Mild Cognitive Impairment: Epidemiology and Dementia Risk in an Elderly Italian Population

Department of Internal Medicine, Cardioangiology, and Hepatology, University Hospital S. Orsola-Malpighi, Bologna, Italy.
Journal of the American Geriatrics Society (Impact Factor: 4.57). 02/2008; 56(1):51-8. DOI: 10.1111/j.1532-5415.2007.01503.x
Source: PubMed


To investigate prevalence and incidence of mild cognitive impairment (MCI) and its risk of progression to dementia in an elderly Italian population.
Population-based cohort aged 65 and older resident in an Italian municipality.
A total of 1,016 subjects underwent baseline evaluation in 1999/2000. In 2003/04, information about cognitive outcome was collected for 745 participants who were free of dementia at baseline.
MCI (classified as with or without impairment of the memory domain), dementia, Alzheimer's dementia (AD), and vascular dementia (VaD) diagnosed according to current international criteria.
Overall prevalence of MCI was 7.7% (95% confidence interval (CI)=6.1-9.7 %) and was greater with older age and poor education. During 4 years of follow-up, 155 incident MCI cases were diagnosed, with an incidence rate of 76.8 (95% CI=66.8-88.4) per 1,000 person-years. Approximately half of prevalent and incident MCI cases had memory impairment. Compared with normal cognition, multivariable-adjusted risk for progression from MCI with memory impairment to dementia was 4.78 (95% CI=2.78-8.07) for any dementia, 5.92 (95% CI=3.20-10.91) for AD, and 1.61 (95% CI=0.37-7.00) for VaD. No association with dementia risk was found for MCI without memory impairment. Approximately one-third of MCI cases with memory impairment did not progress to dementia.
MCI occurs often in this elderly Italian cohort and is associated with greater risk of AD, but only when the impairment involves the memory domain. However, a substantial proportion of MCI cases with memory impairment do not progress to dementia.

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    • "Age associations were uncertain in older age groups: while a majority of studies (7 out of 11) observed an increase in prevalence with estimates >20% at ages ≥85 years; two MCI studies observed flat or moderately decreasing relationship in old age ([8] ≥85 years & [12] ≥90 years), and two CIND studies observed a convex relationship with lowest prevalence levels in 75–80 years old and a rapid increase afterwards [10] [13]). Regarding aMCI, the three studies gave conflicting results: one flat, one positive and one negative relationship with age [10] [11] [14]. "
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    ABSTRACT: Abstract: The prevalence of mild cognitive impairment (MCI) and dementia according to age remain uncertain. We systematically extracted age-stratified estimates of MCI and dementia prevalence reported in European studies since 1995, and performed meta-analyses for dementia. We identified 10 relevant studies on MCI and 26 studies on dementia. Studies on MCI presented visually substantial heterogeneity preventing a meta-analysis, a majority reporting an increase in prevalence at ≥75 years old. Prevalence of dementia rose continuously from 55 years of age, reaching 44.7% (39.8; 49.6) in those ≥95 years of age. Homogenization of MCI criteria, and additional studies in Northern European population would be warranted.
    Journal of Alzheimer's disease: JAD 01/2015; 48(2). · 4.15 Impact Factor
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    • "People with MCI develop dementia at a rate of 10–15% per year, while the rate for healthy controls is 1–2% per year [30]. Indeed, the risk of dementia is higher in persons with MCI compared to cognitively normal individuals [31] [32] [33]. In the present study, 12 cases had MCI giving a CPR of 1.74/100 for persons aged ≥60 years, which is lower than that reported by other studies [6] [34] [35]. "
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    ABSTRACT: Background: There are only a few reports which provide prevalence rates of mild cognitive impairment (MCI) and dementia specifically in Arabic countries. Objective: This study is aimed at estimating the prevalence of MCI and dementia among subjects aged ≥60 years using door-to-door survey in Qena Governorate/Egypt. Methods: We conducted a door-to-door survey with multistage probability random sampling. Screening of all subjects aged ≥60 years (n = 691) employed a simple questionnaire including changes in memory, behavior, and daily activity as well as the Mini-Mental State Examination. Suspected cases were referred to the hospital for full clinical examination, DSM-IV diagnostic criteria, Hachinski Ischemic Score, neuroimaging, and laboratory investigations if indicated. Results: Of the 691 participants, 12 cases had MCI, giving a crude prevalence rate (CPR) of 1.72/100 and 35 were identified as positive for dementia with a CPR of 5.07/100. The highest age-specific prevalence rates were recorded among subjects ≥85 years old (100/100). The CPRs were significantly higher in urban than rural areas (7.1 versus 3.27/100, respectively; p = 0.03), in industrial areas than non-industrial areas (13.23 versus 1.99; p = 0.00001), and in illiterate than literate participants (10.12 versus 2.25/100; p = 0.00001). Conclusion: Overall, the prevalence rate of MCI and dementia were lower in Qena/Egypt than in other countries. Advanced age, illiteracy, and living in an industrial area were found to be associated with dementia.
    Journal of Alzheimer's disease: JAD 12/2014; 45(1). DOI:10.3233/JAD-142655 · 4.15 Impact Factor
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    • "The prevalence of cognitive impairment, either CIND or MCI, reported in epidemiological studies varies considerably: in one systematic review, the prevalence of MCI ranged between 3% and 42% while that of CIND ranged between 5.1% and 35.9% (Ward et al., 2012). In Italian studies the prevalence of MCI in the over sixties ranged between 3.2% and 7.7%, and in 70–74-year-olds between 0% and 5.6% (Ravaglia et al., 2008; Solfrizzi et al., 2004); CIND had a prevalence of between 5.1% and 9.5% (De Ronchi et al., 2005; Di Carlo et al., 2007), with a rate of 4.2% recorded in 70–74- year olds (Di Carlo et al., 2007). This heterogeneity in prevalence estimates is probably due to the use of different diagnostic tools and criteria, both for dementia and for cognitive impairment, different study designs and small sample sizes. "
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    ABSTRACT: The age-specific prevalence rates of dementia vary widely. Studies focusing on specific age groups are needed to provide reliable estimates for healthcare providers and policy makers. We estimated the prevalence of dementia, dementia subtypes and cognitive impairment in "InveCe.Ab" (, NCT01345110), a single-step multidimensional population-based study of 70-74-year olds living in Abbiategrasso (Milan, Italy). We also looked for associations with socio-demographic factors and the presence of the apolipoprotein E-ɛ4 allele. The overall dementia prevalence was 3% (95%CI: 2.1-4.1%) [Alzheimer's disease (AD): 1.2% (95%CI 0.6-1.9%); vascular dementia (VD): 1.4% (95%CI: 0.8-2.2%)]. Being single was found to be a risk factor for vascular dementia; subjects born in southern Italy were shown to be at greater risk both of overall dementia and of vascular dementia. The prevalence of cognitive impairment, with or without subjective cognitive complaints (cognitive impairment, no dementia, CIND) was 7.8% (95%CI: 6.4-9.4%). As regards the CIND subgroups, the prevalence of subjects with subjective cognitive complaints (mild cognitive impairment, MCI) was 5.0% (95%CI 3.9-6.3%), while the prevalence of those without MCI (CIND-other) was 2.8% (95%CI: 1.9-3.8). The males had a higher risk of MCI and CIND-other; the older subjects were more likely to have MCI, and those born in north-eastern Italy to have CIND-other. The prevalence of AD was higher among the apolipoprotein E-ɛ4 carriers. Our data highlight the importance of dementia and cognitive impairment in the transitional period from adulthood to old age, and reveal the presence of different associations with socio-demographic and genetic factors. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.
    Archives of Gerontology and Geriatrics 11/2014; 60(2). DOI:10.1016/j.archger.2014.11.006 · 1.85 Impact Factor
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