Browsing by Author "Gao, Su"

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    Statin Use, Incident Dementia and Alzheimer Disease in Elderly African Americans
    (International Society on Hypertension in Blacks, 2015) Hendrie, Hugh C.; Hake, Ann; Lane, Kathleen; Purnell, Christianna; Unverzagt, Frederick; Smith-Gamble, Valerie; Murrell, Jill; Ogunniyi, Adesola; Baiyewu, Olusegun; Callahan, Chris; Saykin, Andrew J.; Taylor, Stanley; Hall, Kathleen; Gao, Su; Department of Neurology, IU School of Medicine
    OBJECTIVE: To investigate the association between statin use, incident dementia, and Alzheimer disease (AD) in a prospective elderly African American cohort. DESIGN: Two stage design with a screening interview followed by a comprehensive in-home assessment conducted over an eight-year period. Diagnoses of incident AD and dementia were made by consensus. Statin use was collected at each evaluation. Measurements of low-density lipoprotein cholesterol (LDL), C-reactive protein (CRP) and APOE genotype were obtained from baseline blood samples. Logistic regression models were used to test the association of statin use on incident dementia and AD and its possible association with lipid and CRP levels. SETTING: Indianapolis, Indiana. PARTICIPANTS: From an original cohort of 2629 participants, a subsample of 974 African Americans aged >70 years with normal cognition, at least one follow up evaluation, complete statin information, and biomarker availability were included. MAIN OUTCOME MEASURES: Incident dementia and incident AD. RESULTS: After controlling for age at diagnosis, sex, education level, presence of the APOE ε4 allele and history of stroke for the incident dementia model, baseline use of statins was associated with a significantly decreased risk of incident dementia (OR=.44, P=.029) and incident AD (OR=.40, P=.029). The significant effect of statin use on reduced AD risk and trend for dementia risk was found only for those participants who reported consistent use over the observational period (incident AD: P=.034; incident dementia: P=.061). Additional models found no significant interaction between baseline statin use, baseline LDL, or CRP level and incident dementia/AD. CONCLUSIONS: Consistent use of statin medications during eight years of follow-up resulted in significantly reduced risk for incident AD and a trend toward reduced risk for incident dementia.
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    Variants in the Mitochondrial Intermediate Peptidase (MIPEP) Gene are Associated with Gray Matter Density in the Alzheimer’s Disease Neuroimaging Initiative Cohort
    (Office of the Vice Chancellor for Research, 2015-04-17) Nudelman, Kelly N. H.; Risacher, Shannon L.; West, John D.; McDonald, Brenna C.; Gao, Su; Saykin, Andrew J.
    Cancer and Alzheimer’s disease (AD) incidence is inversely correlated, but the genetic underpinnings of this relationship remain to be elucidated. Recent findings identified lower gray matter density in frontal regions of participants of the Alzheimer’s Disease Neuroimaging Initiative (ADNI) with cancer history compared to those without such history, across diagnostic groups (Nudelman et al., 2014). Pathways proposed to impact cancer and AD, including metabolism and survival, may play an important role in the observed difference. To test this hypothesis, a genome-wide association study (GWAS) using mean frontal gray matter cluster values was performed for all Caucasian participants in this cohort with neuroimaging and genetic data (n=1405). Analysis covaried for age, sex, AD, and cancer history. Of the two genes with the most significant SNPs (p<10-5), WD repeat domain 5B (WDR5B) and mitochondrial intermediate peptidase (MIPEP), MIPEP was selected for further analysis given the hypothesis focus on metabolism. ANOVA analysis of MIPEP top SNP rs8181878 with frontal gray matter cluster values in SPSS indicated that while this SNP is significantly associated with gray matter density (p=2x10-6), no interaction was observed with cancer history or AD diagnosis. Furthermore, whole brain gray matter voxel-wise analysis of this SNP using Statistical Parametric Mapping 8 software showed that minor allele(s) of this SNP were significantly (PFWE<0.05) associated with higher gray matter density. These results suggest that the minor allele of MIPEP SNP rs8181878 may be protective against gray matter density loss, highlighting the importance of metabolic processes in aging and disease.