Browsing by Author "Callahan, Chris M."

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    Changes of glucose levels precede dementia in African Americans with diabetes but not in Caucasians
    (Elsevier, 2018-12) Hendrie, Hugh C.; Zheng, Mengjie; Lane, Kathleen A.; Ambuehl, Roberta; Purnell, Christianna; Li, Shanshan; Unverzagt, Frederick W.; Murray, Michael D.; Balasubramanyam, Ashok; Callahan, Chris M.; Gao, Sujuan; Psychiatry, School of Medicine
    INTRODUCTION Changes in glucose levels may represent a powerful metabolic indicator for dementia in African Americans with diabetes. It is unclear whether these changes also occur in Caucasians. METHODS A secondary data analysis using electronic medical records from 5228 African Americans and Caucasians 65 years and older. Mixed effects models with repeated serum glucose measurements were used to compare changes in glucose levels between African Americans and Caucasian patients with and without incident dementia. RESULTS African Americans and Caucasians with diabetes had significantly different changes in glucose levels by dementia status (p<0.0001). African Americans experienced a significant decline in glucose levels before the dementia diagnosis (estimated glucose decline 1.3421 mg/dL per year, p<0.0001) than those who did not develop dementia. Caucasians with and without dementia showed stable glucose levels over time (p=0.3071). DISCUSSION Significant changes in glucose levels precede dementia in African American patients with diabetes but not in Caucasians.
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    Glucose level decline precedes dementia in elderly African Americans with diabetes
    (Elsevier, 2017-02) Hendrie, Hugh C.; Zheng, Mengjie; Li, Wei; Lane, Kathleen; Ambuehl, Roberta; Purnell, Christianna; Unverzagt, Frederick W.; Torke, Alexia; Balasubramanyam, Ashok; Callahan, Chris M.; Gao, Sujuan; Psychiatry, School of Medicine
    INTRODUCTION: High blood glucose levels may be responsible for the increased risk for dementia in diabetic patients. METHODS: A secondary data analysis merging electronic medical records (EMRs) with data collected from the Indianapolis-Ibadan Dementia project (IIDP). Of the enrolled 4105 African Americans, 3778 were identified in the EMR. Study endpoints were dementia, mild cognitive impairment (MCI), or normal cognition. Repeated serum glucose measurements were used as the outcome variables. RESULTS: Diabetic participants who developed incident dementia had a significant decrease in serum glucose levels in the years preceding the diagnosis compared to the participants with normal cognition (P = .0002). They also had significantly higher glucose levels up to 9 years before the dementia diagnosis (P = .0367). DISCUSSION: High glucose levels followed by a decline occurring years before diagnosis in African American participants with diabetes may represent a powerful presymptomatic metabolic indicator of dementia.
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    Incidence of Dementia and Alzheimer Disease Over Time: A Meta-Analysis
    (Wiley, 2019-06-20) Gao, Sujuan; Burney, Heather N.; Callahan, Chris M.; Purnell, Christianna E.; Hendrie, Hugh C.; Biostatistics, School of Public Health
    Background/Objectives: Population-based incidence estimates of dementia and Alzheimer’s disease (AD) provide important information for public health policy and resource allocation. We conducted a meta-analysis of published studies that reported age-specific incidence rates of dementia and AD to determine whether dementia and AD incidence rates are changing over time. Design: PubMed and MEDLINE were searched for publications through June 30, 2017 using keywords dementia, Alzheimer, and incidence. Inclusion criteria for the meta-analysis are: (1) population-based studies using personal interviews and direct examinations of the study subjects, (2) Standardized clinical diagnosis criteria, (3) Reporting age-specific incidence rates, (4) Published in English, and (5) Sample size greater or equal to 500 and length of follow-up greater or equal than two years. Mixed effects models were used to determine the association between birth year and incidence rates. Measurements: Age-specific dementia/AD incidence rates and their standard errors reported in each study. Results: Thirty-eight articles with 53 cohorts on dementia incidence and 31 articles with 35 cohorts on AD incidence met the inclusion criteria. There were significant associations between later birth years and decreased dementia incidence rates in all three age groups (65-74, 75-84 and 85+). There were no significant associations between birth year and AD incident rates in any of the three age groups. In particular, AD incidence rates reported from Western countries stayed steady in all age groups while studies in non-Western countries showed significantly increased AD incidence rates for the 65-74 age group (OR=2.78, p=0.04), but non-significant association for the 75-84 or 85+ groups. Conclusion: Dementia incidence declined over the last four decades, but AD incidence did not decline. Further research, especially from non-Western countries, is needed to elucidate the mechanism underlying the trends in dementia and AD incidence over time.
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    Medication adherence and tolerability of Alzheimer’s disease medications: study protocol for a randomized controlled trial
    (BMC, 2013-05-04) Campbell, Noll L.; Dexter, Paul; Perkins, Anthony J.; Gao, Sujuan; Li, Lang; Skaar, Todd C.; Frame, Amie; Hendrie, Hugh C.; Callahan, Chris M.; Boustani, Malaz A.
    Background: The class of acetylcholinesterase inhibitors (ChEI), including donepezil, rivastigmine, and galantamine, have similar efficacy profiles in patients with mild to moderate Alzheimer's disease (AD). However, few studies have evaluated adherence to these agents. We sought to prospectively capture the rates and reasons for nonadherence to ChEI and determine factors influencing tolerability and adherence. Methods/design: We designed a pragmatic randomized clinical trial to evaluate the adherence to ChEIs among older adults with AD. Participants include AD patients receiving care within memory care practices in the greater Indianapolis area. Participants will be followed at 6-week intervals up to 18 weeks to measure the primary outcome of ChEI discontinuation and adherence rates and secondary outcomes of behavioral and psychological symptoms of dementia. The primary outcome will be assessed through two methods, a telephone interview of an informal caregiver and electronic medical record data captured from each healthcare system through a regional health information exchange. The secondary outcome will be measured by the Healthy Aging Brain Care Monitor and the Neuropsychiatric Inventory. In addition, the trial will conduct an exploratory evaluation of the pharmacogenomic signatures for the efficacy and the adverse effect responses to ChEIs. We hypothesized that patient-specific factors, including pharmacogenomics and pharmacokinetic characteristics, may influence the study outcomes. Discussion: This pragmatic trial will engage a diverse population from multiple memory care practices to evaluate the adherence to and tolerability of ChEIs in a real world setting. Engaging participants from multiple healthcare systems connected through a health information exchange will capture valuable clinical and non-clinical influences on the patterns of utilization and tolerability of a class of medications with a high rate of discontinuation.