The validity of the family history method for identifying Alzheimer disease

The Israel Registry for Alzheimer's Prevention (IRAP) Study: Design and Baseline Characteristics

BACKGROUND

Family history of Alzheimer's disease (AD) is associated with increased dementia-risk.

OBJECTIVE

The Israel Registry for Alzheimer's Prevention (IRAP) is a prospective longitudinal study of asymptomatic middle-aged offspring of AD patients (family history positive; FH+) and controls (whose parents have aged without dementia; FH-) aimed to unravel the contribution of midlife factors to future cognitive decline and dementia. Here we present the study design, methods, and baseline characteristics.

METHODS

Participants are members of the Maccabi Health Services, 40-65 years of age, with exquisitely detailed laboratory, medical diagnoses and medication data available in the Maccabi electronic medical records since 1998. Data collected through IRAP include genetic, sociodemographic, cognitive, brain imaging, lifestyle, and health-related characteristics at baseline and every three years thereafter.

RESULTS

Currently IRAP has 483 participants [mean age 54.95 (SD = 6.68) and 64.8% (n = 313) women], 379 (78.5%) FH+, and 104 (21.5%) FH-. Compared to FH-, FH+ participants were younger (p = 0.011), more often males (p = 0.003) and with a higher prevalence of the APOE E4 allele carriers (32.9% FH+, 22% FH-; p = 0.040). Adjusting for age, sex, and education, FH+ performed worse than FH-in global cognition (p = 0.027) and episodic memory (p = 0.022).

CONCLUSION

Lower cognitive scores and higher rates of the APOE E4 allele carriers among the FH+ group suggest that FH ascertainment is good. The combination of long-term historical health-related data available through Maccabi with the multifactorial information collected through IRAP will potentially enable development of dementia-prevention strategies already in midlife, a critical period in terms of risk factor exposure and initiation of AD-neuropathology.

Association of the CD2AP locus with cognitive functioning among middle-aged individuals with a family history of Alzheimer's disease

First-degree family history is an established risk factor for Alzheimer's disease (AD). We investigated the association of late-onset AD risk loci with cognitive functioning among 315 offspring of AD patients. Participants were cognitively normal Jewish individuals, aged 40-65 years, from the Israel Registry for Alzheimer's Prevention (IRAP) study. Twenty-two single-nucleotide polymorphisms (SNPs) within these loci and the APOE E4 allele were included in the final analyses, and a polygenic risk score was also calculated. Using linear regression (assuming an additive genetic model), we found a significant association only for SNP rs9473117, located near the CD2-associated protein (CD2AP) gene, with global cognition. Controlling for demographic variables (age, sex, years of education, and ancestry), the late-onset AD risk allele C was associated with lower global cognitive functioning (p = 0.0005), and withstood correction for multiple testing. After adjusting for additional characteristics (APOE E4 status and then also for cardiovascular factors), the results remained essentially unchanged (p = 0.0003 and p = 0.0005, respectively). In secondary analyses examining specific cognitive domains, rs9473117 was similarly associated with episodic memory (p = 0.005), language (p = 0.009), and working memory/attention (p = 0.018) but not with executive functions (p = 0.27). Again, the results were similar after adjusting for APOE E4 status and cardiovascular factors. The polygenic risk score was not associated with global cognitive functioning or with any of the 4 domains. In conclusion, our findings suggest a contribution of the CD2AP locus to cognitive functioning in middle-aged individuals with a parental history of AD. Further validations, including in longitudinal studies, are required.

Role of neurodevelopment involved genes in psychiatric comorbidities and modulation of inflammatory processes in Alzheimer's disease

INTRODUCTION

With the increase of the population's average age, Alzheimer's disease (AD) is becoming one of the most disabling diseases worldwide. Recently, neurodevelopment processes have been involved in the AD etiopathogenesis. Genetic studies in this field could contribute to our knowledge and suggest new molecular targets for possible treatments.

METHODS

Our primary aim was to investigate the associations among single nucleotide polymorphisms (SNPs) within neurodevelopment related genes (BDNF, ST8SIA2, C15orf32, NCAPG2, ESYT2, WDR60, LOC154822, VIPR2, GSK3B, NR1I2, ZNF804A, SP4) and AD. A number of exploratory analyses was also performed to evaluate the associations with the presence of behavioral and psychiatric symptoms of dementia (BPSD), as well as with variations in hematological parameters. Two independent samples were investigated, one of 228 Greek subjects and one sample of 229 Italian subjects, including 156Alzheimer's Disease patients CE patients and 301 healthy controls. All patients were affected by late onset AD (LOAD).

RESULTS

None of the analyzed SNPs was associated with AD in our samples. In the exploratory analyses, several genetic variants were associated with inflammation parameters in the Greek sample and in the merged one, suggesting a relationship among these genes and the modulation of inflammation and the immune response. Other exploratory analyses showed associations among several SNPs and psychiatric symptomatology in the Greek sample, suggesting a possible modulation of these variants on psychiatric comorbidities in AD.

CONCLUSIONS

Although we failed to find a direct relationship between AD and the genetic variants investigated, possible connections with inflammation and psychiatric symptoms were suggested.

Self-reported severe memory problems as a screen for cognitive impairment and dementia

Undetected cognitive impairment (CI) and dementia are important clinical and epidemiological problems. This study addresses the effectiveness of using a single self-reported measure of severe memory problems (SMP) as a screen for CI and dementia. For the purposes of the study, 3220 elderly women participated in a mailed Health Survey Questionnaire and telephone interviews. Cognitive scores derived from the Telephone Interview for Cognitive Status–modified (TICSm) were calculated. Based on a multi-stage assessment strategy, all subjects were classified in one of three status categories: dementia, CI, or unimpaired. The SMP question was suggestive of cognitive problems in the majority of responders. t-tests found affirmative responders scored much lower on the cognitive test than negative responders. The SMP question had a sensitivity of .24 and a specificity of .99 for screening CI and dementia. While other assessment measures are needed, the SMP question is highly suggestive of CI and may serve as a first-stage screen in clinical and research settings.

Family history of Alzheimer's disease limits improvement in cognitive function after bariatric surgery

Background/Objective:

Bariatric surgery can reverse cognitive impairments associated with obesity. However, such benefits may be attenuated in individuals with a predisposing risk for cognitive impairment such as family history of Alzheimer’s disease.

Methods:

In all, 94 bariatric surgery participants completed a computerized cognitive test battery before and 12 weeks after surgery. Family history of Alzheimer’s disease was obtained through self-report.

Results:

In the overall sample, cognitive function improved in memory and attention/executive function 12 weeks post-surgery. Repeated measures showed similar rates of improvements in attention/executive function between patients with and without a family history of Alzheimer’s disease. In contrast, only individuals without a family history of Alzheimer’s disease exhibited post-operative improvements in memory. A family history of Alzheimer’s disease was associated with greater post-surgery rates of cognitive impairment.

Conclusions:

Family history of Alzheimer’s disease may limit post-surgery cognitive benefits. Future studies should examine whether weight loss can modify the course of cognitive decline in patients at-risk for Alzheimer’s disease.

Association between Sirtuin 2 gene rs10410544 polymorphism and depression in Alzheimer's disease in two independent European samples

Among the several genes associated with late-onset Alzheimer's disease (LOAD), recently, Sirtuin genes have roused a growing interest because of their involvement in metabolic homeostasis and in brain aging. Particularly SIRT2 gene has been associated with Alzheimer's disease (AD) as well as with mood disorders. The aim of this study is to investigate the possible associations between Sirtuin 2 gene (SIRT2) rs10410544 polymorphism and AD as well as depression in AD. In addition, we performed some exploratory analyses to investigate possible associations between the rs10410544 genotype and clinical features. We investigated these associations in two independent samples: the first one was composed of 275 Greek inhabitants and 117 patients; the second sample counted 181 Italian people and 43 patients. All patients were affected by LOAD. We failed to find any association between rs10410544 genotype and AD in the two samples. On the other hand, we found an association between the single nucleotide polymorphism (SNP) and depressive symptomatology (in the total sample p = 0.002), which was modulated by the tumor necrosis factor (TNF) values. Particularly, TT genotype seems to be protective versus depression. Finally, in the exploratory analyses, we found that the TT genotype was associated with earlier AD onset and a longer duration of the illness. In conclusion, we confirmed the association between SIRT2 gene and mood disturbances, although in AD patients. Further, we provided evidence that the TT genotype may be protective versus depressive symptoms, allowing an easier and thus earlier diagnosis of AD. This awareness may lead to a more detailed approach to these patients concerning diagnosis and therapy.

C-reactive protein and familial risk for dementia: a phenotype for successful cognitive aging

OBJECTIVES

Identifying phenotypes for successful cognitive aging, intact cognition into late-old age (>age 75), can help identify genes and neurobiological systems that may lead to interventions against and prevention of late-life cognitive impairment. The association of C-reactive protein (CRP) with cognitive impairment and dementia, observed primarily in young-elderly samples, appears diminished or reversed in late-old age (75+ years). A family history study determined if high CRP levels in late-old aged cognitively intact probands are associated with a reduced risk of dementia in their first-degree family members, suggesting a familial successful cognitive aging phenotype.

METHODS

The primary sample was 1,329 parents and siblings of 277 cognitively intact male veteran probands at least 75 years old. The replication sample was 202 relatives of 51 cognitively intact community-ascertained probands at least 85 years old. Relatives were assessed for dementia by proband informant interview. Their hazard ratio (HR) for dementia as a function of the proband's log-transformed CRP was calculated using the proportional hazards model.

RESULTS

Covarying for key demographics, higher CRP in probands was strongly associated with lower risk of dementia in relatives (HR = 0.55 [95% confidence interval (CI) 0.41, 0.74], p < 0.02). The replication sample relationship was in the same direction, stronger in magnitude, and also significant (HR = 0.15 [95% CI 0.06, 0.37], p < 0.0001).

CONCLUSIONS

Relatives of successful cognitive aging individuals with high levels of CRP are relatively likely to remain free of dementia. High CRP in successful cognitive aging individuals may constitute a phenotype for familial-and thus possibly genetic-successful cognitive aging.

Exposure to the Holocaust and World War II concentration camps during late adolescence and adulthood is not associated with increased risk for dementia at old age

Holocaust and Nazi concentration camp survivors were subjects to prolonged and multi-dimensional trauma and stress. The aim of the present study was to assess the association between exposure to such trauma during late adolescence and adulthood with dementia at old age. In 1963, approximately 10,000 male civil servants aged 40-71 participated in the Israel Ischemic Heart Disease (IIHD) study. Of them, 691 reported having survived Nazi concentration camps [concentration Camp Survivors (CCS)]. Additional 2316 participants were holocaust survivors but not concentration camp survivors (HSNCC) and 1688 were born in European countries but not exposed to the Holocaust (NH). Dementia was assessed in 1999-2000, over three decades later, in 1889 survivors of the original IIHD cohort; 139 of whom were CCS, 435 were HSNCC, and 236 were NH. Dementia prevalence was 11.5% in CCS, 12.6% in HSNCC, and 15.7% in NH. The odds ratio of dementia prevalence, estimated by age adjusted logistic regression, for CCS as compared to HSNCC was 0.97 (95% CI: 0.53-1.77), approximate Z = -0.10; p = 0.92. Further adjustment for socioeconomic status, diabetes mellitus, and other co-morbidity at midlife (coronary heart disease, lung, and kidney disease), and height did not change the results substantially. Thus, in subjects who survived until old age, late adolescence and adulthood exposure to extreme stress, as reflected by experiencing holocaust and Nazi concentration camps, was not associated with increased prevalence of dementia. Individuals who survived concentration camps and then lived into old age may carry survival advantages that are associated with protection from dementia and mortality.

Altered γ-secretase activity in mild cognitive impairment and Alzheimer's disease

We investigated why the cerebrospinal fluid (CSF) concentrations of Aβ42 are lower in mild cognitive impairment (MCI) and Alzheimer's disease (AD) patients. Because Aβ38/42 and Aβ40/43 are distinct product/precursor pairs, these four species in the CSF together should faithfully reflect the status of brain γ-secretase activity, and were quantified by specific enzyme-linked immunosorbent assays in the CSF from controls and MCI/AD patients. Decreases in the levels of the precursors, Aβ42 and 43, in MCI/AD CSF tended to accompany increases in the levels of the products, Aβ38 and 40, respectively. The ratios Aβ40/43 versus Aβ38/42 in CSF (each representing cleavage efficiency of Aβ43 or Aβ42) were largely proportional to each other but generally higher in MCI/AD patients compared to control subjects. These data suggest that γ-secretase activity in MCI/AD patients is enhanced at the conversion of Aβ43 and 42 to Aβ40 and 38, respectively. Consequently, we measured the in vitro activity of raft-associated γ-secretase isolated from control as well as MCI/AD brains and found the same, significant alterations in the γ-secretase activity in MCI/AD brains.

Repetitive thinking as a psychological cognitive style in midlife is associated with lower risk for dementia three decades later

AIMS

To examine the association of a reported tendency toward repetitive thinking (RT) in midlife when confronting difficulties in family and work settings with dementia many years later.

METHODS

A tendency toward RT was assessed in approximately 9,000 male participants in the Israeli Ischemic Heart Disease study in 1965. The subjects were categorized according to their tendency toward RT in familial and work settings as: 1 = always forget; 2 = tend to forget; 3 = tend to think repetitively, and 4 = usually think repetitively. Dementia was assessed over 3 decades later in 1,889 participants among 2,604 survivors of the original cohort.

RESULTS

The prevalence rates of dementia were 24, 19, 15 and 14% in the 4 groups of tendency toward RT in stressful work situations with superiors (p for trend < 0.0002), respectively. The prevalence rates of dementia were 21, 18, 14 and 14% in the 4 groups of tendency toward RT in familial situations (p for trend < 0.004), respectively. These associations held after multivariate analysis.

CONCLUSIONS

The tendency toward RT when confronting distress is associated with a lower risk for dementia. Future studies should assess possible mechanisms and potentials for intervention and modification.

Increased longevity in offspring of mothers with Alzheimer's disease

Life expectancy is a familial trait. However, the effectiveness of using the age at death of a deceased parent to estimate life expectancy in their offspring can vary depending on whether death in the parent was due to extrinsic versus intrinsic causes, as well as demographic characteristics such as sex. While Alzheimer's disease (AD) risk increases with increased age, mortality for individuals with AD is increased in contrast to comparably aged individuals without AD. Yet in most cases it is not the defining neuropathology of AD that directly terminates life but instead conditions and illnesses extrinsic to AD pathology that nevertheless have increased likelihood in its presence. For this reason, we hypothesized that offspring of AD mothers would have greater longevity than offspring of mothers without AD (insufficient numbers prevented a comparable analysis using fathers with AD). The longevity of 345 offspring of 100 deceased 60+ year old AD mothers was compared with 5,465 offspring in 1,312 deceased 60+ year old non-AD mothers. We used a proportional hazards model that accounted for clustered (nonindependent) observations due to the inclusion of several offspring from the same family. In both an unadjusted model and one that adjusted for the age at death in the mother, and the sex and birth year in the offspring we found evidence for increased longevity in the offspring of AD mothers. The results suggest that, in addition to genes that might directly affect pathways leading to AD, there may be familial/genetic factors not connected to specific pathophysiological processes in AD but instead associated with increased longevity that contribute to the familial aggregation observed in AD.

Religious education and midlife observance are associated with dementia three decades later in Israeli men

OBJECTIVE

The aim of the study was to examine the association of religious education and observance with dementia among participants in the Israeli Ischemic Heart Disease study.

STUDY DESIGN AND SETTING

We assessed dementia in 1,890 participants among 2,604 survivors of 10,059 participants in the Israeli Ischemic Heart Disease study, a longitudinal investigation of the incidence and risk factors for cardiovascular disease among Jewish male civil servants in Israel. Face-to-face interviews were conducted with 651 subjects identified as possibly demented by the Modified Telephone Interview for Cognitive Status.

RESULTS

Of 1,628 subjects included in this analysis (mean age 82 at assessment), 308 (18.9%) had dementia. The prevalence rates of dementia (and odds ratios (ORs) relative to those with exclusively religious education, adjusted for age, area of birth, and socioeconomic status) were 27.1% for those with exclusively religious education, 12.6% (OR=0.49) for those with mixed education, and 16.1% (OR=0.76) for those with secular education. For religious self-definition and practice, the prevalence rates were 9.7%, 17.7%, 14.1%, 19.3%, and 28.8% for categories from least to most religious (ORs relative to the most religious: 0.43, 0.67, 0.48, 0.55).

CONCLUSIONS

Examining lifestyles associated with religiosity might shed light onto environmental risks for dementia. Mechanisms underlying these associations remain elusive.

Social network, cognitive function, and dementia incidence among elderly women

OBJECTIVES

We examined whether social networks had a protective association with incidence of dementia among elderly women.

METHODS

We prospectively studied 2249 members of a health maintenance organization who were 78 years or older, were classified as free of dementia in 2001, and had completed at least 1 follow-up interview in 2002 through 2005. We used the Telephone Interview for Cognitive Status-modified, the Telephone Dementia Questionnaire, and medical record review to assess cognitive status. We used the Lubben Social Network Scale-6 to assess social network. We estimated hazard ratios for incident dementia with Cox proportional hazards models, adjusting for age at entry, education, hormone use, cognitive status scores, and health conditions.

RESULTS

We identified 268 incident cases of dementia during follow-up. Compared with women with smaller social networks, the adjusted hazard ratio for incident dementia in women with larger social networks was 0.74 (95% confidence interval=0.57, 0.97).

CONCLUSIONS

Our findings suggest that larger social networks have a protective influence on cognitive function among elderly women. Future studies should explore which aspects of social networks are associated with dementia risk and maintenance of cognitive health.

Age, family history, and memory and future risk for cognitive impairment

PURPOSE

To provide a clinical tool for calculating a patient's future risk for developing cognitive impairment based on age, family history, and Rey Auditory Verbal Learning Test (AVLT) retention.

PARTICIPANTS

1,019 cognitively normal persons followed for an average of 5 years; 159 participants were eventually diagnosed with cognitive impairment.

RESULTS

Risk of developing cognitive impairment increases with age and family history, but decreases with better memory performance. A nomogram is provided for calculation of relative risk of developing cognitive impairment in combinations of age, family history, and memory performance.

CONCLUSIONS

These results enhance clinicians' ability to provide information to a patient about risk of cognitive impairment.

A phenotype for genetic studies of successful cognitive aging

Survival from Alzheimer's disease (AD) and other dementias into late old age may be a useful phenotype for genetic studies of successful cognitive aging. To support molecular genetics studies for successful cognitive aging, we conducted a two-stage study to determine an optimal age phenotype for successful cognitive aging. First, risk of AD was evaluated, through informant interviews, in 4,794 parents and siblings of 976 elderly nondemented probands who were divided into three different proband age groups: those aged 60-74, 75-89, and 90+. Relatives of probands aged 90+ had a significantly lower risk than the relatives of the other two proband groups. Second, this sample was combined with an earlier sample (combined nondemented elderly probands: n = 2,025; relatives: n = 10,506), and a series of proband age groups (i.e., 75-79, 80-84, 85-89, 90+) were used to determine which optimally identifies a group of relatives with low AD risk. Using the relatives of the nondemented proband aged 60-74 as the reference group, there were reductions in cumulative risk among relatives of probands aged 85-89 and 90+, but only the latter group also showed significant reductions to the relatives of probands aged 75-79, 80-84, and 85-89. This pattern of results varied little by sex. Finally, cumulative AD risk curves were similar between relatives of probands aged 90-94 and 95+. These results suggest that age 90 is an optimal age threshold to use for both men and women in genetic studies seeking to identify genes associated with successful cognitive aging.

Validity of family history in essential tremor

In this study, we found the sensitivity and specificity of family history data given by essential tremor (ET) patients to be 43.3% and 94.4%. Compared to relatives with less severe tremor (tremor score <24), those with more severe tremor (tremor score 24) were more likely to be identified by the ET probands (8/8 vs. 5/22, p=0.001, chi2 14.3). Our study suggests that family history information reported by ET patients was inaccurate, and poorly validated. Clinical and genetic studies in ET should take the limitation of family history data into consideration.

Evidence of shared risk for Alzheimer's disease and Parkinson's disease using family history

This case-control study examined the potential for a common etiology of Parkinson's disease (PD) and Alzheimer's disease (AD) using reported family history. Structured interviews were used to collect AD and PD family history from subjects (n = 1,531) with AD, PD, AD/PD, or controls. Intergroup analysis compared reported AD and PD family histories in the three case groups to the histories reported in the control group. Intragroup analysis stratified each diagnostic group based on positive family history of AD, then compared the subgroups for a family history of PD. Subjects with AD had a higher risk of having a family history of AD [odds ratio (OR) 2.3; 1.5-3.4] and subjects with PD had a higher risk of having a family history of PD (OR 2.2; 1.2-4.0) as compared to control subjects. Intergroup analyses revealed no significant crossed risk, increased risk of subjects with AD having a family history of PD vs controls and vice versa. Intragroup analysis found that subjects with PD and a family history of AD were more likely to have a family history of PD (OR 1.7; 1.1-2.6) when compared to subjects with PD and no family history of AD. A similar trend was found for subjects with AD (OR 1.7; 0.9-3.1). AD and PD cases each have an increased familial risk of their respective disease. Probands with AD or PD and a family history of either disease have a higher crossed risk of a family history of the other disease. These findings suggest the existence of common genetic and/or environmental factors that predispose to both AD and PD in the subset of cases with positive family history of both neurodegenerative diseases.

Socioeconomic status in relationship to death of vascular disease and late-life dementia

It is unclear to what extent coronary heart disease (CHD) and ischemic stroke share several biochemicals clinical and other risk factors with dementia and Alzheimer Disease. Socioeconomic status (SES) has been linked to vascular disease in some investigations and to dementia in a few others. We followed 10,000 Jewish male civil servants in Israel, initially examined in 1963, for mortality. Close to 2000 Survivors of this cohort were assessed between 1999 and 2001 for dementia and AD, yielding 309 cases of dementia. A 5-scale Socioeconomic status (SES) rank, defined during working years, on the basis of education and occupation, was directly but weakly related to CHD mortality but exhibited a clear inverse association with stroke mortality: hazard ratio (HR) 0.89 (95% CI, 0.81-0.97) per "1 step" of SES rank. A similar but more profound association was found for the prevalence of dementia, years later, among long-term survivors. Those at the lowest SES ranks exhibited estimated 3-fold and 6-fold dementia rates. The results are consistent with a "protective" mechanism associated with high education, but survival bias could affect these results and long-term incidence studies of dementia should clarify the SES-dementia association.

Validation of multi-stage telephone-based identification of cognitive impairment and dementia

Background

Many types of research on dementia and cognitive impairment require large sample sizes. Detailed in-person assessment using batteries of neuropyschologic testing is expensive. This study evaluates whether a brief telephone cognitive assessment strategy can reliably classify cognitive status when compared to an in-person "gold-standard" clinical assessment.

Methods

The gold standard assessment of cognitive status was conducted at the University of Southern California Alzheimer Disease Research Center (USC ADRC). It involved an examination of patients with a memory complaint by a neurologist or psychiatrist specializing in cognitive disorders and administration of a battery of neuropsychologic tests. The method being evaluated was a multi-staged assessment using the Telephone Interview of Cognitive Status-modified (TICSm) with patients and the Telephone Dementia Questionnaire (TDQ) with a proxy. Elderly male and female patients who had received the gold standard in-person assessment were asked to also undergo the telephone assessment. The unweighted kappa statistic was calculated to compare the gold standard and the multistage telephone assessment methods. Sensitivity for classification with dementia and specificity for classification as normal were also calculated.

Results

Of 50 patients who underwent the gold standard assessment and were referred for telephone assessment, 38 (76%) completed the TICS. The mean age was 78.1 years and 26 (68%) were female. When comparing the gold standard assessment and the telephone method for classifying subjects as having dementia or no dementia, the sensitivity of the telephone method was 0.83 (95% confidence interval 0.36, 1.00), the specificity was 1.00 (95% confidence interval 0.89,1.00). Kappa was 0.89 (95% confidence interval 0.69, 1.000). Considering a gold-standard assessment of age-associated memory impairment as cognitive impairment, the sensitivity of the telephone approach is 0.38 (95% confidence interval 0.09, 0.76) specificity 0.96 (CI 0.45, 0.89) and kappa 0.61 (CI 0.37, 0.85).

Conclusion

Use of a telephone interview to identify people with dementia or cognitive impairment is a promising and relatively inexpensive strategy for identifying potential participants in intervention and clinical research studies and for classifying subjects in epidemiologic studies.

Relationship between body height and dementia

OBJECTIVE

Structural and functional brain reserves, thought to develop in childhood and adolescence, may be critical in determining the age at onset of cognitive impairment. Body height is affected by childhood conditions that promote growth. The authors examine the relationship of height in midlife and subsequent dementia, Alzheimer disease (AD), and vascular dementia.

METHODS

Dementia was evaluated from 1999 to 2001 in 1,892 men age 76 to 95. Height had been measured when these men participated in the Israeli Ischemic Heart Disease project in 1963. Age, socioeconomic status (SES), and area of birth were also assessed in 1963.

RESULTS

Older men and those with lower SES tended to be shorter. Relative to the shortest quartile, controlling for age, SES, and area of birth, the other quartiles had lesser respective odds ratios for dementia as a whole, AD, and vascular dementia.

CONCLUSION

Height was inversely associated with dementia, AD, and vascular dementia in a male sample. Since height is associated with childhood nutrition and may be associated with other risk factors for dementia, efforts to improve early life conditions that maximize body growth may diminish or delay the onset of dementia in later life.

Brief Screening Tests for the Diagnosis of Dementia: Comparison With the Mini-Mental State Exam

Dementia is a common and under-diagnosed problem among the elderly. An accurate screening test would greatly aid the ability of physicians to evaluate dementia and memory problems in clinical practice. We sought to determine whether simple and brief psychometric tests perform similarly to the Mini-Mental State Examination (MMSE) in screening for dementia. Using a retrospective analysis, a series of standard, brief, psychometric tests were compared with each other and to the MMSE as screening tests for very mild dementia, using DSM-III-R criterion as the gold standard. Two independent cohorts from the Baltimore Longitudinal Study of Aging and the Washington University Alzheimer's Disease Research Center were evaluated. We found that two brief and simple-to-administer tests appear to offer similar degrees of sensitivity and specificity to the MMSE. These are the recall of a five-item name and address, "John Brown 42 Market Street Chicago" and the one-minute verbal fluency for animals. Combining these two tests further improves sensitivity and specificity, surpassing the MMSE, to detect dementia in individuals with memory complaints.

Neurocognitive functioning and schizophrenia spectrum disorders can be independent expressions of familial liability for schizophrenia in community control children: the UCLA family study

This study provided a further test of the hypothesis that certain neuromotor, language and verbal memory dysfunctions reflect genetic predisposition to schizophrenia, by examining the effects of family loading for schizophrenia (FLS) in normal controls without personal histories of schizophrenia or attention deficit hyperactivity disorder. In a case control design, 11 community controls (CC) with FLS were compared to 47 CC without FLS on tests of expressive and receptive language, visual motor coordination, full scale intelligence and verbal memory. In this study, FLS primarily reflects the incidence of schizophrenia spectrum diagnoses in the second-degree relatives of CC probands. CC probands with FLS had significantly poorer general intelligence, expressive and receptive vocabulary abilities, visual motor coordination and slower motor speed than CC probands without FLS. The variance in neurocognitive functioning associated with FLS is not due to the presence of any psychiatric disorders in CC probands, nor the presence of schizophrenia spectrum disorders in their parents. The relation between FLS and neurocognitive and neuromotor functioning in CC probands was moderated by the parent's cognitive functioning. The results of the present study indicate that familial liability to schizophrenia can be transmitted across two generations, independent of the presence of schizophrenia spectrum disorders in either the parent or proband, and account for significant variance in proband neurocognitive and neuromotor functioning. These findings suggest the neurocognitive and neuromotor functioning and schizophrenia spectrum disorders can be relatively independent expressions of familial liability to schizophrenia.

Has familial aggregation in Alzheimer's disease been overestimated?

Studies of the familial aggregation of Alzheimer's disease have primarily used samples ascertained from tertiary care clinics which may not be representative of many AD patients, for example those residing at geriatric nursing homes. Survival analysis was used to investigate whether estimates of familial aggregation of AD based on a clinic-based AD proband (C-AD) sample (probands: N=544; first degree relatives; N=4267) differ from one ascertained at a nursing home (NH-AD; probands: N=225; first degree relatives; N=1772). The cumulative survival from AD was significantly worse in relatives of the C-AD probands and the overall relative risk (RR) of AD in this group was greater than twice that of relatives of the NH-AD probands. However, age at onset in C-AD probands was significantly earlier than in the NH-AD group and in both groups this factor was negatively associated with familial aggregation. When, for this reason, the proband samples were matched one-to-one by age at onset, dropping those probands with no match, the two curves were close to identical and the RR for the C-AD group of relatives was 1.0 The results suggest that estimates of familial risk of AD based on C-AD samples are not applicable and overestimate the extent of increased risk for relatives of more prevalent, later onset AD probands. However, the overestimate can be explained by the typically earlier age at onset in C-AD samples as opposed to a sampling bias related to the proband's family history status per se. The relationship between onset age and familial aggregation suggests that no single estimate of the age-dependent risk (survival curve) is uniformly appropriate for relatives of AD probands.

Validity of family history for the diagnosis of dementia among siblings of patients with late-onset Alzheimer's disease

We examined 180 siblings of 127 probands with probable or possible Alzheimer's dementia (AD) in a family study of AD. The overall sensitivity of a simple family history questionnaire was 64% and the specificity was 84%. Sensitivity improved 90-100% with minimal decline in specificity when we considered clinic-based vs. population survey patients. Higher education among informants and the availability of a spouse or a sibling as informant significantly increased sensitivity. Awareness of such factors may improve the yield of the family history in AD using a simple questionnaire.

Genetic epidemiological study of maternal and paternal transmission of Alzheimer's disease

Recent evidence for mitochondrial mutations associated with Alzheimers disease (AD) suggests the possibility of maternal transmission of this illness. We investigated this hypothesis by examining, in a variety of ways, the risk of a primary progressive dementia (PPD) in the parents (n = 650) and siblings (n = 1,220) of 325 AD probands. The results did not support maternal transmission in AD: The mothers of AD probands were not at greater risk of PPD than the fathers or the sisters of AD probands; the offspring of affected mothers were not at greater risk than the offspring of affected fathers or families with no affected parent; and, after selecting those proband families with evidence for increased familial loading, such families did not more frequently have affected mothers than fathers. In contrast, the cumulative risk of PPD in fathers of AD probands, while similar to that of mothers, was significantly increased over the brothers of AD probands. In addition, the cumulative risk curve of PPD in the offspring of affected fathers was significantly higher than the offspring of no affected parents. While no evidence for maternal transmission in AD was observed, unexpectedly, we did find evidence of increased paternal transmission.

Validity of family history data on essential tremor

BACKGROUND

In family studies of essential tremor (ET), valid data on the presence of ET in relatives of probands with ET is important. The family history method uses information obtained by interviewing probands with ET to identify ET in their relatives. The validation of this method by direct examination of the relatives has not been performed.

OBJECTIVE

To determine the validity of family history data on ET in families in which the proband has ET.

METHODS

ET cases (probands) and their respective relatives were enrolled in a genetic study of ET in Washington Heights-Inwood, New York. Each underwent a tremor interview and videotaped examination. Two neurologists rated the severity of tremor and assigned diagnoses (ET versus normal). Probands were asked to identify their relatives who had ET. The validity of the probands' responses was tested against the neurologists' diagnoses.

RESULTS

There were 206 subjects: 46 ET cases and 160 relatives. Twelve (7.5%) of 160 relatives were diagnosed with ET (four definite ET and eight probable ET). Probands with ET reported that two of these 12 had tremor (sensitivity of probands' report = 16.7%). Six of the 12 affected relatives (50.0%) reported their own tremor. The probands reported that one of 136 of their unaffected relatives had tremor (specificity of probands' report = 99.3%).

CONCLUSIONS

For family studies of ET, information on reportedly unaffected relatives is of limited use given the low sensitivity of family history data. The neurologic examination remains the only valid means of ascertaining cases of ET among relatives.

Identifying families with likely genetic protective factors against Alzheimer disease

Elderly individuals who lived beyond the age of 90 years without dementia were hypothesized to have increased concentrations of genetic protective factors against Alzheimer disease (AD), conferring a reduced liability for this disease relative to less-aged nondemented elderly. However, testing this hypothesis is complicated by having to distinguish such a group from those who may lack genetic risk factors for AD, have had protective environmental exposures, or have escaped dementia for other reasons. Probands carrying genetic protective factors, however, should have relatives with lower illness rates not only for earlier-onset disease, when genetic risk factors are a strong contributing factor to the incidence of AD, but also for later-onset disease, when the role of these factors appears to be markedly diminished. AD dementia was assessed through family informants in 6,660 first-degree relatives of 1,049 nondemented probands aged 60-102 years. The probands were grouped by age (60-74, 75-89, and 90-102 years), and the cumulative survival from AD and 10-year-age-interval hazard rates of AD were calculated in their first-degree relatives. Cumulative survival from AD was significantly greater in the relatives of the oldest proband group (aged 90-102 years) than it was in the two younger groups. In addition, the reduction in the rate of illness for this group was relatively constant across the entire late life span. The results suggest that genetic factors conferring a lifelong reduced liability of AD may be more highly concentrated among nondemented probands aged >/=90 years and their relatives. Efforts to identify protective allele-bearing genes that are associated with very late-onset AD should target the families of nonagenarians and centenarians.