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The objective is to identify cofactors of leukocyte telomere length (LTL) in a Latin American population, specifically the association of LTL with 36 socio-demographic, early childhood, and health characteristics, as well as with DNA sample collection and storage procedures. The analysis is based on longitudinal information from a subsample of 1,261 individuals aged 60+ years at baseline from the Costa Rican Study of Longevity and Healthy Aging (CRELES): a nationally representative sample of elderly population. Random effects regression models for panel data were used to estimate the associations with LTL and its longitudinal changes. Sample collection procedures and DNA refrigerator storage time were strongly associated with LTL: telomeres are longer in blood collected in October-December, in DNA extracted from

Elderly Costa Ricans have lower mortality rates compared to their counterparts from developed countries. Reasons for this survival advantage are not completely known. In the present study, we aimed to identify dietary factors associated with leukocyte telomere length (LTL), a marker of biologic aging, in the elderly population of Costa Rica. We conducted prospective analysis in 909 participants aged 60+ years from the Costa Rican Longevity and Healthy Aging Study (CRELES). We used a food frequency questionnaire to assess usual diet. We calculated dietary patterns using Principal Component Analysis (PCA). We used generalized linear models to examine the association of dietary patterns and food groups with leukocyte telomere length. We found two major dietary patterns explaining 9.15% and 7.18% of the total variation of food intake, respectively. The first dietary pattern, which represents a traditional Costa Rican rice and beans pattern, was more frequent in rural parts of the country and was positively associated with baseline LTL: β (95% CI) = 42.0 base-pairs (bp) (9.9 bp, 74.1 bp) per one-unit increase of the traditional dietary pattern. In analysis of individual food groups, intake of grains was positively associated with baseline LTL: β (95% CI) = 43.6 bp (13.9 bp, 73.3 bp) per one-serving/day increase of consumption of grains. Our results suggest that dietary factors, in particular a traditional food pattern, are associated with telomere length and may contribute to the extended longevity of elderly Costa Ricans. [ABSTRACT FROM AUTHOR]

Genetic variation of the Y chromosome in five Chibchan tribes (Bribri, Cabecar, Guaymi, Huetar, and Teribe) of Costa Rica and Panama was analyzed using six microsatellite loci (DYS19, DYS389A, DYS389B, DYS390, DYS391, and DYS393), the Y chromosome-specific alphoid system (αh), the Y-chromosome Alu polymorphism (YAP), and a specific pre-Columbian transition (C ↵ T) (M3 marker) in the DYS199 locus that defines the Q-M3 haplogroup. Thirty-nine haplotypes were found, resulting in a haplotype diversity of 0.937. The Huetar were the most diverse tribe, probably because of their high levels of interethnic admixture. A candidate founder Y-chromosome haplotype was identified (15. 1% of Chibchan chromosomes), with the following constitution: YAP-, DYS199∗T, αh-II, DYS19∗13, DYS389A∗I7, DYS389B∗10, DYS390∗24, DYS391∗10, and DYS393∗13. This haplotype is the same as the one described previously as one of the most frequent founder paternal lineages in native American populations. Analysis of molecular variance indicated that the between population variation was smaller than the within-population variation, and the comparison with mtDNA restriction data showed no evidence of differential structuring between maternally and paternally inherited genes in the Chibchan populations. The mismatch distribution approach indicated estimated coalescence times of the Y chromosomes of the Q-M3 haplogroup of 3.113 and 13.243 years before present; for the mtDNA-restriction haplotypes the estimated coalescence time was between 7.452 and 9,834 years before present. These results are compatible with the suggested time for the origin of the Chibchan group based on archeological, linguistic, and genetic evidence. [ABSTRACT FROM AUTHOR]