = 7.50x10-6) in the discovery data set, and replicated this finding in Ibadan (β = -1.32,SE = 0.52,p-value = 1.15x10-2) and Puerto Rican (β = -1.27,SE = 0.64,p-value = 4.91x10-2) individuals. The non-Hispanic Whites analyses showed an interaction trending in the "protective" direction but failing to pass a 0.05 significance threshold (β = -1.51,SE = 0.84,p-value = 7.26x10-2). The presence of the rs10423769_A allele reduces the odds ratio for Alzheimer disease risk from 7.2 for ApoE ε4/ε4 carriers lacking the A allele to 2.1 for ApoE ε4/ε4 carriers with at least one A allele. This locus is located approximately 2 mB upstream of the ApoE locus, in a large cluster of pregnancy specific beta-1 glycoproteins on chromosome 19 and lies within a long noncoding RNA, ENSG00000282943. This study identified a new African-ancestry specific locus that reduces the risk effect of ApoE ε4 for developing Alzheimer disease. The mechanism of the interaction with ApoEε4 is not known but suggests a novel mechanism for reducing the risk for ε4 carriers opening the possibility for potential ancestry-specific therapeutic intervention.Item Accelerating diversity in Alzheimer's disease research by partnering with a community advisory board(Wiley, 2023-05-28) Pena-Garcia, Alex; Richards, Ralph; Richards, Mollie; Campbell, Christopher; Mosley, Hank; Asper, Joseph; Eliacin, Johanne; Polsinelli, Angelina; Apostolova, Liana; Hendrie, Hugh; Tackett, Andrew; Elliott, Caprice; Van Heiden, Sarah; Gao, Sujuan; Saykin, Andrew; Wang, Sophia; Medicine, School of MedicineIntroduction: Community advisory boards (CABs) and researcher partnerships present a promising opportunity to accelerate enrollment of underrepresented groups (URGs). We outline the framework for how the CAB and researchers at the Indiana Alzheimer's Disease Research Center (IADRC) partnered to accelerate URG participation in AD neuroimaging research. Methods: CAB and the IADRC researchers partnered to increase the CAB's impact on URG study enrollment through community and research interactions. Community interactions included the CAB collaboratively building a network of URG focused community organizations and collaborating with those URG-focused organizations to host IADRC outreach and recruitment events. Research interactions included direct impact (CAB members referring themselves or close contacts as participants) and strategic impact, mainly by the CAB working with researchers to develop and refine URG focused outreach and recruitment strategies for IADRC and affiliated studies to increase URG representation. We created a database infrastructure to measure how these interactions impacted URG study enrollment. Results: Out of the 354 URG research referrals made to the IADRC between October 2019 and December 2022, 267 referrals were directly referred by the CAB (N = 36) or from community events in which CAB members organized and/or volunteered at (N = 231). Out of these 267 referrals, 34 were enrolled in IADRC and 2 were enrolled in Indiana University Longitudinal Early Onset AD Study (IU LEADS). Of note, both studies require the prospective participants to be willing to do MRI and PET scans. As of December 2022, 30 out of the 34 enrolled participants have received a consensus diagnosis; the majority were cognitively normal (64.7%), with the remainder having mild cognitive impairment (17.6%) or early-stage AD (2.9%). Discussion: The IADRC CAB-researcher partnership had a measurable impact on the enrollment of African American/Black adults in AD neuroimaging studies. Future studies will need to test whether this conceptual model works for other sites and for other URGs.Item Additive Impact of Cardiometabolic Multimorbidity and Depression on Cognitive Decline: Findings from Multi‐Regional Cohorts and Generalization from Community to Clinic(Wiley, 2025-01-09) Zhao, Xuhao; Yan, Yifan; Lipnicki, Darren M.; Pang, Ting; Chen, Christopher; Wong, Tien Yin; Cheng, Ching Yu; Venketasubramanian, Narayanaswamy; Chong, Eddie; Costa, Erico; Lipton, Richard B.; Katz, Mindy J.; Ritchie, Karen; Carriere, Isabelle; Scarmeas, Nikolaos; Gureje, Oye; Hendrie, Hugh C.; Gao, Sujuan; Guerra, Ricardo Oliveira; Rolandi, Elena; Riedel-Heller, Steffi G.; Ganguli, Mary; Aiello, Allison E.; Ho, Roger Chun-Man; Sanchez-Juan, Pascual; Lobo, Antonio; Sachdev, Perminder S.; Xu, Xiaolin; Xu, Xin; Psychiatry, School of MedicineBackground: To estimate the additive associations of cardiometabolic multimorbidity (CMM) and depression on long‐term cognitive trajectory in multi‐regional cohorts and validate the generalizability of the findings in varying clinical settings. Method: Data harmonization was performed across 14 longitudinal cohort studies within the Cohort Studies of Memory in an International Consortium (COSMIC) group, spanning North America, South America, Europe, Africa, Asia, and Australia. Three external validation studies with distinct settings were employed to assess generalizability. Cross‐sectional and longitudinal analyses were conducted. CMM was defined as: 1) CMM5: ≥ 2 among hypertension, hyperlipidemia, diabetes mellitus, stroke, and heart disease and 2) CMM3 (aligned with previous studies): ≥ 2 among diabetes mellitus, stroke, and heart disease. Depression was identified using the Geriatric Depression Scale, Center for Epidemiological Studies‐Depression scale, or medical history. A one‐step individual participant data meta‐analysis was utilized to investigate associations between the co‐occurrence of CMM and depression and cognitive outcomes in the COSMIC studies. Stratified analyses were conducted based on baseline dementia status, demographics, and APOE genotype. Repeated analyses were performed in external validation studies for generalization. Result: Of the 32,450 older adults in the 14 COSMIC cohorts, we included 31,243 participants with complete data on CMM, depression, and cognitive assessment for cross‐sectional analyses. Among them, 23,242 who had at least 1 follow‐up cognitive assessment were included in the longitudinal analyses. From the three external studies we included 1964 participants, representing 3 multi‐ethnic Asian elderly cohorts (community cohort, memory clinic cohort, and stroke cohort). In the COSMIC studies analysis, the co‐occurrence of CMM and depression was associated with both cross‐sectional cognitive performance (β = ‐0.20, 95%CI = (‐0.25,‐0.16) for CMM5 and depression, β = ‐0.17, (95%CI = ‐0.044,‐0.031) for CMM3 and depression), and rate of cognitive decline (β = ‐0.038, 95%CI = (‐0.25,‐0.16) for CMM5 and depression, β = ‐0.023, (95%CI = ‐0.036, ‐0.009) for CMM3 and depression). This combined effect remained consistent across different subgroups particularly among participants without dementia. These findings were reproduced in the three external validation studies. Conclusion: Our study demonstrated an additive effect between CMM and depression on cognitive decline. Targeting both cardiometabolic and psychological conditions could lead to greater effectiveness in delaying or preventing cognitive decline.Item Adherence and Tolerability of Alzheimer's Disease Medications: A Pragmatic Randomized Trial(Wiley, 2017-07) Campbell, Noll L.; Perkins, Anthony J.; Gao, Sujuan; Skaar, Todd C.; Li, Lang; Hendrie, Hugh C.; Fowler, Nicole; Callahan, Christopher M.; Boustani, Malaz A.; Department of Medicine, IU School of MedicineBACKGROUND/OBJECTIVES: Post-marketing comparative trials describe medication use patterns in diverse, real-world populations. Our objective was to determine if differences in rates of adherence and tolerability exist among new users to acetylcholinesterase inhibitors (AChEI's). DESIGN: Pragmatic randomized, open label comparative trial of AChEI's currently available in the United States. SETTING: Four memory care practices within four healthcare systems in the greater Indianapolis area. PARTICIPANTS: Eligibility criteria included older adults with a diagnosis of possible or probable Alzheimer's disease (AD) who were initiating treatment with an AChEI. Participants were required to have a caregiver to complete assessments, access to a telephone, and be able to understand English. Exclusion criteria consisted of a prior severe adverse event from AChEIs. INTERVENTION: Participants were randomized to one of three AChEIs in a 1:1:1 ratio and followed for 18 weeks. MEASUREMENTS: Caregiver-reported adherence, defined as taking or not taking study medication, and caregiver-reported adverse events, defined as the presence of an adverse event. RESULTS: 196 participants were included with 74.0% female, 30.6% African Americans, and 72.9% who completed at least twelfth grade. Discontinuation rates after 18 weeks were 38.8% for donepezil, 53.0% for galantamine, and 58.7% for rivastigmine (P = .063) in the intent to treat analysis. Adverse events and cost explained 73.1% and 25.4% of discontinuation. No participants discontinued donepezil due to cost. Adverse events were reported by 81.2% of all participants; no between-group differences in total adverse events were statistically significant. CONCLUSIONS: This pragmatic comparative trial showed high rates of adverse events and cost-related non-adherence with AChEIs. Interventions improving adherence and persistence to AChEIs may improve AD management. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01362686 (https://clinicaltrials.gov/ct2/show/NCT01362686).Item Altered Cerebral Blood Flow in Older Adults with Alzheimer’s Disease: A Systematic Review(Springer, 2023) Swinford, Cecily G.; Risacher, Shannon L.; Wu, Yu-Chien; Apostolova, Liana G.; Gao, Sujuan; Bice, Paula J.; Saykin, Andrew J.; Radiology and Imaging Sciences, School of MedicineThe prevalence of Alzheimer’s disease is projected to reach 13 million in the U.S. by 2050. Although major efforts have been made to avoid this outcome, so far there are no treatments that can stop or reverse the progressive cognitive decline that defines Alzheimer’s disease. The utilization of preventative treatment before significant cognitive decline has occurred may ultimately be the solution, necessitating a reliable biomarker of preclinical/prodromal disease stages to determine which older adults are most at risk. Quantitative cerebral blood flow is a promising potential early biomarker for Alzheimer’s disease, but the spatiotemporal patterns of altered cerebral blood flow in Alzheimer’s disease are not fully understood. The current systematic review compiles the findings of 81 original studies that compared resting gray matter cerebral blood flow in older adults with mild cognitive impairment or Alzheimer’s disease and that of cognitively normal older adults and/or assessed the relationship between cerebral blood flow and objective cognitive function. Individuals with Alzheimer’s disease had relatively decreased cerebral blood flow in all brain regions investigated, especially the temporoparietal and posterior cingulate, while individuals with mild cognitive impairment had consistent results of decreased cerebral blood flow in the posterior cingulate but more mixed results in other regions, especially the frontal lobe. Most papers reported a positive correlation between regional cerebral blood flow and cognitive function. This review highlights the need for more studies assessing cerebral blood flow changes both spatially and temporally over the course of Alzheimer’s disease, as well as the importance of including potential confounding factors in these analyses.Item Altered Default Mode Network Connectivity in Older Adults with Cognitive Complaints and Amnestic Mild Cognitive Impairment(Sage, 2013) Wang, Yang; Risacher, Shannon L.; West, John D.; McDonald, Brenna C.; MaGee, Tamiko R.; Farlow, Martin R.; Gao, Sujuan; O’Neill, Darren P.; Saykin, Andrew J.; Radiology and Imaging Sciences, School of MedicineDefault mode network (DMN) disruption has been reported in Alzheimer's disease (AD), yet the specific pattern of altered connectivity over the course of prodromal AD remains to be characterized. The aim of this study was to assess DMN connectivity in older adults with informant-verified cognitive complaints (CC) but normal neuropsychological performance compared to individuals with mild cognitive impairment (MCI) and healthy controls (HC). DMN maps were derived from resting-state fMRI using independent component analysis. Group comparisons of DMN connectivity were performed between older adults with MCI (n = 18), CC (n = 23), and HC (n = 16). Both CC and MCI showed decreased DMN connectivity in the right hippocampus compared to HC, with the CC group showing greater connectivity than MCI. These differences survived atrophy correction and correlated with cognitive performance. DMN connectivity appears sensitive to early prodromal neurodegenerative changes associated with AD, notably including pre-MCI individuals with cognitive complaints.Item Alzheimer’s disease multiple intervention trial (ADMIT): study protocol for a randomized controlled clinical trial(Springer Nature, 2012-06-27) Callahan, Christopher M.; Boustani, Malaz A.; Schmid, Arlene A.; Austrom, Mary G.; Miller, Douglas K.; Gao, Sujuan; Morris, Carrie S.; Vogel, Mickey; Hendrie, Hugh C.; Medicine, School of MedicineBackground: Given the current lack of disease-modifying therapies, it is important to explore new models of longitudinal care for older adults with dementia that focus on improving quality of life and delaying functional decline. In a previous clinical trial, we demonstrated that collaborative care for Alzheimer's disease reduces patients' neuropsychiatric symptoms as well as caregiver stress. However, these improvements in quality of life were not associated with delays in subjects' functional decline. Trial design: Parallel randomized controlled clinical trial with 1:1 allocation. Participants: A total of 180 community-dwelling patients aged ≥45 years who are diagnosed with possible or probable Alzheimer's disease; subjects must also have a caregiver willing to participate in the study and be willing to accept home visits. Subjects and their caregivers are enrolled from the primary care and geriatric medicine practices of an urban public health system serving Indianapolis, Indiana, USA. Interventions: All patients receive best practices primary care including collaborative care by a dementia care manager over two years; this best practices primary care program represents the local adaptation and implementation of our prior collaborative care intervention in the urban public health system. Intervention patients also receive in-home occupational therapy delivered in twenty-four sessions over two years in addition to best practices primary care. The focus of the occupational therapy intervention is delaying functional decline and helping both subjects and caregivers adapt to functional impairments. The in-home sessions are tailored to the specific needs and goals of each patient-caregiver dyad; these needs are expected to change over the course of the study. Objective: To determine whether best practices primary care plus home-based occupational therapy delays functional decline among patients with Alzheimer's disease compared to subjects treated in the control group. Outcomes: The primary outcome is the Alzheimer's Disease Cooperative Studies Group Activities of Daily Living Scale; secondary outcome measures are two performance-based measures including the Short Physical Performance Battery and Short Portable Sarcopenia Measure. Outcome assessments for both the caregiver-reported scale and subjects' physical performance scales are completed in the subject's home. Randomization: Eligible patient-care giver dyads will be stratified by clinic type and block randomized with a computer developed randomization scheme using a 1:1 allocation ratio. Blinding: Single blinded. Research assistants completing the outcome assessments were blinded to the subjects' treatment group. Trial status: Ongoing CLINICALTRIAL.GOV IDENTIFIER: NCT01314950; date of completed registration 10 March 2011; date first patient randomized 9 March 2011.Item Amyloid and Tau Pathology are Associated with Cerebral Blood Flow in a Mixed Sample of Nondemented Older Adults with and without Vascular Risk Factors for Alzheimer’s Disease(Elsevier, 2023) Swinford, Cecily G.; Risacher, Shannon L.; Vosmeier, Aaron; Deardorff, Rachael; Chumin, Evgeny J.; Dzemidzic, Mario; Wu, Yu-Chien; Gao, Sujuan; McDonald, Brenna C.; Yoder, Karmen K.; Unverzagt, Frederick W.; Wang, Sophia; Farlow, Martin R.; Brosch, Jared R.; Clark, David G.; Apostolova, Liana G.; Sims, Justin; Wang, Danny J.; Saykin, Andrew J.; Radiology and Imaging Sciences, School of MedicineIdentification of biomarkers for the early stages of Alzheimer's disease (AD) is an imperative step in developing effective treatments. Cerebral blood flow (CBF) is a potential early biomarker for AD; generally, older adults with AD have decreased CBF compared to normally aging peers. CBF deviates as the disease process and symptoms progress. However, further characterization of the relationships between CBF and AD risk factors and pathologies is still needed. We assessed the relationships between CBF quantified by arterial spin-labeled magnetic resonance imaging, hypertension, APOEε4, and tau and amyloid positron emission tomography in 77 older adults: cognitively normal, subjective cognitive decline, and mild cognitive impairment. Tau and amyloid aggregation were related to altered CBF, and some of these relationships were dependent on hypertension or APOEε4 status. Our findings suggest a complex relationship between risk factors, AD pathologies, and CBF that warrants future studies of CBF as a potential early biomarker for AD.Item Anticholinergics Influence Transition from Normal Cognition to Mild Cognitive Impairment in Older Adults in Primary Care(Wiley, 2018) Campbell, Noll L.; Lane, Kathleen A.; Gao, Sujuan; Boustani, Malaz A.; Unverzagt, Fred; Medicine, School of MedicineStudy Objective To determine the influence of anticholinergic medications on transitions in cognitive diagnosis of older adults in primary care. Design This observational cohort study was conducted over a mean follow‐up of 3.2 years. Anticholinergic exposure was defined by pharmacy dispensing and claims records. Cognitive diagnosis was performed by an expert panel at baseline and annually up to 4 years. Data Source Medication exposure and other clinical data were extracted from the Indiana Network for Patient Care (INPC). The cognitive diagnosis was derived from a cognitive screening and diagnosis study. Participants A total of 350 adults 65 years and older without dementia and receiving primary care in a safety net health care system. Measurement and Main Results Cognitive diagnosis followed a two‐phase screening and consensus‐based neuropsychiatric examination to determine a baseline diagnosis as normal cognition, mild cognitive impairment (MCI), or dementia, with a follow‐up neuropsychiatric examination and consensus‐based diagnosis repeated annually. The Anticholinergic Cognitive Burden scale was used to identify anticholinergics dispensed up to 10 years before enrollment and annually throughout the study. A total standard daily dose of anticholinergics was calculated by using pharmacy dispensing data from the INPC. Among 350 participants, a total of 978 diagnostic assessments were completed over a mean follow‐up of 3.2 years. Compared with stable cognition, increasing use of strong anticholinergics calculated by total standard daily dose increased the odds of transition from normal cognition to MCI (odds ratio [OR] 1.15, 95% confidence interval [CI] 1.01–1.31, p = 0.0342). Compared with stable MCI, strong anticholinergics did not influence the reversion of MCI to normal cognition (OR 0.95, 95% CI 0.86–1.05, p = 0.3266). Conclusion De‐prescribing interventions in older adults with normal cognition should test anticholinergics as potentially modifiable risk factors for cognitive impairment.