DNA methylation profile of a rural cohort exposed to early-adversity and malnutrition: An exploratory analysis

Barker's hypothesis affirms that undernourishment in early-life induces metabolic reprogramming that compromises organism functions later in life, leading to age-related diseases. We are exposed to environmental and social conditions that impact our life trajectories, leading to ageing phenotypes as we grow. Epigenetic mechanisms constitute the link between both external stimuli and genetic programming. Studies have focused on describing the effect of early adverse events such as trauma, famines, or childhood labor on epigenetic markers in adulthood and the elderly. However, we lack information on epigenetic programming in individuals born in rural communities from underdeveloped countries, exposed to negative influences during fetal and postnatal development, particularly chronic malnutrition. Hence, in this exploratory analysis, we characterize the epigenome of individuals and some parents from Tlaltizapan (a rural community in Mexico originally studied almost 50 years ago) and collect anthropometric data on growth and development, as well on the living conditions of the families. Our results help build a biological hypothesis indicating that most of the epigenetic age measures of the subjects are significantly different among them. Interestingly, the most affected methylated regions correspond to pathways involved in neuronal system development, reproductive behaviour, learning and memory regulation.

Promising biomarkers of human aging: In search of a multi-omics panel to understand the aging process from a multidimensional perspective

The aging process has been linked to the occurrence of chronic diseases and functional impairments, including cancer, sarcopenia, frailty, metabolic, cardiovascular, and neurodegenerative diseases. Nonetheless, aging is highly variable and heterogeneous and represents a challenge for its characterization. In this sense, intrinsic capacity (IC) stands as a novel perspective by the World Health Organization, which integrates the individual wellbeing, environment, and risk factors to understand aging. However, there is a lack of quantitative and qualitative attributes to define it objectively. Therefore, in this review we attempt to summarize the most relevant and promising biomarkers described in clinical studies at date over different molecular levels, including epigenomics, transcriptomics, proteomics, metabolomics, and the microbiome. To aid gerontologists, geriatricians, and biomedical researchers to understand the aging process through the IC. Aging biomarkers reflect the physiological state of individuals and the underlying mechanisms related to homeostatic changes throughout an individual lifespan; they demonstrated that aging could be measured independently of time (that may explain its heterogeneity) and to be helpful to predict age-related syndromes and mortality. In summary, we highlight the areas of opportunity and gaps of knowledge that must be addressed to fully integrate biomedical findings into clinically useful tools and interventions.

Cognitive impairment and low physical activity are the components of frailty more strongly associated with disability

OBJECTIVE

To determine the association of the five frailty criteria from the Cardiovascular Health Study, as well as cognitive impairment, with prevalent disability for the instrumental (IADL) and basic activities of daily living (ADL).

DESIGN

Cross-sectional study of 475 community-dwelling subjects aged 70 and older, participating in the Mexican Study of Nutritional and Psychosocial Markers of Frailty.

MEASUREMENTS

Six probable frailty criteria were considered: weight loss, poor endurance, low physical activity, slowness, weakness, and cognitive impairment. The association of each component of frailty for IADL and ADL disability as main outcomes was determined constructing multivariate logistic regression analyses. Final models were adjusted by socio-demographic factors and the presence of the other five frailty components as covariates.

RESULTS

Mean age of participants was 78.1 (SD=6.2). The unadjusted results showed that each of the components of frailty, except weight loss, was associated with both IADL and ADL disability. However, after adjustment, only low physical activity [Odds ratio (OR) =3.27; 95% CI=1.56 to 6.85] and cognitive impairment (OR=2.06; 95% CI=1.04 to 4.06) remain independently associated with IADL disability. Regarding ADL disability, only a lower physical activity (OR=7.72; 95% CI=1.28 to 46.46) was associated with this outcome, whereas cognitive impairment was marginally associated but was not statistically significant (OR=5.45; 95% CI=0.91 to 32.57).

CONCLUSIONS

Cognitive impairment and low physical activity are the main contributing factors of frailty phenotype to disability. Better understanding the independent contribution of each frailty subdimension to the different adverse-health outcomes may help to provide a more adequate management of frail elderly.