Processing speed and working memory are predicted by components of successful aging: a HUNT study.

BACKGROUND: Research has demonstrated that cognitive heterogeneity occurs with aging both within and between individuals. The purpose of this study was to explore whether the cognitive heterogeneity in aging was related to the subgroups of successful and usual aging. METHOD: Participants were a representative sample of normal older adults (n = 65, age range 70-89 years). All subjects had participated in the third phase of the Nord-Trøndelag Health Survey (HUNT3) and completed all subtests in the Wechsler Memory Scale (WMS-III) and Wechsler Adult Intelligence Scale (WAIS-III). Successful aging was defined in four ways in the study: as (1) absence of disease, (2) high functioning, (3) active engagement with life, or (4) all three components combined. Five domains of memory and intelligence functions were investigated using linear regression analysis, with group membership (successful versus usual aging) as predictors and age, sex and education as correlates. RESULTS: Processing speed performance was correlated with the successful aging component absence of disease, younger age and being of the female sex, while working memory performance was correlated with the successful aging component absence of disease and more years of education. Performance in other domains (verbal, visuospatial, and episodic memory) were not related to any successful aging definition. Age had a consistent negative effect on the processing speed domain for all successful aging definitions. Education was positively linked to cognitive performance on the verbal and working memory domains. Being female was positively linked to processing speed and episodic memory. CONCLUSIONS: Processing speed and working memory were linked to successful aging when it was defined as absence of disease, but not by other components of successful aging, i.e. domain-specific. In contrast, other cognitive domains were not related to any components of successful aging.

Subjective working memory predicts objective memory in cognitively normal aging: a HUNT study.

BACKGROUND: Recent studies have shown that subjective memory is multi-, rather than uni-dimensional, in line with the results of objective memory tests. The purpose of this study was to investigate whether there is an association between aspects of memory measured by the subjective Meta-Memory Questionnaire (MMQ) and aspects of memory measured by the objective Wechsler Memory Scale-III (WMS-III) and Wechsler Adult Intelligence Scale-III (WAIS-III) tests in cognitively normal older adults. METHOD: The study subjects (n = 106) were cognitively normal, were aged 57-89 years and had participated in the third wave of the North-Trøndelag Health survey (HUNT3). All subjects had completed the MMQ, the WMS-III and the WAIS-III. Previous results from the MMQ (measured as the total MMQ score; the Component I score, related to long-term explicit declarative memory; and the Component II score, related to working/short-term memory) were compared with objective results from WMS-III (Logical Memory) and WAIS-III (Vocabulary and Letter-Number Sequencing) subtests. We conducted linear regression analyses with each objective memory test result as the dependent variable, and subjective memory measures and demographics as independent variables, as well as analyses of MMQ items vs. objective memory. RESULTS: Subjective working memory impairment (Component II) was significant related to poor performance in objective episodic memory, according to correlation and regression analyses with demographic covariates. In contrast, ratings of impaired subjective declarative memory (Component I) were not related to poor objective memory performance. CONCLUSIONS: Specific aspects of subjective memory related differentially to performance in specific objective memory tests. Clinicians and researchers might consider targeting working memory aspects of subjective memory tests, when seeking an estimate of objective memory performance.

Lifestyle predictors of successful aging: A 20-year prospective HUNT study.

BACKGROUND: Lifestyle factors predicting successful aging as a unified concept or as separate components of successful aging are important for understanding healthy aging, interventions and preventions. The main objective was to investigate the effect of midlife predictors on subsequent successful aging 20 years later. MATERIALS AND METHODS: Data were from a population-based health survey, the Nord-Trøndelag Health Study (HUNT), with an average follow-up of 22.6 years. Individuals free of major disease at baseline in 1984-86 with complete datasets for the successful aging components in HUNT3 in 2006-08, were included (n = 4497; mean age at baseline 52.7, range 45-59, years). Successful aging was defined either as a unified category or as three components: being free of nine specified diseases and depression, having no physical or cognitive impairment, and being actively engaged with life. The midlife predictors (smoking, physical activity, alcohol consumption, obesity and social support) were analysed both as separate predictors and combined into a lifestyle index controlling for sociodemographic variables, using multivariable regression analysis. RESULTS: Successful aging as a unified concept was related to all the lifestyle factors in the unadjusted analyses, and all except alcohol consumption in the adjusted analyses. The individual components of successful aging were differently associated with the lifestyle factors; engagement with life was less associated with the lifestyle factors. Non- smoking and good social support were the most powerful predictors for successful aging as a unified concept. When the lifestyle factors were summed into a lifestyle index, there was a trend for more positive lifestyle to be related to higher odds for successful aging. CONCLUSIONS: Lifestyle factors predicted an overall measure of SA, as well as the individual components, more than 20 years later. Modifiable risk factors in midlife, exemplified by social support, may be used for interventions to promote overall health and specific aspects of health in aging.

Subjective working and declarative memory in dementia and normal aging.

OBJECTIVE: Subjective memory complaints are common in both elderly individuals and patients with dementia. This study investigated the power of subjective memory, divided into declarative and working memory, to differentiate between patients with dementia and normal elderly individuals. METHOD: Two groups of participants, patients with dementia (n = 117) and normal elderly individuals (n = 117), individually matched with regard to age, gender, and education. All subjects had participated in the third wave of the HUNT population health survey in Nord-Trøndelag County in Norway and completed the Meta-Memory Questionnaire (MMQ) in the HUNT study. The MMQ was subdivided into two components, one associated with declarative memory (episodic and semantic) and the other with working memory. RESULTS: Patients with dementia reported significantly more subjective memory concerns than normal elderly individuals. The difference between working and declarative memory components was significantly greater in patients with dementia than in normal elderly individuals. This finding made it possible to differentiate patients with dementia from the normal elderly individuals. Mental and somatic health conditions did not significantly add power to differentiating the two groups. CONCLUSION: In clinical and research applications, subjective memory components could contribute to differentiation of patients with dementia and normal elderly individuals by using self-reported impairment in working memory, rather than declarative memory.

Smoking and Obesity as Risk Factors in Frontotemporal Dementia and Alzheimer's Disease: The HUNT Study.

BACKGROUND: Few studies have assessed smoking and obesity together as risk factors for frontotemporal dementia (FTD) and Alzheimer's disease (AD). OBJECTIVE: To study smoking and obesity as risk factors for FTD and AD. METHODS: Ninety patients with FTD and 654 patients with AD were compared with 116 cognitively healthy elderly individuals in a longitudinal design with 15-31 years between measurements of risk factors before the dementia diagnosis. RESULTS: There were no associations between smoking and FTD (p = 0.218; odds ratio [OR]: 0.990; 95% confidence interval [CI]: 0.975-1.006). There were significant associations between obesity and FTD (p = 0.049; OR: 2.629; 95% CI: 1.003-6.894). There were significant associations between both smoking (p = 0.014; OR: 0.987; 95% CI: 0.977-0.997) and obesity (p = 0.015; OR: 2.679; 95% CI: 1.211-5.928) and AD. CONCLUSION: Our findings suggest that obesity is a shared risk factor for FTD and AD, while smoking plays various roles as a risk factor for FTD and AD.

Anxiety and Depression as Risk Factors in Frontotemporal Dementia and Alzheimer's Disease: The HUNT Study.

Background: The roles of both anxiety and depression as risk factors for frontotemporal dementia (FTD) and Alzheimer's disease (AD) have not been previously investigated together. Objective: To study anxiety and depression as independent risk factors for FTD and AD. Methods: Eighty-four patients with FTD and 556 patients with AD were compared with 117 cognitively healthy (CH), elderly individuals. Both cases and controls were participants in the second Health Study of Nord-Trøndelag (HUNT2) from 1995 to 1997, in which depression and anxiety were assessed with the Hospital Anxiety and Depression Scale (HADS). Results: Significant associations were found between anxiety and FTD and between depression and AD. A significantly increased risk of developing FTD was observed in patients who had reported anxiety on the HADS (p = 0.017) (odds ratio [OR]: 2.947, 95% confidence interval [CI]: 1.209-7.158) and a significantly increased risk of developing AD was observed in patients who had reported depression on the HADS (p = 0.016) (OR: 4.389, 95% CI: 1.311-14.690). Conclusion: Our study findings suggest that anxiety and depression may play different roles as risk factors for FTD and AD.

Selective impact of disease on short-term and long-term components of self-reported memory: a population-based HUNT study.

BACKGROUND: Subjective memory is commonly considered to be a unidimensional measure. However, theories of performance-based memory suggest that subjective memory could be divided into more than one dimension. OBJECTIVE: To divide subjective memory into theoretically related components of memory and explore the relationship to disease. METHODS: In this study, various aspects of self-reported memory were studied with respect to demographics and diseases in the third wave of the HUNT epidemiological study in middle Norway. The study included all individuals 55 years of age or older, who responded to a nine-item questionnaire on subjective memory and questionnaires on health (n=18 633). RESULTS: A principle component analysis of the memory items resulted in two memory components; the criterion used was an eigenvalue above 1, which accounted for 54% of the total variance. The components were interpreted as long-term memory (LTM; the first component; 43% of the total variance) and short-term memory (STM; the second component; 11% of the total variance). Memory impairment was significantly related to all diseases (except Bechterew's disease), most strongly to brain infarction, heart failure, diabetes, cancer, chronic obstructive pulmonary disease and whiplash. For most diseases, the STM component was more affected than the LTM component; however, in cancer, the opposite pattern was seen. CONCLUSIONS: Subjective memory impairment as measured in HUNT contained two components, which were differentially associated with diseases.

Prevalence and correlates of successful aging in a population-based sample of older adults: the HUNT study.

BACKGROUND: The factors influencing successful aging (SA) are of great interest in an aging society. The aims of this study were to investigate the prevalence of SA, the relative importance across age of the three components used to define it (absence of disease and disability, high cognitive and physical function, and active engagement with life), and its correlates. METHODS: Data were extracted from the population-based cross-sectional Nord-Trøndelag Health Study (HUNT3 2006-2008). Individuals aged 70-89 years with complete datasets for the three components were included (N = 5773 of 8,040, 71.8%). Of the respondents, 54.6% were women. Univariate and multivariate regression analyses were used to analyze possible correlates of SA. RESULTS: Overall, 35.6% of the sample met one of the three criteria, 34.1% met combinations, and 14.5% met all of the three criteria. The most demanding criterion was high function, closely followed by absence of disease, while approximately two-thirds were actively engaged in life. The relative change with age was largest for the high cognitive and physical function component and smallest for active engagement with life. The significant correlates of SA were younger age, female gender, higher education, weekly exercise, more satisfaction with life, non-smoking, and alcohol consumption, whereas marital status was not related to SA. CONCLUSIONS: The prevalence of SA in this study (14.5%) is comparable to previous studies. It may be possible to increase the prevalence by intervention directed toward more exercise, non-smoking, and better satisfaction with life.

A Confirmatory Factor Analytic Study of the Wechsler Memory Scale-III in an Elderly Norwegian Sample.

This study compared the factor structure of the translated Wechsler Memory Scale-III (WMS-III), which is the latest available version in Norway, with the original U.S. version. A sample of 122 healthy, elderly Norwegians (mean age: 74; standard deviation = 8.8) completed the WMS-III. The factor structure of the translated WMS-III was tested, using Confirmatory Factor Analysis, with comparison of model fit based on five a priori hypothesized models. Several model fit indices pointed to a three-factor model (working memory, visual memory, and auditory memory) providing the best fit to the data. Our study supports updated findings of the original WMS-III in nonclinical samples and suggests that the translated version is structurally equal to the original. The study supports the cross-cultural validity of the WMS-III. However, based on the present data, one might expect scores on the Family Pictures subtest to fall below scores on other WMS-III subtests in elderly Norwegians.

Headache as a predictor for dementia: The HUNT Study.

BACKGROUND: The impact of headache on dementia is largely unknown. This study examined the association between headache and dementia using data from a large population-based study. METHODS: This population-based study used data from the Nord-Trøndelag Health Surveys performed in 1995-1997 (HUNT2) and 2006-2008 (HUNT3). The reference group (controls) was participants aged ≥55 years who answered the headache questions in HUNT2 and later participated in HUNT3 (n = 15,601). The association with headache status in HUNT2 was investigated in sample of confirmed non-demented elderly evaluated with psychometric tests after HUNT3 (n = 96), and HUNT2 participants later diagnosed with dementia during 1997-2011 (n = 746). The association with headache was evaluated by logistical regression with adjustment for age, gender, level of education, comorbidity, smoking, and anxiety and depression. RESULTS: Any headache was more likely to be reported in HUNT2 among those who later were included in the dementia registry (OR 1.24; 95 % CI 1.04-1.49) compared to the reference group, but less likely among the confirmed non-demented individuals (OR 0.62; 95 % CI 0.39-0.98). This relationship was even stronger for non-migrainous headache, whereas such association was not found for migraine. CONCLUSIONS: Compared to the reference group, individuals with dementia were more likely to report non-previous migrainous headache in HUNT2, whereas a sample of confirmed non-demented were less likely to report previous non-migrainous headache.

Factor structure of the Norwegian version of the WAIS-III in a clinical sample: the arithmetic problem.

Confirmatory Factor Analyses (CFA) of the Wechsler Adult Intelligence Scale-III (WAIS-III) lend partial support to the four-factor model proposed in the test manual. However, the Arithmetic subtest has been especially difficult to allocate to one factor. Using the new Norwegian WAIS-III version, we tested factor models differing in the number of factors and in the placement of the Arithmetic subtest in a mixed clinical sample (n = 272). Only the four-factor solutions had adequate goodness-of-fit values. Allowing Arithmetic to load on both the Verbal Comprehension and Working Memory factors provided a more parsimonious solution compared to considering the subtest only as a measure of Working Memory. Effects of education were particularly high for both the Verbal Comprehension tests and Arithmetic.