Alzheimer Disease: Qiu C

Qiu C, De Ronchi D, Fratiglioni L. · Aging Research Center, Department of Neurobiology, Caring Sciences and Society (NVS), Karolinska Institutet and the Stockholm Gerontology Research Center, Stockholm, Sweden. · Curr Opin Psychiatry. · Pubmed #17551353 No free full text.

Abstract: PURPOSE OF REVIEW: The epidemiology of dementia is one of the priority fields in aging research. This review aims to highlight the most relevant findings over last years concerning occurrence, risk factors, and prevention of dementia and its major subtypes. RECENT FINDINGS: It is estimated that currently around 24 million people have dementia in the world, with the number being projected to double every 20 years, and that 60% of dementia patients live in developing countries, with the proportion being raised to more than 70% by 2040. Current evidence suggests that vascular factors, such as midlife hypertension, diabetes, and cerebrovascular disease, contribute significantly to the development of dementia and Alzheimer's disease, and that active engagement in mental, physical, and social activities may postpone the onset of dementia by providing cognitive reserve. SUMMARY: Dementia represents a major public health challenge as a consequence of rapid increase in the aging population worldwide, especially in developing countries. This challenge can be partly confronted by successful development of preventive strategies. Evidence has emerged that proper control of vascular disorders and maintenance of active lifestyles may prevent or delay the onset and progression of dementia and Alzheimer's disease. Intervention trials are warranted to determine, to what extent, such programs are effective against dementia.

Qiu C, Winblad B, Fratiglioni L. · Aging Research Centre, Division of Geriatric Epidemiology and Medicine, Department of Neurotec, Karolinska Institute and Stockholm Gerontology Research Centre, Stockholm, Sweden. · Lancet Neurol. · Pubmed #16033691 No free full text.

Abstract: The relation of blood pressure with cognitive function and dementia has, in recent years, received much attention from epidemiological research. Some cross-sectional studies have shown an inverse association between blood pressure and the prevalence of dementia and Alzheimer's disease, whereas longitudinal studies yield mixed results that largely depend on the age at which blood pressure is measured and the time interval between blood pressure and outcome assessments. Some studies suggest that midlife high blood pressure is a risk factor for late-life cognitive impairment and dementia, and that low diastolic pressure and very high systolic pressure in older adults may be associated with subsequent development of dementia and Alzheimer's disease. Observational studies and randomised clinical trials provide limited evidence for a protective effect of antihypertensive therapy against dementia and stroke-related cognitive decline. Atherosclerosis resulting from long-standing hypertension, and cerebral hypoperfusion secondary to severe atherosclerosis and to low blood pressure may be major biological pathways linking both high blood pressure in midlife and low blood pressure in late-life to cognitive decline and dementia.

Xu W, Qiu C, Gatz M, Pedersen NL, Johansson B, Fratiglioni L. · Department of Neurobiology, Care Sciences and Society, Aging Research Center, Karolinska Institutet and Stockholm Gerontology Research Center, Stockholm, Sweden. · Diabetes. · Pubmed #18952836 links to  free full text

Abstract: OBJECTIVE: We aimed to verify the association between diabetes and the risk of dementia, Alzheimer's disease, and vascular dementia in twins and to explore whether genetic and early-life environmental factors could contribute to this association. RESEARCH DESIGN AND METHODS: This study included 13,693 twin individuals aged > or =65 years. Dementia was diagnosed according to DSM-IV (Diagnostic Manual of Mental Disorders, 4th ed.) criteria. Information on diabetes was collected from the inpatient registry and self- or informant-reported history of diabetes. Data were analyzed following two strategies: 1) unmatched case-control analysis for all participants using generalized estimating equation (GEE) models and 2) cotwin matched case-control analysis for dementia-discordant twin pairs using conditional logistic regression. RESULTS: Of all participants, 467 were diagnosed with dementia, including 292 with Alzheimer's disease and 105 with vascular dementia, and an additional 170 were diagnosed with questionable dementia. Diabetes was present in 1,396 subjects. In GEE models, diabetes was associated with adjusted odds ratios (ORs) (95% CI) of 1.89 (1.51-2.38) for dementia, 1.69 (1.16-2.36) for Alzheimer's disease, and 2.17 (1.36-3.47) for vascular dementia. Compared with late-life diabetes (onset age > or =65 years), the risk effect of mid-life diabetes (onset age <65 years) on dementia was stronger. Conditional logistic analysis of 210 dementia-discordant twin pairs led to ORs of 2.41 (1.05-5.51) and 0.68 (0.30-1.53) for dementia related to mid- and late-life diabetes, respectively. CONCLUSIONS: Diabetes increases the risk of Alzheimer disease and vascular dementia. The risk is stronger when diabetes occurs at mid-life than in late life. Genetic and early-life environmental factors might contribute to the late-life diabetes-dementia association but could not account for the mid-life diabetes-dementia association.

Fratiglioni L, Qiu C. · Aging Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and Stockholm Gerontology Research Center, Gavlegatan 16, S-113 30, Stockholm, Sweden. · Exp Gerontol. · Pubmed #18620039 No free full text.

Abstract: Since population aging has become a worldwide phenomenon, the burden of the age-related neurodegenerative diseases is expected to increase dramatically in both developed and developing nations. Alzheimer's disease is the most common neurodegenerative disorder among old people. Prevention may represent an ideal solution to the challenge posed by this condition. Recent epidemiological studies have revealed a number of risk and protective factors that could influence occurrence of dementia including Alzheimer type dementia. We propose that an active and stimulating lifestyle in late life as well as an optimal control of vascular and other chronic diseases both at middle age and late life can be two possible intervention strategies to prevent or postpone the onset of dementia, and perhaps other neurodegenerative disorders such as Parkinson's disease.

Monastero R, Palmer K, Qiu C, Winblad B, Fratiglioni L. · Aging Research Center, Division of Geriatric Epidemiology, Department for Neurobiology, Health Care Sciences, and Society, Karolinska Institutet, Stockholm Gerontology Research Center, Stockholm, Sweden. · Am J Geriatr Psychiatry. · Pubmed #17194816 No free full text.

Abstract: OBJECTIVES: The objectives of this study were to investigate the relation of vascular, neuropsychiatric, social, and frailty-related factors with "Cognitive impairment, no dementia" (CIND) and to verify their effect independently of future progression to Alzheimer disease (AD). METHODS: Seven hundred eighteen subjects aged 75+ years who attended baseline, 3- and 6-year follow-up examinations of the Kungsholmen Project, a Swedish prospective cohort study, were studied. CIND was defined according to the performance on the Mini-Mental State Examination. Potential risk factors were collected at baseline and clustered according to four research hypotheses (frailty, vascular, neuropsychiatric, and social hypothesis), each representing a possible pathophysiological mechanism of CIND independently of subsequent development of AD. RESULTS: Over a mean 3.4 years of follow up, 82 participants (11.4%) developed CIND. When the population was subsequently followed for a mean of 2.7 years, subjects with CIND had a threefold increased risk to progress to AD. After multiple adjustments, including adjustment for the development of AD at the 6-year follow up, risk factors for CIND were hip fracture, polypharmacy, and psychoses. CONCLUSIONS: The results suggest that not only the AD-type neurodegenerative process, but also neuropsychiatric- and frailty-related factors may induce cognitive impairment in nondemented elderly. These findings may have relevant preventive and therapeutic implications.

Xu W, Qiu C, Winblad B, Fratiglioni L. · Aging Research Center, Karolinska Institutet, Stockholm, Sweden. · Diabetes. · Pubmed #17192484 links to  free full text

Abstract: To verify the hypothesis that borderline diabetes may increase the risk of dementia and Alzheimer's disease, a community-based cohort of 1,173 dementia- and diabetes-free individuals aged >or=75 years was longitudinally examined three times to detect patients with dementia and Alzheimer's disease (Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition criteria). Borderline diabetes was defined as a random plasma glucose level of 7.8-11.0 mmol/l. Data were analyzed using Cox proportional hazards models. During the 9-year follow-up, 397 subjects developed dementia, including 307 Alzheimer's cases. At baseline, 47 subjects were identified with borderline diabetes. Borderline diabetes was associated with adjusted hazard ratios (95% CIs) of 1.67 (1.04-2.67) for dementia and 1.77 (1.06-2.97) for Alzheimer's disease; the significant associations were present after additional adjustment for future development of diabetes. Stratified analysis suggested a significant association between borderline diabetes and Alzheimer's disease only among noncarriers of APOE epsilon4 allele. There was an interaction between borderline diabetes and severe systolic hypertension on the risk of Alzheimer's disease (P = 0.04). We conclude that borderline diabetes is associated with increased risks of dementia and Alzheimer's disease; the risk effect is independent of the future development of diabetes. Borderline diabetes may interact with severe systolic hypertension to multiply the risk of Alzheimer's disease.

Qiu C, Winblad B, Marengoni A, Klarin I, Fastbom J, Fratiglioni L. · Aging Research Center, Division of Geriatric Epidemiology and Medicine, Department of Neurotec, Karolinska Institutet and Stockholm Gerontology Research Center, Olivecronas väg 4, S-113 82 Stockholm, Sweden. · Arch Intern Med. · Pubmed #16682574 links to  free full text

Abstract: BACKGROUND: Heart failure has been linked to cognitive impairment in several previous studies, but to our knowledge, no investigations have explored the relationship between heart failure and the risk of dementia. We sought to examine the hypothesis that heart failure is a risk factor for dementia and Alzheimer disease. METHODS: A community-based cohort of 1301 individuals 75 years or older and without dementia in Stockholm, Sweden, was examined 3 times over a 9-year period to detect patients with dementia and Alzheimer disease using the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition. Heart failure was defined according to the guidelines of the Task Force on Heart Failure of the European Society of Cardiology by integrating clinical symptoms and signs with inpatient register entries and use of cardiac medications. Data were analyzed using Cox proportional hazards models with adjustment for major potential confounders. RESULTS: During the 6534 person-years of follow-up (mean, 5.02 years per person), 440 subjects were diagnosed as having dementia, including 333 with Alzheimer disease. At baseline, heart failure was identified in 205 subjects. Heart failure was associated with a multi-adjusted hazard ratio (HR) of 1.84 (95% confidence interval [CI], 1.35-2.51) for dementia and 1.80 (95% CI, 1.25-2.61) for Alzheimer disease. Use of antihypertensive drugs (83% of which are diuretics) seemed to reduce dementia risk due to heart failure (HR, 1.38; 95% CI, 0.99-1.94). Heart failure and low diastolic pressure (< 70 mm Hg) had an additive effect on the risk for dementia (HR, 3.07; 95% CI, 1.67-5.61). CONCLUSIONS: Heart failure is associated with an increased risk of dementia and Alzheimer disease in older adults. Antihypertensive drug therapy may partially counteract the risk effect of heart failure on dementia disorders.

Qiu C, Fratiglioni L. · Aging Research Center, Division of Geriatric Epidemiology, Department of Clinical Neuroscience, Occupational Therapy and Elderly Care Research (NEUROTEC), Karolinska Institute, Stockholm, Sweden. · Int Psychogeriatr. · Pubmed #16191225 No free full text.

Abstract: Cognitive decline is a central component of the dementia process. Population-based prospective studies have confirmed the existence of age-related cognitive decline, although its conceptual basis and nosological status remain controversial. Healthy old people show decline with aging in global cognition and memory function in particular. Preclinical and clinical dementia patients exhibit deficits across multiple cognitive domains, with the largest and most consistent deficits in memory function. Cerebrovascluar disease may lead to cognitive decline and promote the clinical expression of dementia directly or by interaction with APOE epsilon4. Early treatment and prevention of cerebrovascular disease may be the major measures for preventing and postponing the progression of the vascular disease related cognitive decline.

Huang W, Qiu C, von Strauss E, Winblad B, Fratiglioni L. · Aging Research Center, Division of Geriatric Epidemiology and Medicine, Department of Neurotec, Karolinska Institutet, Stockholm Gerontology Research Center, [corrected] Stockholm, Sweden. · Arch Neurol. · Pubmed #15596614 links to  free full text

Abstract: BACKGROUND: Both family aggregation and apolipoprotein E (APOE) epsilon4 allele are well-known risk factors for dementia, but the relation between these two factors remains unclear. OBJECTIVE: To explore whether the risk of dementia and Alzheimer disease (AD) due to a positive family history is explained by APOE genotypes. DESIGN: Community-based cohort study. SETTING: The Kungsholmen district of Stockholm, Sweden. PARTICIPANTS: A total of 907 nondemented people 75 years or older, followed up for 6 years to detect incident dementia and AD cases according to the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition. MAIN OUTCOME MEASURES: Risk of dementia and AD by Cox proportional hazards models after controlling for several potential confounders. RESULTS: Subjects who had at least 2 siblings with dementia were at an increased risk of AD. Individuals with both APOE epsilon4 allele and at least 2 affected first-degree relatives had a higher risk of dementia and AD compared with those without these 2 factors. Similar results were obtained for history of dementia separately in parents or siblings. Among the epsilon4 allele carriers, subjects with 2 or more first-degree demented relatives had increased risk of dementia and AD, whereas no increased risk was detected among non-epsilon4 carriers. CONCLUSIONS: Family history of dementia was associated with an increased risk of dementia and AD in this very old population, but only among APOE epsilon4 carriers. This suggests the existence of other genetic or environmental risk factors that may be active in the presence of the APOE epsilon4 allele.

Qiu C, Fratiglioni L, Karp A, Winblad B, Bellander T. · Aging Research Center, Division of Geriatric Epidemiology and Medicine, Department of Neurotec, Karolinska Institutet, S-113 82 Stockholm, Sweden. · Epidemiology. · Pubmed #15475717 No free full text.

Abstract: BACKGROUND: Extremely-low-frequency magnetic field (ELF-MF) exposure is suspected to increase the risk of Alzheimer's disease. Such fields are present in the vicinity of electrical motors and other electric appliances containing coils. METHODS: We investigated lifetime occupational ELF-MF exposure in relation to Alzheimer's disease and dementia among a community dementia-free cohort (n = 931) age 75 years and older in Stockholm, Sweden. This cohort was followed from 1987-1989 until 1994-1996 to detect dementia cases (Diagnostic and Statistical Manual of Mental Disorders, revised 3rd edition criteria). Information on lifetime job history was obtained by interview, usually of next of kin. ELF-MF exposure was assessed using a job-exposure matrix, measurement on historical equipment, and expert estimation. We analyzed the data with Cox models controlling for potential confounders. RESULTS: Dementia was diagnosed in 265 subjects, including 202 with Alzheimer's disease. Among men, ELF-MF exposure > or=0.2 microT in lifetime principal job was related to multivariate-adjusted relative risks of 2.3 (95% CI = 1.0-5.1) for Alzheimer's disease and 2.0 (1.1-3.7) for dementia. We found no association among women. A similar sex-specific pattern was seen for the associations with average ELF-MF exposure throughout the work life. A dose-response relation was suggested in men, with multivariate-adjusted relative risks of 2.4 (0.8-6.8) for Alzheimer's disease and 2.5 (1.1-5.6) for dementia for the upper tertile of lifetime average exposure. CONCLUSIONS: Long-term occupational exposure to a higher ELF-MF level may increase the risk of Alzheimer's disease and dementia in men. Similar patterns were not seen in women, which may in part be the result of a greater exposure misclassification in women than in men.

Qiu C, von Strauss E, Winblad B, Fratiglioni L. · Aging Research Center, Division of Geriatric Epidemiology and Medicine, Department of Neurotec, Karolinska Institutet, Stockholm, Sweden. · Stroke. · Pubmed #15232128 links to  free full text

Abstract: BACKGROUND AND PURPOSE: Low blood pressure has been related to an increased risk of dementia. We sought to verify blood pressure variations before and after a dementia diagnosis and to relate blood pressure decline to subsequent Alzheimer disease and dementia. METHODS: A community dementia-free cohort aged > or =75 years (n=947) underwent follow-up examinations twice over a period of 6 years to detect dementia cases (Diagnostic and Statistical Manual of Mental Disorders, 3rd edition, revised [DSM-III-R] criteria, n=304). Blood pressure variation before and after dementia diagnosis was verified with linear mixed-effects models. Using the dementia-free cohort identified at first follow-up (n=719), the association between blood pressure decline from baseline to first follow-up and subsequent risk of dementia was examined. RESULTS: Blood pressure markedly decreased over 3 years before dementia diagnosis and afterward, whereas no substantial decline was present 3 to 6 years before the diagnosis. However, among subjects with baseline systolic pressure <160 mm Hg, systolic pressure decline > or =15 mm Hg occurring 3 to 6 years before diagnosis was associated with relative risks (95% CI) of 3.1 (1.3 to 7.0) for Alzheimer disease and 3.1 (1.5 to 6.3) for dementia. There was a dose-response relationship between systolic pressure decline and dementia risk in subjects with vascular disease. CONCLUSIONS: Blood pressure starts to decrease only 3 years before dementia diagnosis and continues to decline afterward. A greater decline in systolic pressure occurring 3 to 6 years before diagnosis is associated with an increased risk of dementia only in older people with already low blood pressure or affected by vascular disorders.

Qiu C, Kivipelto M, Agüero-Torres H, Winblad B, Fratiglioni L. · Ageing Research Centre, Division of Geriatric Epidemiology and Medicine, Department of Neurotec, Karolinska Institutet and the Stockholm Gerontology Research Centre, Stockholm, Sweden. · J Neurol Neurosurg Psychiatry. · Pubmed #15145993 links to  free full text

Abstract: BACKGROUND: The risk effect of APOE epsilon 4 allele for Alzheimer's disease is acknowledged, whereas the putative protective effect of epsilon 2 allele remains in debate. OBJECTIVES: To investigate whether those inconsistent findings may be attributable to differences in age and sex composition of the study populations. METHODS: A community dementia free cohort (n = 985) aged > or =75 years was followed up to detect Alzheimer's disease cases (DSM-III-R criteria). Data were analysed using Cox models with adjustment for major potential confounders. RESULTS: Over a median 5.6 year follow up, Alzheimer's disease was diagnosed in 206 subjects. Compared with APOE epsilon 3/epsilon 3 genotype, the relative risk (RR) of Alzheimer's disease was 1.4 (95% confidence interval (CI), 1.0 to 2.0; p = 0.03) for heterozygous epsilon 4 allele and 3.1 (95% CI, 1.6 to 5.9) for homozygous epsilon 4 allele. The association between epsilon 4 allele and Alzheimer's disease risk was stronger in men than in women (RR related to the interaction term epsilon 4 allele by sex, 0.4; 95% CI, 0.2 to 0.9). The epsilon 4 allele accounted for one third of Alzheimer's disease cases among men, but only one tenth among women. The epsilon 2 allele was related to a reduced Alzheimer's disease risk mainly in people aged <85 years (RR, 0.4; 95% CI, 0.2 to 0.8). The RR of Alzheimer's disease related to the interaction term of epsilon 2 allele by age was 2.4 (95% CI, 1.0 to 6.0; p = 0.06). CONCLUSIONS: The APOE genotype specific effects on Alzheimer's disease vary by age and sex, in which the epsilon 4 allele has a stronger risk effect in men, and the epsilon 2 allele confers a protective effect only in younger-old people.

Karp A, Kåreholt I, Qiu C, Bellander T, Winblad B, Fratiglioni L. · Aging Research Center, Division of Geriatric Epidemiology and Medicine, Neurotec, Karolinska Institutet, Stockholm, Sweden. · Am J Epidemiol. · Pubmed #14718220 links to  free full text

Abstract: In this study, the authors evaluated whether the association between low educational level and increased risk of Alzheimer's disease (AD) and dementia may be explained by occupation-based socioeconomic status (SES). A cohort of 931 nondemented subjects aged > or = 75 years from the Kungsholmen Project, Stockholm, Sweden, was followed for 3 years between 1987 and 1993. A total of 101 incident cases of dementia, 76 involving AD, were detected. Less-educated subjects had an adjusted relative risk of developing AD of 3.4 (95% confidence interval: 2.0, 6.0), and subjects with lower SES had an adjusted relative risk of 1.6 (95% confidence interval: 1.0, 2.5). When both education and SES were introduced into the same model, only education remained significantly associated with AD. Combinations of low education with low or high SES were associated with similar increased risks of AD, but well-educated subjects with low SES were not at high risk. Low SES at 20 years of age, even when SES was high at age 40 or 60 years, was associated with increased risk; however, this increase disappeared when education was entered into the model. In conclusion, the association between low education and increased AD risk was not mediated by adult SES or socioeconomic mobility. This suggests that early life factors may be relevant.

Qiu C, Winblad B, Fastbom J, Fratiglioni L. · Aging Research Center, Division of Geriatric Epidemiology and Medicine, Department of Neurotec, Karolinska Institutet and the Stockholm Gerontology Research Center, Stockholm, Sweden. · Neurology. · Pubmed #12963757 No free full text.

Abstract: OBJECTIVE: To study the hypotheses that APOE-epsilon4 allele may interact with blood pressure to affect Alzheimer's disease (AD) occurrence and that antihypertensive therapy could modify such an effect. METHODS: A dementia-free cohort of 966 community-dwelling persons aged 75 years and older in Stockholm, Sweden was followed to detect patients with AD using the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition (DSM-III-R) diagnostic criteria. Data were analyzed using Cox proportional hazards models with adjustment for several potential confounders. RESULTS: During a 6-year follow-up period, AD was diagnosed in 204 persons. APOE-epsilon4 allele, high systolic pressure (> or = 140 mm Hg), and low diastolic pressure (<70 mm Hg) were associated with an increased risk of AD. APOE-epsilon4 allele combined with low diastolic pressure greatly increased the risk of AD independent of antihypertensive drug use. Antihypertensive therapy significantly reduced the risk of AD regardless of APOE-epsilon4 status and counteracted the combined risk effect of the epsilon4 allele with high systolic pressure on the disease. CONCLUSIONS: Elderly people with genetic susceptibility for Alzheimer's disease may experience a further increased disease risk if they have either high systolic pressure or low diastolic pressure. Antihypertensive therapy decreases the risk of Alzheimer's disease exerted by the APOE-epsilon4 allele.

Qiu C, Winblad B, Viitanen M, Fratiglioni L. · Aging Research Center, Division of Geriatric Epidemiology and Medicine, Department of Neurotec, Karolinska Institutet, Stockholm, Sweden.. · Stroke. · Pubmed #12624277 links to  free full text

Abstract: BACKGROUND AND PURPOSE: Elevated blood pressure has been found to increase the risk of dementia, including Alzheimer disease. We sought to investigate whether pulse pressure was predictive of Alzheimer disease and dementia. METHODS: A community-based, dementia-free cohort (n=1270) aged > or =75 years was clinically examined twice over 6 years to detect incident dementia with the use of the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition. Cox proportional hazards models were used to analyze pulse pressure in association with incident Alzheimer disease and dementia after adjustment for several potential confounders, including systolic pressure and diastolic pressure. RESULTS: During the 5464.6 person-years (median, 4.7 years) of follow-up, 339 subjects developed dementia, including 256 Alzheimer disease cases. Pulse pressure as a continuous variable was not statistically related to the risk of Alzheimer disease and dementia. In the categorical analysis, however, in comparison with median tertile of pulse pressure (70 to 84 mm Hg), subjects with higher pulse pressure had adjusted relative risks (95% CI) of 1.4 (1.0 to 2.0; P=0.04) for Alzheimer disease and 1.3 (0.9 to 1.7) for dementia. The corresponding figures related to lower pulse pressure were 1.7 (1.2 to 2.3) for Alzheimer disease and 1.4 (1.0 to 1.9; P=0.03) for dementia. This association was particularly pronounced among women. CONCLUSIONS: Higher pulse pressure is associated with increased risk for Alzheimer disease and dementia in old adults, which is probably due to artery stiffness and severe atherosclerosis. Poor cerebral perfusion related to decreased pulse pressure may explain the association between lower pulse pressure and increased dementia risk.

Qiu C, von Strauss E, Fastbom J, Winblad B, Fratiglioni L. · Aging Research Center, Department of NEUROTEC, Karolinska Institutet, Stockholm, Sweden. · Arch Neurol. · Pubmed #12580707 links to  free full text

Abstract: BACKGROUND: Previous studies have reported a higher prevalence of dementia in persons with low blood pressure. OBJECTIVE: To examine whether low blood pressure is prospectively associated with the occurrence of Alzheimer disease and dementia in elderly people. SUBJECTS AND METHODS: A community-based, dementia-free cohort (n = 1270) aged 75 to 101 years was longitudinally examined twice within 6 years to detect incident dementia using the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition criteria. Cox proportional hazards models were used to analyze blood pressure in association with dementia after adjustment for several potential confounders. RESULTS: During the 6-year period, 339 subjects were diagnosed with dementia, including 256 persons with Alzheimer disease. Subjects with very high systolic pressure (>180 vs 141-180 mm Hg) had an adjusted relative risk of 1.5 (95% confidence interval [CI], 1.0-2.3; P =.07) for Alzheimer disease, and 1.6 (95% CI, 1.1-2.2) for dementia. Low systolic pressure (</=140 mm Hg) was not related to incident dementia. In contrast, high diastolic pressure (>90 mm Hg) was not associated with dementia incidence, whereas extremely low diastolic pressure (</=65 vs 66-90 mm Hg) produced an adjusted relative risk of 1.7 (95% CI, 1.1-2.4) for Alzheimer disease and 1.5 (95% CI, 1.0-2.1; P =.03) for dementia. The latter association was pronounced particularly in persons who used antihypertensive drugs. CONCLUSIONS: Both low diastolic and high systolic pressure are associated with an increased risk of Alzheimer disease and dementia in this elderly population. The atherosclerotic process may explain the observed associations. In addition, low diastolic pressure may increase dementia risk by affecting cerebral perfusion.

Qiu C, Karp A, von Strauss E, Winblad B, Fratiglioni L, Bellander T. · Aging Research Center, Division of Geriatric Epidemiology and Medicine, Department of Neurotec, Karolinska Institute and the Stockholm Gerontology Research Center, Sweden. · Am J Ind Med. · Pubmed #12541276 No free full text.

Abstract: BACKGROUND: Some studies suggest that manual work is associated with dementia. This study is aimed at identifying the specific occupational categories that may be related to dementia. METHODS: A cohort of 913 non-demented subjects aged 75 + years was longitudinally examined twice over 6 years to detect incident dementia using the DSM-III-R diagnostic criteria. The lifetime longest occupations of all subjects were divided into different categories according to the occupation-based classification system. Data were analyzed with Cox models. RESULTS: During the follow-up period, 260 subjects were diagnosed with dementia (197 with Alzheimer's disease). Manual work was associated with an increased risk of dementia, and the association was dependent on educational level. Compared with non-manual work, manual work involving goods production had a multi-adjusted relative risk (95% CI) of 1.6 (1.0-2.5, P = 0.046) for Alzheimer's disease and 1.4 (0.9-2.1) for dementia. CONCLUSIONS: An association between goods production, manual work and Alzheimer's disease found in this study suggests that factors in the mid-twentieth century goods production environment may be involved in the development of Alzheimer's disease.

Huang W, Qiu C, Winblad B, Fratiglioni L. · Aging Research Center, Division of Geriatric Epidemiology and Medicine, Department of Neurotec, Karolinska Institutet and the Stockholm Gerontology Research Center, Olivecronas väg 4, Box 6401, S-113 82 Stockholm, Sweden. · J Clin Epidemiol. · Pubmed #12464371 No free full text.

Abstract: To explore the relationship between light to moderate alcohol consumption and risk of dementia and Alzheimer's disease in very old people, a community-based dementia-free cohort (n = 402) was followed for almost 6 years to detect incident dementia using the Diagnostic and Statistical Manual of Mental Disorders, 3rd Edition-Revised criteria. Data from the entire cohort and a subpopulation of those with baseline Mini-Mental State Examination score > or =24 (n = 317) were analyzed with Cox models. In the entire population, light to moderate drinking was significantly associated with a decreased risk of incident dementia and Alzheimer's disease compared with nondrinking (adjusted relative risk 0.5, 95% confidence interval 0.3 to 0.7). In the analysis of the subpopulation, however, the inverse association between light to moderate drinking and risk of incident dementia and Alzheimer's disease was less evident and no longer statistically significant. This study suggested that light to moderate alcohol drinking might protect against dementia and Alzheimer's disease among old people, although the possibility that such an association may be due to information bias cannot be totally ruled out.

Qiu C, Bäckman L, Winblad B, Agüero-Torres H, Fratiglioni L. · Stockholm Gerontology Research Center, Box 6401 (Olivecronas väg 4), S-113 82 Stockholm, Sweden. · Arch Neurol. · Pubmed #11735777 links to  free full text

Abstract: BACKGROUND: The relationship between education and Alzheimer disease (AD) or dementia has been widely examined and the evidence obtained is mixed. Several hypotheses have been proposed to explain the observed association between them. OBJECTIVE: To further understand the relationship between education and incidence of clinically diagnosed AD or dementia. SUBJECTS AND METHODS: A community-based, dementia-free cohort of 1296 aged 75 years and older was followed up to detect incident AD or dementia cases using Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition criteria. The vital status of all subjects who underwent the clinical examination at follow-up (n = 983) was ascertained for 5 years further. Data were analyzed with Cox proportional hazards model after adjustment for main potential confounders. RESULTS: Over an average (SD) of 2.8 (1.0) years of follow-up, 147 subjects were diagnosed as having dementia (109 subjects as having AD). Among those who were clinically examined at follow-up, 88 died with dementia (68 died with AD) within 5 years. Subjects with a low level of education (<8 vs > or =8 years) had a relative risk of 2.6 (95% confidence interval, 1.5-4.4) for AD and 1.7 (95% confidence interval, 1.1-2.6) for dementia. A low educational level was significantly related to all-cause mortality (relative risk, 1.3; 95% confidence interval, 1.0-1.7; P<.05), but not to the mortality of subjects with AD (relative risk, 1.1; 95% confidence interval, 0.5-2.2) or dementia (relative risk, 0.9; 95% confidence interval, 0.5-1.5). CONCLUSIONS: A low level of education is related to an increased incidence of clinical AD or dementia, but not to the mortality of subjects with AD or dementia. These findings can be accounted for by the "cognitive reserve" hypothesis. Alternatively, the observed association between educational level and incidence of AD or dementia may partly reflect detection bias, by which subjects with a low level of education tend to be clinically diagnosed at an earlier point in time.