Alzheimer Disease: Plassman BL

Jarvik L, LaRue A, Blacker D, Gatz M, Kawas C, McArdle JJ, Morris JC, Mortimer JA, Ringman JM, Ercoli L, Freimer N, Gokhman I, Manly JJ, Plassman BL, Rasgon N, Roberts JS, Sunderland T, Swan GE, Wolf PA, Zonderman AB. · Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA 90095, USA. · Alzheimer Dis Assoc Disord. · Pubmed #18317242 No free full text.

Abstract: Children of persons with Alzheimer disease (AD), as a group, face an increased risk of developing AD. Many of them, throughout their adult lives, seek input on how to reduce their chances of one day suffering their parent's fate. We examine the state of knowledge with respect to risk and protective factors for AD and recommend a research agenda with special emphasis on AD offspring.

Wang CS, Burke JR, Steffens DC, Hulette CM, Breitner JC, Plassman BL. · Department of Psychiatry, Tainan Hospital, Department of Health, Taiwan. · J Neurol Neurosurg Psychiatry. · Pubmed #19372291 No free full text.

Abstract: AIM: Little is known about the concordance rate in twins for dementia with Lewy bodies (DLB). The rate of agreement between clinical and pathological diagnoses for DLB is typically low, necessitating confirmation of the diagnosis neuropathologically. METHODS: Participants were 17 twin pairs enrolled in the Duke Twins Study of Memory in Aging in which at least one member of the pair had an autopsy confirmed diagnosis of DLB, Alzheimer's disease (AD) with Lewy bodies or frontotemporal dementia with Lewy bodies. The characteristics of those with dementia were assessed and rates of concordance for pathological confirmed dementia were examined. RESULTS: Four monozygotic twin pairs had a proband with neuropathologically confirmed pure DLB; all remained discordant for dementia for periods up to 16 years or more. Five of 13 pairs in which the proband had AD plus DLB were concordant for dementia but only one pair was concordant for AD plus DLB, while the co-twins in the other four pairs had other types of dementia. CONCLUSIONS: The present study indicates that even among twins, a diagnosis of DLB in one twin does not predict the same diagnosis in the other twin. Neuropathological discordance in type of dementia among monozygotic pairs hints at environmental or epigenetic factors playing a role in Lewy body pathology.

Plassman BL, Langa KM, Fisher GG, Heeringa SG, Weir DR, Ofstedal MB, Burke JR, Hurd MD, Potter GG, Rodgers WL, Steffens DC, McArdle JJ, Willis RJ, Wallace RB. · Duke University Medical Center, Durham, North Carolina 27701, USA. · Ann Intern Med. · Pubmed #18347351 links to  free full text

Abstract: BACKGROUND: Cognitive impairment without dementia is associated with increased risk for disability, increased health care costs, and progression to dementia. There are no population-based prevalence estimates of this condition in the United States. OBJECTIVE: To estimate the prevalence of cognitive impairment without dementia in the United States and determine longitudinal cognitive and mortality outcomes. DESIGN: Longitudinal study from July 2001 to March 2005. SETTING: In-home assessment for cognitive impairment. PARTICIPANTS: Participants in ADAMS (Aging, Demographics, and Memory Study) who were age 71 years or older drawn from the nationally representative HRS (Health and Retirement Study). Of 1770 selected individuals, 856 completed initial assessment, and of 241 selected individuals, 180 completed 16- to 18-month follow-up assessment. MEASUREMENTS: Assessments, including neuropsychological testing, neurologic examination, and clinical and medical history, were used to assign a diagnosis of normal cognition, cognitive impairment without dementia, or dementia. National prevalence rates were estimated by using a population-weighted sample. RESULTS: In 2002, an estimated 5.4 million people (22.2%) in the United States age 71 years or older had cognitive impairment without dementia. Prominent subtypes included prodromal Alzheimer disease (8.2%) and cerebrovascular disease (5.7%). Among participants who completed follow-up assessments, 11.7% with cognitive impairment without dementia progressed to dementia annually, whereas those with subtypes of prodromal Alzheimer disease and stroke progressed at annual rates of 17% to 20%. The annual death rate was 8% among those with cognitive impairment without dementia and almost 15% among those with cognitive impairment due to medical conditions. LIMITATIONS: Only 56% of the nondeceased target sample completed the initial assessment. Population sampling weights were derived to adjust for at least some of the potential bias due to nonresponse and attrition. CONCLUSION: Cognitive impairment without dementia is more prevalent in the United States than dementia, and its subtypes vary in prevalence and outcomes.

Steffens DC, Potter GG, McQuoid DR, MacFall JR, Payne ME, Burke JR, Plassman BL, Welsh-Bohmer KA. · Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA. · Am J Geriatr Psychiatry. · Pubmed #17623814 No free full text.

Abstract: OBJECTIVE: Several studies suggest that depression is a risk factor for development of dementia in the elderly. In a study of older depressed individuals, the authors examined both neuroimaging and genetic factors in development of dementia. The authors hypothesized that change in subcortical gray matter and white matter hyperintensity volumes would be associated with development of dementia, as would presence of an apolipoprotein E (APOE) epsilon 4 allele. METHODS: The sample consisted of 161 older depressed subjects without dementia who had magnetic resonance imaging scans at baseline and at two years. Blood samples were also taken to determine APOE genotype. All participants were treated with antidepressants using a guideline-based treatment algorithm. Their cognitive status was evaluated annually. A consensus panel of experts evaluated each case to determine cognitive status and assign a diagnosis. RESULTS: Twenty subjects became demented over the follow-up period (5.4 years on average). Change in white matter hyperintensity volume was significantly associated with development of dementia, especially among non-Alzheimer dementias. There was a trend for change in subcortical gray matter hyperintensity volume to be associated with incident dementia. APOE genotype was not associated with onset of dementia. CONCLUSION: Worsening cerebrovascular disease in older depressed adults is associated with cognitive decline and dementia, particularly of the non-Alzheimer disease type. The association of change in white matter lesion volume and incident dementia among depressed elders extends the vascular depression hypothesis of geriatric depression to include cognitive outcomes of depression in the elderly.

Reed T, Plassman BL, Tanner CM, Dick DM, Rinehart SA, Nichols WC. · Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA. · Twin Res Hum Genet. · Pubmed #16176721 links to  free full text

Abstract: The National Academy of Sciences -- National Research Council (NAS-NRC) twin panel, created nearly 50 years ago, had twin zygosity determined primarily via a similarity questionnaire that has been estimated to correctly classify at least 95% of twins. In the course of a study on the genetics of healthy ageing in the NAS-NRC twins, DNA was collected for genome-wide scanning and zygosity confirmation was examined in 343 participating pairs. The sample was supplemented from two other studies using NAS-NRC twins where one or both co-twins were suspected to have Alzheimer disease or another dementia, or Parkinson's disease. Overall 578 twin pairs with DNA were analyzed. Zygosity assignment for 96.8% (519/536) was confirmed via questionnaire. Among 42 pairs whose questionnaire responses were inconclusive for assigning zygosity, 50% were found to be monozygous (MZ) and 50% were dizygous (DZ). There was some evidence for greater misclassification of presumed DZ pairs in the healthy ageing study where participation favored pairs who were similar in having a favorable health history and willingness to volunteer without any element of perceived risk for a specific disease influencing participation.

Zandi PP, Carlson MC, Plassman BL, Welsh-Bohmer KA, Mayer LS, Steffens DC, Breitner JC, Anonymous00334. · Department of Mental Hygiene, School of Hygiene and Public Health, the Johns Hopkins University, Baltimore, Md, USA. · JAMA. · Pubmed #12413371 links to  free full text

Abstract: CONTEXT: Previous studies have shown a sex-specific increased risk of Alzheimer disease (AD) in women older than 80 years. Basic neuroscience findings suggest that hormone replacement therapy (HRT) could reduce a woman's risk of AD. Epidemiologic findings on AD and HRT are mixed. OBJECTIVE: To examine the relationship between use of HRT and risk of AD among elderly women. DESIGN, SETTING, AND PARTICIPANTS: Prospective study of incident dementia among 1357 men (mean age, 73.2 years) and 1889 women (mean age, 74.5 years) residing in a single county in Utah. Participants were first assessed in 1995-1997, with follow-up conducted in 1998-2000. History of women's current and former use of HRT, as well as of calcium and multivitamin supplements, was ascertained at the initial contact. MAIN OUTCOME MEASURE: Diagnosis of incident AD. RESULTS: Thirty-five men (2.6%) and 88 women (4.7%) developed AD between the initial interview and time of the follow-up (3 years). Incidence among women increased after age 80 years and exceeded the risk among men of similar age (adjusted hazard ratio [HR], 2.11; 95% confidence interval [CI], 1.22-3.86). Women who used HRT had a reduced risk of AD (26 cases among 1066 women) compared with non-HRT users (58 cases among 800 women) (adjusted HR, 0.59; 95% CI, 0.36-0.96). Risk varied with duration of HRT use, so that a woman's sex-specific increase in risk disappeared entirely with more than 10 years of treatment (7 cases among 427 women). Adjusted HRs were 0.41 (95% CI, 0.17-0.86) for HRT users compared with nonusers and 0.77 (95% CI, 0.31-1.67) compared with men. No similar effect was seen with calcium or multivitamin use. Almost all of the HRT-related reduction in incidence reflected former use of HRT (9 cases among 490 women; adjusted HR, 0.33 [95% CI, 0.15-0.65]). There was no effect with current HRT use (17 cases among 576 women; adjusted HR, 1.08 [95% CI, 0.59-1.91]) unless duration of treatment exceeded 10 years (6 cases among 344 women; adjusted HR, 0.55 [95% CI, 0.21-1.23]). CONCLUSIONS: Prior HRT use is associated with reduced risk of AD, but there is no apparent benefit with current HRT use unless such use has exceeded 10 years.

Tschanz JT, Welsh-Bohmer KA, Plassman BL, Norton MC, Wyse BW, Breitner JC, Anonymous00176. · Department of Psychology, Utah State University, Logan, Utah 84322-4440, USA. · Neuropsychiatry Neuropsychol Behav Neurol. · Pubmed #11877549 No free full text.

Abstract: 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.

Plassman BL, Havlik RJ, Steffens DC, Helms MJ, Newman TN, Drosdick D, Phillips C, Gau BA, Welsh-Bohmer KA, Burke JR, Guralnik JM, Breitner JC. · Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA. · Neurology. · Pubmed #11071494 No free full text.

Abstract: BACKGROUND: The association between antecedent head injury and AD is inconsistent. OBJECTIVE: To examine the association between early adult head injury, as documented by military hospital records, and dementia in late life; and to evaluate the interaction between head injury and APOE epsilon4 as risk factors for dementia. METHODS: The study had a population-based prospective historical cohort design. It included men who were World War II Navy and Marine veterans, and were hospitalized during their military service with a diagnosis of either a nonpenetrating head injury or another unrelated condition. In 1996 to 1997, military medical records were abstracted to document the occurrence and details of closed head injury. The entire sample was then evaluated for dementia and AD using a multistage procedure. There were 548 veterans with head injury and 1228 without head injury who completed all assigned stages of the study. The authors estimated risk of dementia, specifically AD, using proportional hazards models. RESULTS: Both moderate head injury (hazard ratio [HR] = 2.32; CI = 1.04 to 5.17) and severe head injury (HR = 4.51; CI = 1.77 to 11.47) were associated with increased risk of AD. Results were similar for dementia in general. The results for mild head injury were inconclusive. When the authors stratified by the number of APOE epsilon4 alleles, they observed a nonsignificant trend toward a stronger association between AD and head injury in men with more epsilon4 alleles. CONCLUSIONS: Moderate and severe head injuries in young men may be associated with increased risk of AD and other dementias in late life. However, the authors cannot exclude the possibility that other unmeasured factors may be influencing this association.

Steffens DC, Plassman BL, Helms MJ, Welsh-Bohmer KA, Newman TT, Breitner JC. · Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA. · Neurology. · Pubmed #10680788 No free full text.

Abstract: OBJECTIVE: To examine the independent effects of the APOE genotype (APOE) and concordance for AD in twin pairs on the occurrence of AD in first-degree relatives. BACKGROUND: Studies of twins have been undertaken to investigate the influence of genes in a variety of conditions, including AD. A previous study, performed before reports linking APOE to AD, demonstrated an increase in AD among first-degree relatives of twins concordant for AD compared with relatives of discordant twins. METHODS: In a sample of 94 twin pairs the authors examined the association between concordance for AD within the twin pair and family history of AD among first-degree relatives of twins. They then examined the extent to which the presence of the APOE epsilon4 allele in the twin pair explains the association between concordance for AD within the twin pair and family history of AD. RESULTS: Concordance among twins was associated with increased risk of AD among relatives (logrank test, chi2 = 12.558; p = 0.0004), and the presence of at least one APOE epsilon4 allele in each member of the twin pair is also associated with increased risk of AD among family members (logrank test, chi2 = 7.712; p = 0.0055). CONCLUSIONS: APOE genotype explains much but not all of the association between concordance among twins and increased familial risk of AD.

Breitner JC, Wyse BW, Anthony JC, Welsh-Bohmer KA, Steffens DC, Norton MC, Tschanz JT, Plassman BL, Meyer MR, Skoog I, Khachaturian A. · Department of Mental Hygiene, The Johns Hopkins University, Baltimore, MD 21205, USA. · Neurology. · Pubmed #10430421 No free full text.

Abstract: OBJECTIVE: To examine the prevalence of Alzheimer's disease (AD) and other dementias in relation to age, education, sex, and genotype at APOE. Recent studies suggest age heterogeneity in the risk of AD associated with the APOE genotype and a possible interaction between APOE-epsilon4 and female sex as risk factors. We studied these topics in the 5,677 elderly residents of Cache County, Utah, a population known for long life expectancy and high participation rates. METHODS: We screened for dementia with a brief cognitive test and structured telephone Dementia Questionnaire, then examined all individuals with apparent cognitive symptoms and a sample of others. We estimated age-specific prevalence of AD and other dementias and used multiple logistic regression models to describe relation of AD prevalence to age, sex, education, and APOE genotype. RESULTS: We found 335 demented individuals, 230 (69%) with definite, probable, or possible AD (positive predictive value versus autopsy confirmation 85%). The adjusted prevalence estimate for AD was 6.5% and for all dementias 9.6%. After age 90, the adjusted prevalence estimate for AD was 28% and for all dementias 38%. Regression models showed strong variation in AD prevalence with age, sex, education, and number of epsilon4 alleles (effect of epsilon2 not significant). Models were improved by a term for age-squared (negative coefficient) and by separate terms for interaction of age with presence of one or two epsilon4 alleles. An association of AD with female sex was ascribable entirely to individuals with epsilon4. CONCLUSIONS: In participants with no epsilon4 alleles, the age-specific prevalence of AD reached a maximum and then declined after age 95. In epsilon4 heterozygotes a similar maximum was noted earlier at age 87, in homozygotes at age 73. Female sex was a risk factor for AD only in those with epsilon4. The epsilon4 allele accounted for 70% of the population attributable risk for AD.