Pathogen Burden, Blood Biomarkers, and Functional Aging in Community-Dwelling Older Adults.

Background: Lifelong accumulation of latent or persistent or repeated infections may be a contributing factor to the deterioration of physical and cognitive function associated with functional aging, but the evidence is limited and the biological underpinnings are unclear.

Methods: We profiled the seropositivity for common viral, bacterial, and plasmodial pathogens of local importance in community-living older adults in 2 studies involving 745 older adults (mean age 67.0, SD: 7.

Pathogenic load and frailty in older adults: Singapore longitudinal ageing study.

Human evidence for the role of continuous antigenic stimulation from persistent latent infections in frailty is limited. We conducted a nested case-control study (99 deceased and 43 survivors) of participants aged 55 and above in a longitudinal ageing cohort followed up from 2003 to 2017. Using blood samples and baseline data collected in 2003-2004, we examined the association of pathogenic load (PL) count of seropositivity to 10 microbes (viruses, bacteria and mycoplasma) with cumulated deficit-frailty index (CD-FI) and the physical frailty (PF) phenotype, and mortality.

Mindfulness improves inflammatory biomarker levels in older adults with mild cognitive impairment: a randomized controlled trial.

Few randomized controlled trials investigated the effects of mindfulness intervention on older adults diagnosed with mild cognitive impairment (MCI). Furthermore, there have been hypotheses and theoretical mechanisms on the benefits of mindfulness intervention on biomarkers of stress, inflammation, and neuroplasticity implicated in MCI that warrant empirical evidence. We conducted a pilot randomized controlled trial to examine whether Mindful Awareness Practice (MAP) improved biomarker levels in older adults with MCI.

Assessment of Sarcopenia Among Community-Dwelling At-Risk Frail Adults Aged 65 Years and Older Who Received Multidomain Lifestyle Interventions: A Secondary Analysis of a Randomized Clinical Trial.

Importance: There is little understanding of the outcomes associated with active lifestyle interventions for sarcopenia among older persons.

Objective: To determine the association of 6-month multidomain lifestyle interventions (physical exercise, nutritional enhancement, cognitive training, combined treatment, and standard care) with change in sarcopenia status and physical function among adults 65 years and older.

Design, Setting, And Participants: Post hoc secondary analysis of a parallel-group randomized clinical trial conducted from September 1, 2012, to September 1, 2014, at community centers providing services to elderly individuals in Singapore.

Recurrent circadian fasting (RCF) improves blood pressure, biomarkers of cardiometabolic risk and regulates inflammation in men.

Background: The effects of fasting on health in non-human models have been widely publicised for a long time and emerging evidence support the idea that these effects can be applicable to human practice.

Methods: In an open label longitudinal follow-up, a cohort of 78 adult men (aged 20 to 85 years) who fasted for 29 consecutive days from sunrise to sunset (16 h fasting-referred to as recurrent circadian fasting) in Pakistan, were studied. The primary outcomes of the fasting study was weight loss/recovery and the associated changes in blood pressure and circulating levels of surrogate markers linked to organ and system functions-including cardiovascular, metabolic and inflammation.

Identification of inflammatory and vascular markers associated with mild cognitive impairment.

Biochemical processes have been associated with the pathogenesis of mild cognitive impairment (MCI) and dementia, including chronic inflammation, dysregulation of membrane lipids and disruption of neurotransmitter pathways. However, research investigating biomarkers of these processes in MCI remained sparse and inconsistent. To collect fresh evidence, we evaluated the performance of several potential markers in a cohort of 57 MCI patients and 57 cognitively healthy controls.

Systemic and Metabolic Signature of Sarcopenia in Community-Dwelling Older Adults.

Background: Evidence suggests the pivotal contribution of nutrition as a modifiable risk factor for sarcopenia. The present cross-sectional study characterized the nutritional and metabolic profile of sarcopenia through an extensive exploration of a wide array of blood biomarkers related to muscle protein metabolism and transcriptomic signatures in community-dwelling elderly adults.

Methods: Among 189 older individuals with a mean age of 73.

Mapping of γ/δ T cells reveals Vδ2+ T cells resistance to senescence.

Background: Immune adaptation with aging is a major of health outcomes. Studies in humans have mainly focus on αβ T cells while γδ T cells have been neglected despite their role in immunosurveillance. We investigated the impact of aging on γδ T cell subsets phenotypes, functions, senescence and their molecular response to stress.

Dysregulated homeostatic pathways in sarcopenia among frail older adults.

Sarcopenia, a core feature of the physical frailty syndrome, is characterized by multisystem physiological dysregulation. No study has explored qualitatively the hierarchical network of relationships among different dysregulated pathways involved in the pathogenesis of sarcopenia. We used 40 blood biomarkers belonging to community-dwelling prefrail and frail older persons to derive measures of multiple physiological pathways, and structural equation modeling to generate path network models of the multisystem physiological dysregulations associated with muscle mass and function (MMF).

The pro-inflammatory phenotype of the human non-classical monocyte subset is attributed to senescence.

Human primary monocytes comprise a heterogeneous population that can be classified into three subsets based on CD14 and CD16 expression: classical (CD14/CD16), intermediate (CD14/CD16), and non-classical (CD14/CD16). The non-classical monocytes are the most pro-inflammatory in response to TLR stimulation in vitro, yet they express a remarkably high basal level of miR-146a, a microRNA known to negatively regulate the TLR pathway. This concurrence of a pro-inflammatory status and a high miR-146a level has been associated with cellular senescence in other cell types.

Vδ2+ and α/ß T cells show divergent trajectories during human aging.

Chronological aging and a variety of stressors are driving forces towards immunosenescence. While much attention was paid to the main T cell component, α/β T cells, few studies concentrate on the impact of age on γ/δ T cells' characteristics. The latter are important players of adaptive immunity but also have features associated with innate immunity.

Inflammatory and immune markers associated with physical frailty syndrome: findings from Singapore longitudinal aging studies.

Chronic systematic inflammation and reduced immune system fitness are considered potential contributing factors to the development of age-related frailty, but the underlying mechanisms are poorly defined. This exploratory study aimed to identify frailty-related inflammatory markers and immunological phenotypes in a cohort of community-dwelling adults aged ≥ 55 years. Frailty was assessed using two models, a Frailty Index and a categorical phenotype, and correlated with levels of circulating immune biomarkers and markers of senescence in immune cell subsets.

Markers of T-cell senescence and physical frailty: insights from Singapore Longitudinal Ageing Studies.

Background: Elderly individuals have an eroded immune system but whether immune senescence is implicated with the development of frailty is unknown. The underlying immune mechanisms and the link between markers of senescence and physical frailty is not well established.

Methods: We explored the association of specific T-cell subset markers of immune differentiation and senescence on CD4 and CD8 cells (CD28, CD27 and CD57) and the immune risk profile (inverted CD4/CD8 ratio <1) with physical frailty among 421 participants who were frail (=32), prefrail (=187) and robust (=202) in the Singapore Longitudinal Ageing Study cohort.

Downregulation of inhibitory SRC homology 2 domain-containing phosphatase-1 (SHP-1) leads to recovery of T cell responses in elderly.

Background: Immune responses are generally impaired in aged mammals. T cells have been extensively studied in this context due to the initial discovery of their reduced proliferative capacity with aging. The decreased responses involve altered signaling events associated with the early steps of T cell activation.