Biomedical subjects

JoAnn T Tschanz

Publications and source records attributed to JoAnn T Tschanz.

11 recordsLinked to original sources

PubMed2006

Antihypertensive medication use and incident Alzheimer disease: the Cache County Study.

BACKGROUND: Recent reports suggest that antihypertensive (AH) medications may reduce the risk of dementing illnesses. OBJECTIVES: To examine the relationship of AH medication use with incidence of Alzheimer disease (AD) among the elderly population (aged 65 years and older) of Cache County, Utah, and to examine whether the relationship varies with different classes of AH medications. METHODS: After an initial (wave 1) multistage assessment (1995 through 1997) to identify prevalent cases of dementia, we used similar methods 3 years later (wave 2) to identify 104 incident cases of AD among the 3308 survivors. At the baseline assessment, we obtained a detailed drug inventory from the study participants. We carried out discrete time survival analyses to examine the association between the use of AH medications (including angiotensin converting enzyme inhibitors, beta-blockers, calcium channel blockers, and diuretics) at baseline with subsequent risk of AD. RESULTS: Use of any AH medication at baseline was associated with lower incidence of AD (adjusted hazard ratio, 0.64; 95% confidence interval, 0.41-0.98). Examination of medication subclasses showed that use of diuretics (adjusted hazard ratio, 0.57; 95% confidence interval, 0.33-0.94), and specifically potassium-sparing diuretics (adjusted hazard ratio, 0.26; 95% confidence interval, 0.08-0.64), was associated with the greatest reduction in risk of AD. Corresponding analysis with a fully examined subsample controlling for blood pressure measurements did not substantially change our findings. CONCLUSIONS: These data suggest that AH medications, and specifically potassium-sparing diuretics, are associated with reduced incidence of AD. Because the latter association is a new finding, it requires confirmation in further study.

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PubMed2006

Gender differences in the association between religious involvement and depression: the Cache County (Utah) study.

We examined the relation between religious involvement, membership in the Church of Jesus Christ of Latter-Day Saints, and major depression in a population-based study of aging and dementia in Cache County, Utah. Participants included 4,468 nondemented individuals between the ages of 65 and 100 years who were interviewed in person. In logistic regression models adjusting for demographic and health variables, frequent church attendance was associated with a reduced prevalence of depression in women but increased prevalence in men. Social role loss and the potential impact of organizational power differential by sex are discussed. Though causality cannot be determined here, these findings suggest that the association between religious involvement and depression may differ substantially between men and women.

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PubMed2005

Apolipoprotein E genotype and mortality: findings from the Cache County Study.

OBJECTIVES: To evaluate the association between apolipoprotein E (apo E) epsilon4 and mortality, the population attributable risk for mortality with epsilon4, and relative contributions of cardiovascular disease (CVD) and Alzheimer's disease (AD). DESIGN: Population-based cohort study. SETTING: Community-based. PARTICIPANTS: Permanent residents of Cache County, Utah, aged 65 and older as of January 1, 1995. MEASUREMENTS: Participants were genotyped at the apo E locus using buccal-swab deoxyribonucleic acid. Cardiovascular health was ascertained using self- or proxy-report interviews at participants' residences. AD was diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised, and National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders criteria. Utah Department of Vital Statistics quarterly reports were reviewed to identify participants who died. RESULTS: Crude evaluations showed nonsignificantly greater risk of death for epsilon2/2 (hazard ratio (HR)=1.66, 95% confidence interval (CI)=0.92-2.76) and epsilon3/4 (HR=1.11, 95% CI=0.97-1.26) genotypes and significantly greater risk for epsilon4/4 (HR=1.48, 95% CI=1.09-1.96). After adjustment for age, age(2), sex, and education, risks increased to 1.98 (95% CI=1.08-3.35), 1.28 (95% CI=1.12-1.46), and 2.02 (95% CI=1.47-2.71), respectively, compared with epsilon3/3 genotypes. Adjustment for presence of any CVD did not change the risk of death for epsilon3/4 and epsilon4/4. Adjustment for AD reduced the risk of death for epsilon3/4 (HR=1.13, 95% CI=0.99-1.30) and epsilon4/4 (HR=1.59, 95% CI=1.15-2.14). The population attributable risk of death for epsilon3/4 and epsilon4/4 genotypes combined is estimated at 9.6%. CONCLUSION: These findings suggested that the epsilon2/2, epsilon3/4, and epsilon4/4 genotypes have greater early mortality risks. Further analyses showed that AD partially mediates the association between epsilon3/4, epsilon4/4, and death.

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PubMed2004

Reduced risk of Alzheimer disease in users of antioxidant vitamin supplements: the Cache County Study.

BACKGROUND: Antioxidants may protect the aging brain against oxidative damage associated with pathological changes of Alzheimer disease (AD). OBJECTIVE: To examine the relationship between antioxidant supplement use and risk of AD. DESIGN: Cross-sectional and prospective study of dementia. Elderly (65 years or older) county residents were assessed in 1995 to 1997 for prevalent dementia and AD, and again in 1998 to 2000 for incident illness. Supplement use was ascertained at the first contact. SETTING: Cache County, Utah. PARTICIPANTS: Among 4740 respondents (93%) with data sufficient to determine cognitive status at the initial assessment, we identified 200 prevalent cases of AD. Among 3227 survivors at risk, we identified 104 incident AD cases at follow-up. MAIN OUTCOME MEASURE: Diagnosis of AD by means of multistage assessment procedures. RESULTS: Analyses of prevalent and incident AD yielded similar results. Use of vitamin E and C (ascorbic acid) supplements in combination was associated with reduced AD prevalence (adjusted odds ratio, 0.22; 95% confidence interval, 0.05-0.60) and incidence (adjusted hazard ratio, 0.36; 95% confidence interval, 0.09-0.99). A trend toward lower AD risk was also evident in users of vitamin E and multivitamins containing vitamin C, but we saw no evidence of a protective effect with use of vitamin E or vitamin C supplements alone, with multivitamins alone, or with vitamin B-complex supplements. CONCLUSIONS: Use of vitamin E and vitamin C supplements in combination is associated with reduced prevalence and incidence of AD. Antioxidant supplements merit further study as agents for the primary prevention of AD.

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PubMed2004

The persistence of neuropsychiatric symptoms in dementia: the Cache County Study.

OBJECTIVE: To estimate the 18-month persistence of neuropsychiatric symptoms in dementia in a population-based sample, and to compare the severity of neuropsychiatric symptoms at baseline to the severity at 18-month follow-up. METHODS: A population-based sample of 329 residents of Cache County, Utah, diagnosed with dementia was rated on the Neuropsychiatric Inventory (NPI). Of the 204 participants with neuropsychiatric symptoms at baseline (defined as total NPI score >0), NPI data were obtained approximately 18 months later on 117 who were alive and available for follow-up. RESULTS: Eighty-one percent of those with neuropsychiatric symptoms at baseline (defined as total NPI score>0) continued to have at least one symptom at follow-up. Sixty-seven percent of participants with a clinically significant total NPI score (defined as > or = 4) at baseline continued to have a clinically significant total NPI score at follow-up. Among the ten neuropsychiatric domains assessed at baseline, delusions persisted in 65.5% of individuals, followed by depression (58.3%), and aberrant motor behavior (55.6%), while hallucinations and disinhibition persisted in only 25.0% and 11.1% respectively. In participants who were symptomatic at both baseline and follow-up, the mean severity scores at the two observation points were comparable in all ten neuropsychiatric domains. CONCLUSIONS: Neuropsychiatric symptoms in dementia overall were highly persistent. Among those in whom symptoms did persist, symptom severity a year and a half later appeared to be comparable.

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PubMed2003

Characteristics of a two-stage screen for incident dementia.

BACKGROUND AND OBJECTIVES: To avoid costly evaluation of healthy individuals, efficient methods of screening for incident dementia must combine adequate sensitivity and high specificity. Two-stage screening may offer improvements over single-stage methods. We therefore investigated a two-stage screening protocol for incident dementia among 3,308 elderly. METHODS: We administered the Modified Mini-Mental-State (3MS) or, rarely, Jorm's IQCODE, to a validation sample of 441 high-risk respondents. Informants then completed the Dementia Questionnaire (DQ). Finally, all 441 sample members underwent physical, neurologic, and neuropsychologic assessment. We studied the sensitivity and specificity of the 3MS/IQCODE and DQ using Receiver-Operating Characteristic analyses. RESULTS: A 3MS cut point of 82/83 (of 100) yielded sensitivity and specificity of 91.5 and 90.1%. With 3MS scores of < or =82, a DQ cut point of 2/3 (of five) yielded conditional sensitivity and specificity of 90.2 and 55.3%. Combining these instruments yielded sensitivity and specificity of 82.5 and 95.6%. Age stratification and use of longitudinal decline score criteria did not materially improve these figures. CONCLUSIONS: The improved specificity of the two-stage approach offers economies that are attractive, particularly if sensitivity can be enhanced, for example, by examination of a high-risk validation sample.

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PubMed2003

Role of white matter lesions, cerebral atrophy, and APOE on cognition in older persons with and without dementia: the Cache County, Utah, study of memory and aging.

Neuropsychological, qualitative, and quantitative magnetic resonance imaging findings were examined in subjects with Alzheimer's disease (AD), non-AD dementia or mixed neuropsychiatric disorder, subjects characterized as mild/ambiguous, and controls, all with known apolipoprotein E (APOE) genotype. Neuropsychological tasks included an expanded Consortium to Establish a Registery for Alzheimer's Disease (J. T. Tschanz et al., 2000; K. A. Welsh, J. M. Hoffman, N. L. Earl, & M. W. Hanson 1994) battery and the Mini-Mental Status Examination (M. F. Folstein, S. E. Folstein, & P. R. McHugh, 1975). Periventricular white matter lesions were the most clinically salient, and generalized measures of cerebral atrophy were the most significant quantitative indicators. APOE genotype was unrelated to imaging or neuropsychological performance. Neuropsychological relationships with neuroimaging findings depend on the qualitative or quantitative method used.

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PubMed2003

The incidence of mental and behavioral disturbances in dementia: the cache county study.

A population-based prevalence sample of 355 residents of Cache County, Utah, who were diagnosed with dementia, was rated on the Neuropsychiatric Inventory (NPI). Of the 355 residents, 119 had no neuropsychiatric symptoms at baseline and were, consequently, at risk for incident mental and behavioral disturbances. The NPI was readministered approximately 18 months later to 61 surviving participants. Sixty-nine percent developed at least one mental or behavioral symptom. Delusions were most common (28%), followed by apathy (21%), and aberrant motor behavior (21%). When this incidence rate of 69% was combined with a previously estimated prevalence rate of 61%, the cumulative 18-month prevalence approached 90%. These results argue for a routine assessment of psychiatric disturbances in all patients with dementia, even among those who have never experienced symptoms of mental or behavioral disturbances.

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PubMed2002

An adaptation of the modified mini-mental state examination: analysis of demographic influences and normative data: the cache county study.

OBJECTIVES: To present a new version of the Modified Mini-Mental State Examination (3MS-R), provide normative information extending to individuals in the 10th decade, and examine the effects of demographic variables on test performance. BACKGROUND: The Modified Mini-Mental State Examination, based originally on the Mini-Mental State Examination, has been used to screen populations for dementia. Providing normative information and an analysis of demographic variables on test performance for this version would support broader use in clinical and other settings. METHODS: Two thousand, nine hundred thirteen elderly individuals determined to be free of dementia and other neurologic and psychiatric conditions served as subjects. An analysis of variance was conducted to examine the effects of age, gender, and education on test performance. Descriptive statistics (means, standard deviations, and percentile ranks) were calculated to summarize the range of normal performance. To examine the sensitivity/specificity of the suggested cut-off points at the 7th and 10th percentiles, two subsamples of elderly individuals, on whom clinical dementia assessments were available, were used to classify individuals with regard to dementia status. RESULTS: Lower age, higher education, and female gender were associated with higher 3MS-R scores. Gender effects were among the weakest, but most important at lower levels of education. Education effects were most prominent in the youngest age groups. Selection of a cut-off point at the 7th percentile revealed 69%-70% sensitivity for detecting dementia, and higher sensitivity for individuals in the youngest age groups. Specificity at this cut-off point was 89%. Raising the cut-off point to the 10th percentile improved sensitivity to 73%-76%, but reduced specificity to 85%-86%. CONCLUSION: We present a version of the Modified Mini-Mental State Examination that has demonstrated utility in screening a population for dementia. An analysis of normative information and the effects of demographic influences suggest that the 7th percentile cut-off point performs very well in detecting dementia in 65-79-year-old individuals but less well for individuals in their 80s and 90s. To increase the sensitivity of the 3MS-R to detect dementia or other forms of cognitive impairment, particularly among the "old-old," the test user may wish to raise the cut-off point for impairment in some demographic groups or to supplement the test with additional cognitive measures.

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PubMedDate not supplied

H2 histamine receptor blockade in the treatment of Alzheimer disease: a randomized, double-blind, placebo-controlled trial of nizatidine.

OBJECTIVES: To evaluate the efficacy of nizatidine, a histamine H2-blocking drug, in delaying the progression of cognitive impairment in older adults with Alzheimer disease (AD). DESIGN: A one-year, randomized, double-blind, placebo-controlled trial. PARTICIPANTS: Fifty-one older men and women aged 67 to 96 years with AD were recruited from the Cache County Study on Memory in Aging. METHODS: Patients were stratified by age and by the presence of one or more epsilon 4 alleles at the APOE locus, then randomized to receive nizatidine 75 mg (Axid ARTM, Whitehall Robins) or a matching placebo tablet twice daily. Cognitive outcomes were assessed at baseline, six, and twelve months after enrollment using tests from the CERAD battery and additional measures of visuospatial memory, verbal memory, and verbal fluency. RESULTS: Subjects showed significant declines in language, fluency, and praxis but most measures of memory had already "bottomed out." Intention-to-treat and compliance-based analyses showed no effect of nizatidine on any of the cognitive outcome measures over the one-year study interval. CONCLUSIONS: These results do not support claims for the efficacy of nizatidine in over-the-counter dosages as a means of preventing symptom progression in AD.

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PubMedDate not supplied

Vascular risk factors for incident Alzheimer disease and vascular dementia: the Cache County study.

Vascular risk factors for Alzheimer disease (AD) and vascular dementia (VaD) have been evaluated; however, few studies have compared risks by dementia subtypes and sex. We evaluated relationships between cardiovascular risk factors (hypertension, high cholesterol, diabetes mellitus, and obesity), events (stroke, coronary artery bypass graft surgery, and myocardial infarction), and subsequent risk of AD and VaD by sex in a community-based cohort of 3264 Cache County residents aged 65 or older. Cardiovascular history was ascertained by self-report or proxy-report in detailed interviews. AD and VaD were diagnosed using standard criteria. Estimates from discrete-time survival models showed no association between self-reported history of hypertension and high cholesterol and AD after adjustments. Hypertension increased the risk of VaD [adjusted hazard ratio (aHR) 2.42, 95% confidence interval (CI) 0.95-7.44]. Obesity increased the risk of AD in females (aHR 2.23, 95% CI 1.09-4.30) but not males. Diabetes increased the risk of VaD in females after adjustments (aHR 3.33, 95% CI 1.03-9.78) but not males. The risk of VaD after stroke was increased in females (aHR 16.90, 95% CI 5.58-49.03) and males (aHR 10.95, 95% CI 2.48-44.78). The results indicate that vascular factors increase risks for AD and VaD differentially by sex. Future studies should focus on specific causal pathways for each of these factors with regard to sex to determine if sex differences in the prevalence of vascular factors have an influence on sex differences in dementia risk.

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