Maëlenn Guerchet

The worldwide costs of dementia 2015 and comparisons with 2010.

In 2010, Alzheimers Disease International presented estimates of the global cost of illness (COI) of dementia. Since then, new studies have been conducted, and the number of people with dementia has increased. Here, we present an update of the global cost estimates.

Recent global trends in the prevalence and incidence of dementia, and survival with dementia

BackgroundCurrent projections of the scale of the coming dementia epidemic assume that the age- and sex-specific prevalence of dementia will not vary over time, and that population ageing alone (increasing the number of older people at risk) drives the projected increases. The basis for this assumption is doubtful, and secular trends (that is, gradual decreases or increases in prevalence over long-term periods) are perfectly plausible.MethodsWe carried out a systematic review of studies of trends in prevalence, incidence and mortality for people with dementia, conducted since 1980.ResultsWe identified nine studies that had tracked dementia prevalence, eight that had tracked dementia incidence, and four that had tracked mortality among people with dementia. There was some moderately consistent evidence to suggest that the incidence of dementia may be declining in high-income countries. Evidence on trends in the prevalence of dementia were inconsistent across studies and did not suggest any clear overall effect. Declining incidence may be balanced by longer survival with dementia, although mortality trends have been little studied. There is some evidence to suggest increasing prevalence in East Asia, consistent with worsening cardiovascular risk factor profiles, although secular changes in diagnostic criteria may also have contributed.ConclusionsWe found no evidence to suggest that the current assumption of constant age-specific prevalence of dementia over time is ill-founded. However, there remains some uncertainty as to the future scale of the dementia epidemic. Population ageing seems destined to play the greatest role, and prudent policymakers should plan future service provision based upon current prevalence projections. Additional priorities should include investing in brain health promotion and dementia prevention programs, and monitoring the future course of the epidemic to chart the effectiveness of these measures.

Meta‐analysis of the association between cysticercosis and epilepsy in Africa

Purpose:  The association between cysticercosis and epilepsy has been widely studied in Latin America and Asia and has proven to be one of the main causes of epilepsy. Despite high prevalences of both diseases in Africa, their association remains unclear. In this article we quantified the strength of the association between epilepsy and cysticercosis in Africa and we proposed some guidelines for future studies.

Cognitive Impairment and Dementia in Elderly People Living in Rural Benin, West Africa

Background/Aims: Dementia is increasing as a priority public health problem because of the ageing of the world population. Our goal was to estimate dementia and cognitive impairment prevalence in an elderly population of rural Benin. Methods: In a door-to-door survey, elderly people aged 65 years and above were screened using the Community Screening Interview for Dementia and the Five-Word Test. Results: The prevalence of cognitive impairment was 10.4% and that of dementia was 2.6%. Age, current depressive disorder and absence of the APOE ε2 allele were significantly associated with cognitive impairment. Conclusion: Prevalence of dementia and cognitive impairment appears to be lower in this study than in developed countries.

Ankle-brachial index as a marker of cognitive impairment and dementia in general population. A systematic review.

OBJECTIVE To investigate the association between a low ankle-brachial index (ABI) and several grades of cognitive disorders: cognitive impairment, dementia and Alzheimers disease (AD), in the general population. METHODS We performed a systematic review of the literature, including all prospective, longitudinal or cross-sectional studies assessing both peripheral artery disease (PAD), defined by a low ABI, and cognitive function. RESULTS 12 publications were included in this review, of whom 6 reported cross-sectional analysis and 6 reported longitudinal analysis. All except one reported a significant association between a low ankle-brachial index and cognitive impairment, dementia or AD. Beyond cognitive impairment, patients with PAD are at an increased risk to develop dementia or Alzheimers disease. CONCLUSION In this review, we confirm that a low (<0.90) ABI can be considered as a marker of cognitive impairment and dementia. ABI provides independent and supplemental information on subjects susceptibility to develop cognitive disorders, along its usefulness to predict cardiovascular diseases (CVD). Given its availability, easiness, safety to patients and low cost, the ABI could be useful in clinical practice and research in the field of cognitive diseases.

Prevalence of dementia in elderly living in two cities of Central Africa: the EDAC survey.

Background: Data on dementia from low- and middle-income countries are still necessary to quantify the burden of this condition. This multicenter cross-sectional study aimed at estimating the prevalence of dementia in 2 large cities of Central Africa. Methods: General population door-to-door surveys were conducted in the districts of Bangui (Republic of Central Africa) and Brazzaville (Congo) in elderly aged ≧65 years. The subjects were screened with the Community Screening Interview for Dementia and the Five-Words Test. Diagnosis of dementia was made according to the DSM-IV criteria and to the clinical criteria proposed by the NINCDS-ADRDA for Alzheimer’s disease. Results: We enrolled 496 subjects in Bangui and 520 in Brazzaville. The prevalence of dementia was estimated at 8.1% (95% CI = 5.8–10.8) in Bangui and 6.7% (95% CI = 4.7–9.2) in Brazzaville. Conclusion: The prevalence of dementia in urban areas of Central Africa is close to those observed in high-income countries.

Epidemiology of Peripheral Artery Disease in Elder General Population of Two Cities of Central Africa: Bangui and Brazzaville

OBJECTIVES Peripheral artery disease (PAD) is a common condition in Western countries, mostly in the elderly. Little is known about the epidemiology of PAD in Africa. We sought to determine the prevalence of this condition in the elderly in two community-dwelling cohorts in Central Africa. DESIGN Prospective cross-sectional survey in general population over the age of 65 years in Bangui (Central African Republic) and Brazzaville (Congo). METHODS We conducted a systematic door-to-door survey in two representative districts of each city. Demographic, clinical and biological data were collected. The ankle-brachial index (ABI) was used to detect PAD (ABI ≤ 0.90). RESULTS Among the 976 participants, the prevalence of PAD was 15.0% in Bangui and 32.4% in Brazzaville, increasing with age. Adjusted to age, regular alcohol consumption was protective for women in Bangui (OR = 0.50, CI95%:0.25-0.98) and men in Brazzaville (OR = 0.43, CI95%:0.21-0.88). Hypertension was associated with PAD in women (OR = 4.14, CI95%:1.65-10.42 in Bangui and OR = 2.17, CI95%:1.16-4.06 in Brazzaville). Diabetes and smoking showed different associations according to gender and city. CONCLUSIONS This first population study in Central Africa highlights the high prevalence of PAD in the older population, and emphasizes specificities regarding the risk factors, being different from data published in Western countries.

Prevalence of dementia among elderly people living in Cotonou, an urban area of Benin (West Africa)

Background/Aims: The population of Benin is, like those of most developing countries, aging; dementia is therefore a major concern. Our goal was to estimate the prevalence of dementia in an elderly population living in urban Benin. Methods: In a cross-sectional community-based study, people aged 65 years and above were screened using the Community Screening Interview for Dementia and the Five-Word Test. Results: The prevalence of dementia was 3.7% (95% CI 2.6–4.8) overall. The figure increased with age and was higher among women than men. Conclusion: Dementia was slightly more prevalent than previously reported in a rural area of Benin, but the rate was similar to that recorded in other cities in developing countries.

Factors Associated with Dementia Among Elderly People Living in Two Cities in Central Africa: The EDAC Multicenter Study

Risk factors for dementia in American and European countries have been well investigated. However, little research has been carried out in sub-Saharan Africa, where life events as well as environmental, socio-economic, and modifiable risk factors (i.e., cardiovascular risk factors) may differ. Two cross-sectional surveys were conducted in representative samples of the older general population living in Bangui (Central African Republic) and Brazzaville (Congo). Dementia was defined according to the DSM-IV criteria. Multivariate regression analyses were performed in order to identify independent factors associated with dementia. Among the 977 elderly Africans included in this analysis, 75 (7.6%) were diagnosed as having dementia. Increasing age, female gender, hypertension, a body mass index <18.5 kg/m2, depressive symptoms, and the lack of a primary education were significantly associated with dementia. Among life events, the death of one parent during childhood and recently having moved house were also associated with dementia. Beyond the usual risk factors for dementia, this study highlights the role of stressful events in low-income countries. Factors associated with dementia in African countries seem different from established factors in high-income countries and require further investigation.

Prevalence of peripheral artery disease in the elderly population in urban and rural areas of Central Africa: the EPIDEMCA study

Objective Data on peripheral artery disease in Africa are sparse and limited to urban areas. Given the urban/rural socio-economical gradient in these countries, we sought to determine the prevalence and risk factors of peripheral artery disease in urban and rural areas of two countries in Central Africa. Methods Individuals ≥65 years old living in two urban and rural areas of the Republic of Central Africa (ROC) and the Central African Republic (CAR) were invited. Demographic, clinical and biological data were collected. Ankle-brachial index ≤0.90 defined peripheral artery disease. Results Among the 1871 participants (age 73 years, 62% female) the prevalence of peripheral artery disease was 14.8%, higher in ROC than in CAR (17.4% vs. 12.2%, p = 0.007) and higher in females than males (16.6% vs. 11.9%, p = 0.012). The prevalence of peripheral artery disease increased with age, respectively at 10.9%, 14.9%, 15.1% and 22.2% for age bands of 65–69, 70–74, 75–79 and 80+years (p < 0.001). Higher rates of peripheral artery disease were found in urban areas in ROC (20.7% vs. 14.4% in rural areas, p = 0.011), but not in CAR (11.5% vs. 12.9%, p = NS). In multivariate analysis, peripheral artery disease was significantly associated with age (odds ratio (OR): 1.03; p = 0.004), dyslipidaemia (OR: 1.88; p = 0.003), smoking (OR: 1.78; p = 0.003), obesity (OR: 1.98; p = 0.034) and underweight (OR: 1.49; p = 0.023). Regular alcohol drinking was associated with decreased risk of peripheral artery disease (OR: 0.73; p = 0.044). Conclusion The prevalence of peripheral artery disease in the elderly is high in Africa, especially in females. In ROC, with a higher urban-rural socio-economic gradient, peripheral artery disease is more frequent in the urban areas.