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Phenotypic aging is ubiquitous across mammalian species, suggesting shared underlying mechanisms of aging. Aging is linked to molecular changes to DNA methylation and gene expression, and environmental factors, such as severe external challenges or adversities, can moderate these age‐related changes. Yet, it remains unclear whether environmental adversities affect gene regulation via the same molecular pathways as chronological, or 'primary', aging. Investigating molecular aging in naturalistic animal populations can fill this gap by providing insight into shared molecular mechanisms of aging and the effects of a greater diversity of environmental adversities – particularly those that can be challenging to study in humans or laboratory organisms. Here, we characterised molecular aging – specifically, CpG methylation – in a sample of free‐ranging rhesus macaques living off the coast of Puerto Rico (n samples = 571, n individuals = 499), which endured a major hurricane during our study. Age was associated with methylation at 78,661 sites (31% of all sites tested). Age‐associated hypermethylation occurred more frequently in areas of active gene regulation, while hypomethylation was enriched in regions that show less activity in immune cells, suggesting these regions may become de‐repressed in older individuals. Age‐associated hypomethylation also co‐occurred with increased chromatin accessibility while hypermethylation showed the opposite trend, hinting at a coordinated, multi‐level loss of epigenetic stability during aging. We detected 32,048 CpG sites significantly associated with exposure to a hurricane, and these sites overlapped age‐associated sites, most strongly in regulatory regions and most weakly in quiescent regions. Together, our results suggest that environmental adversity may contribute to aging‐related molecular phenotypes in regions of active gene transcription, but that primary aging has specific signatures in non‐regulatory regions. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Telomere length (TL) is a biomarker of aging and age‐related decline. Although venous blood is considered the “gold standard” for TL measurement, its collection is often not feasible or desired in nonclinical settings. Saliva and dried blood spots (DBS) have been used as alternatives when venipuncture cannot be performed. However, it is not known whether these sample types yield TL measurements comparable to those obtained from venous blood. We sought to determine whether different samples from the same individual yield comparable TL measurements. Methods: We extracted DNA from matched buffy coat, saliva (Oragene and Oasis), and DBS (venous and capillary) samples from 40 women aged 18‐77 years. We used the monochrome multiplex qPCR (MMQPCR) assay to measure TL in all sample types for each participant and applied quality control measures to retain only high‐quality samples for analysis. We then compared TL from buffy coat and saliva to examine how these measurements differ and to test if TL is correlated across sample types. Results: TL differed significantly across buffy coat, Oragene saliva, and Oasis saliva samples. TL from buffy coat and Oragene saliva was moderately correlated (ρ = 0.48, P = .002) and the most similar in size. Oasis saliva TL was not correlated with buffy coat or Oragene saliva TL, and was the shortest. DBS DNA yields were inadequate for TL measurement using the MMQPCR assay. Conclusions: Using a matched dataset we demonstrate that sample type significantly influences the TL measurement obtained using the MMQPCR assay. [ABSTRACT FROM AUTHOR]

Objectives The obesity epidemic in Mexico is increasing and represents a considerable public health challenge. The population aged 50 years and older is also increasing and is not exempt from the obesity rise. We aimed to determine the current prevalence of Body Mass Index (BMI) categories in a sample of Mexicans aged 50 years and older and to test the associations of BMI with physical activity categories and related factors. Methods Data from 2,032 individuals aged 50 years and older who participated in SAGE Wave 1 (2009-2010) were analyzed. Representativeness of the sample was obtained by using weighted data. Descriptive statistics, chi square tests, simple regression analysis, and multiple regression analysis were performed in relation to BMI, self-reported physical activity categories, and several variables, including demographic characteristics and selected risk factors for non-communicable diseases. Results Among older adults, 0.6% was found to be underweight, 21.4% normal weight, 49.4% overweight, and 28.7% obese. It was also found that practicing vigorous intensity physical activity (−1.32) and being 80 years or older (−2.73) were significantly associated ( P < 0.05) with a lower mean BMI (28.3). In contrast, being in the lowest income quintile (1.35), and living in urban areas (0.86) were significantly associated with a higher mean BMI. Conclusions The study results contribute to the current understanding of obesity etiology in Mexico, and moreover confirm that overweight and obesity are current public health problems that must be addressed in specific subgroups of older adults. Am. J. Hum. Biol. 27:326-333, 2015. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Research in the basic biology of ageing is increasingly identifying mechanisms and modifiers of ageing in short-lived organisms such as worms and mice. The ultimate goal of such work is to improve human health, particularly in the growing segment of the population surviving into old age. Thus far, few interventions have robustly transcended species boundaries in the laboratory, suggesting that changes in approach are needed to avoid costly failures in translational human research. In this review, we discuss both well-established and alternative model organisms for ageing research and outline how research in nonhuman primates is sorely needed, first, to translate findings from short-lived organisms to humans, and second, to understand key aspects of ageing that are unique to primate biology. We focus on rhesus macaques as a particularly promising model organism for ageing research owing to their social and physiological similarity to humans as well as the existence of key resources that have been developed for this species. As a case study, we compare gene regulatory signatures of ageing in the peripheral immune system between humans and rhesus macaques from a free-ranging study population in Cayo Santiago. We show that both mRNA expression and DNA methylation signatures of immune ageing are broadly shared between macaques and humans, indicating strong conservation of the trajectory of ageing in the immune system. We conclude with a review of key issues in the biology of ageing for which macaques and other nonhuman primates may uniquely contribute valuable insights, including the effects of social gradients on health and ageing. We anticipate that continuing research in rhesus macaques and other nonhuman primates will play a critical role in conjunction with the model organism and human biodemographic research in ultimately improving translational outcomes and extending health and longevity in our ageing population. This article is part of the theme issue 'Evolution of the primate ageing process'.

In Charles Darwin's tree model for life's evolution, natural selection adaptively modifies newly arisen species as they branch apart from their common ancestor. In accord with this Darwinian concept, the phylogenomic approach to elucidating adaptive evolution in genes and genomes in the ancestry of modern humans requires a well supported and well sampled phylogeny that accurately places humans and other primates and mammals with respect to one another. For more than a century, first from the comparative immunological work of Nuttall on blood sera and now from comparative genomic studies, molecular findings have demonstrated the close kinship of humans to chimpanzees. The close genetic correspondence of chimpanzees to humans and the relative shortness of our evolutionary separation suggest that most distinctive features of the modern human phenotype had already evolved during our ancestry with chimpanzees. Thus, a phylogenomic assessment of being human should examine earlier stages of human ancestry as well as later stages. In addition, with the availability of a number of mammalian genomes, similarities in phenotype between distantly related taxa should be explored for evidence of convergent or parallel adaptive evolution. As an example, recent phylogenomic evidence has shown that adaptive evolution of aerobic energy metabolism genes may have helped shape such distinctive modern human features as long life spans and enlarged brains in the ancestries of both humans and elephants.