Alzheimer's disease and vascular dementia in developing countries: prevalence, management, and risk factors

Abstract

Despite mortality due to communicable diseases, poverty, and human conflicts, dementia incidence is destined to increase in the developing world in tandem with the ageing population. Current data from developing countries suggest that age-adjusted dementia prevalence estimates in 65 year olds are high (>or=5%) in certain Asian and Latin American countries, but consistently low (1-3%) in India and sub-Saharan Africa; Alzheimer's disease accounts for 60% whereas vascular dementia accounts for approximately 30% of the prevalence. Early-onset familial forms of dementia with single-gene defects occur in Latin America, Asia, and Africa. Illiteracy remains a risk factor for dementia. The APOE epsilon4 allele does not influence dementia progression in sub-Saharan Africans. Vascular factors, such as hypertension and type 2 diabetes, are likely to increase the burden of dementia. Use of traditional diets and medicinal plant extracts might aid prevention and treatment. Dementia costs in developing countries are estimated to be US$73 billion yearly, but care demands social protection, which seems scarce in these regions.

Figure. Sporadic and familial dementias in developing countries

Red-shaded countries have prevalence or incidence estimates of all dementias that have been determined to be similar (>5%) to those in developed countries (grey-shaded countries). Blue-shaded countries have significantly lower prevalence (<3%) of dementia. Sample sizes for the estimates in the various studies were between 700 and 3200 individuals. Green-shaded areas show countries where there are published cases of dementia or subtypes (AD or VaD), where risk factors have been examined but prevalence or incidence are unknown. Reliable information was not available for countries without shading. Red spots show locations of families with neurodegenerative and vascular disorders causing dementia including AD, Parkinson's disease, Lewy body disease, frontotemporal lobar degeneration, Huntington's disease, amyotrophic lateral sclerosis, and CADASIL. Information on dementia prevalence and types was derived from many sources.,,,,–,,,,–,,–