Apolipoprotein E polymorphism distribution in an elderly Brazilian population: the Bambuí Health and Aging Study

Abstract

Apolipoprotein E (ApoE) is one of the most extensively studied genes in the context of aging, but there are few population-based studies on ApoE polymorphism in the elderly in developing countries. The objective of the present study was to assess ApoE allele and genotype distribution in a large elderly community-based sample and its association with age, sex and skin color. Participants included 1408 subjects (80.8% of all residents aged ≥60 years) residing in Bambuí city, MG, Brazil. The DNA samples were subjected to the polymerase chain reaction amplification, followed by the restriction fragment length polymorphism technique, with digestion by HhaI. Analysis was carried out taking into consideration the six ApoE genotypes (ε3/ ε3, ε3/ε4, ε2/ε3, ε4/ε4, ε2/ε4, and ε2/ε2), the three ApoE alleles, and the number of ApoE4 alleles for each individual. The ε3 allele predominated (80.0%), followed by ε4 (13.5%) and ε2 (6.5%). All six possible genotypes were observed, the ε3/ε3 genotype being the most frequent (63.4%). This distribution was similar to that described in other western populations. Sex was not associated with number of ApoE4 alleles. Black skin color was significantly and independently associated with the presence of two ApoE4 alleles (age-sex adjusted OR = 7.38; 95%CI = 1. 93-28.25), showing that the African-Brazilian elderly have a high prevalence of the ε4 allele, as observed in blacks from Africa. No association between number of ApoE4 alleles and age was found, suggesting the absence of association of ApoE genotype with mortality in this population.

Association of ApoE polymorphisms with prevalent hypertension in 1406 older adults: the Bambuí Health Aging Study (BHAS)

“…The mean age of the cohort participants was 69.3 years (range: 60-95 years), and 60.0% were women. White skin color was predominant (60.4%), followed by light brown ("moreno", 33.3%), dark brown ("mulato", 3.6%), and black (2.7%) (22). The prevalence of hypertension (61.5%) was close to that described for the North American elderly (~60%) (23), as well as the prevalence of some traditional risk factors (24).…”

Metabolism of triglyceride-rich lipoproteins and transfer of lipids to high-density lipoproteins (HDL) in vegan and omnivore subjects

“…However, due to the extreme differences in the frequency of apo E isoforms e apo E2 is present in only 5% of the population whereas apo E3 is 80% frequent -requires specific protocols to evaluate this influence [34].…”

Apolipoprotein E polymorphism and functional disability in Brazilian elders: the Bambuí Health and Aging Study

“…Among the elderly who had blood samples taken, 1,408 were genotyped for apoE polymorphism; allele frequencies (ε3: 80.0%; ε4: 13.5%; ε2: 6.5%) were within the Hardy-Weinberg equilibrium expectations 31 . The ε3ε3 genotype was the most commonly observed (63.3%), followed by ε3ε4 (22%), ε2ε3 (11.4%), ε4ε4 (1.8%), ε2ε4 (1.4%) and ε2ε2 (0.1%).…”

“…Furthermore, the participants were classified as ε4 carriers or non-ε4 carriers. Individuals with the ε2ε4 genotype (1,4%) were excluded from all analyses because of the opposing effects of these two alleles on health status 31 .…”