Browsing by Author "Gao, Qi"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Does the Cognitive Change Index Predict Future Cognitive and Clinical Decline? Longitudinal Analysis in a Demographically Diverse Cohort
    (Sage, 2024) Nester, Caroline O.; Gao, Qi; Katz, Mindy J.; Mogle, Jacqueline A.; Wang, Cuiling; Derby, Carol A.; Lipton, Richard B.; Saykin, Andrew J.; Rabin, Laura A.; Radiology and Imaging Sciences, School of Medicine
    Background: The Cognitive Change Index (CCI) is a widely-used measure of self-perceived cognitive ability and change. Unfortunately, it is unclear if the CCI predicts future cognitive and clinical decline. Objective: We evaluated baseline CCI to predict transition from normal cognition to cognitive impairment in nondemented older adults and in predementia groups including, subjective cognitive decline, motoric cognitive risk syndrome, and mild cognitive impairment. Different versions of the CCI were assessed to uncover any differential risk sensitivity. We also examined the effect of ethnicity/race on CCI. Methods: Einstein Aging Study participants (N = 322, Mage = 77.57±4.96, % female=67.1, Meducation = 15.06±3.54, % non-Hispanic white = 46.3) completed an expanded 40-item CCI version (CCI-40) and neuropsychological evaluation (including Clinical Dementia Rating Scale [CDR], Montreal Cognitive Assessment, and Craft Story) at baseline and annual follow-up (Mfollow - up=3.4 years). CCI-40 includes the original 20 items (CCI-20) and the first 12 memory items (CCI-12). Linear mixed effects models (LME) and generalized LME assessed the association of CCI total scores at baseline with rate of decline in neuropsychological tests and CDR. Results: In the overall sample and across predementia groups, the CCI was associated with rate of change in log odds on CDR, with higher CCI at baseline predicting faster increase in the odds of being impaired on CDR. The predictive validity of the CCI broadly held across versions (CCI-12, 20, 40) and ethnic/racial groups (non-Hispanic black and white). Conclusions: Self-perception of cognitive change on the CCI is a useful marker of dementia risk in demographically/clinically diverse nondemented samples. All CCI versions successfully predicted decline.
  • Thumbnail Image
    Item
    Simulation of Turing Machine with uEAC-Computable Functions
    (Hindawi, 2015) Zhu, Yilin; Pan, Feng; Li, Lingxi; Ren, Xuemei; Gao, Qi; Department of Electrical and Computer Engineering, School of Engineering and Technology
    The micro-Extended Analog Computer (uEAC) is an electronic implementation inspired by Rubel’s EAC model. In this study, a fully connected uEACs array is proposed to overcome the limitations of a single uEAC, within which each uEAC unit is connected to all the other units by some weights. Then its computational capabilities are investigated by proving that a Turing machine can be simulated with uEAC-computable functions, even in the presence of bounded noise.
  • Thumbnail Image
    Item
    Use of Antihypertensives, Blood Pressure, and Estimated Risk of Dementia in Late Life: An Individual Participant Data Meta-Analysis
    (American Medical Association, 2023-09-05) Lennon, Matthew J.; Lam, Ben Chun Pan; Lipnicki, Darren M.; Crawford, John D.; Peters, Ruth; Schutte, Aletta E.; Brodaty, Henry; Thalamuthu, Anbupalam; Rydberg-Sterner, Therese; Najar, Jenna; Skoog, Ingmar; Riedel-Heller, Steffi G.; Röhr, Susanne; Pabst, Alexander; Lobo, Antonio; De-la-Cámara, Concepción; Lobo, Elena; Bello, Toyin; Gureje, Oye; Ojagbemi, Akin; Lipton, Richard B.; Katz, Mindy J.; Derby, Carol A.; Kim, Ki Woong; Han, Ji Won; Oh, Dae Jong; Rolandi, Elena; Davin, Annalisa; Rossi, Michele; Scarmeas, Nikolaos; Yannakoulia, Mary; Dardiotis, Themis; Hendrie, Hugh C.; Gao, Sujuan; Carrière, Isabelle; Ritchie, Karen; Anstey, Kaarin J.; Cherbuin, Nicolas; Xiao, Shifu; Yue, Ling; Li, Wei; Guerchet, Maëlenn M.; Preux, Pierre-Marie; Aboyans, Victor; Haan, Mary N.; Aiello, Allison E.; Ng, Tze Pin; Nyunt, Ma Shwe Zin; Gao, Qi; Scazufca, Marcia; Sachdev, Perminder S. S.; Psychiatry, School of Medicine
    Importance: The utility of antihypertensives and ideal blood pressure (BP) for dementia prevention in late life remains unclear and highly contested. Objectives: To assess the associations of hypertension history, antihypertensive use, and baseline measured BP in late life (age >60 years) with dementia and the moderating factors of age, sex, and racial group. Data source and study selection: Longitudinal, population-based studies of aging participating in the Cohort Studies of Memory in an International Consortium (COSMIC) group were included. Participants were individuals without dementia at baseline aged 60 to 110 years and were based in 15 different countries (US, Brazil, Australia, China, Korea, Singapore, Central African Republic, Republic of Congo, Nigeria, Germany, Spain, Italy, France, Sweden, and Greece). Data extraction and synthesis: Participants were grouped in 3 categories based on previous diagnosis of hypertension and baseline antihypertensive use: healthy controls, treated hypertension, and untreated hypertension. Baseline systolic BP (SBP) and diastolic BP (DBP) were treated as continuous variables. Reporting followed the Preferred Reporting Items for Systematic Review and Meta-Analyses of Individual Participant Data reporting guidelines. Main outcomes and measures: The key outcome was all-cause dementia. Mixed-effects Cox proportional hazards models were used to assess the associations between the exposures and the key outcome variable. The association between dementia and baseline BP was modeled using nonlinear natural splines. The main analysis was a partially adjusted Cox proportional hazards model controlling for age, age squared, sex, education, racial group, and a random effect for study. Sensitivity analyses included a fully adjusted analysis, a restricted analysis of those individuals with more than 5 years of follow-up data, and models examining the moderating factors of age, sex, and racial group. Results: The analysis included 17 studies with 34 519 community dwelling older adults (20 160 [58.4%] female) with a mean (SD) age of 72.5 (7.5) years and a mean (SD) follow-up of 4.3 (4.3) years. In the main, partially adjusted analysis including 14 studies, individuals with untreated hypertension had a 42% increased risk of dementia compared with healthy controls (hazard ratio [HR], 1.42; 95% CI 1.15-1.76; P = .001) and 26% increased risk compared with individuals with treated hypertension (HR, 1.26; 95% CI, 1.03-1.53; P = .02). Individuals with treated hypertension had no significant increased dementia risk compared with healthy controls (HR, 1.13; 95% CI, 0.99-1.28; P = .07). The association of antihypertensive use or hypertension status with dementia did not vary with baseline BP. There was no significant association of baseline SBP or DBP with dementia risk in any of the analyses. There were no significant interactions with age, sex, or racial group for any of the analyses. Conclusions and relevance: This individual patient data meta-analysis of longitudinal cohort studies found that antihypertensive use was associated with decreased dementia risk compared with individuals with untreated hypertension through all ages in late life. Individuals with treated hypertension had no increased risk of dementia compared with healthy controls.